4753 lines
147 KiB
C
4753 lines
147 KiB
C
/* Expands front end tree to back end RTL for GNU C-Compiler
|
||
Copyright (C) 1987, 1988, 1989, 1992 Free Software Foundation, Inc.
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This file is part of GNU CC.
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||
GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 2, or (at your option)
|
||
any later version.
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||
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||
GNU CC is distributed in the hope that it will be useful,
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||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
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||
|
||
You should have received a copy of the GNU General Public License
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||
along with GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#ifndef lint
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static char rcsid[] = "$Id: stmt.c,v 1.2 1993/08/02 17:36:07 mycroft Exp $";
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#endif /* not lint */
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/* This file handles the generation of rtl code from tree structure
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above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
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It also creates the rtl expressions for parameters and auto variables
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and has full responsibility for allocating stack slots.
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The functions whose names start with `expand_' are called by the
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parser to generate RTL instructions for various kinds of constructs.
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Some control and binding constructs require calling several such
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functions at different times. For example, a simple if-then
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is expanded by calling `expand_start_cond' (with the condition-expression
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as argument) before parsing the then-clause and calling `expand_end_cond'
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after parsing the then-clause. */
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#include "config.h"
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#include <stdio.h>
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#include <ctype.h>
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#include "rtl.h"
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#include "tree.h"
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#include "flags.h"
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#include "function.h"
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#include "insn-flags.h"
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#include "insn-config.h"
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#include "insn-codes.h"
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#include "expr.h"
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#include "hard-reg-set.h"
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#include "obstack.h"
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#include "loop.h"
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#include "recog.h"
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#define obstack_chunk_alloc xmalloc
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#define obstack_chunk_free free
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struct obstack stmt_obstack;
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/* Filename and line number of last line-number note,
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whether we actually emitted it or not. */
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char *emit_filename;
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int emit_lineno;
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/* Nonzero if within a ({...}) grouping, in which case we must
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always compute a value for each expr-stmt in case it is the last one. */
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int expr_stmts_for_value;
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/* Each time we expand an expression-statement,
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record the expr's type and its RTL value here. */
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static tree last_expr_type;
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static rtx last_expr_value;
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/* Each time we expand the end of a binding contour (in `expand_end_bindings')
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and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
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This is used by the `remember_end_note' function to record the endpoint
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of each generated block in its associated BLOCK node. */
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static rtx last_block_end_note;
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/* Number of binding contours started so far in this function. */
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int block_start_count;
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/* Nonzero if function being compiled needs to
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return the address of where it has put a structure value. */
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extern int current_function_returns_pcc_struct;
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/* Label that will go on parm cleanup code, if any.
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Jumping to this label runs cleanup code for parameters, if
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such code must be run. Following this code is the logical return label. */
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extern rtx cleanup_label;
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/* Label that will go on function epilogue.
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Jumping to this label serves as a "return" instruction
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on machines which require execution of the epilogue on all returns. */
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extern rtx return_label;
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/* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
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So we can mark them all live at the end of the function, if nonopt. */
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extern rtx save_expr_regs;
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/* Offset to end of allocated area of stack frame.
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If stack grows down, this is the address of the last stack slot allocated.
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If stack grows up, this is the address for the next slot. */
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extern int frame_offset;
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/* Label to jump back to for tail recursion, or 0 if we have
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not yet needed one for this function. */
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extern rtx tail_recursion_label;
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/* Place after which to insert the tail_recursion_label if we need one. */
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extern rtx tail_recursion_reentry;
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/* Location at which to save the argument pointer if it will need to be
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referenced. There are two cases where this is done: if nonlocal gotos
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exist, or if vars whose is an offset from the argument pointer will be
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needed by inner routines. */
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extern rtx arg_pointer_save_area;
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/* Chain of all RTL_EXPRs that have insns in them. */
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extern tree rtl_expr_chain;
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#if 0 /* Turned off because 0 seems to work just as well. */
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/* Cleanup lists are required for binding levels regardless of whether
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that binding level has cleanups or not. This node serves as the
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cleanup list whenever an empty list is required. */
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static tree empty_cleanup_list;
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#endif
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/* Functions and data structures for expanding case statements. */
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/* Case label structure, used to hold info on labels within case
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statements. We handle "range" labels; for a single-value label
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as in C, the high and low limits are the same.
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A chain of case nodes is initially maintained via the RIGHT fields
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in the nodes. Nodes with higher case values are later in the list.
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||
Switch statements can be output in one of two forms. A branch table
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is used if there are more than a few labels and the labels are dense
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within the range between the smallest and largest case value. If a
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branch table is used, no further manipulations are done with the case
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node chain.
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The alternative to the use of a branch table is to generate a series
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of compare and jump insns. When that is done, we use the LEFT, RIGHT,
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and PARENT fields to hold a binary tree. Initially the tree is
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totally unbalanced, with everything on the right. We balance the tree
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with nodes on the left having lower case values than the parent
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and nodes on the right having higher values. We then output the tree
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in order. */
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struct case_node
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{
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struct case_node *left; /* Left son in binary tree */
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struct case_node *right; /* Right son in binary tree; also node chain */
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struct case_node *parent; /* Parent of node in binary tree */
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tree low; /* Lowest index value for this label */
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tree high; /* Highest index value for this label */
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tree code_label; /* Label to jump to when node matches */
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};
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typedef struct case_node case_node;
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typedef struct case_node *case_node_ptr;
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/* These are used by estimate_case_costs and balance_case_nodes. */
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/* This must be a signed type, and non-ANSI compilers lack signed char. */
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static short *cost_table;
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static int use_cost_table;
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static int estimate_case_costs ();
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static void balance_case_nodes ();
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static void emit_case_nodes ();
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static void group_case_nodes ();
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static void emit_jump_if_reachable ();
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static int warn_if_unused_value ();
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static void expand_goto_internal ();
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static int expand_fixup ();
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void fixup_gotos ();
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void free_temp_slots ();
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static void expand_cleanups ();
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static void expand_null_return_1 ();
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static int tail_recursion_args ();
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static void do_jump_if_equal ();
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/* Stack of control and binding constructs we are currently inside.
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These constructs begin when you call `expand_start_WHATEVER'
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and end when you call `expand_end_WHATEVER'. This stack records
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info about how the construct began that tells the end-function
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what to do. It also may provide information about the construct
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to alter the behavior of other constructs within the body.
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For example, they may affect the behavior of C `break' and `continue'.
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Each construct gets one `struct nesting' object.
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All of these objects are chained through the `all' field.
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`nesting_stack' points to the first object (innermost construct).
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The position of an entry on `nesting_stack' is in its `depth' field.
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Each type of construct has its own individual stack.
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For example, loops have `loop_stack'. Each object points to the
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next object of the same type through the `next' field.
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Some constructs are visible to `break' exit-statements and others
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are not. Which constructs are visible depends on the language.
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Therefore, the data structure allows each construct to be visible
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or not, according to the args given when the construct is started.
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The construct is visible if the `exit_label' field is non-null.
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In that case, the value should be a CODE_LABEL rtx. */
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struct nesting
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{
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struct nesting *all;
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struct nesting *next;
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int depth;
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rtx exit_label;
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union
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{
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/* For conds (if-then and if-then-else statements). */
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struct
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{
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/* Label for the end of the if construct.
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There is none if EXITFLAG was not set
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and no `else' has been seen yet. */
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rtx endif_label;
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/* Label for the end of this alternative.
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This may be the end of the if or the next else/elseif. */
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rtx next_label;
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} cond;
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/* For loops. */
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struct
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{
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/* Label at the top of the loop; place to loop back to. */
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rtx start_label;
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/* Label at the end of the whole construct. */
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rtx end_label;
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/* Label for `continue' statement to jump to;
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this is in front of the stepper of the loop. */
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rtx continue_label;
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} loop;
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/* For variable binding contours. */
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struct
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{
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/* Sequence number of this binding contour within the function,
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in order of entry. */
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int block_start_count;
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/* Nonzero => value to restore stack to on exit. */
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rtx stack_level;
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/* The NOTE that starts this contour.
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Used by expand_goto to check whether the destination
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is within each contour or not. */
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rtx first_insn;
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/* Innermost containing binding contour that has a stack level. */
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struct nesting *innermost_stack_block;
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/* List of cleanups to be run on exit from this contour.
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This is a list of expressions to be evaluated.
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The TREE_PURPOSE of each link is the ..._DECL node
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which the cleanup pertains to. */
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tree cleanups;
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/* List of cleanup-lists of blocks containing this block,
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as they were at the locus where this block appears.
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There is an element for each containing block,
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ordered innermost containing block first.
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The tail of this list can be 0 (was empty_cleanup_list),
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if all remaining elements would be empty lists.
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The element's TREE_VALUE is the cleanup-list of that block,
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which may be null. */
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tree outer_cleanups;
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/* Chain of labels defined inside this binding contour.
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For contours that have stack levels or cleanups. */
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struct label_chain *label_chain;
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/* Number of function calls seen, as of start of this block. */
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int function_call_count;
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} block;
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/* For switch (C) or case (Pascal) statements,
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and also for dummies (see `expand_start_case_dummy'). */
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struct
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{
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/* The insn after which the case dispatch should finally
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be emitted. Zero for a dummy. */
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rtx start;
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/* A list of case labels, kept in ascending order by value
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as the list is built.
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During expand_end_case, this list may be rearranged into a
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nearly balanced binary tree. */
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struct case_node *case_list;
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/* Label to jump to if no case matches. */
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tree default_label;
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/* The expression to be dispatched on. */
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tree index_expr;
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/* Type that INDEX_EXPR should be converted to. */
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tree nominal_type;
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/* Number of range exprs in case statement. */
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int num_ranges;
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/* Name of this kind of statement, for warnings. */
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char *printname;
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/* Nonzero if a case label has been seen in this case stmt. */
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char seenlabel;
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} case_stmt;
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/* For exception contours. */
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struct
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||
{
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||
/* List of exceptions raised. This is a TREE_LIST
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||
of whatever you want. */
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tree raised;
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||
/* List of exceptions caught. This is also a TREE_LIST
|
||
of whatever you want. As a special case, it has the
|
||
value `void_type_node' if it handles default exceptions. */
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||
tree handled;
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||
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/* First insn of TRY block, in case resumptive model is needed. */
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rtx first_insn;
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/* Label for the catch clauses. */
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rtx except_label;
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/* Label for unhandled exceptions. */
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rtx unhandled_label;
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||
/* Label at the end of whole construct. */
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||
rtx after_label;
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||
/* Label which "escapes" the exception construct.
|
||
Like EXIT_LABEL for BREAK construct, but for exceptions. */
|
||
rtx escape_label;
|
||
} except_stmt;
|
||
} data;
|
||
};
|
||
|
||
/* Chain of all pending binding contours. */
|
||
struct nesting *block_stack;
|
||
|
||
/* If any new stacks are added here, add them to POPSTACKS too. */
|
||
|
||
/* Chain of all pending binding contours that restore stack levels
|
||
or have cleanups. */
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||
struct nesting *stack_block_stack;
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||
|
||
/* Chain of all pending conditional statements. */
|
||
struct nesting *cond_stack;
|
||
|
||
/* Chain of all pending loops. */
|
||
struct nesting *loop_stack;
|
||
|
||
/* Chain of all pending case or switch statements. */
|
||
struct nesting *case_stack;
|
||
|
||
/* Chain of all pending exception contours. */
|
||
struct nesting *except_stack;
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||
|
||
/* Separate chain including all of the above,
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chained through the `all' field. */
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||
struct nesting *nesting_stack;
|
||
|
||
/* Number of entries on nesting_stack now. */
|
||
int nesting_depth;
|
||
|
||
/* Allocate and return a new `struct nesting'. */
|
||
|
||
#define ALLOC_NESTING() \
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||
(struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
|
||
|
||
/* Pop the nesting stack element by element until we pop off
|
||
the element which is at the top of STACK.
|
||
Update all the other stacks, popping off elements from them
|
||
as we pop them from nesting_stack. */
|
||
|
||
#define POPSTACK(STACK) \
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do { struct nesting *target = STACK; \
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struct nesting *this; \
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do { this = nesting_stack; \
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||
if (loop_stack == this) \
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||
loop_stack = loop_stack->next; \
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||
if (cond_stack == this) \
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||
cond_stack = cond_stack->next; \
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||
if (block_stack == this) \
|
||
block_stack = block_stack->next; \
|
||
if (stack_block_stack == this) \
|
||
stack_block_stack = stack_block_stack->next; \
|
||
if (case_stack == this) \
|
||
case_stack = case_stack->next; \
|
||
if (except_stack == this) \
|
||
except_stack = except_stack->next; \
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||
nesting_depth = nesting_stack->depth - 1; \
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||
nesting_stack = this->all; \
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||
obstack_free (&stmt_obstack, this); } \
|
||
while (this != target); } while (0)
|
||
|
||
/* In some cases it is impossible to generate code for a forward goto
|
||
until the label definition is seen. This happens when it may be necessary
|
||
for the goto to reset the stack pointer: we don't yet know how to do that.
|
||
So expand_goto puts an entry on this fixup list.
|
||
Each time a binding contour that resets the stack is exited,
|
||
we check each fixup.
|
||
If the target label has now been defined, we can insert the proper code. */
|
||
|
||
struct goto_fixup
|
||
{
|
||
/* Points to following fixup. */
|
||
struct goto_fixup *next;
|
||
/* Points to the insn before the jump insn.
|
||
If more code must be inserted, it goes after this insn. */
|
||
rtx before_jump;
|
||
/* The LABEL_DECL that this jump is jumping to, or 0
|
||
for break, continue or return. */
|
||
tree target;
|
||
/* The BLOCK for the place where this goto was found. */
|
||
tree context;
|
||
/* The CODE_LABEL rtx that this is jumping to. */
|
||
rtx target_rtl;
|
||
/* Number of binding contours started in current function
|
||
before the label reference. */
|
||
int block_start_count;
|
||
/* The outermost stack level that should be restored for this jump.
|
||
Each time a binding contour that resets the stack is exited,
|
||
if the target label is *not* yet defined, this slot is updated. */
|
||
rtx stack_level;
|
||
/* List of lists of cleanup expressions to be run by this goto.
|
||
There is one element for each block that this goto is within.
|
||
The tail of this list can be 0 (was empty_cleanup_list),
|
||
if all remaining elements would be empty.
|
||
The TREE_VALUE contains the cleanup list of that block as of the
|
||
time this goto was seen.
|
||
The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
|
||
tree cleanup_list_list;
|
||
};
|
||
|
||
static struct goto_fixup *goto_fixup_chain;
|
||
|
||
/* Within any binding contour that must restore a stack level,
|
||
all labels are recorded with a chain of these structures. */
|
||
|
||
struct label_chain
|
||
{
|
||
/* Points to following fixup. */
|
||
struct label_chain *next;
|
||
tree label;
|
||
};
|
||
|
||
void
|
||
init_stmt ()
|
||
{
|
||
gcc_obstack_init (&stmt_obstack);
|
||
#if 0
|
||
empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE);
|
||
#endif
|
||
}
|
||
|
||
void
|
||
init_stmt_for_function ()
|
||
{
|
||
/* We are not currently within any block, conditional, loop or case. */
|
||
block_stack = 0;
|
||
loop_stack = 0;
|
||
case_stack = 0;
|
||
cond_stack = 0;
|
||
nesting_stack = 0;
|
||
nesting_depth = 0;
|
||
|
||
block_start_count = 0;
|
||
|
||
/* No gotos have been expanded yet. */
|
||
goto_fixup_chain = 0;
|
||
|
||
/* We are not processing a ({...}) grouping. */
|
||
expr_stmts_for_value = 0;
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
void
|
||
save_stmt_status (p)
|
||
struct function *p;
|
||
{
|
||
p->block_stack = block_stack;
|
||
p->stack_block_stack = stack_block_stack;
|
||
p->cond_stack = cond_stack;
|
||
p->loop_stack = loop_stack;
|
||
p->case_stack = case_stack;
|
||
p->nesting_stack = nesting_stack;
|
||
p->nesting_depth = nesting_depth;
|
||
p->block_start_count = block_start_count;
|
||
p->last_expr_type = last_expr_type;
|
||
p->last_expr_value = last_expr_value;
|
||
p->expr_stmts_for_value = expr_stmts_for_value;
|
||
p->emit_filename = emit_filename;
|
||
p->emit_lineno = emit_lineno;
|
||
p->goto_fixup_chain = goto_fixup_chain;
|
||
}
|
||
|
||
void
|
||
restore_stmt_status (p)
|
||
struct function *p;
|
||
{
|
||
block_stack = p->block_stack;
|
||
stack_block_stack = p->stack_block_stack;
|
||
cond_stack = p->cond_stack;
|
||
loop_stack = p->loop_stack;
|
||
case_stack = p->case_stack;
|
||
nesting_stack = p->nesting_stack;
|
||
nesting_depth = p->nesting_depth;
|
||
block_start_count = p->block_start_count;
|
||
last_expr_type = p->last_expr_type;
|
||
last_expr_value = p->last_expr_value;
|
||
expr_stmts_for_value = p->expr_stmts_for_value;
|
||
emit_filename = p->emit_filename;
|
||
emit_lineno = p->emit_lineno;
|
||
goto_fixup_chain = p->goto_fixup_chain;
|
||
}
|
||
|
||
/* Emit a no-op instruction. */
|
||
|
||
void
|
||
emit_nop ()
|
||
{
|
||
rtx last_insn = get_last_insn ();
|
||
if (!optimize
|
||
&& (GET_CODE (last_insn) == CODE_LABEL
|
||
|| prev_real_insn (last_insn) == 0))
|
||
emit_insn (gen_nop ());
|
||
}
|
||
|
||
/* Return the rtx-label that corresponds to a LABEL_DECL,
|
||
creating it if necessary. */
|
||
|
||
rtx
|
||
label_rtx (label)
|
||
tree label;
|
||
{
|
||
if (TREE_CODE (label) != LABEL_DECL)
|
||
abort ();
|
||
|
||
if (DECL_RTL (label))
|
||
return DECL_RTL (label);
|
||
|
||
return DECL_RTL (label) = gen_label_rtx ();
|
||
}
|
||
|
||
/* Add an unconditional jump to LABEL as the next sequential instruction. */
|
||
|
||
void
|
||
emit_jump (label)
|
||
rtx label;
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_jump_insn (gen_jump (label));
|
||
emit_barrier ();
|
||
}
|
||
|
||
/* Emit code to jump to the address
|
||
specified by the pointer expression EXP. */
|
||
|
||
void
|
||
expand_computed_goto (exp)
|
||
tree exp;
|
||
{
|
||
rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
|
||
emit_queue ();
|
||
emit_indirect_jump (x);
|
||
}
|
||
|
||
/* Handle goto statements and the labels that they can go to. */
|
||
|
||
/* Specify the location in the RTL code of a label LABEL,
|
||
which is a LABEL_DECL tree node.
|
||
|
||
This is used for the kind of label that the user can jump to with a
|
||
goto statement, and for alternatives of a switch or case statement.
|
||
RTL labels generated for loops and conditionals don't go through here;
|
||
they are generated directly at the RTL level, by other functions below.
|
||
|
||
Note that this has nothing to do with defining label *names*.
|
||
Languages vary in how they do that and what that even means. */
|
||
|
||
void
|
||
expand_label (label)
|
||
tree label;
|
||
{
|
||
struct label_chain *p;
|
||
|
||
do_pending_stack_adjust ();
|
||
emit_label (label_rtx (label));
|
||
if (DECL_NAME (label))
|
||
LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
|
||
|
||
if (stack_block_stack != 0)
|
||
{
|
||
p = (struct label_chain *) oballoc (sizeof (struct label_chain));
|
||
p->next = stack_block_stack->data.block.label_chain;
|
||
stack_block_stack->data.block.label_chain = p;
|
||
p->label = label;
|
||
}
|
||
}
|
||
|
||
/* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
|
||
from nested functions. */
|
||
|
||
void
|
||
declare_nonlocal_label (label)
|
||
tree label;
|
||
{
|
||
nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
|
||
LABEL_PRESERVE_P (label_rtx (label)) = 1;
|
||
if (nonlocal_goto_handler_slot == 0)
|
||
{
|
||
nonlocal_goto_handler_slot
|
||
= assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
|
||
emit_stack_save (SAVE_NONLOCAL,
|
||
&nonlocal_goto_stack_level,
|
||
PREV_INSN (tail_recursion_reentry));
|
||
}
|
||
}
|
||
|
||
/* Generate RTL code for a `goto' statement with target label LABEL.
|
||
LABEL should be a LABEL_DECL tree node that was or will later be
|
||
defined with `expand_label'. */
|
||
|
||
void
|
||
expand_goto (label)
|
||
tree label;
|
||
{
|
||
/* Check for a nonlocal goto to a containing function. */
|
||
tree context = decl_function_context (label);
|
||
if (context != 0 && context != current_function_decl)
|
||
{
|
||
struct function *p = find_function_data (context);
|
||
rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
|
||
rtx temp;
|
||
|
||
p->has_nonlocal_label = 1;
|
||
LABEL_REF_NONLOCAL_P (label_ref) = 1;
|
||
|
||
/* Copy the rtl for the slots so that they won't be shared in
|
||
case the virtual stack vars register gets instantiated differently
|
||
in the parent than in the child. */
|
||
|
||
#if HAVE_nonlocal_goto
|
||
if (HAVE_nonlocal_goto)
|
||
emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
|
||
copy_rtx (p->nonlocal_goto_handler_slot),
|
||
copy_rtx (p->nonlocal_goto_stack_level),
|
||
label_ref));
|
||
else
|
||
#endif
|
||
{
|
||
rtx addr;
|
||
|
||
/* Restore frame pointer for containing function.
|
||
This sets the actual hard register used for the frame pointer
|
||
to the location of the function's incoming static chain info.
|
||
The non-local goto handler will then adjust it to contain the
|
||
proper value and reload the argument pointer, if needed. */
|
||
emit_move_insn (frame_pointer_rtx, lookup_static_chain (label));
|
||
|
||
/* We have now loaded the frame pointer hardware register with
|
||
the address of that corresponds to the start of the virtual
|
||
stack vars. So replace virtual_stack_vars_rtx in all
|
||
addresses we use with stack_pointer_rtx. */
|
||
|
||
/* Get addr of containing function's current nonlocal goto handler,
|
||
which will do any cleanups and then jump to the label. */
|
||
addr = copy_rtx (p->nonlocal_goto_handler_slot);
|
||
temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
|
||
frame_pointer_rtx));
|
||
|
||
/* Restore the stack pointer. Note this uses fp just restored. */
|
||
addr = p->nonlocal_goto_stack_level;
|
||
if (addr)
|
||
addr = replace_rtx (copy_rtx (addr),
|
||
virtual_stack_vars_rtx, frame_pointer_rtx);
|
||
|
||
emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
|
||
|
||
/* Put in the static chain register the nonlocal label address. */
|
||
emit_move_insn (static_chain_rtx, label_ref);
|
||
/* USE of frame_pointer_rtx added for consistency; not clear if
|
||
really needed. */
|
||
emit_insn (gen_rtx (USE, VOIDmode, frame_pointer_rtx));
|
||
emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
|
||
emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
|
||
emit_indirect_jump (temp);
|
||
}
|
||
}
|
||
else
|
||
expand_goto_internal (label, label_rtx (label), NULL_RTX);
|
||
}
|
||
|
||
/* Generate RTL code for a `goto' statement with target label BODY.
|
||
LABEL should be a LABEL_REF.
|
||
LAST_INSN, if non-0, is the rtx we should consider as the last
|
||
insn emitted (for the purposes of cleaning up a return). */
|
||
|
||
static void
|
||
expand_goto_internal (body, label, last_insn)
|
||
tree body;
|
||
rtx label;
|
||
rtx last_insn;
|
||
{
|
||
struct nesting *block;
|
||
rtx stack_level = 0;
|
||
|
||
if (GET_CODE (label) != CODE_LABEL)
|
||
abort ();
|
||
|
||
/* If label has already been defined, we can tell now
|
||
whether and how we must alter the stack level. */
|
||
|
||
if (PREV_INSN (label) != 0)
|
||
{
|
||
/* Find the innermost pending block that contains the label.
|
||
(Check containment by comparing insn-uids.)
|
||
Then restore the outermost stack level within that block,
|
||
and do cleanups of all blocks contained in it. */
|
||
for (block = block_stack; block; block = block->next)
|
||
{
|
||
if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
|
||
break;
|
||
if (block->data.block.stack_level != 0)
|
||
stack_level = block->data.block.stack_level;
|
||
/* Execute the cleanups for blocks we are exiting. */
|
||
if (block->data.block.cleanups != 0)
|
||
{
|
||
expand_cleanups (block->data.block.cleanups, NULL_TREE);
|
||
do_pending_stack_adjust ();
|
||
}
|
||
}
|
||
|
||
if (stack_level)
|
||
{
|
||
/* Ensure stack adjust isn't done by emit_jump, as this would clobber
|
||
the stack pointer. This one should be deleted as dead by flow. */
|
||
clear_pending_stack_adjust ();
|
||
do_pending_stack_adjust ();
|
||
emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
|
||
}
|
||
|
||
if (body != 0 && DECL_TOO_LATE (body))
|
||
error ("jump to `%s' invalidly jumps into binding contour",
|
||
IDENTIFIER_POINTER (DECL_NAME (body)));
|
||
}
|
||
/* Label not yet defined: may need to put this goto
|
||
on the fixup list. */
|
||
else if (! expand_fixup (body, label, last_insn))
|
||
{
|
||
/* No fixup needed. Record that the label is the target
|
||
of at least one goto that has no fixup. */
|
||
if (body != 0)
|
||
TREE_ADDRESSABLE (body) = 1;
|
||
}
|
||
|
||
emit_jump (label);
|
||
}
|
||
|
||
/* Generate if necessary a fixup for a goto
|
||
whose target label in tree structure (if any) is TREE_LABEL
|
||
and whose target in rtl is RTL_LABEL.
|
||
|
||
If LAST_INSN is nonzero, we pretend that the jump appears
|
||
after insn LAST_INSN instead of at the current point in the insn stream.
|
||
|
||
The fixup will be used later to insert insns just before the goto.
|
||
Those insns will restore the stack level as appropriate for the
|
||
target label, and will (in the case of C++) also invoke any object
|
||
destructors which have to be invoked when we exit the scopes which
|
||
are exited by the goto.
|
||
|
||
Value is nonzero if a fixup is made. */
|
||
|
||
static int
|
||
expand_fixup (tree_label, rtl_label, last_insn)
|
||
tree tree_label;
|
||
rtx rtl_label;
|
||
rtx last_insn;
|
||
{
|
||
struct nesting *block, *end_block;
|
||
|
||
/* See if we can recognize which block the label will be output in.
|
||
This is possible in some very common cases.
|
||
If we succeed, set END_BLOCK to that block.
|
||
Otherwise, set it to 0. */
|
||
|
||
if (cond_stack
|
||
&& (rtl_label == cond_stack->data.cond.endif_label
|
||
|| rtl_label == cond_stack->data.cond.next_label))
|
||
end_block = cond_stack;
|
||
/* If we are in a loop, recognize certain labels which
|
||
are likely targets. This reduces the number of fixups
|
||
we need to create. */
|
||
else if (loop_stack
|
||
&& (rtl_label == loop_stack->data.loop.start_label
|
||
|| rtl_label == loop_stack->data.loop.end_label
|
||
|| rtl_label == loop_stack->data.loop.continue_label))
|
||
end_block = loop_stack;
|
||
else
|
||
end_block = 0;
|
||
|
||
/* Now set END_BLOCK to the binding level to which we will return. */
|
||
|
||
if (end_block)
|
||
{
|
||
struct nesting *next_block = end_block->all;
|
||
block = block_stack;
|
||
|
||
/* First see if the END_BLOCK is inside the innermost binding level.
|
||
If so, then no cleanups or stack levels are relevant. */
|
||
while (next_block && next_block != block)
|
||
next_block = next_block->all;
|
||
|
||
if (next_block)
|
||
return 0;
|
||
|
||
/* Otherwise, set END_BLOCK to the innermost binding level
|
||
which is outside the relevant control-structure nesting. */
|
||
next_block = block_stack->next;
|
||
for (block = block_stack; block != end_block; block = block->all)
|
||
if (block == next_block)
|
||
next_block = next_block->next;
|
||
end_block = next_block;
|
||
}
|
||
|
||
/* Does any containing block have a stack level or cleanups?
|
||
If not, no fixup is needed, and that is the normal case
|
||
(the only case, for standard C). */
|
||
for (block = block_stack; block != end_block; block = block->next)
|
||
if (block->data.block.stack_level != 0
|
||
|| block->data.block.cleanups != 0)
|
||
break;
|
||
|
||
if (block != end_block)
|
||
{
|
||
/* Ok, a fixup is needed. Add a fixup to the list of such. */
|
||
struct goto_fixup *fixup
|
||
= (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
|
||
/* In case an old stack level is restored, make sure that comes
|
||
after any pending stack adjust. */
|
||
/* ?? If the fixup isn't to come at the present position,
|
||
doing the stack adjust here isn't useful. Doing it with our
|
||
settings at that location isn't useful either. Let's hope
|
||
someone does it! */
|
||
if (last_insn == 0)
|
||
do_pending_stack_adjust ();
|
||
fixup->target = tree_label;
|
||
fixup->target_rtl = rtl_label;
|
||
|
||
/* Create a BLOCK node and a corresponding matched set of
|
||
NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
|
||
this point. The notes will encapsulate any and all fixup
|
||
code which we might later insert at this point in the insn
|
||
stream. Also, the BLOCK node will be the parent (i.e. the
|
||
`SUPERBLOCK') of any other BLOCK nodes which we might create
|
||
later on when we are expanding the fixup code. */
|
||
|
||
{
|
||
register rtx original_before_jump
|
||
= last_insn ? last_insn : get_last_insn ();
|
||
|
||
start_sequence ();
|
||
pushlevel (0);
|
||
fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
|
||
last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
|
||
fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
|
||
end_sequence ();
|
||
emit_insns_after (fixup->before_jump, original_before_jump);
|
||
}
|
||
|
||
fixup->block_start_count = block_start_count;
|
||
fixup->stack_level = 0;
|
||
fixup->cleanup_list_list
|
||
= (((block->data.block.outer_cleanups
|
||
#if 0
|
||
&& block->data.block.outer_cleanups != empty_cleanup_list
|
||
#endif
|
||
)
|
||
|| block->data.block.cleanups)
|
||
? tree_cons (NULL_TREE, block->data.block.cleanups,
|
||
block->data.block.outer_cleanups)
|
||
: 0);
|
||
fixup->next = goto_fixup_chain;
|
||
goto_fixup_chain = fixup;
|
||
}
|
||
|
||
return block != 0;
|
||
}
|
||
|
||
/* When exiting a binding contour, process all pending gotos requiring fixups.
|
||
THISBLOCK is the structure that describes the block being exited.
|
||
STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
|
||
CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
|
||
FIRST_INSN is the insn that began this contour.
|
||
|
||
Gotos that jump out of this contour must restore the
|
||
stack level and do the cleanups before actually jumping.
|
||
|
||
DONT_JUMP_IN nonzero means report error there is a jump into this
|
||
contour from before the beginning of the contour.
|
||
This is also done if STACK_LEVEL is nonzero. */
|
||
|
||
void
|
||
fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
|
||
struct nesting *thisblock;
|
||
rtx stack_level;
|
||
tree cleanup_list;
|
||
rtx first_insn;
|
||
int dont_jump_in;
|
||
{
|
||
register struct goto_fixup *f, *prev;
|
||
|
||
/* F is the fixup we are considering; PREV is the previous one. */
|
||
/* We run this loop in two passes so that cleanups of exited blocks
|
||
are run first, and blocks that are exited are marked so
|
||
afterwards. */
|
||
|
||
for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
|
||
{
|
||
/* Test for a fixup that is inactive because it is already handled. */
|
||
if (f->before_jump == 0)
|
||
{
|
||
/* Delete inactive fixup from the chain, if that is easy to do. */
|
||
if (prev != 0)
|
||
prev->next = f->next;
|
||
}
|
||
/* Has this fixup's target label been defined?
|
||
If so, we can finalize it. */
|
||
else if (PREV_INSN (f->target_rtl) != 0)
|
||
{
|
||
register rtx cleanup_insns;
|
||
|
||
/* Get the first non-label after the label
|
||
this goto jumps to. If that's before this scope begins,
|
||
we don't have a jump into the scope. */
|
||
rtx after_label = f->target_rtl;
|
||
while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
|
||
after_label = NEXT_INSN (after_label);
|
||
|
||
/* If this fixup jumped into this contour from before the beginning
|
||
of this contour, report an error. */
|
||
/* ??? Bug: this does not detect jumping in through intermediate
|
||
blocks that have stack levels or cleanups.
|
||
It detects only a problem with the innermost block
|
||
around the label. */
|
||
if (f->target != 0
|
||
&& (dont_jump_in || stack_level || cleanup_list)
|
||
/* If AFTER_LABEL is 0, it means the jump goes to the end
|
||
of the rtl, which means it jumps into this scope. */
|
||
&& (after_label == 0
|
||
|| INSN_UID (first_insn) < INSN_UID (after_label))
|
||
&& INSN_UID (first_insn) > INSN_UID (f->before_jump)
|
||
&& ! DECL_REGISTER (f->target))
|
||
{
|
||
error_with_decl (f->target,
|
||
"label `%s' used before containing binding contour");
|
||
/* Prevent multiple errors for one label. */
|
||
DECL_REGISTER (f->target) = 1;
|
||
}
|
||
|
||
/* We will expand the cleanups into a sequence of their own and
|
||
then later on we will attach this new sequence to the insn
|
||
stream just ahead of the actual jump insn. */
|
||
|
||
start_sequence ();
|
||
|
||
/* Temporarily restore the lexical context where we will
|
||
logically be inserting the fixup code. We do this for the
|
||
sake of getting the debugging information right. */
|
||
|
||
pushlevel (0);
|
||
set_block (f->context);
|
||
|
||
/* Expand the cleanups for blocks this jump exits. */
|
||
if (f->cleanup_list_list)
|
||
{
|
||
tree lists;
|
||
for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
|
||
/* Marked elements correspond to blocks that have been closed.
|
||
Do their cleanups. */
|
||
if (TREE_ADDRESSABLE (lists)
|
||
&& TREE_VALUE (lists) != 0)
|
||
{
|
||
expand_cleanups (TREE_VALUE (lists), 0);
|
||
/* Pop any pushes done in the cleanups,
|
||
in case function is about to return. */
|
||
do_pending_stack_adjust ();
|
||
}
|
||
}
|
||
|
||
/* Restore stack level for the biggest contour that this
|
||
jump jumps out of. */
|
||
if (f->stack_level)
|
||
emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
|
||
|
||
/* Finish up the sequence containing the insns which implement the
|
||
necessary cleanups, and then attach that whole sequence to the
|
||
insn stream just ahead of the actual jump insn. Attaching it
|
||
at that point insures that any cleanups which are in fact
|
||
implicit C++ object destructions (which must be executed upon
|
||
leaving the block) appear (to the debugger) to be taking place
|
||
in an area of the generated code where the object(s) being
|
||
destructed are still "in scope". */
|
||
|
||
cleanup_insns = get_insns ();
|
||
poplevel (1, 0, 0);
|
||
|
||
end_sequence ();
|
||
emit_insns_after (cleanup_insns, f->before_jump);
|
||
|
||
|
||
f->before_jump = 0;
|
||
}
|
||
}
|
||
|
||
/* Mark the cleanups of exited blocks so that they are executed
|
||
by the code above. */
|
||
for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
|
||
if (f->before_jump != 0
|
||
&& PREV_INSN (f->target_rtl) == 0
|
||
/* Label has still not appeared. If we are exiting a block with
|
||
a stack level to restore, that started before the fixup,
|
||
mark this stack level as needing restoration
|
||
when the fixup is later finalized.
|
||
Also mark the cleanup_list_list element for F
|
||
that corresponds to this block, so that ultimately
|
||
this block's cleanups will be executed by the code above. */
|
||
&& thisblock != 0
|
||
/* Note: if THISBLOCK == 0 and we have a label that hasn't appeared,
|
||
it means the label is undefined. That's erroneous, but possible. */
|
||
&& (thisblock->data.block.block_start_count
|
||
<= f->block_start_count))
|
||
{
|
||
tree lists = f->cleanup_list_list;
|
||
for (; lists; lists = TREE_CHAIN (lists))
|
||
/* If the following elt. corresponds to our containing block
|
||
then the elt. must be for this block. */
|
||
if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
|
||
TREE_ADDRESSABLE (lists) = 1;
|
||
|
||
if (stack_level)
|
||
f->stack_level = stack_level;
|
||
}
|
||
}
|
||
|
||
/* Generate RTL for an asm statement (explicit assembler code).
|
||
BODY is a STRING_CST node containing the assembler code text,
|
||
or an ADDR_EXPR containing a STRING_CST. */
|
||
|
||
void
|
||
expand_asm (body)
|
||
tree body;
|
||
{
|
||
if (TREE_CODE (body) == ADDR_EXPR)
|
||
body = TREE_OPERAND (body, 0);
|
||
|
||
emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
|
||
TREE_STRING_POINTER (body)));
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
/* Generate RTL for an asm statement with arguments.
|
||
STRING is the instruction template.
|
||
OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
|
||
Each output or input has an expression in the TREE_VALUE and
|
||
a constraint-string in the TREE_PURPOSE.
|
||
CLOBBERS is a list of STRING_CST nodes each naming a hard register
|
||
that is clobbered by this insn.
|
||
|
||
Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
|
||
Some elements of OUTPUTS may be replaced with trees representing temporary
|
||
values. The caller should copy those temporary values to the originally
|
||
specified lvalues.
|
||
|
||
VOL nonzero means the insn is volatile; don't optimize it. */
|
||
|
||
void
|
||
expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
|
||
tree string, outputs, inputs, clobbers;
|
||
int vol;
|
||
char *filename;
|
||
int line;
|
||
{
|
||
rtvec argvec, constraints;
|
||
rtx body;
|
||
int ninputs = list_length (inputs);
|
||
int noutputs = list_length (outputs);
|
||
int nclobbers;
|
||
tree tail;
|
||
register int i;
|
||
/* Vector of RTX's of evaluated output operands. */
|
||
rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
|
||
/* The insn we have emitted. */
|
||
rtx insn;
|
||
|
||
/* Count the number of meaningful clobbered registers, ignoring what
|
||
we would ignore later. */
|
||
nclobbers = 0;
|
||
for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
|
||
i = decode_reg_name (regname);
|
||
if (i >= 0 || i == -4)
|
||
++nclobbers;
|
||
}
|
||
|
||
last_expr_type = 0;
|
||
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
tree val = TREE_VALUE (tail);
|
||
tree val1;
|
||
int j;
|
||
int found_equal;
|
||
|
||
/* If there's an erroneous arg, emit no insn. */
|
||
if (TREE_TYPE (val) == error_mark_node)
|
||
return;
|
||
|
||
/* Make sure constraint has `=' and does not have `+'. */
|
||
|
||
found_equal = 0;
|
||
for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
|
||
{
|
||
if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
|
||
{
|
||
error ("output operand constraint contains `+'");
|
||
return;
|
||
}
|
||
if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=')
|
||
found_equal = 1;
|
||
}
|
||
if (! found_equal)
|
||
{
|
||
error ("output operand constraint lacks `='");
|
||
return;
|
||
}
|
||
|
||
/* If an output operand is not a variable or indirect ref,
|
||
or a part of one,
|
||
create a SAVE_EXPR which is a pseudo-reg
|
||
to act as an intermediate temporary.
|
||
Make the asm insn write into that, then copy it to
|
||
the real output operand. */
|
||
|
||
while (TREE_CODE (val) == COMPONENT_REF
|
||
|| TREE_CODE (val) == ARRAY_REF)
|
||
val = TREE_OPERAND (val, 0);
|
||
|
||
if (TREE_CODE (val) != VAR_DECL
|
||
&& TREE_CODE (val) != PARM_DECL
|
||
&& TREE_CODE (val) != INDIRECT_REF)
|
||
{
|
||
TREE_VALUE (tail) = save_expr (TREE_VALUE (tail));
|
||
/* If it's a constant, print error now so don't crash later. */
|
||
if (TREE_CODE (TREE_VALUE (tail)) != SAVE_EXPR)
|
||
{
|
||
error ("invalid output in `asm'");
|
||
return;
|
||
}
|
||
}
|
||
|
||
output_rtx[i] = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
|
||
}
|
||
|
||
if (ninputs + noutputs > MAX_RECOG_OPERANDS)
|
||
{
|
||
error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
|
||
return;
|
||
}
|
||
|
||
/* Make vectors for the expression-rtx and constraint strings. */
|
||
|
||
argvec = rtvec_alloc (ninputs);
|
||
constraints = rtvec_alloc (ninputs);
|
||
|
||
body = gen_rtx (ASM_OPERANDS, VOIDmode,
|
||
TREE_STRING_POINTER (string), "", 0, argvec, constraints,
|
||
filename, line);
|
||
MEM_VOLATILE_P (body) = vol;
|
||
|
||
/* Eval the inputs and put them into ARGVEC.
|
||
Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
|
||
|
||
i = 0;
|
||
for (tail = inputs; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
int j;
|
||
|
||
/* If there's an erroneous arg, emit no insn,
|
||
because the ASM_INPUT would get VOIDmode
|
||
and that could cause a crash in reload. */
|
||
if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
|
||
return;
|
||
if (TREE_PURPOSE (tail) == NULL_TREE)
|
||
{
|
||
error ("hard register `%s' listed as input operand to `asm'",
|
||
TREE_STRING_POINTER (TREE_VALUE (tail)) );
|
||
return;
|
||
}
|
||
|
||
/* Make sure constraint has neither `=' nor `+'. */
|
||
|
||
for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
|
||
if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '='
|
||
|| TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
|
||
{
|
||
error ("input operand constraint contains `%c'",
|
||
TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
|
||
return;
|
||
}
|
||
|
||
XVECEXP (body, 3, i) /* argvec */
|
||
= expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
|
||
XVECEXP (body, 4, i) /* constraints */
|
||
= gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
|
||
TREE_STRING_POINTER (TREE_PURPOSE (tail)));
|
||
i++;
|
||
}
|
||
|
||
/* Protect all the operands from the queue,
|
||
now that they have all been evaluated. */
|
||
|
||
for (i = 0; i < ninputs; i++)
|
||
XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
|
||
|
||
for (i = 0; i < noutputs; i++)
|
||
output_rtx[i] = protect_from_queue (output_rtx[i], 1);
|
||
|
||
/* Now, for each output, construct an rtx
|
||
(set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
|
||
ARGVEC CONSTRAINTS))
|
||
If there is more than one, put them inside a PARALLEL. */
|
||
|
||
if (noutputs == 1 && nclobbers == 0)
|
||
{
|
||
XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
|
||
insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
|
||
}
|
||
else if (noutputs == 0 && nclobbers == 0)
|
||
{
|
||
/* No output operands: put in a raw ASM_OPERANDS rtx. */
|
||
insn = emit_insn (body);
|
||
}
|
||
else
|
||
{
|
||
rtx obody = body;
|
||
int num = noutputs;
|
||
if (num == 0) num = 1;
|
||
body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
|
||
|
||
/* For each output operand, store a SET. */
|
||
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
XVECEXP (body, 0, i)
|
||
= gen_rtx (SET, VOIDmode,
|
||
output_rtx[i],
|
||
gen_rtx (ASM_OPERANDS, VOIDmode,
|
||
TREE_STRING_POINTER (string),
|
||
TREE_STRING_POINTER (TREE_PURPOSE (tail)),
|
||
i, argvec, constraints,
|
||
filename, line));
|
||
MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
|
||
}
|
||
|
||
/* If there are no outputs (but there are some clobbers)
|
||
store the bare ASM_OPERANDS into the PARALLEL. */
|
||
|
||
if (i == 0)
|
||
XVECEXP (body, 0, i++) = obody;
|
||
|
||
/* Store (clobber REG) for each clobbered register specified. */
|
||
|
||
for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
|
||
int j = decode_reg_name (regname);
|
||
|
||
if (j < 0)
|
||
{
|
||
if (j == -3) /* `cc', which is not a register */
|
||
continue;
|
||
|
||
if (j == -4) /* `memory', don't cache memory across asm */
|
||
{
|
||
XVECEXP (body, 0, i++)
|
||
= gen_rtx (CLOBBER, VOIDmode,
|
||
gen_rtx (MEM, QImode,
|
||
gen_rtx (SCRATCH, VOIDmode, 0)));
|
||
continue;
|
||
}
|
||
|
||
error ("unknown register name `%s' in `asm'", regname);
|
||
return;
|
||
}
|
||
|
||
/* Use QImode since that's guaranteed to clobber just one reg. */
|
||
XVECEXP (body, 0, i++)
|
||
= gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
|
||
}
|
||
|
||
insn = emit_insn (body);
|
||
}
|
||
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* Generate RTL to evaluate the expression EXP
|
||
and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
|
||
|
||
void
|
||
expand_expr_stmt (exp)
|
||
tree exp;
|
||
{
|
||
/* If -W, warn about statements with no side effects,
|
||
except for an explicit cast to void (e.g. for assert()), and
|
||
except inside a ({...}) where they may be useful. */
|
||
if (expr_stmts_for_value == 0 && exp != error_mark_node)
|
||
{
|
||
if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
|
||
&& !(TREE_CODE (exp) == CONVERT_EXPR
|
||
&& TREE_TYPE (exp) == void_type_node))
|
||
warning_with_file_and_line (emit_filename, emit_lineno,
|
||
"statement with no effect");
|
||
else if (warn_unused)
|
||
warn_if_unused_value (exp);
|
||
}
|
||
last_expr_type = TREE_TYPE (exp);
|
||
if (! flag_syntax_only)
|
||
last_expr_value = expand_expr (exp,
|
||
(expr_stmts_for_value
|
||
? NULL_RTX : const0_rtx),
|
||
VOIDmode, 0);
|
||
|
||
/* If all we do is reference a volatile value in memory,
|
||
copy it to a register to be sure it is actually touched. */
|
||
if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
|
||
&& TREE_THIS_VOLATILE (exp))
|
||
{
|
||
if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
|
||
;
|
||
else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
|
||
copy_to_reg (last_expr_value);
|
||
else
|
||
{
|
||
rtx lab = gen_label_rtx ();
|
||
|
||
/* Compare the value with itself to reference it. */
|
||
emit_cmp_insn (last_expr_value, last_expr_value, EQ,
|
||
expand_expr (TYPE_SIZE (last_expr_type),
|
||
NULL_RTX, VOIDmode, 0),
|
||
BLKmode, 0,
|
||
TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
|
||
emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
|
||
emit_label (lab);
|
||
}
|
||
}
|
||
|
||
/* If this expression is part of a ({...}) and is in memory, we may have
|
||
to preserve temporaries. */
|
||
preserve_temp_slots (last_expr_value);
|
||
|
||
/* Free any temporaries used to evaluate this expression. Any temporary
|
||
used as a result of this expression will already have been preserved
|
||
above. */
|
||
free_temp_slots ();
|
||
|
||
emit_queue ();
|
||
}
|
||
|
||
/* Warn if EXP contains any computations whose results are not used.
|
||
Return 1 if a warning is printed; 0 otherwise. */
|
||
|
||
static int
|
||
warn_if_unused_value (exp)
|
||
tree exp;
|
||
{
|
||
if (TREE_USED (exp))
|
||
return 0;
|
||
|
||
switch (TREE_CODE (exp))
|
||
{
|
||
case PREINCREMENT_EXPR:
|
||
case POSTINCREMENT_EXPR:
|
||
case PREDECREMENT_EXPR:
|
||
case POSTDECREMENT_EXPR:
|
||
case MODIFY_EXPR:
|
||
case INIT_EXPR:
|
||
case TARGET_EXPR:
|
||
case CALL_EXPR:
|
||
case METHOD_CALL_EXPR:
|
||
case RTL_EXPR:
|
||
case WITH_CLEANUP_EXPR:
|
||
case EXIT_EXPR:
|
||
/* We don't warn about COND_EXPR because it may be a useful
|
||
construct if either arm contains a side effect. */
|
||
case COND_EXPR:
|
||
return 0;
|
||
|
||
case BIND_EXPR:
|
||
/* For a binding, warn if no side effect within it. */
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 1));
|
||
|
||
case TRUTH_ORIF_EXPR:
|
||
case TRUTH_ANDIF_EXPR:
|
||
/* In && or ||, warn if 2nd operand has no side effect. */
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 1));
|
||
|
||
case COMPOUND_EXPR:
|
||
if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
|
||
return 1;
|
||
/* Let people do `(foo (), 0)' without a warning. */
|
||
if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
|
||
return 0;
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 1));
|
||
|
||
case NOP_EXPR:
|
||
case CONVERT_EXPR:
|
||
case NON_LVALUE_EXPR:
|
||
/* Don't warn about values cast to void. */
|
||
if (TREE_TYPE (exp) == void_type_node)
|
||
return 0;
|
||
/* Don't warn about conversions not explicit in the user's program. */
|
||
if (TREE_NO_UNUSED_WARNING (exp))
|
||
return 0;
|
||
/* Assignment to a cast usually results in a cast of a modify.
|
||
Don't complain about that. */
|
||
if (TREE_CODE (TREE_OPERAND (exp, 0)) == MODIFY_EXPR)
|
||
return 0;
|
||
/* Sometimes it results in a cast of a cast of a modify.
|
||
Don't complain about that. */
|
||
if ((TREE_CODE (TREE_OPERAND (exp, 0)) == CONVERT_EXPR
|
||
|| TREE_CODE (TREE_OPERAND (exp, 0)) == NOP_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) == MODIFY_EXPR)
|
||
return 0;
|
||
|
||
default:
|
||
/* Referencing a volatile value is a side effect, so don't warn. */
|
||
if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
|
||
|| TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
|
||
&& TREE_THIS_VOLATILE (exp))
|
||
return 0;
|
||
warning_with_file_and_line (emit_filename, emit_lineno,
|
||
"value computed is not used");
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
/* Clear out the memory of the last expression evaluated. */
|
||
|
||
void
|
||
clear_last_expr ()
|
||
{
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
/* Begin a statement which will return a value.
|
||
Return the RTL_EXPR for this statement expr.
|
||
The caller must save that value and pass it to expand_end_stmt_expr. */
|
||
|
||
tree
|
||
expand_start_stmt_expr ()
|
||
{
|
||
/* Make the RTL_EXPR node temporary, not momentary,
|
||
so that rtl_expr_chain doesn't become garbage. */
|
||
int momentary = suspend_momentary ();
|
||
tree t = make_node (RTL_EXPR);
|
||
resume_momentary (momentary);
|
||
start_sequence ();
|
||
NO_DEFER_POP;
|
||
expr_stmts_for_value++;
|
||
return t;
|
||
}
|
||
|
||
/* Restore the previous state at the end of a statement that returns a value.
|
||
Returns a tree node representing the statement's value and the
|
||
insns to compute the value.
|
||
|
||
The nodes of that expression have been freed by now, so we cannot use them.
|
||
But we don't want to do that anyway; the expression has already been
|
||
evaluated and now we just want to use the value. So generate a RTL_EXPR
|
||
with the proper type and RTL value.
|
||
|
||
If the last substatement was not an expression,
|
||
return something with type `void'. */
|
||
|
||
tree
|
||
expand_end_stmt_expr (t)
|
||
tree t;
|
||
{
|
||
OK_DEFER_POP;
|
||
|
||
if (last_expr_type == 0)
|
||
{
|
||
last_expr_type = void_type_node;
|
||
last_expr_value = const0_rtx;
|
||
}
|
||
else if (last_expr_value == 0)
|
||
/* There are some cases where this can happen, such as when the
|
||
statement is void type. */
|
||
last_expr_value = const0_rtx;
|
||
else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
|
||
/* Remove any possible QUEUED. */
|
||
last_expr_value = protect_from_queue (last_expr_value, 0);
|
||
|
||
emit_queue ();
|
||
|
||
TREE_TYPE (t) = last_expr_type;
|
||
RTL_EXPR_RTL (t) = last_expr_value;
|
||
RTL_EXPR_SEQUENCE (t) = get_insns ();
|
||
|
||
rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
|
||
|
||
end_sequence ();
|
||
|
||
/* Don't consider deleting this expr or containing exprs at tree level. */
|
||
TREE_SIDE_EFFECTS (t) = 1;
|
||
/* Propagate volatility of the actual RTL expr. */
|
||
TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
|
||
|
||
last_expr_type = 0;
|
||
expr_stmts_for_value--;
|
||
|
||
return t;
|
||
}
|
||
|
||
/* The exception handling nesting looks like this:
|
||
|
||
<-- Level N-1
|
||
{ <-- exception handler block
|
||
<-- Level N
|
||
<-- in an exception handler
|
||
{ <-- try block
|
||
: <-- in a TRY block
|
||
: <-- in an exception handler
|
||
:
|
||
}
|
||
|
||
{ <-- except block
|
||
: <-- in an except block
|
||
: <-- in an exception handler
|
||
:
|
||
}
|
||
|
||
}
|
||
*/
|
||
|
||
/* Return nonzero iff in a try block at level LEVEL. */
|
||
|
||
int
|
||
in_try_block (level)
|
||
int level;
|
||
{
|
||
struct nesting *n = except_stack;
|
||
while (1)
|
||
{
|
||
while (n && n->data.except_stmt.after_label != 0)
|
||
n = n->next;
|
||
if (n == 0)
|
||
return 0;
|
||
if (level == 0)
|
||
return n != 0;
|
||
level--;
|
||
n = n->next;
|
||
}
|
||
}
|
||
|
||
/* Return nonzero iff in an except block at level LEVEL. */
|
||
|
||
int
|
||
in_except_block (level)
|
||
int level;
|
||
{
|
||
struct nesting *n = except_stack;
|
||
while (1)
|
||
{
|
||
while (n && n->data.except_stmt.after_label == 0)
|
||
n = n->next;
|
||
if (n == 0)
|
||
return 0;
|
||
if (level == 0)
|
||
return n != 0;
|
||
level--;
|
||
n = n->next;
|
||
}
|
||
}
|
||
|
||
/* Return nonzero iff in an exception handler at level LEVEL. */
|
||
|
||
int
|
||
in_exception_handler (level)
|
||
int level;
|
||
{
|
||
struct nesting *n = except_stack;
|
||
while (n && level--)
|
||
n = n->next;
|
||
return n != 0;
|
||
}
|
||
|
||
/* Record the fact that the current exception nesting raises
|
||
exception EX. If not in an exception handler, return 0. */
|
||
int
|
||
expand_raise (ex)
|
||
tree ex;
|
||
{
|
||
tree *raises_ptr;
|
||
|
||
if (except_stack == 0)
|
||
return 0;
|
||
raises_ptr = &except_stack->data.except_stmt.raised;
|
||
if (! value_member (ex, *raises_ptr))
|
||
*raises_ptr = tree_cons (NULL_TREE, ex, *raises_ptr);
|
||
return 1;
|
||
}
|
||
|
||
/* Generate RTL for the start of a try block.
|
||
|
||
TRY_CLAUSE is the condition to test to enter the try block. */
|
||
|
||
void
|
||
expand_start_try (try_clause, exitflag, escapeflag)
|
||
tree try_clause;
|
||
int exitflag;
|
||
int escapeflag;
|
||
{
|
||
struct nesting *thishandler = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on cond_stack for the cond we are entering. */
|
||
|
||
thishandler->next = except_stack;
|
||
thishandler->all = nesting_stack;
|
||
thishandler->depth = ++nesting_depth;
|
||
thishandler->data.except_stmt.raised = 0;
|
||
thishandler->data.except_stmt.handled = 0;
|
||
thishandler->data.except_stmt.first_insn = get_insns ();
|
||
thishandler->data.except_stmt.except_label = gen_label_rtx ();
|
||
thishandler->data.except_stmt.unhandled_label = 0;
|
||
thishandler->data.except_stmt.after_label = 0;
|
||
thishandler->data.except_stmt.escape_label
|
||
= escapeflag ? thishandler->data.except_stmt.except_label : 0;
|
||
thishandler->exit_label = exitflag ? gen_label_rtx () : 0;
|
||
except_stack = thishandler;
|
||
nesting_stack = thishandler;
|
||
|
||
do_jump (try_clause, thishandler->data.except_stmt.except_label, NULL_RTX);
|
||
}
|
||
|
||
/* End of a TRY block. Nothing to do for now. */
|
||
|
||
void
|
||
expand_end_try ()
|
||
{
|
||
except_stack->data.except_stmt.after_label = gen_label_rtx ();
|
||
expand_goto_internal (NULL_TREE, except_stack->data.except_stmt.after_label,
|
||
NULL_RTX);
|
||
}
|
||
|
||
/* Start an `except' nesting contour.
|
||
EXITFLAG says whether this contour should be able to `exit' something.
|
||
ESCAPEFLAG says whether this contour should be escapable. */
|
||
|
||
void
|
||
expand_start_except (exitflag, escapeflag)
|
||
int exitflag;
|
||
int escapeflag;
|
||
{
|
||
if (exitflag)
|
||
{
|
||
struct nesting *n;
|
||
/* An `exit' from catch clauses goes out to next exit level,
|
||
if there is one. Otherwise, it just goes to the end
|
||
of the construct. */
|
||
for (n = except_stack->next; n; n = n->next)
|
||
if (n->exit_label != 0)
|
||
{
|
||
except_stack->exit_label = n->exit_label;
|
||
break;
|
||
}
|
||
if (n == 0)
|
||
except_stack->exit_label = except_stack->data.except_stmt.after_label;
|
||
}
|
||
if (escapeflag)
|
||
{
|
||
struct nesting *n;
|
||
/* An `escape' from catch clauses goes out to next escape level,
|
||
if there is one. Otherwise, it just goes to the end
|
||
of the construct. */
|
||
for (n = except_stack->next; n; n = n->next)
|
||
if (n->data.except_stmt.escape_label != 0)
|
||
{
|
||
except_stack->data.except_stmt.escape_label
|
||
= n->data.except_stmt.escape_label;
|
||
break;
|
||
}
|
||
if (n == 0)
|
||
except_stack->data.except_stmt.escape_label
|
||
= except_stack->data.except_stmt.after_label;
|
||
}
|
||
do_pending_stack_adjust ();
|
||
emit_label (except_stack->data.except_stmt.except_label);
|
||
}
|
||
|
||
/* Generate code to `escape' from an exception contour. This
|
||
is like `exiting', but does not conflict with constructs which
|
||
use `exit_label'.
|
||
|
||
Return nonzero if this contour is escapable, otherwise
|
||
return zero, and language-specific code will emit the
|
||
appropriate error message. */
|
||
int
|
||
expand_escape_except ()
|
||
{
|
||
struct nesting *n;
|
||
last_expr_type = 0;
|
||
for (n = except_stack; n; n = n->next)
|
||
if (n->data.except_stmt.escape_label != 0)
|
||
{
|
||
expand_goto_internal (NULL_TREE,
|
||
n->data.except_stmt.escape_label, NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Finish processing and `except' contour.
|
||
Culls out all exceptions which might be raise but not
|
||
handled, and returns the list to the caller.
|
||
Language-specific code is responsible for dealing with these
|
||
exceptions. */
|
||
|
||
tree
|
||
expand_end_except ()
|
||
{
|
||
struct nesting *n;
|
||
tree raised = NULL_TREE;
|
||
|
||
do_pending_stack_adjust ();
|
||
emit_label (except_stack->data.except_stmt.after_label);
|
||
|
||
n = except_stack->next;
|
||
if (n)
|
||
{
|
||
/* Propagate exceptions raised but not handled to next
|
||
highest level. */
|
||
tree handled = except_stack->data.except_stmt.raised;
|
||
if (handled != void_type_node)
|
||
{
|
||
tree prev = NULL_TREE;
|
||
raised = except_stack->data.except_stmt.raised;
|
||
while (handled)
|
||
{
|
||
tree this_raise;
|
||
for (this_raise = raised, prev = 0; this_raise;
|
||
this_raise = TREE_CHAIN (this_raise))
|
||
{
|
||
if (value_member (TREE_VALUE (this_raise), handled))
|
||
{
|
||
if (prev)
|
||
TREE_CHAIN (prev) = TREE_CHAIN (this_raise);
|
||
else
|
||
{
|
||
raised = TREE_CHAIN (raised);
|
||
if (raised == NULL_TREE)
|
||
goto nada;
|
||
}
|
||
}
|
||
else
|
||
prev = this_raise;
|
||
}
|
||
handled = TREE_CHAIN (handled);
|
||
}
|
||
if (prev == NULL_TREE)
|
||
prev = raised;
|
||
if (prev)
|
||
TREE_CHAIN (prev) = n->data.except_stmt.raised;
|
||
nada:
|
||
n->data.except_stmt.raised = raised;
|
||
}
|
||
}
|
||
|
||
POPSTACK (except_stack);
|
||
last_expr_type = 0;
|
||
return raised;
|
||
}
|
||
|
||
/* Record that exception EX is caught by this exception handler.
|
||
Return nonzero if in exception handling construct, otherwise return 0. */
|
||
int
|
||
expand_catch (ex)
|
||
tree ex;
|
||
{
|
||
tree *raises_ptr;
|
||
|
||
if (except_stack == 0)
|
||
return 0;
|
||
raises_ptr = &except_stack->data.except_stmt.handled;
|
||
if (*raises_ptr != void_type_node
|
||
&& ex != NULL_TREE
|
||
&& ! value_member (ex, *raises_ptr))
|
||
*raises_ptr = tree_cons (NULL_TREE, ex, *raises_ptr);
|
||
return 1;
|
||
}
|
||
|
||
/* Record that this exception handler catches all exceptions.
|
||
Return nonzero if in exception handling construct, otherwise return 0. */
|
||
|
||
int
|
||
expand_catch_default ()
|
||
{
|
||
if (except_stack == 0)
|
||
return 0;
|
||
except_stack->data.except_stmt.handled = void_type_node;
|
||
return 1;
|
||
}
|
||
|
||
int
|
||
expand_end_catch ()
|
||
{
|
||
if (except_stack == 0 || except_stack->data.except_stmt.after_label == 0)
|
||
return 0;
|
||
expand_goto_internal (NULL_TREE, except_stack->data.except_stmt.after_label,
|
||
NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
/* Generate RTL for the start of an if-then. COND is the expression
|
||
whose truth should be tested.
|
||
|
||
If EXITFLAG is nonzero, this conditional is visible to
|
||
`exit_something'. */
|
||
|
||
void
|
||
expand_start_cond (cond, exitflag)
|
||
tree cond;
|
||
int exitflag;
|
||
{
|
||
struct nesting *thiscond = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on cond_stack for the cond we are entering. */
|
||
|
||
thiscond->next = cond_stack;
|
||
thiscond->all = nesting_stack;
|
||
thiscond->depth = ++nesting_depth;
|
||
thiscond->data.cond.next_label = gen_label_rtx ();
|
||
/* Before we encounter an `else', we don't need a separate exit label
|
||
unless there are supposed to be exit statements
|
||
to exit this conditional. */
|
||
thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
|
||
thiscond->data.cond.endif_label = thiscond->exit_label;
|
||
cond_stack = thiscond;
|
||
nesting_stack = thiscond;
|
||
|
||
do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
|
||
}
|
||
|
||
/* Generate RTL between then-clause and the elseif-clause
|
||
of an if-then-elseif-.... */
|
||
|
||
void
|
||
expand_start_elseif (cond)
|
||
tree cond;
|
||
{
|
||
if (cond_stack->data.cond.endif_label == 0)
|
||
cond_stack->data.cond.endif_label = gen_label_rtx ();
|
||
emit_jump (cond_stack->data.cond.endif_label);
|
||
emit_label (cond_stack->data.cond.next_label);
|
||
cond_stack->data.cond.next_label = gen_label_rtx ();
|
||
do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
|
||
}
|
||
|
||
/* Generate RTL between the then-clause and the else-clause
|
||
of an if-then-else. */
|
||
|
||
void
|
||
expand_start_else ()
|
||
{
|
||
if (cond_stack->data.cond.endif_label == 0)
|
||
cond_stack->data.cond.endif_label = gen_label_rtx ();
|
||
emit_jump (cond_stack->data.cond.endif_label);
|
||
emit_label (cond_stack->data.cond.next_label);
|
||
cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
|
||
}
|
||
|
||
/* Generate RTL for the end of an if-then.
|
||
Pop the record for it off of cond_stack. */
|
||
|
||
void
|
||
expand_end_cond ()
|
||
{
|
||
struct nesting *thiscond = cond_stack;
|
||
|
||
do_pending_stack_adjust ();
|
||
if (thiscond->data.cond.next_label)
|
||
emit_label (thiscond->data.cond.next_label);
|
||
if (thiscond->data.cond.endif_label)
|
||
emit_label (thiscond->data.cond.endif_label);
|
||
|
||
POPSTACK (cond_stack);
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
/* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
|
||
loop should be exited by `exit_something'. This is a loop for which
|
||
`expand_continue' will jump to the top of the loop.
|
||
|
||
Make an entry on loop_stack to record the labels associated with
|
||
this loop. */
|
||
|
||
struct nesting *
|
||
expand_start_loop (exit_flag)
|
||
int exit_flag;
|
||
{
|
||
register struct nesting *thisloop = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on loop_stack for the loop we are entering. */
|
||
|
||
thisloop->next = loop_stack;
|
||
thisloop->all = nesting_stack;
|
||
thisloop->depth = ++nesting_depth;
|
||
thisloop->data.loop.start_label = gen_label_rtx ();
|
||
thisloop->data.loop.end_label = gen_label_rtx ();
|
||
thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
|
||
thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
|
||
loop_stack = thisloop;
|
||
nesting_stack = thisloop;
|
||
|
||
do_pending_stack_adjust ();
|
||
emit_queue ();
|
||
emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
|
||
emit_label (thisloop->data.loop.start_label);
|
||
|
||
return thisloop;
|
||
}
|
||
|
||
/* Like expand_start_loop but for a loop where the continuation point
|
||
(for expand_continue_loop) will be specified explicitly. */
|
||
|
||
struct nesting *
|
||
expand_start_loop_continue_elsewhere (exit_flag)
|
||
int exit_flag;
|
||
{
|
||
struct nesting *thisloop = expand_start_loop (exit_flag);
|
||
loop_stack->data.loop.continue_label = gen_label_rtx ();
|
||
return thisloop;
|
||
}
|
||
|
||
/* Specify the continuation point for a loop started with
|
||
expand_start_loop_continue_elsewhere.
|
||
Use this at the point in the code to which a continue statement
|
||
should jump. */
|
||
|
||
void
|
||
expand_loop_continue_here ()
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
|
||
emit_label (loop_stack->data.loop.continue_label);
|
||
}
|
||
|
||
/* Finish a loop. Generate a jump back to the top and the loop-exit label.
|
||
Pop the block off of loop_stack. */
|
||
|
||
void
|
||
expand_end_loop ()
|
||
{
|
||
register rtx insn = get_last_insn ();
|
||
register rtx start_label = loop_stack->data.loop.start_label;
|
||
rtx last_test_insn = 0;
|
||
int num_insns = 0;
|
||
|
||
/* Mark the continue-point at the top of the loop if none elsewhere. */
|
||
if (start_label == loop_stack->data.loop.continue_label)
|
||
emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* If optimizing, perhaps reorder the loop. If the loop
|
||
starts with a conditional exit, roll that to the end
|
||
where it will optimize together with the jump back.
|
||
|
||
We look for the last conditional branch to the exit that we encounter
|
||
before hitting 30 insns or a CALL_INSN. If we see an unconditional
|
||
branch to the exit first, use it.
|
||
|
||
We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
|
||
because moving them is not valid. */
|
||
|
||
if (optimize
|
||
&&
|
||
! (GET_CODE (insn) == JUMP_INSN
|
||
&& GET_CODE (PATTERN (insn)) == SET
|
||
&& SET_DEST (PATTERN (insn)) == pc_rtx
|
||
&& GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
|
||
{
|
||
/* Scan insns from the top of the loop looking for a qualified
|
||
conditional exit. */
|
||
for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
|
||
insn = NEXT_INSN (insn))
|
||
{
|
||
if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
|
||
break;
|
||
|
||
if (GET_CODE (insn) == NOTE
|
||
&& (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
|
||
|| NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
|
||
break;
|
||
|
||
if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
|
||
num_insns++;
|
||
|
||
if (last_test_insn && num_insns > 30)
|
||
break;
|
||
|
||
if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
|
||
&& SET_DEST (PATTERN (insn)) == pc_rtx
|
||
&& GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
|
||
&& ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
|
||
&& (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
|
||
== loop_stack->data.loop.end_label))
|
||
|| (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
|
||
&& (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
|
||
== loop_stack->data.loop.end_label))))
|
||
last_test_insn = insn;
|
||
|
||
if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
|
||
&& GET_CODE (PATTERN (insn)) == SET
|
||
&& SET_DEST (PATTERN (insn)) == pc_rtx
|
||
&& GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
|
||
&& (XEXP (SET_SRC (PATTERN (insn)), 0)
|
||
== loop_stack->data.loop.end_label))
|
||
/* Include BARRIER. */
|
||
last_test_insn = NEXT_INSN (insn);
|
||
}
|
||
|
||
if (last_test_insn != 0 && last_test_insn != get_last_insn ())
|
||
{
|
||
/* We found one. Move everything from there up
|
||
to the end of the loop, and add a jump into the loop
|
||
to jump to there. */
|
||
register rtx newstart_label = gen_label_rtx ();
|
||
register rtx start_move = start_label;
|
||
|
||
/* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
|
||
then we want to move this note also. */
|
||
if (GET_CODE (PREV_INSN (start_move)) == NOTE
|
||
&& (NOTE_LINE_NUMBER (PREV_INSN (start_move))
|
||
== NOTE_INSN_LOOP_CONT))
|
||
start_move = PREV_INSN (start_move);
|
||
|
||
emit_label_after (newstart_label, PREV_INSN (start_move));
|
||
reorder_insns (start_move, last_test_insn, get_last_insn ());
|
||
emit_jump_insn_after (gen_jump (start_label),
|
||
PREV_INSN (newstart_label));
|
||
emit_barrier_after (PREV_INSN (newstart_label));
|
||
start_label = newstart_label;
|
||
}
|
||
}
|
||
|
||
emit_jump (start_label);
|
||
emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
|
||
emit_label (loop_stack->data.loop.end_label);
|
||
|
||
POPSTACK (loop_stack);
|
||
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
/* Generate a jump to the current loop's continue-point.
|
||
This is usually the top of the loop, but may be specified
|
||
explicitly elsewhere. If not currently inside a loop,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_continue_loop (whichloop)
|
||
struct nesting *whichloop;
|
||
{
|
||
last_expr_type = 0;
|
||
if (whichloop == 0)
|
||
whichloop = loop_stack;
|
||
if (whichloop == 0)
|
||
return 0;
|
||
expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
|
||
NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
/* Generate a jump to exit the current loop. If not currently inside a loop,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_exit_loop (whichloop)
|
||
struct nesting *whichloop;
|
||
{
|
||
last_expr_type = 0;
|
||
if (whichloop == 0)
|
||
whichloop = loop_stack;
|
||
if (whichloop == 0)
|
||
return 0;
|
||
expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
/* Generate a conditional jump to exit the current loop if COND
|
||
evaluates to zero. If not currently inside a loop,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_exit_loop_if_false (whichloop, cond)
|
||
struct nesting *whichloop;
|
||
tree cond;
|
||
{
|
||
last_expr_type = 0;
|
||
if (whichloop == 0)
|
||
whichloop = loop_stack;
|
||
if (whichloop == 0)
|
||
return 0;
|
||
do_jump (cond, whichloop->data.loop.end_label, NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
/* Return non-zero if we should preserve sub-expressions as separate
|
||
pseudos. We never do so if we aren't optimizing. We always do so
|
||
if -fexpensive-optimizations.
|
||
|
||
Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
|
||
the loop may still be a small one. */
|
||
|
||
int
|
||
preserve_subexpressions_p ()
|
||
{
|
||
rtx insn;
|
||
|
||
if (flag_expensive_optimizations)
|
||
return 1;
|
||
|
||
if (optimize == 0 || loop_stack == 0)
|
||
return 0;
|
||
|
||
insn = get_last_insn_anywhere ();
|
||
|
||
return (insn
|
||
&& (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
|
||
< n_non_fixed_regs * 3));
|
||
|
||
}
|
||
|
||
/* Generate a jump to exit the current loop, conditional, binding contour
|
||
or case statement. Not all such constructs are visible to this function,
|
||
only those started with EXIT_FLAG nonzero. Individual languages use
|
||
the EXIT_FLAG parameter to control which kinds of constructs you can
|
||
exit this way.
|
||
|
||
If not currently inside anything that can be exited,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_exit_something ()
|
||
{
|
||
struct nesting *n;
|
||
last_expr_type = 0;
|
||
for (n = nesting_stack; n; n = n->all)
|
||
if (n->exit_label != 0)
|
||
{
|
||
expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Generate RTL to return from the current function, with no value.
|
||
(That is, we do not do anything about returning any value.) */
|
||
|
||
void
|
||
expand_null_return ()
|
||
{
|
||
struct nesting *block = block_stack;
|
||
rtx last_insn = 0;
|
||
|
||
/* Does any pending block have cleanups? */
|
||
|
||
while (block && block->data.block.cleanups == 0)
|
||
block = block->next;
|
||
|
||
/* If yes, use a goto to return, since that runs cleanups. */
|
||
|
||
expand_null_return_1 (last_insn, block != 0);
|
||
}
|
||
|
||
/* Generate RTL to return from the current function, with value VAL. */
|
||
|
||
void
|
||
expand_value_return (val)
|
||
rtx val;
|
||
{
|
||
struct nesting *block = block_stack;
|
||
rtx last_insn = get_last_insn ();
|
||
rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
|
||
|
||
/* Copy the value to the return location
|
||
unless it's already there. */
|
||
|
||
if (return_reg != val)
|
||
{
|
||
#ifdef PROMOTE_FUNCTION_RETURN
|
||
enum machine_mode mode = DECL_MODE (DECL_RESULT (current_function_decl));
|
||
tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
|
||
int unsignedp = TREE_UNSIGNED (type);
|
||
|
||
if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
|
||
|| TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
|
||
|| TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
|
||
|| TREE_CODE (type) == OFFSET_TYPE)
|
||
{
|
||
PROMOTE_MODE (mode, unsignedp, type);
|
||
}
|
||
|
||
if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
|
||
convert_move (return_reg, val, unsignedp);
|
||
else
|
||
#endif
|
||
emit_move_insn (return_reg, val);
|
||
}
|
||
if (GET_CODE (return_reg) == REG
|
||
&& REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
|
||
emit_insn (gen_rtx (USE, VOIDmode, return_reg));
|
||
|
||
/* Does any pending block have cleanups? */
|
||
|
||
while (block && block->data.block.cleanups == 0)
|
||
block = block->next;
|
||
|
||
/* If yes, use a goto to return, since that runs cleanups.
|
||
Use LAST_INSN to put cleanups *before* the move insn emitted above. */
|
||
|
||
expand_null_return_1 (last_insn, block != 0);
|
||
}
|
||
|
||
/* Output a return with no value. If LAST_INSN is nonzero,
|
||
pretend that the return takes place after LAST_INSN.
|
||
If USE_GOTO is nonzero then don't use a return instruction;
|
||
go to the return label instead. This causes any cleanups
|
||
of pending blocks to be executed normally. */
|
||
|
||
static void
|
||
expand_null_return_1 (last_insn, use_goto)
|
||
rtx last_insn;
|
||
int use_goto;
|
||
{
|
||
rtx end_label = cleanup_label ? cleanup_label : return_label;
|
||
|
||
clear_pending_stack_adjust ();
|
||
do_pending_stack_adjust ();
|
||
last_expr_type = 0;
|
||
|
||
/* PCC-struct return always uses an epilogue. */
|
||
if (current_function_returns_pcc_struct || use_goto)
|
||
{
|
||
if (end_label == 0)
|
||
end_label = return_label = gen_label_rtx ();
|
||
expand_goto_internal (NULL_TREE, end_label, last_insn);
|
||
return;
|
||
}
|
||
|
||
/* Otherwise output a simple return-insn if one is available,
|
||
unless it won't do the job. */
|
||
#ifdef HAVE_return
|
||
if (HAVE_return && use_goto == 0 && cleanup_label == 0)
|
||
{
|
||
emit_jump_insn (gen_return ());
|
||
emit_barrier ();
|
||
return;
|
||
}
|
||
#endif
|
||
|
||
/* Otherwise jump to the epilogue. */
|
||
expand_goto_internal (NULL_TREE, end_label, last_insn);
|
||
}
|
||
|
||
/* Generate RTL to evaluate the expression RETVAL and return it
|
||
from the current function. */
|
||
|
||
void
|
||
expand_return (retval)
|
||
tree retval;
|
||
{
|
||
/* If there are any cleanups to be performed, then they will
|
||
be inserted following LAST_INSN. It is desirable
|
||
that the last_insn, for such purposes, should be the
|
||
last insn before computing the return value. Otherwise, cleanups
|
||
which call functions can clobber the return value. */
|
||
/* ??? rms: I think that is erroneous, because in C++ it would
|
||
run destructors on variables that might be used in the subsequent
|
||
computation of the return value. */
|
||
rtx last_insn = 0;
|
||
register rtx val = 0;
|
||
register rtx op0;
|
||
tree retval_rhs;
|
||
int cleanups;
|
||
struct nesting *block;
|
||
|
||
/* If function wants no value, give it none. */
|
||
if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
|
||
{
|
||
expand_expr (retval, NULL_RTX, VOIDmode, 0);
|
||
emit_queue ();
|
||
expand_null_return ();
|
||
return;
|
||
}
|
||
|
||
/* Are any cleanups needed? E.g. C++ destructors to be run? */
|
||
cleanups = any_pending_cleanups (1);
|
||
|
||
if (TREE_CODE (retval) == RESULT_DECL)
|
||
retval_rhs = retval;
|
||
else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
|
||
retval_rhs = TREE_OPERAND (retval, 1);
|
||
else if (TREE_TYPE (retval) == void_type_node)
|
||
/* Recognize tail-recursive call to void function. */
|
||
retval_rhs = retval;
|
||
else
|
||
retval_rhs = NULL_TREE;
|
||
|
||
/* Only use `last_insn' if there are cleanups which must be run. */
|
||
if (cleanups || cleanup_label != 0)
|
||
last_insn = get_last_insn ();
|
||
|
||
/* Distribute return down conditional expr if either of the sides
|
||
may involve tail recursion (see test below). This enhances the number
|
||
of tail recursions we see. Don't do this always since it can produce
|
||
sub-optimal code in some cases and we distribute assignments into
|
||
conditional expressions when it would help. */
|
||
|
||
if (optimize && retval_rhs != 0
|
||
&& frame_offset == 0
|
||
&& TREE_CODE (retval_rhs) == COND_EXPR
|
||
&& (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
|
||
|| TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
|
||
{
|
||
rtx label = gen_label_rtx ();
|
||
do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
|
||
expand_return (build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
|
||
DECL_RESULT (current_function_decl),
|
||
TREE_OPERAND (retval_rhs, 1)));
|
||
emit_label (label);
|
||
expand_return (build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
|
||
DECL_RESULT (current_function_decl),
|
||
TREE_OPERAND (retval_rhs, 2)));
|
||
return;
|
||
}
|
||
|
||
/* For tail-recursive call to current function,
|
||
just jump back to the beginning.
|
||
It's unsafe if any auto variable in this function
|
||
has its address taken; for simplicity,
|
||
require stack frame to be empty. */
|
||
if (optimize && retval_rhs != 0
|
||
&& frame_offset == 0
|
||
&& TREE_CODE (retval_rhs) == CALL_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
|
||
&& TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
|
||
/* Finish checking validity, and if valid emit code
|
||
to set the argument variables for the new call. */
|
||
&& tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
|
||
DECL_ARGUMENTS (current_function_decl)))
|
||
{
|
||
if (tail_recursion_label == 0)
|
||
{
|
||
tail_recursion_label = gen_label_rtx ();
|
||
emit_label_after (tail_recursion_label,
|
||
tail_recursion_reentry);
|
||
}
|
||
emit_queue ();
|
||
expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
|
||
emit_barrier ();
|
||
return;
|
||
}
|
||
#ifdef HAVE_return
|
||
/* This optimization is safe if there are local cleanups
|
||
because expand_null_return takes care of them.
|
||
??? I think it should also be safe when there is a cleanup label,
|
||
because expand_null_return takes care of them, too.
|
||
Any reason why not? */
|
||
if (HAVE_return && cleanup_label == 0
|
||
&& ! current_function_returns_pcc_struct)
|
||
{
|
||
/* If this is return x == y; then generate
|
||
if (x == y) return 1; else return 0;
|
||
if we can do it with explicit return insns. */
|
||
if (retval_rhs)
|
||
switch (TREE_CODE (retval_rhs))
|
||
{
|
||
case EQ_EXPR:
|
||
case NE_EXPR:
|
||
case GT_EXPR:
|
||
case GE_EXPR:
|
||
case LT_EXPR:
|
||
case LE_EXPR:
|
||
case TRUTH_ANDIF_EXPR:
|
||
case TRUTH_ORIF_EXPR:
|
||
case TRUTH_AND_EXPR:
|
||
case TRUTH_OR_EXPR:
|
||
case TRUTH_NOT_EXPR:
|
||
case TRUTH_XOR_EXPR:
|
||
op0 = gen_label_rtx ();
|
||
jumpifnot (retval_rhs, op0);
|
||
expand_value_return (const1_rtx);
|
||
emit_label (op0);
|
||
expand_value_return (const0_rtx);
|
||
return;
|
||
}
|
||
}
|
||
#endif /* HAVE_return */
|
||
|
||
if (cleanups
|
||
&& retval_rhs != 0
|
||
&& TREE_TYPE (retval_rhs) != void_type_node
|
||
&& GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
|
||
{
|
||
/* Calculate the return value into a pseudo reg. */
|
||
val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
|
||
emit_queue ();
|
||
/* All temporaries have now been used. */
|
||
free_temp_slots ();
|
||
/* Return the calculated value, doing cleanups first. */
|
||
expand_value_return (val);
|
||
}
|
||
else
|
||
{
|
||
/* No cleanups or no hard reg used;
|
||
calculate value into hard return reg. */
|
||
expand_expr (retval, NULL_RTX, VOIDmode, 0);
|
||
emit_queue ();
|
||
free_temp_slots ();
|
||
expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
|
||
}
|
||
}
|
||
|
||
/* Return 1 if the end of the generated RTX is not a barrier.
|
||
This means code already compiled can drop through. */
|
||
|
||
int
|
||
drop_through_at_end_p ()
|
||
{
|
||
rtx insn = get_last_insn ();
|
||
while (insn && GET_CODE (insn) == NOTE)
|
||
insn = PREV_INSN (insn);
|
||
return insn && GET_CODE (insn) != BARRIER;
|
||
}
|
||
|
||
/* Emit code to alter this function's formal parms for a tail-recursive call.
|
||
ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
|
||
FORMALS is the chain of decls of formals.
|
||
Return 1 if this can be done;
|
||
otherwise return 0 and do not emit any code. */
|
||
|
||
static int
|
||
tail_recursion_args (actuals, formals)
|
||
tree actuals, formals;
|
||
{
|
||
register tree a = actuals, f = formals;
|
||
register int i;
|
||
register rtx *argvec;
|
||
|
||
/* Check that number and types of actuals are compatible
|
||
with the formals. This is not always true in valid C code.
|
||
Also check that no formal needs to be addressable
|
||
and that all formals are scalars. */
|
||
|
||
/* Also count the args. */
|
||
|
||
for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
|
||
{
|
||
if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
|
||
return 0;
|
||
if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
|
||
return 0;
|
||
}
|
||
if (a != 0 || f != 0)
|
||
return 0;
|
||
|
||
/* Compute all the actuals. */
|
||
|
||
argvec = (rtx *) alloca (i * sizeof (rtx));
|
||
|
||
for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
|
||
argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
|
||
|
||
/* Find which actual values refer to current values of previous formals.
|
||
Copy each of them now, before any formal is changed. */
|
||
|
||
for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
|
||
{
|
||
int copy = 0;
|
||
register int j;
|
||
for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
|
||
if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
|
||
{ copy = 1; break; }
|
||
if (copy)
|
||
argvec[i] = copy_to_reg (argvec[i]);
|
||
}
|
||
|
||
/* Store the values of the actuals into the formals. */
|
||
|
||
for (f = formals, a = actuals, i = 0; f;
|
||
f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
|
||
{
|
||
if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
|
||
emit_move_insn (DECL_RTL (f), argvec[i]);
|
||
else
|
||
convert_move (DECL_RTL (f), argvec[i],
|
||
TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
|
||
}
|
||
|
||
free_temp_slots ();
|
||
return 1;
|
||
}
|
||
|
||
/* Generate the RTL code for entering a binding contour.
|
||
The variables are declared one by one, by calls to `expand_decl'.
|
||
|
||
EXIT_FLAG is nonzero if this construct should be visible to
|
||
`exit_something'. */
|
||
|
||
void
|
||
expand_start_bindings (exit_flag)
|
||
int exit_flag;
|
||
{
|
||
struct nesting *thisblock = ALLOC_NESTING ();
|
||
|
||
rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
|
||
|
||
/* Make an entry on block_stack for the block we are entering. */
|
||
|
||
thisblock->next = block_stack;
|
||
thisblock->all = nesting_stack;
|
||
thisblock->depth = ++nesting_depth;
|
||
thisblock->data.block.stack_level = 0;
|
||
thisblock->data.block.cleanups = 0;
|
||
thisblock->data.block.function_call_count = 0;
|
||
#if 0
|
||
if (block_stack)
|
||
{
|
||
if (block_stack->data.block.cleanups == NULL_TREE
|
||
&& (block_stack->data.block.outer_cleanups == NULL_TREE
|
||
|| block_stack->data.block.outer_cleanups == empty_cleanup_list))
|
||
thisblock->data.block.outer_cleanups = empty_cleanup_list;
|
||
else
|
||
thisblock->data.block.outer_cleanups
|
||
= tree_cons (NULL_TREE, block_stack->data.block.cleanups,
|
||
block_stack->data.block.outer_cleanups);
|
||
}
|
||
else
|
||
thisblock->data.block.outer_cleanups = 0;
|
||
#endif
|
||
#if 1
|
||
if (block_stack
|
||
&& !(block_stack->data.block.cleanups == NULL_TREE
|
||
&& block_stack->data.block.outer_cleanups == NULL_TREE))
|
||
thisblock->data.block.outer_cleanups
|
||
= tree_cons (NULL_TREE, block_stack->data.block.cleanups,
|
||
block_stack->data.block.outer_cleanups);
|
||
else
|
||
thisblock->data.block.outer_cleanups = 0;
|
||
#endif
|
||
thisblock->data.block.label_chain = 0;
|
||
thisblock->data.block.innermost_stack_block = stack_block_stack;
|
||
thisblock->data.block.first_insn = note;
|
||
thisblock->data.block.block_start_count = ++block_start_count;
|
||
thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
|
||
block_stack = thisblock;
|
||
nesting_stack = thisblock;
|
||
|
||
/* Make a new level for allocating stack slots. */
|
||
push_temp_slots ();
|
||
}
|
||
|
||
/* Given a pointer to a BLOCK node, save a pointer to the most recently
|
||
generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
|
||
BLOCK node. */
|
||
|
||
void
|
||
remember_end_note (block)
|
||
register tree block;
|
||
{
|
||
BLOCK_END_NOTE (block) = last_block_end_note;
|
||
last_block_end_note = NULL_RTX;
|
||
}
|
||
|
||
/* Generate RTL code to terminate a binding contour.
|
||
VARS is the chain of VAR_DECL nodes
|
||
for the variables bound in this contour.
|
||
MARK_ENDS is nonzero if we should put a note at the beginning
|
||
and end of this binding contour.
|
||
|
||
DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
|
||
(That is true automatically if the contour has a saved stack level.) */
|
||
|
||
void
|
||
expand_end_bindings (vars, mark_ends, dont_jump_in)
|
||
tree vars;
|
||
int mark_ends;
|
||
int dont_jump_in;
|
||
{
|
||
register struct nesting *thisblock = block_stack;
|
||
register tree decl;
|
||
|
||
if (warn_unused)
|
||
for (decl = vars; decl; decl = TREE_CHAIN (decl))
|
||
if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
|
||
&& ! DECL_IN_SYSTEM_HEADER (decl))
|
||
warning_with_decl (decl, "unused variable `%s'");
|
||
|
||
if (thisblock->exit_label)
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_label (thisblock->exit_label);
|
||
}
|
||
|
||
/* If necessary, make a handler for nonlocal gotos taking
|
||
place in the function calls in this block. */
|
||
if (function_call_count != thisblock->data.block.function_call_count
|
||
&& nonlocal_labels
|
||
/* Make handler for outermost block
|
||
if there were any nonlocal gotos to this function. */
|
||
&& (thisblock->next == 0 ? current_function_has_nonlocal_label
|
||
/* Make handler for inner block if it has something
|
||
special to do when you jump out of it. */
|
||
: (thisblock->data.block.cleanups != 0
|
||
|| thisblock->data.block.stack_level != 0)))
|
||
{
|
||
tree link;
|
||
rtx afterward = gen_label_rtx ();
|
||
rtx handler_label = gen_label_rtx ();
|
||
rtx save_receiver = gen_reg_rtx (Pmode);
|
||
|
||
/* Don't let jump_optimize delete the handler. */
|
||
LABEL_PRESERVE_P (handler_label) = 1;
|
||
|
||
/* Record the handler address in the stack slot for that purpose,
|
||
during this block, saving and restoring the outer value. */
|
||
if (thisblock->next != 0)
|
||
{
|
||
emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
|
||
emit_insn_before (gen_move_insn (save_receiver,
|
||
nonlocal_goto_handler_slot),
|
||
thisblock->data.block.first_insn);
|
||
}
|
||
emit_insn_before (gen_move_insn (nonlocal_goto_handler_slot,
|
||
gen_rtx (LABEL_REF, Pmode,
|
||
handler_label)),
|
||
thisblock->data.block.first_insn);
|
||
|
||
/* Jump around the handler; it runs only when specially invoked. */
|
||
emit_jump (afterward);
|
||
emit_label (handler_label);
|
||
|
||
#ifdef HAVE_nonlocal_goto
|
||
if (! HAVE_nonlocal_goto)
|
||
#endif
|
||
/* First adjust our frame pointer to its actual value. It was
|
||
previously set to the start of the virtual area corresponding to
|
||
the stacked variables when we branched here and now needs to be
|
||
adjusted to the actual hardware fp value.
|
||
|
||
Assignments are to virtual registers are converted by
|
||
instantiate_virtual_regs into the corresponding assignment
|
||
to the underlying register (fp in this case) that makes
|
||
the original assignment true.
|
||
So the following insn will actually be
|
||
decrementing fp by STARTING_FRAME_OFFSET. */
|
||
emit_move_insn (virtual_stack_vars_rtx, frame_pointer_rtx);
|
||
|
||
#if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
|
||
if (fixed_regs[ARG_POINTER_REGNUM])
|
||
{
|
||
#ifdef ELIMINABLE_REGS
|
||
/* If the argument pointer can be eliminated in favor of the
|
||
frame pointer, we don't need to restore it. We assume here
|
||
that if such an elimination is present, it can always be used.
|
||
This is the case on all known machines; if we don't make this
|
||
assumption, we do unnecessary saving on many machines. */
|
||
static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
|
||
int i;
|
||
|
||
for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
|
||
if (elim_regs[i].from == ARG_POINTER_REGNUM
|
||
&& elim_regs[i].to == FRAME_POINTER_REGNUM)
|
||
break;
|
||
|
||
if (i == sizeof elim_regs / sizeof elim_regs [0])
|
||
#endif
|
||
{
|
||
/* Now restore our arg pointer from the address at which it
|
||
was saved in our stack frame.
|
||
If there hasn't be space allocated for it yet, make
|
||
some now. */
|
||
if (arg_pointer_save_area == 0)
|
||
arg_pointer_save_area
|
||
= assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
|
||
emit_move_insn (virtual_incoming_args_rtx,
|
||
/* We need a pseudo here, or else
|
||
instantiate_virtual_regs_1 complains. */
|
||
copy_to_reg (arg_pointer_save_area));
|
||
}
|
||
}
|
||
#endif
|
||
|
||
/* The handler expects the desired label address in the static chain
|
||
register. It tests the address and does an appropriate jump
|
||
to whatever label is desired. */
|
||
for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
|
||
/* Skip any labels we shouldn't be able to jump to from here. */
|
||
if (! DECL_TOO_LATE (TREE_VALUE (link)))
|
||
{
|
||
rtx not_this = gen_label_rtx ();
|
||
rtx this = gen_label_rtx ();
|
||
do_jump_if_equal (static_chain_rtx,
|
||
gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
|
||
this, 0);
|
||
emit_jump (not_this);
|
||
emit_label (this);
|
||
expand_goto (TREE_VALUE (link));
|
||
emit_label (not_this);
|
||
}
|
||
/* If label is not recognized, abort. */
|
||
emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
|
||
VOIDmode, 0);
|
||
emit_label (afterward);
|
||
}
|
||
|
||
/* Don't allow jumping into a block that has cleanups or a stack level. */
|
||
if (dont_jump_in
|
||
|| thisblock->data.block.stack_level != 0
|
||
|| thisblock->data.block.cleanups != 0)
|
||
{
|
||
struct label_chain *chain;
|
||
|
||
/* Any labels in this block are no longer valid to go to.
|
||
Mark them to cause an error message. */
|
||
for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
|
||
{
|
||
DECL_TOO_LATE (chain->label) = 1;
|
||
/* If any goto without a fixup came to this label,
|
||
that must be an error, because gotos without fixups
|
||
come from outside all saved stack-levels and all cleanups. */
|
||
if (TREE_ADDRESSABLE (chain->label))
|
||
error_with_decl (chain->label,
|
||
"label `%s' used before containing binding contour");
|
||
}
|
||
}
|
||
|
||
/* Restore stack level in effect before the block
|
||
(only if variable-size objects allocated). */
|
||
/* Perform any cleanups associated with the block. */
|
||
|
||
if (thisblock->data.block.stack_level != 0
|
||
|| thisblock->data.block.cleanups != 0)
|
||
{
|
||
/* Don't let cleanups affect ({...}) constructs. */
|
||
int old_expr_stmts_for_value = expr_stmts_for_value;
|
||
rtx old_last_expr_value = last_expr_value;
|
||
tree old_last_expr_type = last_expr_type;
|
||
expr_stmts_for_value = 0;
|
||
|
||
/* Do the cleanups. */
|
||
expand_cleanups (thisblock->data.block.cleanups, NULL_TREE);
|
||
do_pending_stack_adjust ();
|
||
|
||
expr_stmts_for_value = old_expr_stmts_for_value;
|
||
last_expr_value = old_last_expr_value;
|
||
last_expr_type = old_last_expr_type;
|
||
|
||
/* Restore the stack level. */
|
||
|
||
if (thisblock->data.block.stack_level != 0)
|
||
{
|
||
emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
|
||
thisblock->data.block.stack_level, NULL_RTX);
|
||
if (nonlocal_goto_handler_slot != 0)
|
||
emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
|
||
NULL_RTX);
|
||
}
|
||
|
||
/* Any gotos out of this block must also do these things.
|
||
Also report any gotos with fixups that came to labels in this
|
||
level. */
|
||
fixup_gotos (thisblock,
|
||
thisblock->data.block.stack_level,
|
||
thisblock->data.block.cleanups,
|
||
thisblock->data.block.first_insn,
|
||
dont_jump_in);
|
||
}
|
||
|
||
/* Mark the beginning and end of the scope if requested.
|
||
We do this now, after running cleanups on the variables
|
||
just going out of scope, so they are in scope for their cleanups. */
|
||
|
||
if (mark_ends)
|
||
last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
|
||
else
|
||
/* Get rid of the beginning-mark if we don't make an end-mark. */
|
||
NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
|
||
|
||
/* If doing stupid register allocation, make sure lives of all
|
||
register variables declared here extend thru end of scope. */
|
||
|
||
if (obey_regdecls)
|
||
for (decl = vars; decl; decl = TREE_CHAIN (decl))
|
||
{
|
||
rtx rtl = DECL_RTL (decl);
|
||
if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
|
||
use_variable (rtl);
|
||
}
|
||
|
||
/* Restore block_stack level for containing block. */
|
||
|
||
stack_block_stack = thisblock->data.block.innermost_stack_block;
|
||
POPSTACK (block_stack);
|
||
|
||
/* Pop the stack slot nesting and free any slots at this level. */
|
||
pop_temp_slots ();
|
||
}
|
||
|
||
/* Generate RTL for the automatic variable declaration DECL.
|
||
(Other kinds of declarations are simply ignored if seen here.)
|
||
CLEANUP is an expression to be executed at exit from this binding contour;
|
||
for example, in C++, it might call the destructor for this variable.
|
||
|
||
If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
|
||
either before or after calling `expand_decl' but before compiling
|
||
any subsequent expressions. This is because CLEANUP may be expanded
|
||
more than once, on different branches of execution.
|
||
For the same reason, CLEANUP may not contain a CALL_EXPR
|
||
except as its topmost node--else `preexpand_calls' would get confused.
|
||
|
||
If CLEANUP is nonzero and DECL is zero, we record a cleanup
|
||
that is not associated with any particular variable.
|
||
|
||
There is no special support here for C++ constructors.
|
||
They should be handled by the proper code in DECL_INITIAL. */
|
||
|
||
void
|
||
expand_decl (decl)
|
||
register tree decl;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
tree type = TREE_TYPE (decl);
|
||
|
||
/* Only automatic variables need any expansion done.
|
||
Static and external variables, and external functions,
|
||
will be handled by `assemble_variable' (called from finish_decl).
|
||
TYPE_DECL and CONST_DECL require nothing.
|
||
PARM_DECLs are handled in `assign_parms'. */
|
||
|
||
if (TREE_CODE (decl) != VAR_DECL)
|
||
return;
|
||
if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
|
||
return;
|
||
|
||
/* Create the RTL representation for the variable. */
|
||
|
||
if (type == error_mark_node)
|
||
DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
|
||
else if (DECL_SIZE (decl) == 0)
|
||
/* Variable with incomplete type. */
|
||
{
|
||
if (DECL_INITIAL (decl) == 0)
|
||
/* Error message was already done; now avoid a crash. */
|
||
DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
|
||
else
|
||
/* An initializer is going to decide the size of this array.
|
||
Until we know the size, represent its address with a reg. */
|
||
DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
|
||
}
|
||
else if (DECL_MODE (decl) != BLKmode
|
||
/* If -ffloat-store, don't put explicit float vars
|
||
into regs. */
|
||
&& !(flag_float_store
|
||
&& TREE_CODE (type) == REAL_TYPE)
|
||
&& ! TREE_THIS_VOLATILE (decl)
|
||
&& ! TREE_ADDRESSABLE (decl)
|
||
&& (DECL_REGISTER (decl) || ! obey_regdecls))
|
||
{
|
||
/* Automatic variable that can go in a register. */
|
||
enum machine_mode reg_mode = DECL_MODE (decl);
|
||
int unsignedp = TREE_UNSIGNED (type);
|
||
|
||
if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
|
||
|| TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
|
||
|| TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
|
||
|| TREE_CODE (type) == OFFSET_TYPE)
|
||
{
|
||
PROMOTE_MODE (reg_mode, unsignedp, type);
|
||
}
|
||
|
||
DECL_RTL (decl) = gen_reg_rtx (reg_mode);
|
||
if (TREE_CODE (type) == POINTER_TYPE)
|
||
mark_reg_pointer (DECL_RTL (decl));
|
||
REG_USERVAR_P (DECL_RTL (decl)) = 1;
|
||
}
|
||
else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
|
||
{
|
||
/* Variable of fixed size that goes on the stack. */
|
||
rtx oldaddr = 0;
|
||
rtx addr;
|
||
|
||
/* If we previously made RTL for this decl, it must be an array
|
||
whose size was determined by the initializer.
|
||
The old address was a register; set that register now
|
||
to the proper address. */
|
||
if (DECL_RTL (decl) != 0)
|
||
{
|
||
if (GET_CODE (DECL_RTL (decl)) != MEM
|
||
|| GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
|
||
abort ();
|
||
oldaddr = XEXP (DECL_RTL (decl), 0);
|
||
}
|
||
|
||
DECL_RTL (decl)
|
||
= assign_stack_temp (DECL_MODE (decl),
|
||
((TREE_INT_CST_LOW (DECL_SIZE (decl))
|
||
+ BITS_PER_UNIT - 1)
|
||
/ BITS_PER_UNIT),
|
||
1);
|
||
|
||
/* Set alignment we actually gave this decl. */
|
||
DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
|
||
: GET_MODE_BITSIZE (DECL_MODE (decl)));
|
||
|
||
if (oldaddr)
|
||
{
|
||
addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
|
||
if (addr != oldaddr)
|
||
emit_move_insn (oldaddr, addr);
|
||
}
|
||
|
||
/* If this is a memory ref that contains aggregate components,
|
||
mark it as such for cse and loop optimize. */
|
||
MEM_IN_STRUCT_P (DECL_RTL (decl))
|
||
= (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
|
||
|| TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
|
||
|| TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
|
||
|| TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE);
|
||
#if 0
|
||
/* If this is in memory because of -ffloat-store,
|
||
set the volatile bit, to prevent optimizations from
|
||
undoing the effects. */
|
||
if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
|
||
MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
|
||
#endif
|
||
}
|
||
else
|
||
/* Dynamic-size object: must push space on the stack. */
|
||
{
|
||
rtx address, size;
|
||
|
||
/* Record the stack pointer on entry to block, if have
|
||
not already done so. */
|
||
if (thisblock->data.block.stack_level == 0)
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
|
||
&thisblock->data.block.stack_level,
|
||
thisblock->data.block.first_insn);
|
||
stack_block_stack = thisblock;
|
||
}
|
||
|
||
/* Compute the variable's size, in bytes. */
|
||
size = expand_expr (size_binop (CEIL_DIV_EXPR,
|
||
DECL_SIZE (decl),
|
||
size_int (BITS_PER_UNIT)),
|
||
NULL_RTX, VOIDmode, 0);
|
||
free_temp_slots ();
|
||
|
||
/* This is equivalent to calling alloca. */
|
||
current_function_calls_alloca = 1;
|
||
|
||
/* Allocate space on the stack for the variable. */
|
||
address = allocate_dynamic_stack_space (size, NULL_RTX,
|
||
DECL_ALIGN (decl));
|
||
|
||
if (nonlocal_goto_handler_slot != 0)
|
||
emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
|
||
|
||
/* Reference the variable indirect through that rtx. */
|
||
DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
|
||
|
||
/* If this is a memory ref that contains aggregate components,
|
||
mark it as such for cse and loop optimize. */
|
||
MEM_IN_STRUCT_P (DECL_RTL (decl))
|
||
= (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
|
||
|| TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
|
||
|| TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
|
||
|| TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE);
|
||
|
||
/* Indicate the alignment we actually gave this variable. */
|
||
#ifdef STACK_BOUNDARY
|
||
DECL_ALIGN (decl) = STACK_BOUNDARY;
|
||
#else
|
||
DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
|
||
#endif
|
||
}
|
||
|
||
if (TREE_THIS_VOLATILE (decl))
|
||
MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
|
||
#if 0 /* A variable is not necessarily unchanging
|
||
just because it is const. RTX_UNCHANGING_P
|
||
means no change in the function,
|
||
not merely no change in the variable's scope.
|
||
It is correct to set RTX_UNCHANGING_P if the variable's scope
|
||
is the whole function. There's no convenient way to test that. */
|
||
if (TREE_READONLY (decl))
|
||
RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
|
||
#endif
|
||
|
||
/* If doing stupid register allocation, make sure life of any
|
||
register variable starts here, at the start of its scope. */
|
||
|
||
if (obey_regdecls)
|
||
use_variable (DECL_RTL (decl));
|
||
}
|
||
|
||
/* Emit code to perform the initialization of a declaration DECL. */
|
||
|
||
void
|
||
expand_decl_init (decl)
|
||
tree decl;
|
||
{
|
||
int was_used = TREE_USED (decl);
|
||
|
||
if (TREE_STATIC (decl))
|
||
return;
|
||
|
||
/* Compute and store the initial value now. */
|
||
|
||
if (DECL_INITIAL (decl) == error_mark_node)
|
||
{
|
||
enum tree_code code = TREE_CODE (TREE_TYPE (decl));
|
||
if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
|
||
|| code == POINTER_TYPE)
|
||
expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
|
||
0, 0);
|
||
emit_queue ();
|
||
}
|
||
else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
|
||
{
|
||
emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
|
||
expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
|
||
emit_queue ();
|
||
}
|
||
|
||
/* Don't let the initialization count as "using" the variable. */
|
||
TREE_USED (decl) = was_used;
|
||
|
||
/* Free any temporaries we made while initializing the decl. */
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* CLEANUP is an expression to be executed at exit from this binding contour;
|
||
for example, in C++, it might call the destructor for this variable.
|
||
|
||
If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
|
||
either before or after calling `expand_decl' but before compiling
|
||
any subsequent expressions. This is because CLEANUP may be expanded
|
||
more than once, on different branches of execution.
|
||
For the same reason, CLEANUP may not contain a CALL_EXPR
|
||
except as its topmost node--else `preexpand_calls' would get confused.
|
||
|
||
If CLEANUP is nonzero and DECL is zero, we record a cleanup
|
||
that is not associated with any particular variable. */
|
||
|
||
int
|
||
expand_decl_cleanup (decl, cleanup)
|
||
tree decl, cleanup;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
|
||
/* Error if we are not in any block. */
|
||
if (thisblock == 0)
|
||
return 0;
|
||
|
||
/* Record the cleanup if there is one. */
|
||
|
||
if (cleanup != 0)
|
||
{
|
||
thisblock->data.block.cleanups
|
||
= temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
|
||
/* If this block has a cleanup, it belongs in stack_block_stack. */
|
||
stack_block_stack = thisblock;
|
||
}
|
||
return 1;
|
||
}
|
||
|
||
/* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
|
||
DECL_ELTS is the list of elements that belong to DECL's type.
|
||
In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
|
||
|
||
void
|
||
expand_anon_union_decl (decl, cleanup, decl_elts)
|
||
tree decl, cleanup, decl_elts;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
rtx x;
|
||
|
||
expand_decl (decl, cleanup);
|
||
x = DECL_RTL (decl);
|
||
|
||
while (decl_elts)
|
||
{
|
||
tree decl_elt = TREE_VALUE (decl_elts);
|
||
tree cleanup_elt = TREE_PURPOSE (decl_elts);
|
||
enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
|
||
|
||
/* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
|
||
instead create a new MEM rtx with the proper mode. */
|
||
if (GET_CODE (x) == MEM)
|
||
{
|
||
if (mode == GET_MODE (x))
|
||
DECL_RTL (decl_elt) = x;
|
||
else
|
||
{
|
||
DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
|
||
MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
|
||
RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
|
||
}
|
||
}
|
||
else if (GET_CODE (x) == REG)
|
||
{
|
||
if (mode == GET_MODE (x))
|
||
DECL_RTL (decl_elt) = x;
|
||
else
|
||
DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
|
||
}
|
||
else
|
||
abort ();
|
||
|
||
/* Record the cleanup if there is one. */
|
||
|
||
if (cleanup != 0)
|
||
thisblock->data.block.cleanups
|
||
= temp_tree_cons (decl_elt, cleanup_elt,
|
||
thisblock->data.block.cleanups);
|
||
|
||
decl_elts = TREE_CHAIN (decl_elts);
|
||
}
|
||
}
|
||
|
||
/* Expand a list of cleanups LIST.
|
||
Elements may be expressions or may be nested lists.
|
||
|
||
If DONT_DO is nonnull, then any list-element
|
||
whose TREE_PURPOSE matches DONT_DO is omitted.
|
||
This is sometimes used to avoid a cleanup associated with
|
||
a value that is being returned out of the scope. */
|
||
|
||
static void
|
||
expand_cleanups (list, dont_do)
|
||
tree list;
|
||
tree dont_do;
|
||
{
|
||
tree tail;
|
||
for (tail = list; tail; tail = TREE_CHAIN (tail))
|
||
if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
|
||
{
|
||
if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
|
||
expand_cleanups (TREE_VALUE (tail), dont_do);
|
||
else
|
||
{
|
||
/* Cleanups may be run multiple times. For example,
|
||
when exiting a binding contour, we expand the
|
||
cleanups associated with that contour. When a goto
|
||
within that binding contour has a target outside that
|
||
contour, it will expand all cleanups from its scope to
|
||
the target. Though the cleanups are expanded multiple
|
||
times, the control paths are non-overlapping so the
|
||
cleanups will not be executed twice. */
|
||
expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
|
||
free_temp_slots ();
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Move all cleanups from the current block_stack
|
||
to the containing block_stack, where they are assumed to
|
||
have been created. If anything can cause a temporary to
|
||
be created, but not expanded for more than one level of
|
||
block_stacks, then this code will have to change. */
|
||
|
||
void
|
||
move_cleanups_up ()
|
||
{
|
||
struct nesting *block = block_stack;
|
||
struct nesting *outer = block->next;
|
||
|
||
outer->data.block.cleanups
|
||
= chainon (block->data.block.cleanups,
|
||
outer->data.block.cleanups);
|
||
block->data.block.cleanups = 0;
|
||
}
|
||
|
||
tree
|
||
last_cleanup_this_contour ()
|
||
{
|
||
if (block_stack == 0)
|
||
return 0;
|
||
|
||
return block_stack->data.block.cleanups;
|
||
}
|
||
|
||
/* Return 1 if there are any pending cleanups at this point.
|
||
If THIS_CONTOUR is nonzero, check the current contour as well.
|
||
Otherwise, look only at the contours that enclose this one. */
|
||
|
||
int
|
||
any_pending_cleanups (this_contour)
|
||
int this_contour;
|
||
{
|
||
struct nesting *block;
|
||
|
||
if (block_stack == 0)
|
||
return 0;
|
||
|
||
if (this_contour && block_stack->data.block.cleanups != NULL)
|
||
return 1;
|
||
if (block_stack->data.block.cleanups == 0
|
||
&& (block_stack->data.block.outer_cleanups == 0
|
||
#if 0
|
||
|| block_stack->data.block.outer_cleanups == empty_cleanup_list
|
||
#endif
|
||
))
|
||
return 0;
|
||
|
||
for (block = block_stack->next; block; block = block->next)
|
||
if (block->data.block.cleanups != 0)
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Enter a case (Pascal) or switch (C) statement.
|
||
Push a block onto case_stack and nesting_stack
|
||
to accumulate the case-labels that are seen
|
||
and to record the labels generated for the statement.
|
||
|
||
EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
|
||
Otherwise, this construct is transparent for `exit_something'.
|
||
|
||
EXPR is the index-expression to be dispatched on.
|
||
TYPE is its nominal type. We could simply convert EXPR to this type,
|
||
but instead we take short cuts. */
|
||
|
||
void
|
||
expand_start_case (exit_flag, expr, type, printname)
|
||
int exit_flag;
|
||
tree expr;
|
||
tree type;
|
||
char *printname;
|
||
{
|
||
register struct nesting *thiscase = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on case_stack for the case we are entering. */
|
||
|
||
thiscase->next = case_stack;
|
||
thiscase->all = nesting_stack;
|
||
thiscase->depth = ++nesting_depth;
|
||
thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
|
||
thiscase->data.case_stmt.case_list = 0;
|
||
thiscase->data.case_stmt.index_expr = expr;
|
||
thiscase->data.case_stmt.nominal_type = type;
|
||
thiscase->data.case_stmt.default_label = 0;
|
||
thiscase->data.case_stmt.num_ranges = 0;
|
||
thiscase->data.case_stmt.printname = printname;
|
||
thiscase->data.case_stmt.seenlabel = 0;
|
||
case_stack = thiscase;
|
||
nesting_stack = thiscase;
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* Make sure case_stmt.start points to something that won't
|
||
need any transformation before expand_end_case. */
|
||
if (GET_CODE (get_last_insn ()) != NOTE)
|
||
emit_note (NULL_PTR, NOTE_INSN_DELETED);
|
||
|
||
thiscase->data.case_stmt.start = get_last_insn ();
|
||
}
|
||
|
||
/* Start a "dummy case statement" within which case labels are invalid
|
||
and are not connected to any larger real case statement.
|
||
This can be used if you don't want to let a case statement jump
|
||
into the middle of certain kinds of constructs. */
|
||
|
||
void
|
||
expand_start_case_dummy ()
|
||
{
|
||
register struct nesting *thiscase = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on case_stack for the dummy. */
|
||
|
||
thiscase->next = case_stack;
|
||
thiscase->all = nesting_stack;
|
||
thiscase->depth = ++nesting_depth;
|
||
thiscase->exit_label = 0;
|
||
thiscase->data.case_stmt.case_list = 0;
|
||
thiscase->data.case_stmt.start = 0;
|
||
thiscase->data.case_stmt.nominal_type = 0;
|
||
thiscase->data.case_stmt.default_label = 0;
|
||
thiscase->data.case_stmt.num_ranges = 0;
|
||
case_stack = thiscase;
|
||
nesting_stack = thiscase;
|
||
}
|
||
|
||
/* End a dummy case statement. */
|
||
|
||
void
|
||
expand_end_case_dummy ()
|
||
{
|
||
POPSTACK (case_stack);
|
||
}
|
||
|
||
/* Return the data type of the index-expression
|
||
of the innermost case statement, or null if none. */
|
||
|
||
tree
|
||
case_index_expr_type ()
|
||
{
|
||
if (case_stack)
|
||
return TREE_TYPE (case_stack->data.case_stmt.index_expr);
|
||
return 0;
|
||
}
|
||
|
||
/* Accumulate one case or default label inside a case or switch statement.
|
||
VALUE is the value of the case (a null pointer, for a default label).
|
||
|
||
If not currently inside a case or switch statement, return 1 and do
|
||
nothing. The caller will print a language-specific error message.
|
||
If VALUE is a duplicate or overlaps, return 2 and do nothing
|
||
except store the (first) duplicate node in *DUPLICATE.
|
||
If VALUE is out of range, return 3 and do nothing.
|
||
If we are jumping into the scope of a cleaup or var-sized array, return 5.
|
||
Return 0 on success.
|
||
|
||
Extended to handle range statements. */
|
||
|
||
int
|
||
pushcase (value, label, duplicate)
|
||
register tree value;
|
||
register tree label;
|
||
tree *duplicate;
|
||
{
|
||
register struct case_node **l;
|
||
register struct case_node *n;
|
||
tree index_type;
|
||
tree nominal_type;
|
||
|
||
/* Fail if not inside a real case statement. */
|
||
if (! (case_stack && case_stack->data.case_stmt.start))
|
||
return 1;
|
||
|
||
if (stack_block_stack
|
||
&& stack_block_stack->depth > case_stack->depth)
|
||
return 5;
|
||
|
||
index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
|
||
nominal_type = case_stack->data.case_stmt.nominal_type;
|
||
|
||
/* If the index is erroneous, avoid more problems: pretend to succeed. */
|
||
if (index_type == error_mark_node)
|
||
return 0;
|
||
|
||
/* Convert VALUE to the type in which the comparisons are nominally done. */
|
||
if (value != 0)
|
||
value = convert (nominal_type, value);
|
||
|
||
/* If this is the first label, warn if any insns have been emitted. */
|
||
if (case_stack->data.case_stmt.seenlabel == 0)
|
||
{
|
||
rtx insn;
|
||
for (insn = case_stack->data.case_stmt.start;
|
||
insn;
|
||
insn = NEXT_INSN (insn))
|
||
{
|
||
if (GET_CODE (insn) == CODE_LABEL)
|
||
break;
|
||
if (GET_CODE (insn) != NOTE
|
||
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
|
||
{
|
||
warning ("unreachable code at beginning of %s",
|
||
case_stack->data.case_stmt.printname);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
case_stack->data.case_stmt.seenlabel = 1;
|
||
|
||
/* Fail if this value is out of range for the actual type of the index
|
||
(which may be narrower than NOMINAL_TYPE). */
|
||
if (value != 0 && ! int_fits_type_p (value, index_type))
|
||
return 3;
|
||
|
||
/* Fail if this is a duplicate or overlaps another entry. */
|
||
if (value == 0)
|
||
{
|
||
if (case_stack->data.case_stmt.default_label != 0)
|
||
{
|
||
*duplicate = case_stack->data.case_stmt.default_label;
|
||
return 2;
|
||
}
|
||
case_stack->data.case_stmt.default_label = label;
|
||
}
|
||
else
|
||
{
|
||
/* Find the elt in the chain before which to insert the new value,
|
||
to keep the chain sorted in increasing order.
|
||
But report an error if this element is a duplicate. */
|
||
for (l = &case_stack->data.case_stmt.case_list;
|
||
/* Keep going past elements distinctly less than VALUE. */
|
||
*l != 0 && tree_int_cst_lt ((*l)->high, value);
|
||
l = &(*l)->right)
|
||
;
|
||
if (*l)
|
||
{
|
||
/* Element we will insert before must be distinctly greater;
|
||
overlap means error. */
|
||
if (! tree_int_cst_lt (value, (*l)->low))
|
||
{
|
||
*duplicate = (*l)->code_label;
|
||
return 2;
|
||
}
|
||
}
|
||
|
||
/* Add this label to the chain, and succeed.
|
||
Copy VALUE so it is on temporary rather than momentary
|
||
obstack and will thus survive till the end of the case statement. */
|
||
n = (struct case_node *) oballoc (sizeof (struct case_node));
|
||
n->left = 0;
|
||
n->right = *l;
|
||
n->high = n->low = copy_node (value);
|
||
n->code_label = label;
|
||
*l = n;
|
||
}
|
||
|
||
expand_label (label);
|
||
return 0;
|
||
}
|
||
|
||
/* Like pushcase but this case applies to all values
|
||
between VALUE1 and VALUE2 (inclusive).
|
||
The return value is the same as that of pushcase
|
||
but there is one additional error code:
|
||
4 means the specified range was empty. */
|
||
|
||
int
|
||
pushcase_range (value1, value2, label, duplicate)
|
||
register tree value1, value2;
|
||
register tree label;
|
||
tree *duplicate;
|
||
{
|
||
register struct case_node **l;
|
||
register struct case_node *n;
|
||
tree index_type;
|
||
tree nominal_type;
|
||
|
||
/* Fail if not inside a real case statement. */
|
||
if (! (case_stack && case_stack->data.case_stmt.start))
|
||
return 1;
|
||
|
||
if (stack_block_stack
|
||
&& stack_block_stack->depth > case_stack->depth)
|
||
return 5;
|
||
|
||
index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
|
||
nominal_type = case_stack->data.case_stmt.nominal_type;
|
||
|
||
/* If the index is erroneous, avoid more problems: pretend to succeed. */
|
||
if (index_type == error_mark_node)
|
||
return 0;
|
||
|
||
/* If this is the first label, warn if any insns have been emitted. */
|
||
if (case_stack->data.case_stmt.seenlabel == 0)
|
||
{
|
||
rtx insn;
|
||
for (insn = case_stack->data.case_stmt.start;
|
||
insn;
|
||
insn = NEXT_INSN (insn))
|
||
{
|
||
if (GET_CODE (insn) == CODE_LABEL)
|
||
break;
|
||
if (GET_CODE (insn) != NOTE
|
||
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
|
||
{
|
||
warning ("unreachable code at beginning of %s",
|
||
case_stack->data.case_stmt.printname);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
case_stack->data.case_stmt.seenlabel = 1;
|
||
|
||
/* Convert VALUEs to type in which the comparisons are nominally done. */
|
||
if (value1 == 0) /* Negative infinity. */
|
||
value1 = TYPE_MIN_VALUE(index_type);
|
||
value1 = convert (nominal_type, value1);
|
||
|
||
if (value2 == 0) /* Positive infinity. */
|
||
value2 = TYPE_MAX_VALUE(index_type);
|
||
value2 = convert (nominal_type, value2);
|
||
|
||
/* Fail if these values are out of range. */
|
||
if (! int_fits_type_p (value1, index_type))
|
||
return 3;
|
||
|
||
if (! int_fits_type_p (value2, index_type))
|
||
return 3;
|
||
|
||
/* Fail if the range is empty. */
|
||
if (tree_int_cst_lt (value2, value1))
|
||
return 4;
|
||
|
||
/* If the bounds are equal, turn this into the one-value case. */
|
||
if (tree_int_cst_equal (value1, value2))
|
||
return pushcase (value1, label, duplicate);
|
||
|
||
/* Find the elt in the chain before which to insert the new value,
|
||
to keep the chain sorted in increasing order.
|
||
But report an error if this element is a duplicate. */
|
||
for (l = &case_stack->data.case_stmt.case_list;
|
||
/* Keep going past elements distinctly less than this range. */
|
||
*l != 0 && tree_int_cst_lt ((*l)->high, value1);
|
||
l = &(*l)->right)
|
||
;
|
||
if (*l)
|
||
{
|
||
/* Element we will insert before must be distinctly greater;
|
||
overlap means error. */
|
||
if (! tree_int_cst_lt (value2, (*l)->low))
|
||
{
|
||
*duplicate = (*l)->code_label;
|
||
return 2;
|
||
}
|
||
}
|
||
|
||
/* Add this label to the chain, and succeed.
|
||
Copy VALUE1, VALUE2 so they are on temporary rather than momentary
|
||
obstack and will thus survive till the end of the case statement. */
|
||
|
||
n = (struct case_node *) oballoc (sizeof (struct case_node));
|
||
n->left = 0;
|
||
n->right = *l;
|
||
n->low = copy_node (value1);
|
||
n->high = copy_node (value2);
|
||
n->code_label = label;
|
||
*l = n;
|
||
|
||
expand_label (label);
|
||
|
||
case_stack->data.case_stmt.num_ranges++;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Called when the index of a switch statement is an enumerated type
|
||
and there is no default label.
|
||
|
||
Checks that all enumeration literals are covered by the case
|
||
expressions of a switch. Also, warn if there are any extra
|
||
switch cases that are *not* elements of the enumerated type.
|
||
|
||
If all enumeration literals were covered by the case expressions,
|
||
turn one of the expressions into the default expression since it should
|
||
not be possible to fall through such a switch. */
|
||
|
||
void
|
||
check_for_full_enumeration_handling (type)
|
||
tree type;
|
||
{
|
||
register struct case_node *n;
|
||
register struct case_node **l;
|
||
register tree chain;
|
||
int all_values = 1;
|
||
|
||
/* The time complexity of this loop is currently O(N * M), with
|
||
N being the number of members in the enumerated type, and
|
||
M being the number of case expressions in the switch. */
|
||
|
||
for (chain = TYPE_VALUES (type);
|
||
chain;
|
||
chain = TREE_CHAIN (chain))
|
||
{
|
||
/* Find a match between enumeral and case expression, if possible.
|
||
Quit looking when we've gone too far (since case expressions
|
||
are kept sorted in ascending order). Warn about enumerators not
|
||
handled in the switch statement case expression list. */
|
||
|
||
for (n = case_stack->data.case_stmt.case_list;
|
||
n && tree_int_cst_lt (n->high, TREE_VALUE (chain));
|
||
n = n->right)
|
||
;
|
||
|
||
if (!n || tree_int_cst_lt (TREE_VALUE (chain), n->low))
|
||
{
|
||
if (warn_switch)
|
||
warning ("enumeration value `%s' not handled in switch",
|
||
IDENTIFIER_POINTER (TREE_PURPOSE (chain)));
|
||
all_values = 0;
|
||
}
|
||
}
|
||
|
||
/* Now we go the other way around; we warn if there are case
|
||
expressions that don't correspond to enumerators. This can
|
||
occur since C and C++ don't enforce type-checking of
|
||
assignments to enumeration variables. */
|
||
|
||
if (warn_switch)
|
||
for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
|
||
{
|
||
for (chain = TYPE_VALUES (type);
|
||
chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
|
||
chain = TREE_CHAIN (chain))
|
||
;
|
||
|
||
if (!chain)
|
||
{
|
||
if (TYPE_NAME (type) == 0)
|
||
warning ("case value `%d' not in enumerated type",
|
||
TREE_INT_CST_LOW (n->low));
|
||
else
|
||
warning ("case value `%d' not in enumerated type `%s'",
|
||
TREE_INT_CST_LOW (n->low),
|
||
IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
|
||
== IDENTIFIER_NODE)
|
||
? TYPE_NAME (type)
|
||
: DECL_NAME (TYPE_NAME (type))));
|
||
}
|
||
if (!tree_int_cst_equal (n->low, n->high))
|
||
{
|
||
for (chain = TYPE_VALUES (type);
|
||
chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
|
||
chain = TREE_CHAIN (chain))
|
||
;
|
||
|
||
if (!chain)
|
||
{
|
||
if (TYPE_NAME (type) == 0)
|
||
warning ("case value `%d' not in enumerated type",
|
||
TREE_INT_CST_LOW (n->high));
|
||
else
|
||
warning ("case value `%d' not in enumerated type `%s'",
|
||
TREE_INT_CST_LOW (n->high),
|
||
IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
|
||
== IDENTIFIER_NODE)
|
||
? TYPE_NAME (type)
|
||
: DECL_NAME (TYPE_NAME (type))));
|
||
}
|
||
}
|
||
}
|
||
|
||
#if 0
|
||
/* ??? This optimization is disabled because it causes valid programs to
|
||
fail. ANSI C does not guarantee that an expression with enum type
|
||
will have a value that is the same as one of the enumation literals. */
|
||
|
||
/* If all values were found as case labels, make one of them the default
|
||
label. Thus, this switch will never fall through. We arbitrarily pick
|
||
the last one to make the default since this is likely the most
|
||
efficient choice. */
|
||
|
||
if (all_values)
|
||
{
|
||
for (l = &case_stack->data.case_stmt.case_list;
|
||
(*l)->right != 0;
|
||
l = &(*l)->right)
|
||
;
|
||
|
||
case_stack->data.case_stmt.default_label = (*l)->code_label;
|
||
*l = 0;
|
||
}
|
||
#endif /* 0 */
|
||
}
|
||
|
||
/* Terminate a case (Pascal) or switch (C) statement
|
||
in which ORIG_INDEX is the expression to be tested.
|
||
Generate the code to test it and jump to the right place. */
|
||
|
||
void
|
||
expand_end_case (orig_index)
|
||
tree orig_index;
|
||
{
|
||
tree minval, maxval, range;
|
||
rtx default_label = 0;
|
||
register struct case_node *n;
|
||
int count;
|
||
rtx index;
|
||
rtx table_label = gen_label_rtx ();
|
||
int ncases;
|
||
rtx *labelvec;
|
||
register int i;
|
||
rtx before_case;
|
||
register struct nesting *thiscase = case_stack;
|
||
tree index_expr = thiscase->data.case_stmt.index_expr;
|
||
int unsignedp = TREE_UNSIGNED (TREE_TYPE (index_expr));
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* An ERROR_MARK occurs for various reasons including invalid data type. */
|
||
if (TREE_TYPE (index_expr) != error_mark_node)
|
||
{
|
||
/* If switch expression was an enumerated type, check that all
|
||
enumeration literals are covered by the cases.
|
||
No sense trying this if there's a default case, however. */
|
||
|
||
if (!thiscase->data.case_stmt.default_label
|
||
&& TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
|
||
&& TREE_CODE (index_expr) != INTEGER_CST)
|
||
check_for_full_enumeration_handling (TREE_TYPE (orig_index));
|
||
|
||
/* If this is the first label, warn if any insns have been emitted. */
|
||
if (thiscase->data.case_stmt.seenlabel == 0)
|
||
{
|
||
rtx insn;
|
||
for (insn = get_last_insn ();
|
||
insn != case_stack->data.case_stmt.start;
|
||
insn = PREV_INSN (insn))
|
||
if (GET_CODE (insn) != NOTE
|
||
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
|
||
{
|
||
warning ("unreachable code at beginning of %s",
|
||
case_stack->data.case_stmt.printname);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* If we don't have a default-label, create one here,
|
||
after the body of the switch. */
|
||
if (thiscase->data.case_stmt.default_label == 0)
|
||
{
|
||
thiscase->data.case_stmt.default_label
|
||
= build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
expand_label (thiscase->data.case_stmt.default_label);
|
||
}
|
||
default_label = label_rtx (thiscase->data.case_stmt.default_label);
|
||
|
||
before_case = get_last_insn ();
|
||
|
||
/* Simplify the case-list before we count it. */
|
||
group_case_nodes (thiscase->data.case_stmt.case_list);
|
||
|
||
/* Get upper and lower bounds of case values.
|
||
Also convert all the case values to the index expr's data type. */
|
||
|
||
count = 0;
|
||
for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
|
||
{
|
||
/* Check low and high label values are integers. */
|
||
if (TREE_CODE (n->low) != INTEGER_CST)
|
||
abort ();
|
||
if (TREE_CODE (n->high) != INTEGER_CST)
|
||
abort ();
|
||
|
||
n->low = convert (TREE_TYPE (index_expr), n->low);
|
||
n->high = convert (TREE_TYPE (index_expr), n->high);
|
||
|
||
/* Count the elements and track the largest and smallest
|
||
of them (treating them as signed even if they are not). */
|
||
if (count++ == 0)
|
||
{
|
||
minval = n->low;
|
||
maxval = n->high;
|
||
}
|
||
else
|
||
{
|
||
if (INT_CST_LT (n->low, minval))
|
||
minval = n->low;
|
||
if (INT_CST_LT (maxval, n->high))
|
||
maxval = n->high;
|
||
}
|
||
/* A range counts double, since it requires two compares. */
|
||
if (! tree_int_cst_equal (n->low, n->high))
|
||
count++;
|
||
}
|
||
|
||
/* Compute span of values. */
|
||
if (count != 0)
|
||
range = fold (build (MINUS_EXPR, TREE_TYPE (index_expr),
|
||
maxval, minval));
|
||
|
||
if (count == 0 || TREE_CODE (TREE_TYPE (index_expr)) == ERROR_MARK)
|
||
{
|
||
expand_expr (index_expr, const0_rtx, VOIDmode, 0);
|
||
emit_queue ();
|
||
emit_jump (default_label);
|
||
}
|
||
/* If range of values is much bigger than number of values,
|
||
make a sequence of conditional branches instead of a dispatch.
|
||
If the switch-index is a constant, do it this way
|
||
because we can optimize it. */
|
||
|
||
#ifndef CASE_VALUES_THRESHOLD
|
||
#ifdef HAVE_casesi
|
||
#define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
|
||
#else
|
||
/* If machine does not have a case insn that compares the
|
||
bounds, this means extra overhead for dispatch tables
|
||
which raises the threshold for using them. */
|
||
#define CASE_VALUES_THRESHOLD 5
|
||
#endif /* HAVE_casesi */
|
||
#endif /* CASE_VALUES_THRESHOLD */
|
||
|
||
else if (TREE_INT_CST_HIGH (range) != 0
|
||
|| count < CASE_VALUES_THRESHOLD
|
||
|| ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
|
||
> 10 * count)
|
||
|| TREE_CODE (index_expr) == INTEGER_CST
|
||
/* These will reduce to a constant. */
|
||
|| (TREE_CODE (index_expr) == CALL_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
|
||
&& DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
|
||
|| (TREE_CODE (index_expr) == COMPOUND_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
|
||
{
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
|
||
/* If the index is a short or char that we do not have
|
||
an insn to handle comparisons directly, convert it to
|
||
a full integer now, rather than letting each comparison
|
||
generate the conversion. */
|
||
|
||
if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
|
||
&& (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
|
||
== CODE_FOR_nothing))
|
||
{
|
||
enum machine_mode wider_mode;
|
||
for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
|
||
wider_mode = GET_MODE_WIDER_MODE (wider_mode))
|
||
if (cmp_optab->handlers[(int) wider_mode].insn_code
|
||
!= CODE_FOR_nothing)
|
||
{
|
||
index = convert_to_mode (wider_mode, index, unsignedp);
|
||
break;
|
||
}
|
||
}
|
||
|
||
emit_queue ();
|
||
do_pending_stack_adjust ();
|
||
|
||
index = protect_from_queue (index, 0);
|
||
if (GET_CODE (index) == MEM)
|
||
index = copy_to_reg (index);
|
||
if (GET_CODE (index) == CONST_INT
|
||
|| TREE_CODE (index_expr) == INTEGER_CST)
|
||
{
|
||
/* Make a tree node with the proper constant value
|
||
if we don't already have one. */
|
||
if (TREE_CODE (index_expr) != INTEGER_CST)
|
||
{
|
||
index_expr
|
||
= build_int_2 (INTVAL (index),
|
||
!unsignedp && INTVAL (index) >= 0 ? 0 : -1);
|
||
index_expr = convert (TREE_TYPE (index_expr), index_expr);
|
||
}
|
||
|
||
/* For constant index expressions we need only
|
||
issue a unconditional branch to the appropriate
|
||
target code. The job of removing any unreachable
|
||
code is left to the optimisation phase if the
|
||
"-O" option is specified. */
|
||
for (n = thiscase->data.case_stmt.case_list;
|
||
n;
|
||
n = n->right)
|
||
{
|
||
if (! tree_int_cst_lt (index_expr, n->low)
|
||
&& ! tree_int_cst_lt (n->high, index_expr))
|
||
break;
|
||
}
|
||
if (n)
|
||
emit_jump (label_rtx (n->code_label));
|
||
else
|
||
emit_jump (default_label);
|
||
}
|
||
else
|
||
{
|
||
/* If the index expression is not constant we generate
|
||
a binary decision tree to select the appropriate
|
||
target code. This is done as follows:
|
||
|
||
The list of cases is rearranged into a binary tree,
|
||
nearly optimal assuming equal probability for each case.
|
||
|
||
The tree is transformed into RTL, eliminating
|
||
redundant test conditions at the same time.
|
||
|
||
If program flow could reach the end of the
|
||
decision tree an unconditional jump to the
|
||
default code is emitted. */
|
||
|
||
use_cost_table
|
||
= (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
|
||
&& estimate_case_costs (thiscase->data.case_stmt.case_list));
|
||
balance_case_nodes (&thiscase->data.case_stmt.case_list,
|
||
NULL_PTR);
|
||
emit_case_nodes (index, thiscase->data.case_stmt.case_list,
|
||
default_label, TREE_TYPE (index_expr));
|
||
emit_jump_if_reachable (default_label);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
int win = 0;
|
||
#ifdef HAVE_casesi
|
||
if (HAVE_casesi)
|
||
{
|
||
enum machine_mode index_mode = SImode;
|
||
int index_bits = GET_MODE_BITSIZE (index_mode);
|
||
|
||
/* Convert the index to SImode. */
|
||
if (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (index_expr)))
|
||
> GET_MODE_BITSIZE (index_mode))
|
||
{
|
||
enum machine_mode omode = TYPE_MODE (TREE_TYPE (index_expr));
|
||
rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
|
||
|
||
/* We must handle the endpoints in the original mode. */
|
||
index_expr = build (MINUS_EXPR, TREE_TYPE (index_expr),
|
||
index_expr, minval);
|
||
minval = integer_zero_node;
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 0, 0);
|
||
emit_jump_insn (gen_bltu (default_label));
|
||
/* Now we can safely truncate. */
|
||
index = convert_to_mode (index_mode, index, 0);
|
||
}
|
||
else
|
||
{
|
||
if (TYPE_MODE (TREE_TYPE (index_expr)) != index_mode)
|
||
index_expr = convert (type_for_size (index_bits, 0),
|
||
index_expr);
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
}
|
||
emit_queue ();
|
||
index = protect_from_queue (index, 0);
|
||
do_pending_stack_adjust ();
|
||
|
||
emit_jump_insn (gen_casesi (index, expand_expr (minval, NULL_RTX,
|
||
VOIDmode, 0),
|
||
expand_expr (range, NULL_RTX,
|
||
VOIDmode, 0),
|
||
table_label, default_label));
|
||
win = 1;
|
||
}
|
||
#endif
|
||
#ifdef HAVE_tablejump
|
||
if (! win && HAVE_tablejump)
|
||
{
|
||
index_expr = convert (thiscase->data.case_stmt.nominal_type,
|
||
fold (build (MINUS_EXPR,
|
||
TREE_TYPE (index_expr),
|
||
index_expr, minval)));
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
emit_queue ();
|
||
index = protect_from_queue (index, 0);
|
||
do_pending_stack_adjust ();
|
||
|
||
do_tablejump (index, TYPE_MODE (TREE_TYPE (index_expr)),
|
||
expand_expr (range, NULL_RTX, VOIDmode, 0),
|
||
table_label, default_label);
|
||
win = 1;
|
||
}
|
||
#endif
|
||
if (! win)
|
||
abort ();
|
||
|
||
/* Get table of labels to jump to, in order of case index. */
|
||
|
||
ncases = TREE_INT_CST_LOW (range) + 1;
|
||
labelvec = (rtx *) alloca (ncases * sizeof (rtx));
|
||
bzero (labelvec, ncases * sizeof (rtx));
|
||
|
||
for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
|
||
{
|
||
register HOST_WIDE_INT i
|
||
= TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (minval);
|
||
|
||
while (1)
|
||
{
|
||
labelvec[i]
|
||
= gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
|
||
if (i + TREE_INT_CST_LOW (minval)
|
||
== TREE_INT_CST_LOW (n->high))
|
||
break;
|
||
i++;
|
||
}
|
||
}
|
||
|
||
/* Fill in the gaps with the default. */
|
||
for (i = 0; i < ncases; i++)
|
||
if (labelvec[i] == 0)
|
||
labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
|
||
|
||
/* Output the table */
|
||
emit_label (table_label);
|
||
|
||
/* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
|
||
were an expression, instead of an #ifdef/#ifndef. */
|
||
if (
|
||
#ifdef CASE_VECTOR_PC_RELATIVE
|
||
1 ||
|
||
#endif
|
||
flag_pic)
|
||
emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
|
||
gen_rtx (LABEL_REF, Pmode, table_label),
|
||
gen_rtvec_v (ncases, labelvec)));
|
||
else
|
||
emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
|
||
gen_rtvec_v (ncases, labelvec)));
|
||
|
||
/* If the case insn drops through the table,
|
||
after the table we must jump to the default-label.
|
||
Otherwise record no drop-through after the table. */
|
||
#ifdef CASE_DROPS_THROUGH
|
||
emit_jump (default_label);
|
||
#else
|
||
emit_barrier ();
|
||
#endif
|
||
}
|
||
|
||
before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
|
||
reorder_insns (before_case, get_last_insn (),
|
||
thiscase->data.case_stmt.start);
|
||
}
|
||
if (thiscase->exit_label)
|
||
emit_label (thiscase->exit_label);
|
||
|
||
POPSTACK (case_stack);
|
||
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* Generate code to jump to LABEL if OP1 and OP2 are equal. */
|
||
|
||
static void
|
||
do_jump_if_equal (op1, op2, label, unsignedp)
|
||
rtx op1, op2, label;
|
||
int unsignedp;
|
||
{
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& GET_CODE (op2) == CONST_INT)
|
||
{
|
||
if (INTVAL (op1) == INTVAL (op2))
|
||
emit_jump (label);
|
||
}
|
||
else
|
||
{
|
||
enum machine_mode mode = GET_MODE (op1);
|
||
if (mode == VOIDmode)
|
||
mode = GET_MODE (op2);
|
||
emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn (gen_beq (label));
|
||
}
|
||
}
|
||
|
||
/* Not all case values are encountered equally. This function
|
||
uses a heuristic to weight case labels, in cases where that
|
||
looks like a reasonable thing to do.
|
||
|
||
Right now, all we try to guess is text, and we establish the
|
||
following weights:
|
||
|
||
chars above space: 16
|
||
digits: 16
|
||
default: 12
|
||
space, punct: 8
|
||
tab: 4
|
||
newline: 2
|
||
other "\" chars: 1
|
||
remaining chars: 0
|
||
|
||
If we find any cases in the switch that are not either -1 or in the range
|
||
of valid ASCII characters, or are control characters other than those
|
||
commonly used with "\", don't treat this switch scanning text.
|
||
|
||
Return 1 if these nodes are suitable for cost estimation, otherwise
|
||
return 0. */
|
||
|
||
static int
|
||
estimate_case_costs (node)
|
||
case_node_ptr node;
|
||
{
|
||
tree min_ascii = build_int_2 (-1, -1);
|
||
tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
|
||
case_node_ptr n;
|
||
int i;
|
||
|
||
/* If we haven't already made the cost table, make it now. Note that the
|
||
lower bound of the table is -1, not zero. */
|
||
|
||
if (cost_table == NULL)
|
||
{
|
||
cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
|
||
bzero (cost_table - 1, 129 * sizeof (short));
|
||
|
||
for (i = 0; i < 128; i++)
|
||
{
|
||
if (isalnum (i))
|
||
cost_table[i] = 16;
|
||
else if (ispunct (i))
|
||
cost_table[i] = 8;
|
||
else if (iscntrl (i))
|
||
cost_table[i] = -1;
|
||
}
|
||
|
||
cost_table[' '] = 8;
|
||
cost_table['\t'] = 4;
|
||
cost_table['\0'] = 4;
|
||
cost_table['\n'] = 2;
|
||
cost_table['\f'] = 1;
|
||
cost_table['\v'] = 1;
|
||
cost_table['\b'] = 1;
|
||
}
|
||
|
||
/* See if all the case expressions look like text. It is text if the
|
||
constant is >= -1 and the highest constant is <= 127. Do all comparisons
|
||
as signed arithmetic since we don't want to ever access cost_table with a
|
||
value less than -1. Also check that none of the constants in a range
|
||
are strange control characters. */
|
||
|
||
for (n = node; n; n = n->right)
|
||
{
|
||
if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
|
||
return 0;
|
||
|
||
for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
|
||
if (cost_table[i] < 0)
|
||
return 0;
|
||
}
|
||
|
||
/* All interesting values are within the range of interesting
|
||
ASCII characters. */
|
||
return 1;
|
||
}
|
||
|
||
/* Scan an ordered list of case nodes
|
||
combining those with consecutive values or ranges.
|
||
|
||
Eg. three separate entries 1: 2: 3: become one entry 1..3: */
|
||
|
||
static void
|
||
group_case_nodes (head)
|
||
case_node_ptr head;
|
||
{
|
||
case_node_ptr node = head;
|
||
|
||
while (node)
|
||
{
|
||
rtx lb = next_real_insn (label_rtx (node->code_label));
|
||
case_node_ptr np = node;
|
||
|
||
/* Try to group the successors of NODE with NODE. */
|
||
while (((np = np->right) != 0)
|
||
/* Do they jump to the same place? */
|
||
&& next_real_insn (label_rtx (np->code_label)) == lb
|
||
/* Are their ranges consecutive? */
|
||
&& tree_int_cst_equal (np->low,
|
||
fold (build (PLUS_EXPR,
|
||
TREE_TYPE (node->high),
|
||
node->high,
|
||
integer_one_node)))
|
||
/* An overflow is not consecutive. */
|
||
&& tree_int_cst_lt (node->high,
|
||
fold (build (PLUS_EXPR,
|
||
TREE_TYPE (node->high),
|
||
node->high,
|
||
integer_one_node))))
|
||
{
|
||
node->high = np->high;
|
||
}
|
||
/* NP is the first node after NODE which can't be grouped with it.
|
||
Delete the nodes in between, and move on to that node. */
|
||
node->right = np;
|
||
node = np;
|
||
}
|
||
}
|
||
|
||
/* Take an ordered list of case nodes
|
||
and transform them into a near optimal binary tree,
|
||
on the assumption that any target code selection value is as
|
||
likely as any other.
|
||
|
||
The transformation is performed by splitting the ordered
|
||
list into two equal sections plus a pivot. The parts are
|
||
then attached to the pivot as left and right branches. Each
|
||
branch is is then transformed recursively. */
|
||
|
||
static void
|
||
balance_case_nodes (head, parent)
|
||
case_node_ptr *head;
|
||
case_node_ptr parent;
|
||
{
|
||
register case_node_ptr np;
|
||
|
||
np = *head;
|
||
if (np)
|
||
{
|
||
int cost = 0;
|
||
int i = 0;
|
||
int ranges = 0;
|
||
register case_node_ptr *npp;
|
||
case_node_ptr left;
|
||
|
||
/* Count the number of entries on branch. Also count the ranges. */
|
||
|
||
while (np)
|
||
{
|
||
if (!tree_int_cst_equal (np->low, np->high))
|
||
{
|
||
ranges++;
|
||
if (use_cost_table)
|
||
cost += cost_table[TREE_INT_CST_LOW (np->high)];
|
||
}
|
||
|
||
if (use_cost_table)
|
||
cost += cost_table[TREE_INT_CST_LOW (np->low)];
|
||
|
||
i++;
|
||
np = np->right;
|
||
}
|
||
|
||
if (i > 2)
|
||
{
|
||
/* Split this list if it is long enough for that to help. */
|
||
npp = head;
|
||
left = *npp;
|
||
if (use_cost_table)
|
||
{
|
||
/* Find the place in the list that bisects the list's total cost,
|
||
Here I gets half the total cost. */
|
||
int n_moved = 0;
|
||
i = (cost + 1) / 2;
|
||
while (1)
|
||
{
|
||
/* Skip nodes while their cost does not reach that amount. */
|
||
if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
|
||
i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
|
||
i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
|
||
if (i <= 0)
|
||
break;
|
||
npp = &(*npp)->right;
|
||
n_moved += 1;
|
||
}
|
||
if (n_moved == 0)
|
||
{
|
||
/* Leave this branch lopsided, but optimize left-hand
|
||
side and fill in `parent' fields for right-hand side. */
|
||
np = *head;
|
||
np->parent = parent;
|
||
balance_case_nodes (&np->left, np);
|
||
for (; np->right; np = np->right)
|
||
np->right->parent = np;
|
||
return;
|
||
}
|
||
}
|
||
/* If there are just three nodes, split at the middle one. */
|
||
else if (i == 3)
|
||
npp = &(*npp)->right;
|
||
else
|
||
{
|
||
/* Find the place in the list that bisects the list's total cost,
|
||
where ranges count as 2.
|
||
Here I gets half the total cost. */
|
||
i = (i + ranges + 1) / 2;
|
||
while (1)
|
||
{
|
||
/* Skip nodes while their cost does not reach that amount. */
|
||
if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
|
||
i--;
|
||
i--;
|
||
if (i <= 0)
|
||
break;
|
||
npp = &(*npp)->right;
|
||
}
|
||
}
|
||
*head = np = *npp;
|
||
*npp = 0;
|
||
np->parent = parent;
|
||
np->left = left;
|
||
|
||
/* Optimize each of the two split parts. */
|
||
balance_case_nodes (&np->left, np);
|
||
balance_case_nodes (&np->right, np);
|
||
}
|
||
else
|
||
{
|
||
/* Else leave this branch as one level,
|
||
but fill in `parent' fields. */
|
||
np = *head;
|
||
np->parent = parent;
|
||
for (; np->right; np = np->right)
|
||
np->right->parent = np;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Search the parent sections of the case node tree
|
||
to see if a test for the lower bound of NODE would be redundant.
|
||
INDEX_TYPE is the type of the index expression.
|
||
|
||
The instructions to generate the case decision tree are
|
||
output in the same order as nodes are processed so it is
|
||
known that if a parent node checks the range of the current
|
||
node minus one that the current node is bounded at its lower
|
||
span. Thus the test would be redundant. */
|
||
|
||
static int
|
||
node_has_low_bound (node, index_type)
|
||
case_node_ptr node;
|
||
tree index_type;
|
||
{
|
||
tree low_minus_one;
|
||
case_node_ptr pnode;
|
||
|
||
/* If the lower bound of this node is the lowest value in the index type,
|
||
we need not test it. */
|
||
|
||
if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
|
||
return 1;
|
||
|
||
/* If this node has a left branch, the value at the left must be less
|
||
than that at this node, so it cannot be bounded at the bottom and
|
||
we need not bother testing any further. */
|
||
|
||
if (node->left)
|
||
return 0;
|
||
|
||
low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
|
||
node->low, integer_one_node));
|
||
|
||
/* If the subtraction above overflowed, we can't verify anything.
|
||
Otherwise, look for a parent that tests our value - 1. */
|
||
|
||
if (! tree_int_cst_lt (low_minus_one, node->low))
|
||
return 0;
|
||
|
||
for (pnode = node->parent; pnode; pnode = pnode->parent)
|
||
if (tree_int_cst_equal (low_minus_one, pnode->high))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Search the parent sections of the case node tree
|
||
to see if a test for the upper bound of NODE would be redundant.
|
||
INDEX_TYPE is the type of the index expression.
|
||
|
||
The instructions to generate the case decision tree are
|
||
output in the same order as nodes are processed so it is
|
||
known that if a parent node checks the range of the current
|
||
node plus one that the current node is bounded at its upper
|
||
span. Thus the test would be redundant. */
|
||
|
||
static int
|
||
node_has_high_bound (node, index_type)
|
||
case_node_ptr node;
|
||
tree index_type;
|
||
{
|
||
tree high_plus_one;
|
||
case_node_ptr pnode;
|
||
|
||
/* If the upper bound of this node is the highest value in the type
|
||
of the index expression, we need not test against it. */
|
||
|
||
if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
|
||
return 1;
|
||
|
||
/* If this node has a right branch, the value at the right must be greater
|
||
than that at this node, so it cannot be bounded at the top and
|
||
we need not bother testing any further. */
|
||
|
||
if (node->right)
|
||
return 0;
|
||
|
||
high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
|
||
node->high, integer_one_node));
|
||
|
||
/* If the addition above overflowed, we can't verify anything.
|
||
Otherwise, look for a parent that tests our value + 1. */
|
||
|
||
if (! tree_int_cst_lt (node->high, high_plus_one))
|
||
return 0;
|
||
|
||
for (pnode = node->parent; pnode; pnode = pnode->parent)
|
||
if (tree_int_cst_equal (high_plus_one, pnode->low))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Search the parent sections of the
|
||
case node tree to see if both tests for the upper and lower
|
||
bounds of NODE would be redundant. */
|
||
|
||
static int
|
||
node_is_bounded (node, index_type)
|
||
case_node_ptr node;
|
||
tree index_type;
|
||
{
|
||
return (node_has_low_bound (node, index_type)
|
||
&& node_has_high_bound (node, index_type));
|
||
}
|
||
|
||
/* Emit an unconditional jump to LABEL unless it would be dead code. */
|
||
|
||
static void
|
||
emit_jump_if_reachable (label)
|
||
rtx label;
|
||
{
|
||
if (GET_CODE (get_last_insn ()) != BARRIER)
|
||
emit_jump (label);
|
||
}
|
||
|
||
/* Emit step-by-step code to select a case for the value of INDEX.
|
||
The thus generated decision tree follows the form of the
|
||
case-node binary tree NODE, whose nodes represent test conditions.
|
||
INDEX_TYPE is the type of the index of the switch.
|
||
|
||
Care is taken to prune redundant tests from the decision tree
|
||
by detecting any boundary conditions already checked by
|
||
emitted rtx. (See node_has_high_bound, node_has_low_bound
|
||
and node_is_bounded, above.)
|
||
|
||
Where the test conditions can be shown to be redundant we emit
|
||
an unconditional jump to the target code. As a further
|
||
optimization, the subordinates of a tree node are examined to
|
||
check for bounded nodes. In this case conditional and/or
|
||
unconditional jumps as a result of the boundary check for the
|
||
current node are arranged to target the subordinates associated
|
||
code for out of bound conditions on the current node node.
|
||
|
||
We can assume that when control reaches the code generated here,
|
||
the index value has already been compared with the parents
|
||
of this node, and determined to be on the same side of each parent
|
||
as this node is. Thus, if this node tests for the value 51,
|
||
and a parent tested for 52, we don't need to consider
|
||
the possibility of a value greater than 51. If another parent
|
||
tests for the value 50, then this node need not test anything. */
|
||
|
||
static void
|
||
emit_case_nodes (index, node, default_label, index_type)
|
||
rtx index;
|
||
case_node_ptr node;
|
||
rtx default_label;
|
||
tree index_type;
|
||
{
|
||
/* If INDEX has an unsigned type, we must make unsigned branches. */
|
||
int unsignedp = TREE_UNSIGNED (index_type);
|
||
typedef rtx rtx_function ();
|
||
rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
|
||
rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
|
||
rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
|
||
rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
|
||
enum machine_mode mode = GET_MODE (index);
|
||
|
||
/* See if our parents have already tested everything for us.
|
||
If they have, emit an unconditional jump for this node. */
|
||
if (node_is_bounded (node, index_type))
|
||
emit_jump (label_rtx (node->code_label));
|
||
|
||
else if (tree_int_cst_equal (node->low, node->high))
|
||
{
|
||
/* Node is single valued. First see if the index expression matches
|
||
this node and then check our children, if any. */
|
||
|
||
do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
|
||
label_rtx (node->code_label), unsignedp);
|
||
|
||
if (node->right != 0 && node->left != 0)
|
||
{
|
||
/* This node has children on both sides.
|
||
Dispatch to one side or the other
|
||
by comparing the index value with this node's value.
|
||
If one subtree is bounded, check that one first,
|
||
so we can avoid real branches in the tree. */
|
||
|
||
if (node_is_bounded (node->right, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0);
|
||
|
||
emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
|
||
else if (node_is_bounded (node->left, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Neither node is bounded. First distinguish the two sides;
|
||
then emit the code for one side at a time. */
|
||
|
||
tree test_label
|
||
= build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
|
||
/* See if the value is on the right. */
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
|
||
|
||
/* Value must be on the left.
|
||
Handle the left-hand subtree. */
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
/* If left-hand subtree does nothing,
|
||
go to default. */
|
||
emit_jump_if_reachable (default_label);
|
||
|
||
/* Code branches here for the right-hand subtree. */
|
||
expand_label (test_label);
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
}
|
||
|
||
else if (node->right != 0 && node->left == 0)
|
||
{
|
||
/* Here we have a right child but no left so we issue conditional
|
||
branch to default and process the right child.
|
||
|
||
Omit the conditional branch to default if we it avoid only one
|
||
right child; it costs too much space to save so little time. */
|
||
|
||
if (node->right->right || node->right->left
|
||
|| !tree_int_cst_equal (node->right->low, node->right->high))
|
||
{
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_blt_pat) (default_label));
|
||
}
|
||
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
else
|
||
/* We cannot process node->right normally
|
||
since we haven't ruled out the numbers less than
|
||
this node's value. So handle node->right explicitly. */
|
||
do_jump_if_equal (index,
|
||
expand_expr (node->right->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
label_rtx (node->right->code_label), unsignedp);
|
||
}
|
||
|
||
else if (node->right == 0 && node->left != 0)
|
||
{
|
||
/* Just one subtree, on the left. */
|
||
|
||
#if 0 /* The following code and comment were formerly part
|
||
of the condition here, but they didn't work
|
||
and I don't understand what the idea was. -- rms. */
|
||
/* If our "most probable entry" is less probable
|
||
than the default label, emit a jump to
|
||
the default label using condition codes
|
||
already lying around. With no right branch,
|
||
a branch-greater-than will get us to the default
|
||
label correctly. */
|
||
if (use_cost_table
|
||
&& cost_table[TREE_INT_CST_LOW (node->high)] < 12)
|
||
;
|
||
#endif /* 0 */
|
||
if (node->left->left || node->left->right
|
||
|| !tree_int_cst_equal (node->left->low, node->left->high))
|
||
{
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_bgt_pat) (default_label));
|
||
}
|
||
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
else
|
||
/* We cannot process node->left normally
|
||
since we haven't ruled out the numbers less than
|
||
this node's value. So handle node->left explicitly. */
|
||
do_jump_if_equal (index,
|
||
expand_expr (node->left->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
label_rtx (node->left->code_label), unsignedp);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Node is a range. These cases are very similar to those for a single
|
||
value, except that we do not start by testing whether this node
|
||
is the one to branch to. */
|
||
|
||
if (node->right != 0 && node->left != 0)
|
||
{
|
||
/* Node has subtrees on both sides.
|
||
If the right-hand subtree is bounded,
|
||
test for it first, since we can go straight there.
|
||
Otherwise, we need to make a branch in the control structure,
|
||
then handle the two subtrees. */
|
||
tree test_label = 0;
|
||
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0);
|
||
|
||
if (node_is_bounded (node->right, index_type))
|
||
/* Right hand node is fully bounded so we can eliminate any
|
||
testing and branch directly to the target code. */
|
||
emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
|
||
else
|
||
{
|
||
/* Right hand node requires testing.
|
||
Branch to a label where we will handle it later. */
|
||
|
||
test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
|
||
}
|
||
|
||
/* Value belongs to this node or to the left-hand subtree. */
|
||
|
||
emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
|
||
GE, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
|
||
|
||
/* Handle the left-hand subtree. */
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
|
||
/* If right node had to be handled later, do that now. */
|
||
|
||
if (test_label)
|
||
{
|
||
/* If the left-hand subtree fell through,
|
||
don't let it fall into the right-hand subtree. */
|
||
emit_jump_if_reachable (default_label);
|
||
|
||
expand_label (test_label);
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
}
|
||
|
||
else if (node->right != 0 && node->left == 0)
|
||
{
|
||
/* Deal with values to the left of this node,
|
||
if they are possible. */
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_blt_pat) (default_label));
|
||
}
|
||
|
||
/* Value belongs to this node or to the right-hand subtree. */
|
||
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LE, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
|
||
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
|
||
else if (node->right == 0 && node->left != 0)
|
||
{
|
||
/* Deal with values to the right of this node,
|
||
if they are possible. */
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_bgt_pat) (default_label));
|
||
}
|
||
|
||
/* Value belongs to this node or to the left-hand subtree. */
|
||
|
||
emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
|
||
GE, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
|
||
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Node has no children so we check low and high bounds to remove
|
||
redundant tests. Only one of the bounds can exist,
|
||
since otherwise this node is bounded--a case tested already. */
|
||
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_bgt_pat) (default_label));
|
||
}
|
||
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0);
|
||
emit_jump_insn ((*gen_blt_pat) (default_label));
|
||
}
|
||
|
||
emit_jump (label_rtx (node->code_label));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* These routines are used by the loop unrolling code. They copy BLOCK trees
|
||
so that the debugging info will be correct for the unrolled loop. */
|
||
|
||
/* Indexed by block number, contains a pointer to the N'th block node. */
|
||
|
||
static tree *block_vector;
|
||
|
||
void
|
||
find_loop_tree_blocks ()
|
||
{
|
||
tree block = DECL_INITIAL (current_function_decl);
|
||
|
||
/* There first block is for the function body, and does not have
|
||
corresponding block notes. Don't include it in the block vector. */
|
||
block = BLOCK_SUBBLOCKS (block);
|
||
|
||
block_vector = identify_blocks (block, get_insns ());
|
||
}
|
||
|
||
void
|
||
unroll_block_trees ()
|
||
{
|
||
tree block = DECL_INITIAL (current_function_decl);
|
||
|
||
reorder_blocks (block_vector, block, get_insns ());
|
||
}
|
||
|