3033 lines
87 KiB
C
3033 lines
87 KiB
C
/* Register to Stack convert for GNU compiler.
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Copyright (C) 1992, 93-98, 1999 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
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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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
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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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, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* This pass converts stack-like registers from the "flat register
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file" model that gcc uses, to a stack convention that the 387 uses.
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* The form of the input:
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On input, the function consists of insn that have had their
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registers fully allocated to a set of "virtual" registers. Note that
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the word "virtual" is used differently here than elsewhere in gcc: for
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each virtual stack reg, there is a hard reg, but the mapping between
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them is not known until this pass is run. On output, hard register
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numbers have been substituted, and various pop and exchange insns have
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been emitted. The hard register numbers and the virtual register
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numbers completely overlap - before this pass, all stack register
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numbers are virtual, and afterward they are all hard.
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The virtual registers can be manipulated normally by gcc, and their
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semantics are the same as for normal registers. After the hard
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register numbers are substituted, the semantics of an insn containing
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stack-like regs are not the same as for an insn with normal regs: for
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instance, it is not safe to delete an insn that appears to be a no-op
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move. In general, no insn containing hard regs should be changed
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after this pass is done.
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* The form of the output:
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After this pass, hard register numbers represent the distance from
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the current top of stack to the desired register. A reference to
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FIRST_STACK_REG references the top of stack, FIRST_STACK_REG + 1,
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represents the register just below that, and so forth. Also, REG_DEAD
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notes indicate whether or not a stack register should be popped.
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A "swap" insn looks like a parallel of two patterns, where each
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pattern is a SET: one sets A to B, the other B to A.
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A "push" or "load" insn is a SET whose SET_DEST is FIRST_STACK_REG
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and whose SET_DEST is REG or MEM. Any other SET_DEST, such as PLUS,
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will replace the existing stack top, not push a new value.
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A store insn is a SET whose SET_DEST is FIRST_STACK_REG, and whose
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SET_SRC is REG or MEM.
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The case where the SET_SRC and SET_DEST are both FIRST_STACK_REG
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appears ambiguous. As a special case, the presence of a REG_DEAD note
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for FIRST_STACK_REG differentiates between a load insn and a pop.
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If a REG_DEAD is present, the insn represents a "pop" that discards
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the top of the register stack. If there is no REG_DEAD note, then the
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insn represents a "dup" or a push of the current top of stack onto the
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stack.
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* Methodology:
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Existing REG_DEAD and REG_UNUSED notes for stack registers are
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deleted and recreated from scratch. REG_DEAD is never created for a
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SET_DEST, only REG_UNUSED.
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* asm_operands:
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There are several rules on the usage of stack-like regs in
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asm_operands insns. These rules apply only to the operands that are
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stack-like regs:
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1. Given a set of input regs that die in an asm_operands, it is
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necessary to know which are implicitly popped by the asm, and
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which must be explicitly popped by gcc.
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An input reg that is implicitly popped by the asm must be
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explicitly clobbered, unless it is constrained to match an
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output operand.
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2. For any input reg that is implicitly popped by an asm, it is
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necessary to know how to adjust the stack to compensate for the pop.
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If any non-popped input is closer to the top of the reg-stack than
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the implicitly popped reg, it would not be possible to know what the
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stack looked like - it's not clear how the rest of the stack "slides
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up".
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All implicitly popped input regs must be closer to the top of
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the reg-stack than any input that is not implicitly popped.
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3. It is possible that if an input dies in an insn, reload might
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use the input reg for an output reload. Consider this example:
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asm ("foo" : "=t" (a) : "f" (b));
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This asm says that input B is not popped by the asm, and that
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the asm pushes a result onto the reg-stack, ie, the stack is one
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deeper after the asm than it was before. But, it is possible that
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reload will think that it can use the same reg for both the input and
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the output, if input B dies in this insn.
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If any input operand uses the "f" constraint, all output reg
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constraints must use the "&" earlyclobber.
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The asm above would be written as
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asm ("foo" : "=&t" (a) : "f" (b));
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4. Some operands need to be in particular places on the stack. All
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output operands fall in this category - there is no other way to
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know which regs the outputs appear in unless the user indicates
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this in the constraints.
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Output operands must specifically indicate which reg an output
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appears in after an asm. "=f" is not allowed: the operand
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constraints must select a class with a single reg.
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5. Output operands may not be "inserted" between existing stack regs.
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Since no 387 opcode uses a read/write operand, all output operands
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are dead before the asm_operands, and are pushed by the asm_operands.
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It makes no sense to push anywhere but the top of the reg-stack.
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Output operands must start at the top of the reg-stack: output
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operands may not "skip" a reg.
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6. Some asm statements may need extra stack space for internal
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calculations. This can be guaranteed by clobbering stack registers
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unrelated to the inputs and outputs.
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Here are a couple of reasonable asms to want to write. This asm
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takes one input, which is internally popped, and produces two outputs.
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asm ("fsincos" : "=t" (cos), "=u" (sin) : "0" (inp));
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This asm takes two inputs, which are popped by the fyl2xp1 opcode,
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and replaces them with one output. The user must code the "st(1)"
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clobber for reg-stack.c to know that fyl2xp1 pops both inputs.
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asm ("fyl2xp1" : "=t" (result) : "0" (x), "u" (y) : "st(1)");
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*/
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#include "config.h"
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#include "system.h"
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#include "tree.h"
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#include "rtl.h"
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#include "insn-config.h"
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#include "regs.h"
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#include "hard-reg-set.h"
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#include "flags.h"
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#include "insn-flags.h"
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#include "recog.h"
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#include "toplev.h"
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#include "varray.h"
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#ifdef STACK_REGS
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#define REG_STACK_SIZE (LAST_STACK_REG - FIRST_STACK_REG + 1)
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/* This is the basic stack record. TOP is an index into REG[] such
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that REG[TOP] is the top of stack. If TOP is -1 the stack is empty.
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If TOP is -2, REG[] is not yet initialized. Stack initialization
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consists of placing each live reg in array `reg' and setting `top'
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appropriately.
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REG_SET indicates which registers are live. */
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typedef struct stack_def
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{
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int top; /* index to top stack element */
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HARD_REG_SET reg_set; /* set of live registers */
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char reg[REG_STACK_SIZE]; /* register - stack mapping */
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} *stack;
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/* highest instruction uid */
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static int max_uid = 0;
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/* Number of basic blocks in the current function. */
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static int blocks;
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/* Element N is first insn in basic block N.
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This info lasts until we finish compiling the function. */
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static rtx *block_begin;
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/* Element N is last insn in basic block N.
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This info lasts until we finish compiling the function. */
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static rtx *block_end;
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/* Element N is nonzero if control can drop into basic block N */
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static char *block_drops_in;
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/* Element N says all about the stack at entry block N */
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static stack block_stack_in;
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/* Element N says all about the stack life at the end of block N */
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static HARD_REG_SET *block_out_reg_set;
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/* This is where the BLOCK_NUM values are really stored. This is set
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up by find_blocks and used there and in life_analysis. It can be used
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later, but only to look up an insn that is the head or tail of some
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block. life_analysis and the stack register conversion process can
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add insns within a block. */
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static int *block_number;
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/* We use this array to cache info about insns, because otherwise we
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spend too much time in stack_regs_mentioned_p.
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Indexed by insn UIDs. A value of zero is uninitialized, one indicates
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the insn uses stack registers, two indicates the insn does not use
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stack registers. */
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static varray_type stack_regs_mentioned_data;
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/* This is the register file for all register after conversion */
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static rtx
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FP_mode_reg[LAST_STACK_REG+1-FIRST_STACK_REG][(int) MAX_MACHINE_MODE];
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#define FP_MODE_REG(regno,mode) \
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(FP_mode_reg[(regno)-FIRST_STACK_REG][(int)(mode)])
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/* Get the basic block number of an insn. See note at block_number
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definition are validity of this information. */
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static int BLOCK_NUM PROTO((rtx));
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#ifdef __GNUC__
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__inline__
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#endif
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static int
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BLOCK_NUM(insn)
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rtx insn;
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{
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int tmp = INSN_UID (insn);
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if (tmp > max_uid)
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abort ();
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tmp = block_number[tmp];
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if (tmp < 0)
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abort ();
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return tmp;
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}
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extern rtx forced_labels;
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/* Forward declarations */
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static void mark_regs_pat PROTO((rtx, HARD_REG_SET *));
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static void straighten_stack PROTO((rtx, stack));
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static void pop_stack PROTO((stack, int));
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static void record_label_references PROTO((rtx, rtx));
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static rtx *get_true_reg PROTO((rtx *));
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static void record_asm_reg_life PROTO((rtx, stack));
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static void record_reg_life_pat PROTO((rtx, HARD_REG_SET *,
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HARD_REG_SET *, int));
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static int get_asm_operand_n_inputs PROTO((rtx));
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static void record_reg_life PROTO((rtx, int, stack));
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static void find_blocks PROTO((rtx));
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static rtx stack_result PROTO((tree));
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static void stack_reg_life_analysis PROTO((rtx, HARD_REG_SET *));
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static void replace_reg PROTO((rtx *, int));
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static void remove_regno_note PROTO((rtx, enum reg_note, int));
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static int get_hard_regnum PROTO((stack, rtx));
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static void delete_insn_for_stacker PROTO((rtx));
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static rtx emit_pop_insn PROTO((rtx, stack, rtx, rtx (*) ()));
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static void emit_swap_insn PROTO((rtx, stack, rtx));
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static void move_for_stack_reg PROTO((rtx, stack, rtx));
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static void swap_rtx_condition PROTO((rtx));
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static void compare_for_stack_reg PROTO((rtx, stack, rtx));
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static void subst_stack_regs_pat PROTO((rtx, stack, rtx));
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static void subst_asm_stack_regs PROTO((rtx, stack));
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static void subst_stack_regs PROTO((rtx, stack));
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static void change_stack PROTO((rtx, stack, stack, rtx (*) ()));
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static void goto_block_pat PROTO((rtx, stack, rtx));
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static void convert_regs PROTO((void));
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static void print_blocks PROTO((FILE *, rtx, rtx));
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static void dump_stack_info PROTO((FILE *));
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static int check_stack_regs_mentioned PROTO((rtx insn));
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/* Initialize stack_regs_mentioned_data for INSN (growing the virtual array
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if needed. Return nonzero if INSN mentions stacked registers. */
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static int
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check_stack_regs_mentioned (insn)
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rtx insn;
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{
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unsigned int uid = INSN_UID (insn);
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if (uid >= VARRAY_SIZE (stack_regs_mentioned_data))
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/* Allocate some extra size to avoid too many reallocs, but
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do not grow exponentially. */
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VARRAY_GROW (stack_regs_mentioned_data, uid + uid / 20);
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if (stack_regs_mentioned_p (PATTERN (insn)))
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{
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VARRAY_CHAR (stack_regs_mentioned_data, uid) = 1;
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return 1;
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}
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else
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VARRAY_CHAR (stack_regs_mentioned_data, uid) = 2;
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return 0;
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}
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/* Return nonzero if INSN mentions stacked registers, else return
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zero. */
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int
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stack_regs_mentioned (insn)
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rtx insn;
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{
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unsigned int uid;
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if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
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return 0;
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uid = INSN_UID (insn);
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if (uid >= VARRAY_SIZE (stack_regs_mentioned_data)
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|| ! VARRAY_CHAR (stack_regs_mentioned_data, uid))
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return (check_stack_regs_mentioned (insn));
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return VARRAY_CHAR (stack_regs_mentioned_data, uid) == 1;
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}
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/* Mark all registers needed for this pattern. */
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static void
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mark_regs_pat (pat, set)
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rtx pat;
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HARD_REG_SET *set;
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{
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enum machine_mode mode;
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register int regno;
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register int count;
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if (GET_CODE (pat) == SUBREG)
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{
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mode = GET_MODE (pat);
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regno = SUBREG_WORD (pat);
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regno += REGNO (SUBREG_REG (pat));
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}
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else
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regno = REGNO (pat), mode = GET_MODE (pat);
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for (count = HARD_REGNO_NREGS (regno, mode);
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count; count--, regno++)
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SET_HARD_REG_BIT (*set, regno);
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}
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/* Reorganise the stack into ascending numbers,
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after this insn. */
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static void
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straighten_stack (insn, regstack)
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rtx insn;
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stack regstack;
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{
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||
struct stack_def temp_stack;
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int top;
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||
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/* If there is only a single register on the stack, then the stack is
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already in increasing order and no reorganization is needed.
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Similarly if the stack is empty. */
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if (regstack->top <= 0)
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return;
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temp_stack.reg_set = regstack->reg_set;
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||
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for (top = temp_stack.top = regstack->top; top >= 0; top--)
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temp_stack.reg[top] = FIRST_STACK_REG + temp_stack.top - top;
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change_stack (insn, regstack, &temp_stack, emit_insn_after);
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}
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||
|
||
/* Pop a register from the stack */
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||
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||
static void
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pop_stack (regstack, regno)
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||
stack regstack;
|
||
int regno;
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||
{
|
||
int top = regstack->top;
|
||
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, regno);
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||
regstack->top--;
|
||
/* If regno was not at the top of stack then adjust stack */
|
||
if (regstack->reg [top] != regno)
|
||
{
|
||
int i;
|
||
for (i = regstack->top; i >= 0; i--)
|
||
if (regstack->reg [i] == regno)
|
||
{
|
||
int j;
|
||
for (j = i; j < top; j++)
|
||
regstack->reg [j] = regstack->reg [j + 1];
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Return non-zero if any stack register is mentioned somewhere within PAT. */
|
||
|
||
int
|
||
stack_regs_mentioned_p (pat)
|
||
rtx pat;
|
||
{
|
||
register char *fmt;
|
||
register int i;
|
||
|
||
if (STACK_REG_P (pat))
|
||
return 1;
|
||
|
||
fmt = GET_RTX_FORMAT (GET_CODE (pat));
|
||
for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
|
||
{
|
||
if (fmt[i] == 'E')
|
||
{
|
||
register int j;
|
||
|
||
for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
|
||
if (stack_regs_mentioned_p (XVECEXP (pat, i, j)))
|
||
return 1;
|
||
}
|
||
else if (fmt[i] == 'e' && stack_regs_mentioned_p (XEXP (pat, i)))
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Convert register usage from "flat" register file usage to a "stack
|
||
register file. FIRST is the first insn in the function, FILE is the
|
||
dump file, if used.
|
||
|
||
First compute the beginning and end of each basic block. Do a
|
||
register life analysis on the stack registers, recording the result
|
||
for the head and tail of each basic block. The convert each insn one
|
||
by one. Run a last jump_optimize() pass, if optimizing, to eliminate
|
||
any cross-jumping created when the converter inserts pop insns.*/
|
||
|
||
void
|
||
reg_to_stack (first, file)
|
||
rtx first;
|
||
FILE *file;
|
||
{
|
||
register rtx insn;
|
||
register int i;
|
||
int stack_reg_seen = 0;
|
||
enum machine_mode mode;
|
||
HARD_REG_SET stackentry;
|
||
|
||
max_uid = get_max_uid ();
|
||
VARRAY_CHAR_INIT (stack_regs_mentioned_data, max_uid + 1,
|
||
"stack_regs_mentioned cache");
|
||
|
||
CLEAR_HARD_REG_SET (stackentry);
|
||
|
||
{
|
||
static int initialised;
|
||
if (!initialised)
|
||
{
|
||
#if 0
|
||
initialised = 1; /* This array can not have been previously
|
||
initialised, because the rtx's are
|
||
thrown away between compilations of
|
||
functions. */
|
||
#endif
|
||
for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
|
||
{
|
||
for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
|
||
mode = GET_MODE_WIDER_MODE (mode))
|
||
FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i);
|
||
for (mode = GET_CLASS_NARROWEST_MODE (MODE_COMPLEX_FLOAT); mode != VOIDmode;
|
||
mode = GET_MODE_WIDER_MODE (mode))
|
||
FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Count the basic blocks. Also find maximum insn uid. */
|
||
{
|
||
register RTX_CODE prev_code = BARRIER;
|
||
register RTX_CODE code;
|
||
register int before_function_beg = 1;
|
||
|
||
max_uid = 0;
|
||
blocks = 0;
|
||
for (insn = first; insn; insn = NEXT_INSN (insn))
|
||
{
|
||
/* Note that this loop must select the same block boundaries
|
||
as code in find_blocks. Also note that this code is not the
|
||
same as that used in flow.c. */
|
||
|
||
if (INSN_UID (insn) > max_uid)
|
||
max_uid = INSN_UID (insn);
|
||
|
||
code = GET_CODE (insn);
|
||
|
||
if (code == CODE_LABEL
|
||
|| (prev_code != INSN
|
||
&& prev_code != CALL_INSN
|
||
&& prev_code != CODE_LABEL
|
||
&& GET_RTX_CLASS (code) == 'i'))
|
||
blocks++;
|
||
|
||
if (code == NOTE && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
|
||
before_function_beg = 0;
|
||
|
||
/* Remember whether or not this insn mentions an FP regs.
|
||
Check JUMP_INSNs too, in case someone creates a funny PARALLEL. */
|
||
|
||
if (GET_RTX_CLASS (code) == 'i'
|
||
&& stack_regs_mentioned_p (PATTERN (insn)))
|
||
{
|
||
stack_reg_seen = 1;
|
||
VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 1;
|
||
|
||
/* Note any register passing parameters. */
|
||
|
||
if (before_function_beg && code == INSN
|
||
&& GET_CODE (PATTERN (insn)) == USE)
|
||
record_reg_life_pat (PATTERN (insn), (HARD_REG_SET *) 0,
|
||
&stackentry, 1);
|
||
}
|
||
else
|
||
VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 2;
|
||
|
||
if (code == CODE_LABEL)
|
||
LABEL_REFS (insn) = insn; /* delete old chain */
|
||
|
||
if (code != NOTE)
|
||
prev_code = code;
|
||
}
|
||
}
|
||
|
||
/* If no stack register reference exists in this insn, there isn't
|
||
anything to convert. */
|
||
|
||
if (! stack_reg_seen)
|
||
{
|
||
VARRAY_FREE (stack_regs_mentioned_data);
|
||
return;
|
||
}
|
||
|
||
/* If there are stack registers, there must be at least one block. */
|
||
|
||
if (! blocks)
|
||
abort ();
|
||
|
||
/* Allocate some tables that last till end of compiling this function
|
||
and some needed only in find_blocks and life_analysis. */
|
||
|
||
block_begin = (rtx *) alloca (blocks * sizeof (rtx));
|
||
block_end = (rtx *) alloca (blocks * sizeof (rtx));
|
||
block_drops_in = (char *) alloca (blocks);
|
||
|
||
block_stack_in = (stack) alloca (blocks * sizeof (struct stack_def));
|
||
block_out_reg_set = (HARD_REG_SET *) alloca (blocks * sizeof (HARD_REG_SET));
|
||
bzero ((char *) block_stack_in, blocks * sizeof (struct stack_def));
|
||
bzero ((char *) block_out_reg_set, blocks * sizeof (HARD_REG_SET));
|
||
|
||
block_number = (int *) alloca ((max_uid + 1) * sizeof (int));
|
||
memset (block_number, -1, (max_uid + 1) * sizeof (int));
|
||
|
||
find_blocks (first);
|
||
stack_reg_life_analysis (first, &stackentry);
|
||
|
||
/* Dump the life analysis debug information before jump
|
||
optimization, as that will destroy the LABEL_REFS we keep the
|
||
information in. */
|
||
|
||
if (file)
|
||
dump_stack_info (file);
|
||
|
||
convert_regs ();
|
||
|
||
if (optimize)
|
||
jump_optimize (first, 2, 0, 0);
|
||
|
||
VARRAY_FREE (stack_regs_mentioned_data);
|
||
}
|
||
|
||
/* Check PAT, which is in INSN, for LABEL_REFs. Add INSN to the
|
||
label's chain of references, and note which insn contains each
|
||
reference. */
|
||
|
||
static void
|
||
record_label_references (insn, pat)
|
||
rtx insn, pat;
|
||
{
|
||
register enum rtx_code code = GET_CODE (pat);
|
||
register int i;
|
||
register char *fmt;
|
||
|
||
if (code == LABEL_REF)
|
||
{
|
||
register rtx label = XEXP (pat, 0);
|
||
register rtx ref;
|
||
|
||
if (GET_CODE (label) != CODE_LABEL)
|
||
abort ();
|
||
|
||
/* If this is an undefined label, LABEL_REFS (label) contains
|
||
garbage. */
|
||
if (INSN_UID (label) == 0)
|
||
return;
|
||
|
||
/* Don't make a duplicate in the code_label's chain. */
|
||
|
||
for (ref = LABEL_REFS (label);
|
||
ref && ref != label;
|
||
ref = LABEL_NEXTREF (ref))
|
||
if (CONTAINING_INSN (ref) == insn)
|
||
return;
|
||
|
||
CONTAINING_INSN (pat) = insn;
|
||
LABEL_NEXTREF (pat) = LABEL_REFS (label);
|
||
LABEL_REFS (label) = pat;
|
||
|
||
return;
|
||
}
|
||
|
||
fmt = GET_RTX_FORMAT (code);
|
||
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
||
{
|
||
if (fmt[i] == 'e')
|
||
record_label_references (insn, XEXP (pat, i));
|
||
if (fmt[i] == 'E')
|
||
{
|
||
register int j;
|
||
for (j = 0; j < XVECLEN (pat, i); j++)
|
||
record_label_references (insn, XVECEXP (pat, i, j));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Return a pointer to the REG expression within PAT. If PAT is not a
|
||
REG, possible enclosed by a conversion rtx, return the inner part of
|
||
PAT that stopped the search. */
|
||
|
||
static rtx *
|
||
get_true_reg (pat)
|
||
rtx *pat;
|
||
{
|
||
for (;;)
|
||
switch (GET_CODE (*pat))
|
||
{
|
||
case SUBREG:
|
||
/* eliminate FP subregister accesses in favour of the
|
||
actual FP register in use. */
|
||
{
|
||
rtx subreg;
|
||
if (FP_REG_P (subreg = SUBREG_REG (*pat)))
|
||
{
|
||
*pat = FP_MODE_REG (REGNO (subreg) + SUBREG_WORD (*pat),
|
||
GET_MODE (subreg));
|
||
default:
|
||
return pat;
|
||
}
|
||
}
|
||
case FLOAT:
|
||
case FIX:
|
||
case FLOAT_EXTEND:
|
||
pat = & XEXP (*pat, 0);
|
||
}
|
||
}
|
||
|
||
/* Record the life info of each stack reg in INSN, updating REGSTACK.
|
||
N_INPUTS is the number of inputs; N_OUTPUTS the outputs.
|
||
OPERANDS is an array of all operands for the insn, and is assumed to
|
||
contain all output operands, then all inputs operands.
|
||
|
||
There are many rules that an asm statement for stack-like regs must
|
||
follow. Those rules are explained at the top of this file: the rule
|
||
numbers below refer to that explanation. */
|
||
|
||
static void
|
||
record_asm_reg_life (insn, regstack)
|
||
rtx insn;
|
||
stack regstack;
|
||
{
|
||
int i;
|
||
int n_clobbers;
|
||
int malformed_asm = 0;
|
||
rtx body = PATTERN (insn);
|
||
|
||
int reg_used_as_output[FIRST_PSEUDO_REGISTER];
|
||
int implicitly_dies[FIRST_PSEUDO_REGISTER];
|
||
int alt;
|
||
|
||
rtx *clobber_reg;
|
||
int n_inputs, n_outputs;
|
||
|
||
/* Find out what the constraints require. If no constraint
|
||
alternative matches, this asm is malformed. */
|
||
extract_insn (insn);
|
||
constrain_operands (1);
|
||
alt = which_alternative;
|
||
|
||
preprocess_constraints ();
|
||
|
||
n_inputs = get_asm_operand_n_inputs (body);
|
||
n_outputs = recog_n_operands - n_inputs;
|
||
|
||
if (alt < 0)
|
||
{
|
||
malformed_asm = 1;
|
||
/* Avoid further trouble with this insn. */
|
||
PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
|
||
VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 2;
|
||
return;
|
||
}
|
||
|
||
/* Strip SUBREGs here to make the following code simpler. */
|
||
for (i = 0; i < recog_n_operands; i++)
|
||
if (GET_CODE (recog_operand[i]) == SUBREG
|
||
&& GET_CODE (SUBREG_REG (recog_operand[i])) == REG)
|
||
recog_operand[i] = SUBREG_REG (recog_operand[i]);
|
||
|
||
/* Set up CLOBBER_REG. */
|
||
|
||
n_clobbers = 0;
|
||
|
||
if (GET_CODE (body) == PARALLEL)
|
||
{
|
||
clobber_reg = (rtx *) alloca (XVECLEN (body, 0) * sizeof (rtx));
|
||
|
||
for (i = 0; i < XVECLEN (body, 0); i++)
|
||
if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
|
||
{
|
||
rtx clobber = XVECEXP (body, 0, i);
|
||
rtx reg = XEXP (clobber, 0);
|
||
|
||
if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG)
|
||
reg = SUBREG_REG (reg);
|
||
|
||
if (STACK_REG_P (reg))
|
||
{
|
||
clobber_reg[n_clobbers] = reg;
|
||
n_clobbers++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Enforce rule #4: Output operands must specifically indicate which
|
||
reg an output appears in after an asm. "=f" is not allowed: the
|
||
operand constraints must select a class with a single reg.
|
||
|
||
Also enforce rule #5: Output operands must start at the top of
|
||
the reg-stack: output operands may not "skip" a reg. */
|
||
|
||
bzero ((char *) reg_used_as_output, sizeof (reg_used_as_output));
|
||
for (i = 0; i < n_outputs; i++)
|
||
if (STACK_REG_P (recog_operand[i]))
|
||
{
|
||
if (reg_class_size[(int) recog_op_alt[i][alt].class] != 1)
|
||
{
|
||
error_for_asm (insn, "Output constraint %d must specify a single register", i);
|
||
malformed_asm = 1;
|
||
}
|
||
else
|
||
reg_used_as_output[REGNO (recog_operand[i])] = 1;
|
||
}
|
||
|
||
|
||
/* Search for first non-popped reg. */
|
||
for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++)
|
||
if (! reg_used_as_output[i])
|
||
break;
|
||
|
||
/* If there are any other popped regs, that's an error. */
|
||
for (; i < LAST_STACK_REG + 1; i++)
|
||
if (reg_used_as_output[i])
|
||
break;
|
||
|
||
if (i != LAST_STACK_REG + 1)
|
||
{
|
||
error_for_asm (insn, "Output regs must be grouped at top of stack");
|
||
malformed_asm = 1;
|
||
}
|
||
|
||
/* Enforce rule #2: All implicitly popped input regs must be closer
|
||
to the top of the reg-stack than any input that is not implicitly
|
||
popped. */
|
||
|
||
bzero ((char *) implicitly_dies, sizeof (implicitly_dies));
|
||
for (i = n_outputs; i < n_outputs + n_inputs; i++)
|
||
if (STACK_REG_P (recog_operand[i]))
|
||
{
|
||
/* An input reg is implicitly popped if it is tied to an
|
||
output, or if there is a CLOBBER for it. */
|
||
int j;
|
||
|
||
for (j = 0; j < n_clobbers; j++)
|
||
if (operands_match_p (clobber_reg[j], recog_operand[i]))
|
||
break;
|
||
|
||
if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0)
|
||
implicitly_dies[REGNO (recog_operand[i])] = 1;
|
||
}
|
||
|
||
/* Search for first non-popped reg. */
|
||
for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++)
|
||
if (! implicitly_dies[i])
|
||
break;
|
||
|
||
/* If there are any other popped regs, that's an error. */
|
||
for (; i < LAST_STACK_REG + 1; i++)
|
||
if (implicitly_dies[i])
|
||
break;
|
||
|
||
if (i != LAST_STACK_REG + 1)
|
||
{
|
||
error_for_asm (insn,
|
||
"Implicitly popped regs must be grouped at top of stack");
|
||
malformed_asm = 1;
|
||
}
|
||
|
||
/* Enfore rule #3: If any input operand uses the "f" constraint, all
|
||
output constraints must use the "&" earlyclobber.
|
||
|
||
??? Detect this more deterministically by having constraint_asm_operands
|
||
record any earlyclobber. */
|
||
|
||
for (i = n_outputs; i < n_outputs + n_inputs; i++)
|
||
if (recog_op_alt[i][alt].matches == -1)
|
||
{
|
||
int j;
|
||
|
||
for (j = 0; j < n_outputs; j++)
|
||
if (operands_match_p (recog_operand[j], recog_operand[i]))
|
||
{
|
||
error_for_asm (insn,
|
||
"Output operand %d must use `&' constraint", j);
|
||
malformed_asm = 1;
|
||
}
|
||
}
|
||
|
||
if (malformed_asm)
|
||
{
|
||
/* Avoid further trouble with this insn. */
|
||
PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
|
||
VARRAY_CHAR (stack_regs_mentioned_data, INSN_UID (insn)) = 2;
|
||
return;
|
||
}
|
||
|
||
/* Process all outputs */
|
||
for (i = 0; i < n_outputs; i++)
|
||
{
|
||
rtx op = recog_operand[i];
|
||
|
||
if (! STACK_REG_P (op))
|
||
{
|
||
if (stack_regs_mentioned_p (op))
|
||
abort ();
|
||
else
|
||
continue;
|
||
}
|
||
|
||
/* Each destination is dead before this insn. If the
|
||
destination is not used after this insn, record this with
|
||
REG_UNUSED. */
|
||
|
||
if (! TEST_HARD_REG_BIT (regstack->reg_set, REGNO (op)))
|
||
REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_UNUSED, op,
|
||
REG_NOTES (insn));
|
||
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (op));
|
||
}
|
||
|
||
/* Process all inputs */
|
||
for (i = n_outputs; i < n_outputs + n_inputs; i++)
|
||
{
|
||
rtx op = recog_operand[i];
|
||
if (! STACK_REG_P (op))
|
||
{
|
||
if (stack_regs_mentioned_p (op))
|
||
abort ();
|
||
else
|
||
continue;
|
||
}
|
||
|
||
/* If an input is dead after the insn, record a death note.
|
||
But don't record a death note if there is already a death note,
|
||
or if the input is also an output. */
|
||
|
||
if (! TEST_HARD_REG_BIT (regstack->reg_set, REGNO (op))
|
||
&& recog_op_alt[i][alt].matches == -1
|
||
&& find_regno_note (insn, REG_DEAD, REGNO (op)) == NULL_RTX)
|
||
REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, op, REG_NOTES (insn));
|
||
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (op));
|
||
}
|
||
}
|
||
|
||
/* Scan PAT, which is part of INSN, and record registers appearing in
|
||
a SET_DEST in DEST, and other registers in SRC.
|
||
|
||
This function does not know about SET_DESTs that are both input and
|
||
output (such as ZERO_EXTRACT) - this cannot happen on a 387. */
|
||
|
||
static void
|
||
record_reg_life_pat (pat, src, dest, douse)
|
||
rtx pat;
|
||
HARD_REG_SET *src, *dest;
|
||
int douse;
|
||
{
|
||
register char *fmt;
|
||
register int i;
|
||
|
||
if (STACK_REG_P (pat)
|
||
|| (GET_CODE (pat) == SUBREG && STACK_REG_P (SUBREG_REG (pat))))
|
||
{
|
||
if (src)
|
||
mark_regs_pat (pat, src);
|
||
|
||
if (dest)
|
||
mark_regs_pat (pat, dest);
|
||
|
||
return;
|
||
}
|
||
|
||
if (GET_CODE (pat) == SET)
|
||
{
|
||
record_reg_life_pat (XEXP (pat, 0), NULL_PTR, dest, 0);
|
||
record_reg_life_pat (XEXP (pat, 1), src, NULL_PTR, 0);
|
||
return;
|
||
}
|
||
|
||
/* We don't need to consider either of these cases. */
|
||
if ((GET_CODE (pat) == USE && !douse) || GET_CODE (pat) == CLOBBER)
|
||
return;
|
||
|
||
fmt = GET_RTX_FORMAT (GET_CODE (pat));
|
||
for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
|
||
{
|
||
if (fmt[i] == 'E')
|
||
{
|
||
register int j;
|
||
|
||
for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
|
||
record_reg_life_pat (XVECEXP (pat, i, j), src, dest, 0);
|
||
}
|
||
else if (fmt[i] == 'e')
|
||
record_reg_life_pat (XEXP (pat, i), src, dest, 0);
|
||
}
|
||
}
|
||
|
||
/* Calculate the number of inputs and outputs in BODY, an
|
||
asm_operands. N_OPERANDS is the total number of operands, and
|
||
N_INPUTS and N_OUTPUTS are pointers to ints into which the results are
|
||
placed. */
|
||
|
||
static int
|
||
get_asm_operand_n_inputs (body)
|
||
rtx body;
|
||
{
|
||
if (GET_CODE (body) == SET && GET_CODE (SET_SRC (body)) == ASM_OPERANDS)
|
||
return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (body));
|
||
|
||
else if (GET_CODE (body) == ASM_OPERANDS)
|
||
return ASM_OPERANDS_INPUT_LENGTH (body);
|
||
|
||
else if (GET_CODE (body) == PARALLEL
|
||
&& GET_CODE (XVECEXP (body, 0, 0)) == SET)
|
||
return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (XVECEXP (body, 0, 0)));
|
||
|
||
else if (GET_CODE (body) == PARALLEL
|
||
&& GET_CODE (XVECEXP (body, 0, 0)) == ASM_OPERANDS)
|
||
return ASM_OPERANDS_INPUT_LENGTH (XVECEXP (body, 0, 0));
|
||
|
||
abort ();
|
||
}
|
||
|
||
/* Scan INSN, which is in BLOCK, and record the life & death of stack
|
||
registers in REGSTACK. This function is called to process insns from
|
||
the last insn in a block to the first. The actual scanning is done in
|
||
record_reg_life_pat.
|
||
|
||
If a register is live after a CALL_INSN, but is not a value return
|
||
register for that CALL_INSN, then code is emitted to initialize that
|
||
register. The block_end[] data is kept accurate.
|
||
|
||
Existing death and unset notes for stack registers are deleted
|
||
before processing the insn. */
|
||
|
||
static void
|
||
record_reg_life (insn, block, regstack)
|
||
rtx insn;
|
||
int block;
|
||
stack regstack;
|
||
{
|
||
rtx note, *note_link;
|
||
int n_operands;
|
||
|
||
if ((GET_CODE (insn) != INSN && GET_CODE (insn) != CALL_INSN)
|
||
|| INSN_DELETED_P (insn))
|
||
return;
|
||
|
||
/* Strip death notes for stack regs from this insn */
|
||
|
||
note_link = ®_NOTES(insn);
|
||
for (note = *note_link; note; note = XEXP (note, 1))
|
||
if (STACK_REG_P (XEXP (note, 0))
|
||
&& (REG_NOTE_KIND (note) == REG_DEAD
|
||
|| REG_NOTE_KIND (note) == REG_UNUSED))
|
||
*note_link = XEXP (note, 1);
|
||
else
|
||
note_link = &XEXP (note, 1);
|
||
|
||
/* Process all patterns in the insn. */
|
||
|
||
n_operands = asm_noperands (PATTERN (insn));
|
||
if (n_operands >= 0)
|
||
{
|
||
record_asm_reg_life (insn, regstack);
|
||
return;
|
||
}
|
||
|
||
{
|
||
HARD_REG_SET src, dest;
|
||
int regno;
|
||
|
||
CLEAR_HARD_REG_SET (src);
|
||
CLEAR_HARD_REG_SET (dest);
|
||
|
||
if (GET_CODE (insn) == CALL_INSN)
|
||
for (note = CALL_INSN_FUNCTION_USAGE (insn);
|
||
note;
|
||
note = XEXP (note, 1))
|
||
if (GET_CODE (XEXP (note, 0)) == USE)
|
||
record_reg_life_pat (SET_DEST (XEXP (note, 0)), &src, NULL_PTR, 0);
|
||
|
||
record_reg_life_pat (PATTERN (insn), &src, &dest, 0);
|
||
for (regno = FIRST_STACK_REG; regno <= LAST_STACK_REG; regno++)
|
||
if (! TEST_HARD_REG_BIT (regstack->reg_set, regno))
|
||
{
|
||
if (TEST_HARD_REG_BIT (src, regno)
|
||
&& ! TEST_HARD_REG_BIT (dest, regno))
|
||
REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD,
|
||
FP_MODE_REG (regno, DFmode),
|
||
REG_NOTES (insn));
|
||
else if (TEST_HARD_REG_BIT (dest, regno))
|
||
REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_UNUSED,
|
||
FP_MODE_REG (regno, DFmode),
|
||
REG_NOTES (insn));
|
||
}
|
||
|
||
if (GET_CODE (insn) == CALL_INSN)
|
||
{
|
||
int reg;
|
||
|
||
/* There might be a reg that is live after a function call.
|
||
Initialize it to zero so that the program does not crash. See
|
||
comment towards the end of stack_reg_life_analysis(). */
|
||
|
||
for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; reg++)
|
||
if (! TEST_HARD_REG_BIT (dest, reg)
|
||
&& TEST_HARD_REG_BIT (regstack->reg_set, reg))
|
||
{
|
||
rtx init, pat;
|
||
|
||
/* The insn will use virtual register numbers, and so
|
||
convert_regs is expected to process these. But BLOCK_NUM
|
||
cannot be used on these insns, because they do not appear in
|
||
block_number[]. */
|
||
|
||
pat = gen_rtx_SET (VOIDmode, FP_MODE_REG (reg, DFmode),
|
||
CONST0_RTX (DFmode));
|
||
init = emit_insn_after (pat, insn);
|
||
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, reg);
|
||
|
||
/* If the CALL_INSN was the end of a block, move the
|
||
block_end to point to the new insn. */
|
||
|
||
if (block_end[block] == insn)
|
||
block_end[block] = init;
|
||
}
|
||
|
||
/* Some regs do not survive a CALL */
|
||
AND_COMPL_HARD_REG_SET (regstack->reg_set, call_used_reg_set);
|
||
}
|
||
|
||
AND_COMPL_HARD_REG_SET (regstack->reg_set, dest);
|
||
IOR_HARD_REG_SET (regstack->reg_set, src);
|
||
}
|
||
}
|
||
|
||
/* Find all basic blocks of the function, which starts with FIRST.
|
||
For each JUMP_INSN, build the chain of LABEL_REFS on each CODE_LABEL. */
|
||
|
||
static void
|
||
find_blocks (first)
|
||
rtx first;
|
||
{
|
||
register rtx insn;
|
||
register int block;
|
||
register RTX_CODE prev_code = BARRIER;
|
||
register RTX_CODE code;
|
||
rtx label_value_list = 0;
|
||
|
||
/* Record where all the blocks start and end.
|
||
Record which basic blocks control can drop in to. */
|
||
|
||
block = -1;
|
||
for (insn = first; insn; insn = NEXT_INSN (insn))
|
||
{
|
||
/* Note that this loop must select the same block boundaries
|
||
as code in reg_to_stack, but that these are not the same
|
||
as those selected in flow.c. */
|
||
|
||
code = GET_CODE (insn);
|
||
|
||
if (code == CODE_LABEL
|
||
|| (prev_code != INSN
|
||
&& prev_code != CALL_INSN
|
||
&& prev_code != CODE_LABEL
|
||
&& GET_RTX_CLASS (code) == 'i'))
|
||
{
|
||
block_begin[++block] = insn;
|
||
block_end[block] = insn;
|
||
block_drops_in[block] = prev_code != BARRIER;
|
||
}
|
||
else if (GET_RTX_CLASS (code) == 'i')
|
||
block_end[block] = insn;
|
||
|
||
if (GET_RTX_CLASS (code) == 'i')
|
||
{
|
||
rtx note;
|
||
|
||
/* Make a list of all labels referred to other than by jumps. */
|
||
for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
|
||
if (REG_NOTE_KIND (note) == REG_LABEL)
|
||
label_value_list = gen_rtx_EXPR_LIST (VOIDmode, XEXP (note, 0),
|
||
label_value_list);
|
||
}
|
||
|
||
block_number[INSN_UID (insn)] = block;
|
||
|
||
if (code != NOTE)
|
||
prev_code = code;
|
||
}
|
||
|
||
if (block + 1 != blocks)
|
||
abort ();
|
||
|
||
/* generate all label references to the corresponding jump insn */
|
||
for (block = 0; block < blocks; block++)
|
||
{
|
||
insn = block_end[block];
|
||
|
||
if (GET_CODE (insn) == JUMP_INSN)
|
||
{
|
||
rtx pat = PATTERN (insn);
|
||
rtx x;
|
||
|
||
if (computed_jump_p (insn))
|
||
{
|
||
for (x = label_value_list; x; x = XEXP (x, 1))
|
||
record_label_references (insn,
|
||
gen_rtx_LABEL_REF (VOIDmode,
|
||
XEXP (x, 0)));
|
||
|
||
for (x = forced_labels; x; x = XEXP (x, 1))
|
||
record_label_references (insn,
|
||
gen_rtx_LABEL_REF (VOIDmode,
|
||
XEXP (x, 0)));
|
||
}
|
||
|
||
record_label_references (insn, pat);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If current function returns its result in an fp stack register,
|
||
return the REG. Otherwise, return 0. */
|
||
|
||
static rtx
|
||
stack_result (decl)
|
||
tree decl;
|
||
{
|
||
rtx result;
|
||
|
||
/* If the value is supposed to be returned in memory, then clearly
|
||
it is not returned in a stack register. */
|
||
if (aggregate_value_p (DECL_RESULT (decl)))
|
||
return 0;
|
||
|
||
result = DECL_RTL (DECL_RESULT (decl));
|
||
/* ?!? What is this code supposed to do? Can this code actually
|
||
trigger if we kick out aggregates above? */
|
||
if (result != 0
|
||
&& ! (GET_CODE (result) == REG
|
||
&& REGNO (result) < FIRST_PSEUDO_REGISTER))
|
||
{
|
||
#ifdef FUNCTION_OUTGOING_VALUE
|
||
result
|
||
= FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (decl)), decl);
|
||
#else
|
||
result = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (decl)), decl);
|
||
#endif
|
||
}
|
||
|
||
return result != 0 && STACK_REG_P (result) ? result : 0;
|
||
}
|
||
|
||
/* Determine the which registers are live at the start of each basic
|
||
block of the function whose first insn is FIRST.
|
||
|
||
First, if the function returns a real_type, mark the function
|
||
return type as live at each return point, as the RTL may not give any
|
||
hint that the register is live.
|
||
|
||
Then, start with the last block and work back to the first block.
|
||
Similarly, work backwards within each block, insn by insn, recording
|
||
which regs are dead and which are used (and therefore live) in the
|
||
hard reg set of block_stack_in[].
|
||
|
||
After processing each basic block, if there is a label at the start
|
||
of the block, propagate the live registers to all jumps to this block.
|
||
|
||
As a special case, if there are regs live in this block, that are
|
||
not live in a block containing a jump to this label, and the block
|
||
containing the jump has already been processed, we must propagate this
|
||
block's entry register life back to the block containing the jump, and
|
||
restart life analysis from there.
|
||
|
||
In the worst case, this function may traverse the insns
|
||
REG_STACK_SIZE times. This is necessary, since a jump towards the end
|
||
of the insns may not know that a reg is live at a target that is early
|
||
in the insns. So we back up and start over with the new reg live.
|
||
|
||
If there are registers that are live at the start of the function,
|
||
insns are emitted to initialize these registers. Something similar is
|
||
done after CALL_INSNs in record_reg_life. */
|
||
|
||
static void
|
||
stack_reg_life_analysis (first, stackentry)
|
||
rtx first;
|
||
HARD_REG_SET *stackentry;
|
||
{
|
||
int reg, block;
|
||
struct stack_def regstack;
|
||
|
||
{
|
||
rtx retvalue;
|
||
|
||
if ((retvalue = stack_result (current_function_decl)))
|
||
{
|
||
/* Find all RETURN insns and mark them. */
|
||
|
||
for (block = blocks - 1; --block >= 0;)
|
||
if (GET_CODE (block_end[block]) == JUMP_INSN
|
||
&& returnjump_p (block_end[block]))
|
||
mark_regs_pat (retvalue, block_out_reg_set+block);
|
||
|
||
/* Mark off the end of last block if we "fall off" the end of the
|
||
function into the epilogue. */
|
||
|
||
if (GET_CODE (block_end[blocks-1]) != JUMP_INSN
|
||
|| returnjump_p (block_end[blocks-1]))
|
||
mark_regs_pat (retvalue, block_out_reg_set+blocks-1);
|
||
}
|
||
}
|
||
|
||
/* now scan all blocks backward for stack register use */
|
||
|
||
block = blocks - 1;
|
||
while (block >= 0)
|
||
{
|
||
register rtx insn, prev;
|
||
|
||
/* current register status at last instruction */
|
||
|
||
COPY_HARD_REG_SET (regstack.reg_set, block_out_reg_set[block]);
|
||
|
||
prev = block_end[block];
|
||
do
|
||
{
|
||
insn = prev;
|
||
prev = PREV_INSN (insn);
|
||
|
||
/* If the insn is a CALL_INSN, we need to ensure that
|
||
everything dies. But otherwise don't process unless there
|
||
are some stack regs present. */
|
||
|
||
if (stack_regs_mentioned (insn) || GET_CODE (insn) == CALL_INSN)
|
||
record_reg_life (insn, block, ®stack);
|
||
|
||
} while (insn != block_begin[block]);
|
||
|
||
/* Set the state at the start of the block. Mark that no
|
||
register mapping information known yet. */
|
||
|
||
COPY_HARD_REG_SET (block_stack_in[block].reg_set, regstack.reg_set);
|
||
block_stack_in[block].top = -2;
|
||
|
||
/* If there is a label, propagate our register life to all jumps
|
||
to this label. */
|
||
|
||
if (GET_CODE (insn) == CODE_LABEL)
|
||
{
|
||
register rtx label;
|
||
int must_restart = 0;
|
||
|
||
for (label = LABEL_REFS (insn); label != insn;
|
||
label = LABEL_NEXTREF (label))
|
||
{
|
||
int jump_block = BLOCK_NUM (CONTAINING_INSN (label));
|
||
|
||
if (jump_block < block)
|
||
IOR_HARD_REG_SET (block_out_reg_set[jump_block],
|
||
block_stack_in[block].reg_set);
|
||
else
|
||
{
|
||
/* The block containing the jump has already been
|
||
processed. If there are registers that were not known
|
||
to be live then, but are live now, we must back up
|
||
and restart life analysis from that point with the new
|
||
life information. */
|
||
|
||
GO_IF_HARD_REG_SUBSET (block_stack_in[block].reg_set,
|
||
block_out_reg_set[jump_block],
|
||
win);
|
||
|
||
IOR_HARD_REG_SET (block_out_reg_set[jump_block],
|
||
block_stack_in[block].reg_set);
|
||
|
||
block = jump_block;
|
||
must_restart = 1;
|
||
break;
|
||
|
||
win:
|
||
;
|
||
}
|
||
}
|
||
if (must_restart)
|
||
continue;
|
||
}
|
||
|
||
if (block_drops_in[block])
|
||
IOR_HARD_REG_SET (block_out_reg_set[block-1],
|
||
block_stack_in[block].reg_set);
|
||
|
||
block -= 1;
|
||
}
|
||
|
||
/* If any reg is live at the start of the first block of a
|
||
function, then we must guarantee that the reg holds some value by
|
||
generating our own "load" of that register. Otherwise a 387 would
|
||
fault trying to access an empty register. */
|
||
|
||
/* Load zero into each live register. The fact that a register
|
||
appears live at the function start necessarily implies an error
|
||
in the user program: it means that (unless the offending code is *never*
|
||
executed) this program is using uninitialised floating point
|
||
variables. In order to keep broken code like this happy, we initialise
|
||
those variables with zero.
|
||
|
||
Note that we are inserting virtual register references here:
|
||
these insns must be processed by convert_regs later. Also, these
|
||
insns will not be in block_number, so BLOCK_NUM() will fail for them. */
|
||
|
||
for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; reg--)
|
||
if (TEST_HARD_REG_BIT (block_stack_in[0].reg_set, reg)
|
||
&& ! TEST_HARD_REG_BIT (*stackentry, reg))
|
||
{
|
||
rtx init_rtx;
|
||
|
||
init_rtx = gen_rtx_SET (VOIDmode, FP_MODE_REG(reg, DFmode),
|
||
CONST0_RTX (DFmode));
|
||
block_begin[0] = emit_insn_after (init_rtx, first);
|
||
|
||
CLEAR_HARD_REG_BIT (block_stack_in[0].reg_set, reg);
|
||
}
|
||
}
|
||
|
||
/*****************************************************************************
|
||
This section deals with stack register substitution, and forms the second
|
||
pass over the RTL.
|
||
*****************************************************************************/
|
||
|
||
/* Replace REG, which is a pointer to a stack reg RTX, with an RTX for
|
||
the desired hard REGNO. */
|
||
|
||
static void
|
||
replace_reg (reg, regno)
|
||
rtx *reg;
|
||
int regno;
|
||
{
|
||
if (regno < FIRST_STACK_REG || regno > LAST_STACK_REG
|
||
|| ! STACK_REG_P (*reg))
|
||
abort ();
|
||
|
||
switch (GET_MODE_CLASS (GET_MODE (*reg)))
|
||
{
|
||
default: abort ();
|
||
case MODE_FLOAT:
|
||
case MODE_COMPLEX_FLOAT:;
|
||
}
|
||
|
||
*reg = FP_MODE_REG (regno, GET_MODE (*reg));
|
||
}
|
||
|
||
/* Remove a note of type NOTE, which must be found, for register
|
||
number REGNO from INSN. Remove only one such note. */
|
||
|
||
static void
|
||
remove_regno_note (insn, note, regno)
|
||
rtx insn;
|
||
enum reg_note note;
|
||
int regno;
|
||
{
|
||
register rtx *note_link, this;
|
||
|
||
note_link = ®_NOTES(insn);
|
||
for (this = *note_link; this; this = XEXP (this, 1))
|
||
if (REG_NOTE_KIND (this) == note
|
||
&& REG_P (XEXP (this, 0)) && REGNO (XEXP (this, 0)) == regno)
|
||
{
|
||
*note_link = XEXP (this, 1);
|
||
return;
|
||
}
|
||
else
|
||
note_link = &XEXP (this, 1);
|
||
|
||
abort ();
|
||
}
|
||
|
||
/* Find the hard register number of virtual register REG in REGSTACK.
|
||
The hard register number is relative to the top of the stack. -1 is
|
||
returned if the register is not found. */
|
||
|
||
static int
|
||
get_hard_regnum (regstack, reg)
|
||
stack regstack;
|
||
rtx reg;
|
||
{
|
||
int i;
|
||
|
||
if (! STACK_REG_P (reg))
|
||
abort ();
|
||
|
||
for (i = regstack->top; i >= 0; i--)
|
||
if (regstack->reg[i] == REGNO (reg))
|
||
break;
|
||
|
||
return i >= 0 ? (FIRST_STACK_REG + regstack->top - i) : -1;
|
||
}
|
||
|
||
/* Delete INSN from the RTL. Mark the insn, but don't remove it from
|
||
the chain of insns. Doing so could confuse block_begin and block_end
|
||
if this were the only insn in the block. */
|
||
|
||
static void
|
||
delete_insn_for_stacker (insn)
|
||
rtx insn;
|
||
{
|
||
int i;
|
||
|
||
/* Ensure that the side effects were clobbers when deleting a PARALLEL. */
|
||
if (GET_CODE (PATTERN (insn)) == PARALLEL)
|
||
for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++)
|
||
if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) != CLOBBER)
|
||
abort ();
|
||
|
||
PUT_CODE (insn, NOTE);
|
||
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
|
||
NOTE_SOURCE_FILE (insn) = 0;
|
||
}
|
||
|
||
/* Emit an insn to pop virtual register REG before or after INSN.
|
||
REGSTACK is the stack state after INSN and is updated to reflect this
|
||
pop. WHEN is either emit_insn_before, emit_insn_after or NULL.
|
||
in case WHEN is NULL we don't really emit the insn, just modify stack
|
||
information. Caller is expected to emit insn himself.
|
||
|
||
A pop insn is represented as a SET whose destination is the register to
|
||
be popped and source is the top of stack. A death note for the top of stack
|
||
cases the movdf pattern to pop. */
|
||
|
||
static rtx
|
||
emit_pop_insn (insn, regstack, reg, when)
|
||
rtx insn;
|
||
stack regstack;
|
||
rtx reg;
|
||
rtx (*when)();
|
||
{
|
||
rtx pop_insn, pop_rtx;
|
||
int hard_regno;
|
||
|
||
hard_regno = get_hard_regnum (regstack, reg);
|
||
|
||
if (hard_regno < FIRST_STACK_REG)
|
||
abort ();
|
||
|
||
if (when)
|
||
{
|
||
pop_rtx = gen_rtx_SET (VOIDmode, FP_MODE_REG (hard_regno, DFmode),
|
||
FP_MODE_REG (FIRST_STACK_REG, DFmode));
|
||
|
||
pop_insn = (*when) (pop_rtx, insn);
|
||
|
||
REG_NOTES (pop_insn) = gen_rtx_EXPR_LIST (REG_DEAD,
|
||
FP_MODE_REG (FIRST_STACK_REG,
|
||
DFmode),
|
||
REG_NOTES (pop_insn));
|
||
}
|
||
|
||
regstack->reg[regstack->top - (hard_regno - FIRST_STACK_REG)]
|
||
= regstack->reg[regstack->top];
|
||
regstack->top -= 1;
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (reg));
|
||
|
||
return pop_insn;
|
||
}
|
||
|
||
/* Emit an insn before or after INSN to swap virtual register REG with the
|
||
top of stack. WHEN should be `emit_insn_before' or `emit_insn_before'
|
||
REGSTACK is the stack state before the swap, and is updated to reflect
|
||
the swap. A swap insn is represented as a PARALLEL of two patterns:
|
||
each pattern moves one reg to the other.
|
||
|
||
If REG is already at the top of the stack, no insn is emitted. */
|
||
|
||
static void
|
||
emit_swap_insn (insn, regstack, reg)
|
||
rtx insn;
|
||
stack regstack;
|
||
rtx reg;
|
||
{
|
||
int hard_regno;
|
||
rtx gen_swapdf();
|
||
rtx swap_rtx, swap_insn;
|
||
int tmp, other_reg; /* swap regno temps */
|
||
rtx i1; /* the stack-reg insn prior to INSN */
|
||
rtx i1set = NULL_RTX; /* the SET rtx within I1 */
|
||
|
||
hard_regno = get_hard_regnum (regstack, reg);
|
||
|
||
if (hard_regno < FIRST_STACK_REG)
|
||
abort ();
|
||
if (hard_regno == FIRST_STACK_REG)
|
||
return;
|
||
|
||
other_reg = regstack->top - (hard_regno - FIRST_STACK_REG);
|
||
|
||
tmp = regstack->reg[other_reg];
|
||
regstack->reg[other_reg] = regstack->reg[regstack->top];
|
||
regstack->reg[regstack->top] = tmp;
|
||
|
||
/* Find the previous insn involving stack regs, but don't go past
|
||
any labels, calls or jumps. */
|
||
i1 = prev_nonnote_insn (insn);
|
||
while (i1 && GET_CODE (i1) == INSN && !stack_regs_mentioned (i1))
|
||
i1 = prev_nonnote_insn (i1);
|
||
|
||
if (i1)
|
||
i1set = single_set (i1);
|
||
|
||
if (i1set)
|
||
{
|
||
rtx i1src = *get_true_reg (&SET_SRC (i1set));
|
||
rtx i1dest = *get_true_reg (&SET_DEST (i1set));
|
||
|
||
/* If the previous register stack push was from the reg we are to
|
||
swap with, omit the swap. */
|
||
|
||
if (GET_CODE (i1dest) == REG && REGNO (i1dest) == FIRST_STACK_REG
|
||
&& GET_CODE (i1src) == REG && REGNO (i1src) == hard_regno - 1
|
||
&& find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
|
||
return;
|
||
|
||
/* If the previous insn wrote to the reg we are to swap with,
|
||
omit the swap. */
|
||
|
||
if (GET_CODE (i1dest) == REG && REGNO (i1dest) == hard_regno
|
||
&& GET_CODE (i1src) == REG && REGNO (i1src) == FIRST_STACK_REG
|
||
&& find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
|
||
return;
|
||
}
|
||
|
||
if (GET_RTX_CLASS (GET_CODE (i1)) == 'i' && sets_cc0_p (PATTERN (i1)))
|
||
{
|
||
i1 = next_nonnote_insn (i1);
|
||
if (i1 == insn)
|
||
abort ();
|
||
}
|
||
|
||
swap_rtx = gen_swapdf (FP_MODE_REG (hard_regno, DFmode),
|
||
FP_MODE_REG (FIRST_STACK_REG, DFmode));
|
||
swap_insn = emit_insn_after (swap_rtx, i1);
|
||
}
|
||
|
||
/* Handle a move to or from a stack register in PAT, which is in INSN.
|
||
REGSTACK is the current stack. */
|
||
|
||
static void
|
||
move_for_stack_reg (insn, regstack, pat)
|
||
rtx insn;
|
||
stack regstack;
|
||
rtx pat;
|
||
{
|
||
rtx *psrc = get_true_reg (&SET_SRC (pat));
|
||
rtx *pdest = get_true_reg (&SET_DEST (pat));
|
||
rtx src, dest;
|
||
rtx note;
|
||
|
||
src = *psrc; dest = *pdest;
|
||
|
||
if (STACK_REG_P (src) && STACK_REG_P (dest))
|
||
{
|
||
/* Write from one stack reg to another. If SRC dies here, then
|
||
just change the register mapping and delete the insn. */
|
||
|
||
note = find_regno_note (insn, REG_DEAD, REGNO (src));
|
||
if (note)
|
||
{
|
||
int i;
|
||
|
||
/* If this is a no-op move, there must not be a REG_DEAD note. */
|
||
if (REGNO (src) == REGNO (dest))
|
||
abort ();
|
||
|
||
for (i = regstack->top; i >= 0; i--)
|
||
if (regstack->reg[i] == REGNO (src))
|
||
break;
|
||
|
||
/* The source must be live, and the dest must be dead. */
|
||
if (i < 0 || get_hard_regnum (regstack, dest) >= FIRST_STACK_REG)
|
||
abort ();
|
||
|
||
/* It is possible that the dest is unused after this insn.
|
||
If so, just pop the src. */
|
||
|
||
if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
|
||
{
|
||
emit_pop_insn (insn, regstack, src, emit_insn_after);
|
||
|
||
delete_insn_for_stacker (insn);
|
||
return;
|
||
}
|
||
|
||
regstack->reg[i] = REGNO (dest);
|
||
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
|
||
|
||
delete_insn_for_stacker (insn);
|
||
|
||
return;
|
||
}
|
||
|
||
/* The source reg does not die. */
|
||
|
||
/* If this appears to be a no-op move, delete it, or else it
|
||
will confuse the machine description output patterns. But if
|
||
it is REG_UNUSED, we must pop the reg now, as per-insn processing
|
||
for REG_UNUSED will not work for deleted insns. */
|
||
|
||
if (REGNO (src) == REGNO (dest))
|
||
{
|
||
if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
|
||
emit_pop_insn (insn, regstack, dest, emit_insn_after);
|
||
|
||
delete_insn_for_stacker (insn);
|
||
return;
|
||
}
|
||
|
||
/* The destination ought to be dead */
|
||
if (get_hard_regnum (regstack, dest) >= FIRST_STACK_REG)
|
||
abort ();
|
||
|
||
replace_reg (psrc, get_hard_regnum (regstack, src));
|
||
|
||
regstack->reg[++regstack->top] = REGNO (dest);
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
|
||
replace_reg (pdest, FIRST_STACK_REG);
|
||
}
|
||
else if (STACK_REG_P (src))
|
||
{
|
||
/* Save from a stack reg to MEM, or possibly integer reg. Since
|
||
only top of stack may be saved, emit an exchange first if
|
||
needs be. */
|
||
|
||
emit_swap_insn (insn, regstack, src);
|
||
|
||
note = find_regno_note (insn, REG_DEAD, REGNO (src));
|
||
if (note)
|
||
{
|
||
replace_reg (&XEXP (note, 0), FIRST_STACK_REG);
|
||
regstack->top--;
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
|
||
}
|
||
else if (GET_MODE (src) == XFmode && regstack->top < REG_STACK_SIZE - 1)
|
||
{
|
||
/* A 387 cannot write an XFmode value to a MEM without
|
||
clobbering the source reg. The output code can handle
|
||
this by reading back the value from the MEM.
|
||
But it is more efficient to use a temp register if one is
|
||
available. Push the source value here if the register
|
||
stack is not full, and then write the value to memory via
|
||
a pop. */
|
||
rtx push_rtx, push_insn;
|
||
rtx top_stack_reg = FP_MODE_REG (FIRST_STACK_REG, XFmode);
|
||
|
||
push_rtx = gen_movxf (top_stack_reg, top_stack_reg);
|
||
push_insn = emit_insn_before (push_rtx, insn);
|
||
REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, top_stack_reg,
|
||
REG_NOTES (insn));
|
||
}
|
||
|
||
replace_reg (psrc, FIRST_STACK_REG);
|
||
}
|
||
else if (STACK_REG_P (dest))
|
||
{
|
||
/* Load from MEM, or possibly integer REG or constant, into the
|
||
stack regs. The actual target is always the top of the
|
||
stack. The stack mapping is changed to reflect that DEST is
|
||
now at top of stack. */
|
||
|
||
/* The destination ought to be dead */
|
||
if (get_hard_regnum (regstack, dest) >= FIRST_STACK_REG)
|
||
abort ();
|
||
|
||
if (regstack->top >= REG_STACK_SIZE)
|
||
abort ();
|
||
|
||
regstack->reg[++regstack->top] = REGNO (dest);
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
|
||
replace_reg (pdest, FIRST_STACK_REG);
|
||
}
|
||
else
|
||
abort ();
|
||
}
|
||
|
||
static void
|
||
swap_rtx_condition (pat)
|
||
rtx pat;
|
||
{
|
||
register char *fmt;
|
||
register int i;
|
||
|
||
if (GET_RTX_CLASS (GET_CODE (pat)) == '<')
|
||
{
|
||
PUT_CODE (pat, swap_condition (GET_CODE (pat)));
|
||
return;
|
||
}
|
||
|
||
fmt = GET_RTX_FORMAT (GET_CODE (pat));
|
||
for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
|
||
{
|
||
if (fmt[i] == 'E')
|
||
{
|
||
register int j;
|
||
|
||
for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
|
||
swap_rtx_condition (XVECEXP (pat, i, j));
|
||
}
|
||
else if (fmt[i] == 'e')
|
||
swap_rtx_condition (XEXP (pat, i));
|
||
}
|
||
}
|
||
|
||
/* Handle a comparison. Special care needs to be taken to avoid
|
||
causing comparisons that a 387 cannot do correctly, such as EQ.
|
||
|
||
Also, a fstp instruction may need to be emitted. The 387 does have an
|
||
`fcompp' insn that can pop two regs, but it is sometimes too expensive
|
||
to do this - a `fcomp' followed by a `fstpl %st(0)' may be easier to
|
||
set up.
|
||
|
||
We can not handle this by emiting fpop instruction after compare, because
|
||
it appears between cc0 setter and user. So we emit only
|
||
REG_DEAD note and handle it as a special case in machine description.
|
||
|
||
This code used trick with delay_slot filling to emit pop insn after
|
||
comparsion but it didn't worked because it caused confusion with cc_status
|
||
in final pass. */
|
||
|
||
static void
|
||
compare_for_stack_reg (insn, regstack, pat)
|
||
rtx insn;
|
||
stack regstack;
|
||
rtx pat;
|
||
{
|
||
rtx *src1, *src2;
|
||
rtx src1_note, src2_note;
|
||
rtx cc0_user;
|
||
int have_cmove;
|
||
int hard_regno;
|
||
|
||
src1 = get_true_reg (&XEXP (SET_SRC (pat), 0));
|
||
src2 = get_true_reg (&XEXP (SET_SRC (pat), 1));
|
||
cc0_user = next_cc0_user (insn);
|
||
|
||
/* If the insn that uses cc0 is an FP-conditional move, then the destination
|
||
must be the top of stack */
|
||
if (GET_CODE (PATTERN (cc0_user)) == SET
|
||
&& SET_DEST (PATTERN (cc0_user)) != pc_rtx
|
||
&& GET_CODE (SET_SRC (PATTERN (cc0_user))) == IF_THEN_ELSE
|
||
&& (GET_MODE_CLASS (GET_MODE (SET_DEST (PATTERN (cc0_user))))
|
||
== MODE_FLOAT))
|
||
{
|
||
rtx *dest;
|
||
|
||
dest = get_true_reg (&SET_DEST (PATTERN (cc0_user)));
|
||
|
||
have_cmove = 1;
|
||
if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG
|
||
&& REGNO (*dest) != regstack->reg[regstack->top])
|
||
{
|
||
emit_swap_insn (insn, regstack, *dest);
|
||
}
|
||
}
|
||
else
|
||
have_cmove = 0;
|
||
|
||
/* ??? If fxch turns out to be cheaper than fstp, give priority to
|
||
registers that die in this insn - move those to stack top first. */
|
||
if (! STACK_REG_P (*src1)
|
||
|| (STACK_REG_P (*src2)
|
||
&& get_hard_regnum (regstack, *src2) == FIRST_STACK_REG))
|
||
{
|
||
rtx temp, next;
|
||
|
||
temp = XEXP (SET_SRC (pat), 0);
|
||
XEXP (SET_SRC (pat), 0) = XEXP (SET_SRC (pat), 1);
|
||
XEXP (SET_SRC (pat), 1) = temp;
|
||
|
||
src1 = get_true_reg (&XEXP (SET_SRC (pat), 0));
|
||
src2 = get_true_reg (&XEXP (SET_SRC (pat), 1));
|
||
|
||
next = next_cc0_user (insn);
|
||
if (next == NULL_RTX)
|
||
abort ();
|
||
|
||
swap_rtx_condition (PATTERN (next));
|
||
INSN_CODE (next) = -1;
|
||
INSN_CODE (insn) = -1;
|
||
}
|
||
|
||
/* We will fix any death note later. */
|
||
|
||
src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
|
||
|
||
if (STACK_REG_P (*src2))
|
||
src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
|
||
else
|
||
src2_note = NULL_RTX;
|
||
|
||
if (! have_cmove)
|
||
emit_swap_insn (insn, regstack, *src1);
|
||
|
||
replace_reg (src1, FIRST_STACK_REG);
|
||
|
||
if (STACK_REG_P (*src2))
|
||
{
|
||
hard_regno = get_hard_regnum (regstack, *src2);
|
||
replace_reg (src2, hard_regno);
|
||
}
|
||
|
||
if (src1_note)
|
||
{
|
||
pop_stack (regstack, REGNO (XEXP (src1_note, 0)));
|
||
replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
|
||
}
|
||
|
||
/* If the second operand dies, handle that. But if the operands are
|
||
the same stack register, don't bother, because only one death is
|
||
needed, and it was just handled. */
|
||
|
||
if (src2_note
|
||
&& ! (STACK_REG_P (*src1) && STACK_REG_P (*src2)
|
||
&& REGNO (*src1) == REGNO (*src2)))
|
||
{
|
||
/* As a special case, two regs may die in this insn if src2 is
|
||
next to top of stack and the top of stack also dies. Since
|
||
we have already popped src1, "next to top of stack" is really
|
||
at top (FIRST_STACK_REG) now. */
|
||
|
||
if (get_hard_regnum (regstack, XEXP (src2_note, 0)) == FIRST_STACK_REG
|
||
&& src1_note)
|
||
{
|
||
pop_stack (regstack, REGNO (XEXP (src2_note, 0)));
|
||
replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1);
|
||
}
|
||
else
|
||
{
|
||
/* Pop of second operand is handled using special REG_DEAD note
|
||
because we can't emit pop insn after cc0 setter. */
|
||
|
||
emit_pop_insn (insn, regstack, XEXP (src2_note, 0), NULL);
|
||
replace_reg (&XEXP (src2_note, 0), hard_regno);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Substitute new registers in PAT, which is part of INSN. REGSTACK
|
||
is the current register layout. */
|
||
|
||
static void
|
||
subst_stack_regs_pat (insn, regstack, pat)
|
||
rtx insn;
|
||
stack regstack;
|
||
rtx pat;
|
||
{
|
||
rtx *dest, *src;
|
||
rtx *src1 = (rtx *) NULL_PTR, *src2;
|
||
rtx src1_note, src2_note;
|
||
|
||
if (GET_CODE (pat) != SET)
|
||
return;
|
||
|
||
dest = get_true_reg (&SET_DEST (pat));
|
||
src = get_true_reg (&SET_SRC (pat));
|
||
|
||
/* See if this is a `movM' pattern, and handle elsewhere if so. */
|
||
|
||
if (*dest != cc0_rtx
|
||
&& (STACK_REG_P (*src)
|
||
|| (STACK_REG_P (*dest)
|
||
&& (GET_CODE (*src) == REG || GET_CODE (*src) == MEM
|
||
|| GET_CODE (*src) == CONST_DOUBLE))))
|
||
move_for_stack_reg (insn, regstack, pat);
|
||
else
|
||
switch (GET_CODE (SET_SRC (pat)))
|
||
{
|
||
case COMPARE:
|
||
compare_for_stack_reg (insn, regstack, pat);
|
||
break;
|
||
|
||
case CALL:
|
||
{
|
||
int count;
|
||
for (count = HARD_REGNO_NREGS (REGNO (*dest), GET_MODE (*dest));
|
||
--count >= 0;)
|
||
{
|
||
regstack->reg[++regstack->top] = REGNO (*dest) + count;
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest) + count);
|
||
}
|
||
}
|
||
replace_reg (dest, FIRST_STACK_REG);
|
||
break;
|
||
|
||
case REG:
|
||
/* This is a `tstM2' case. */
|
||
if (*dest != cc0_rtx)
|
||
abort ();
|
||
|
||
src1 = src;
|
||
|
||
/* Fall through. */
|
||
|
||
case FLOAT_TRUNCATE:
|
||
case SQRT:
|
||
case ABS:
|
||
case NEG:
|
||
/* These insns only operate on the top of the stack. DEST might
|
||
be cc0_rtx if we're processing a tstM pattern. Also, it's
|
||
possible that the tstM case results in a REG_DEAD note on the
|
||
source. */
|
||
|
||
if (src1 == 0)
|
||
src1 = get_true_reg (&XEXP (SET_SRC (pat), 0));
|
||
|
||
emit_swap_insn (insn, regstack, *src1);
|
||
|
||
src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
|
||
|
||
if (STACK_REG_P (*dest))
|
||
replace_reg (dest, FIRST_STACK_REG);
|
||
|
||
if (src1_note)
|
||
{
|
||
replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
|
||
regstack->top--;
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1));
|
||
}
|
||
|
||
replace_reg (src1, FIRST_STACK_REG);
|
||
|
||
break;
|
||
|
||
case MINUS:
|
||
case DIV:
|
||
/* On i386, reversed forms of subM3 and divM3 exist for
|
||
MODE_FLOAT, so the same code that works for addM3 and mulM3
|
||
can be used. */
|
||
case MULT:
|
||
case PLUS:
|
||
/* These insns can accept the top of stack as a destination
|
||
from a stack reg or mem, or can use the top of stack as a
|
||
source and some other stack register (possibly top of stack)
|
||
as a destination. */
|
||
|
||
src1 = get_true_reg (&XEXP (SET_SRC (pat), 0));
|
||
src2 = get_true_reg (&XEXP (SET_SRC (pat), 1));
|
||
|
||
/* We will fix any death note later. */
|
||
|
||
if (STACK_REG_P (*src1))
|
||
src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
|
||
else
|
||
src1_note = NULL_RTX;
|
||
if (STACK_REG_P (*src2))
|
||
src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
|
||
else
|
||
src2_note = NULL_RTX;
|
||
|
||
/* If either operand is not a stack register, then the dest
|
||
must be top of stack. */
|
||
|
||
if (! STACK_REG_P (*src1) || ! STACK_REG_P (*src2))
|
||
emit_swap_insn (insn, regstack, *dest);
|
||
else
|
||
{
|
||
/* Both operands are REG. If neither operand is already
|
||
at the top of stack, choose to make the one that is the dest
|
||
the new top of stack. */
|
||
|
||
int src1_hard_regnum, src2_hard_regnum;
|
||
|
||
src1_hard_regnum = get_hard_regnum (regstack, *src1);
|
||
src2_hard_regnum = get_hard_regnum (regstack, *src2);
|
||
if (src1_hard_regnum == -1 || src2_hard_regnum == -1)
|
||
abort ();
|
||
|
||
if (src1_hard_regnum != FIRST_STACK_REG
|
||
&& src2_hard_regnum != FIRST_STACK_REG)
|
||
emit_swap_insn (insn, regstack, *dest);
|
||
}
|
||
|
||
if (STACK_REG_P (*src1))
|
||
replace_reg (src1, get_hard_regnum (regstack, *src1));
|
||
if (STACK_REG_P (*src2))
|
||
replace_reg (src2, get_hard_regnum (regstack, *src2));
|
||
|
||
if (src1_note)
|
||
{
|
||
/* If the register that dies is at the top of stack, then
|
||
the destination is somewhere else - merely substitute it.
|
||
But if the reg that dies is not at top of stack, then
|
||
move the top of stack to the dead reg, as though we had
|
||
done the insn and then a store-with-pop. */
|
||
|
||
if (REGNO (XEXP (src1_note, 0)) == regstack->reg[regstack->top])
|
||
{
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
|
||
replace_reg (dest, get_hard_regnum (regstack, *dest));
|
||
}
|
||
else
|
||
{
|
||
int regno = get_hard_regnum (regstack, XEXP (src1_note, 0));
|
||
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
|
||
replace_reg (dest, regno);
|
||
|
||
regstack->reg[regstack->top - (regno - FIRST_STACK_REG)]
|
||
= regstack->reg[regstack->top];
|
||
}
|
||
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set,
|
||
REGNO (XEXP (src1_note, 0)));
|
||
replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
|
||
regstack->top--;
|
||
}
|
||
else if (src2_note)
|
||
{
|
||
if (REGNO (XEXP (src2_note, 0)) == regstack->reg[regstack->top])
|
||
{
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
|
||
replace_reg (dest, get_hard_regnum (regstack, *dest));
|
||
}
|
||
else
|
||
{
|
||
int regno = get_hard_regnum (regstack, XEXP (src2_note, 0));
|
||
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
|
||
replace_reg (dest, regno);
|
||
|
||
regstack->reg[regstack->top - (regno - FIRST_STACK_REG)]
|
||
= regstack->reg[regstack->top];
|
||
}
|
||
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set,
|
||
REGNO (XEXP (src2_note, 0)));
|
||
replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG);
|
||
regstack->top--;
|
||
}
|
||
else
|
||
{
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
|
||
replace_reg (dest, get_hard_regnum (regstack, *dest));
|
||
}
|
||
|
||
break;
|
||
|
||
case UNSPEC:
|
||
switch (XINT (SET_SRC (pat), 1))
|
||
{
|
||
case 1: /* sin */
|
||
case 2: /* cos */
|
||
/* These insns only operate on the top of the stack. */
|
||
|
||
src1 = get_true_reg (&XVECEXP (SET_SRC (pat), 0, 0));
|
||
|
||
emit_swap_insn (insn, regstack, *src1);
|
||
|
||
src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
|
||
|
||
if (STACK_REG_P (*dest))
|
||
replace_reg (dest, FIRST_STACK_REG);
|
||
|
||
if (src1_note)
|
||
{
|
||
replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
|
||
regstack->top--;
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1));
|
||
}
|
||
|
||
replace_reg (src1, FIRST_STACK_REG);
|
||
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
break;
|
||
|
||
case IF_THEN_ELSE:
|
||
/* dest has to be on stack. */
|
||
if (get_hard_regnum (regstack, *dest) < FIRST_STACK_REG)
|
||
abort ();
|
||
|
||
/* This insn requires the top of stack to be the destination. */
|
||
|
||
/* If the comparison operator is an FP comparison operator,
|
||
it is handled correctly by compare_for_stack_reg () who
|
||
will move the destination to the top of stack. But if the
|
||
comparison operator is not an FP comparison operator, we
|
||
have to handle it here. */
|
||
if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG
|
||
&& REGNO (*dest) != regstack->reg[regstack->top])
|
||
emit_swap_insn (insn, regstack, *dest);
|
||
|
||
src1 = get_true_reg (&XEXP (SET_SRC (pat), 1));
|
||
src2 = get_true_reg (&XEXP (SET_SRC (pat), 2));
|
||
|
||
src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
|
||
src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
|
||
|
||
{
|
||
rtx src_note [3];
|
||
int i;
|
||
|
||
src_note[0] = 0;
|
||
src_note[1] = src1_note;
|
||
src_note[2] = src2_note;
|
||
|
||
if (STACK_REG_P (*src1))
|
||
replace_reg (src1, get_hard_regnum (regstack, *src1));
|
||
if (STACK_REG_P (*src2))
|
||
replace_reg (src2, get_hard_regnum (regstack, *src2));
|
||
|
||
for (i = 1; i <= 2; i++)
|
||
if (src_note [i])
|
||
{
|
||
/* If the register that dies is not at the top of stack, then
|
||
move the top of stack to the dead reg */
|
||
if (REGNO (XEXP (src_note[i], 0))
|
||
!= regstack->reg[regstack->top])
|
||
{
|
||
remove_regno_note (insn, REG_DEAD,
|
||
REGNO (XEXP (src_note [i], 0)));
|
||
emit_pop_insn (insn, regstack, XEXP (src_note[i], 0),
|
||
emit_insn_after);
|
||
}
|
||
else
|
||
{
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set,
|
||
REGNO (XEXP (src_note[i], 0)));
|
||
replace_reg (&XEXP (src_note[i], 0), FIRST_STACK_REG);
|
||
regstack->top--;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Make dest the top of stack. */
|
||
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
|
||
replace_reg (dest, FIRST_STACK_REG);
|
||
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Substitute hard regnums for any stack regs in INSN, which has
|
||
N_INPUTS inputs and N_OUTPUTS outputs. REGSTACK is the stack info
|
||
before the insn, and is updated with changes made here.
|
||
|
||
There are several requirements and assumptions about the use of
|
||
stack-like regs in asm statements. These rules are enforced by
|
||
record_asm_stack_regs; see comments there for details. Any
|
||
asm_operands left in the RTL at this point may be assume to meet the
|
||
requirements, since record_asm_stack_regs removes any problem asm. */
|
||
|
||
static void
|
||
subst_asm_stack_regs (insn, regstack)
|
||
rtx insn;
|
||
stack regstack;
|
||
{
|
||
rtx body = PATTERN (insn);
|
||
int alt;
|
||
|
||
rtx *note_reg; /* Array of note contents */
|
||
rtx **note_loc; /* Address of REG field of each note */
|
||
enum reg_note *note_kind; /* The type of each note */
|
||
|
||
rtx *clobber_reg;
|
||
rtx **clobber_loc;
|
||
|
||
struct stack_def temp_stack;
|
||
int n_notes;
|
||
int n_clobbers;
|
||
rtx note;
|
||
int i;
|
||
int n_inputs, n_outputs;
|
||
|
||
/* Find out what the constraints required. If no constraint
|
||
alternative matches, that is a compiler bug: we should have caught
|
||
such an insn during the life analysis pass (and reload should have
|
||
caught it regardless). */
|
||
extract_insn (insn);
|
||
constrain_operands (1);
|
||
alt = which_alternative;
|
||
|
||
preprocess_constraints ();
|
||
|
||
n_inputs = get_asm_operand_n_inputs (body);
|
||
n_outputs = recog_n_operands - n_inputs;
|
||
|
||
if (alt < 0)
|
||
abort ();
|
||
|
||
/* Strip SUBREGs here to make the following code simpler. */
|
||
for (i = 0; i < recog_n_operands; i++)
|
||
if (GET_CODE (recog_operand[i]) == SUBREG
|
||
&& GET_CODE (SUBREG_REG (recog_operand[i])) == REG)
|
||
{
|
||
recog_operand_loc[i] = & SUBREG_REG (recog_operand[i]);
|
||
recog_operand[i] = SUBREG_REG (recog_operand[i]);
|
||
}
|
||
|
||
/* Set up NOTE_REG, NOTE_LOC and NOTE_KIND. */
|
||
|
||
for (i = 0, note = REG_NOTES (insn); note; note = XEXP (note, 1))
|
||
i++;
|
||
|
||
note_reg = (rtx *) alloca (i * sizeof (rtx));
|
||
note_loc = (rtx **) alloca (i * sizeof (rtx *));
|
||
note_kind = (enum reg_note *) alloca (i * sizeof (enum reg_note));
|
||
|
||
n_notes = 0;
|
||
for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
|
||
{
|
||
rtx reg = XEXP (note, 0);
|
||
rtx *loc = & XEXP (note, 0);
|
||
|
||
if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG)
|
||
{
|
||
loc = & SUBREG_REG (reg);
|
||
reg = SUBREG_REG (reg);
|
||
}
|
||
|
||
if (STACK_REG_P (reg)
|
||
&& (REG_NOTE_KIND (note) == REG_DEAD
|
||
|| REG_NOTE_KIND (note) == REG_UNUSED))
|
||
{
|
||
note_reg[n_notes] = reg;
|
||
note_loc[n_notes] = loc;
|
||
note_kind[n_notes] = REG_NOTE_KIND (note);
|
||
n_notes++;
|
||
}
|
||
}
|
||
|
||
/* Set up CLOBBER_REG and CLOBBER_LOC. */
|
||
|
||
n_clobbers = 0;
|
||
|
||
if (GET_CODE (body) == PARALLEL)
|
||
{
|
||
clobber_reg = (rtx *) alloca (XVECLEN (body, 0) * sizeof (rtx));
|
||
clobber_loc = (rtx **) alloca (XVECLEN (body, 0) * sizeof (rtx *));
|
||
|
||
for (i = 0; i < XVECLEN (body, 0); i++)
|
||
if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
|
||
{
|
||
rtx clobber = XVECEXP (body, 0, i);
|
||
rtx reg = XEXP (clobber, 0);
|
||
rtx *loc = & XEXP (clobber, 0);
|
||
|
||
if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG)
|
||
{
|
||
loc = & SUBREG_REG (reg);
|
||
reg = SUBREG_REG (reg);
|
||
}
|
||
|
||
if (STACK_REG_P (reg))
|
||
{
|
||
clobber_reg[n_clobbers] = reg;
|
||
clobber_loc[n_clobbers] = loc;
|
||
n_clobbers++;
|
||
}
|
||
}
|
||
}
|
||
|
||
bcopy ((char *) regstack, (char *) &temp_stack, sizeof (temp_stack));
|
||
|
||
/* Put the input regs into the desired place in TEMP_STACK. */
|
||
|
||
for (i = n_outputs; i < n_outputs + n_inputs; i++)
|
||
if (STACK_REG_P (recog_operand[i])
|
||
&& reg_class_subset_p (recog_op_alt[i][alt].class,
|
||
FLOAT_REGS)
|
||
&& recog_op_alt[i][alt].class != FLOAT_REGS)
|
||
{
|
||
/* If an operand needs to be in a particular reg in
|
||
FLOAT_REGS, the constraint was either 't' or 'u'. Since
|
||
these constraints are for single register classes, and reload
|
||
guaranteed that operand[i] is already in that class, we can
|
||
just use REGNO (recog_operand[i]) to know which actual reg this
|
||
operand needs to be in. */
|
||
|
||
int regno = get_hard_regnum (&temp_stack, recog_operand[i]);
|
||
|
||
if (regno < 0)
|
||
abort ();
|
||
|
||
if (regno != REGNO (recog_operand[i]))
|
||
{
|
||
/* recog_operand[i] is not in the right place. Find it
|
||
and swap it with whatever is already in I's place.
|
||
K is where recog_operand[i] is now. J is where it should
|
||
be. */
|
||
int j, k, temp;
|
||
|
||
k = temp_stack.top - (regno - FIRST_STACK_REG);
|
||
j = (temp_stack.top
|
||
- (REGNO (recog_operand[i]) - FIRST_STACK_REG));
|
||
|
||
temp = temp_stack.reg[k];
|
||
temp_stack.reg[k] = temp_stack.reg[j];
|
||
temp_stack.reg[j] = temp;
|
||
}
|
||
}
|
||
|
||
/* emit insns before INSN to make sure the reg-stack is in the right
|
||
order. */
|
||
|
||
change_stack (insn, regstack, &temp_stack, emit_insn_before);
|
||
|
||
/* Make the needed input register substitutions. Do death notes and
|
||
clobbers too, because these are for inputs, not outputs. */
|
||
|
||
for (i = n_outputs; i < n_outputs + n_inputs; i++)
|
||
if (STACK_REG_P (recog_operand[i]))
|
||
{
|
||
int regnum = get_hard_regnum (regstack, recog_operand[i]);
|
||
|
||
if (regnum < 0)
|
||
abort ();
|
||
|
||
replace_reg (recog_operand_loc[i], regnum);
|
||
}
|
||
|
||
for (i = 0; i < n_notes; i++)
|
||
if (note_kind[i] == REG_DEAD)
|
||
{
|
||
int regnum = get_hard_regnum (regstack, note_reg[i]);
|
||
|
||
if (regnum < 0)
|
||
abort ();
|
||
|
||
replace_reg (note_loc[i], regnum);
|
||
}
|
||
|
||
for (i = 0; i < n_clobbers; i++)
|
||
{
|
||
/* It's OK for a CLOBBER to reference a reg that is not live.
|
||
Don't try to replace it in that case. */
|
||
int regnum = get_hard_regnum (regstack, clobber_reg[i]);
|
||
|
||
if (regnum >= 0)
|
||
{
|
||
/* Sigh - clobbers always have QImode. But replace_reg knows
|
||
that these regs can't be MODE_INT and will abort. Just put
|
||
the right reg there without calling replace_reg. */
|
||
|
||
*clobber_loc[i] = FP_MODE_REG (regnum, DFmode);
|
||
}
|
||
}
|
||
|
||
/* Now remove from REGSTACK any inputs that the asm implicitly popped. */
|
||
|
||
for (i = n_outputs; i < n_outputs + n_inputs; i++)
|
||
if (STACK_REG_P (recog_operand[i]))
|
||
{
|
||
/* An input reg is implicitly popped if it is tied to an
|
||
output, or if there is a CLOBBER for it. */
|
||
int j;
|
||
|
||
for (j = 0; j < n_clobbers; j++)
|
||
if (operands_match_p (clobber_reg[j], recog_operand[i]))
|
||
break;
|
||
|
||
if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0)
|
||
{
|
||
/* recog_operand[i] might not be at the top of stack. But that's
|
||
OK, because all we need to do is pop the right number of regs
|
||
off of the top of the reg-stack. record_asm_stack_regs
|
||
guaranteed that all implicitly popped regs were grouped
|
||
at the top of the reg-stack. */
|
||
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set,
|
||
regstack->reg[regstack->top]);
|
||
regstack->top--;
|
||
}
|
||
}
|
||
|
||
/* Now add to REGSTACK any outputs that the asm implicitly pushed.
|
||
Note that there isn't any need to substitute register numbers.
|
||
??? Explain why this is true. */
|
||
|
||
for (i = LAST_STACK_REG; i >= FIRST_STACK_REG; i--)
|
||
{
|
||
/* See if there is an output for this hard reg. */
|
||
int j;
|
||
|
||
for (j = 0; j < n_outputs; j++)
|
||
if (STACK_REG_P (recog_operand[j]) && REGNO (recog_operand[j]) == i)
|
||
{
|
||
regstack->reg[++regstack->top] = i;
|
||
SET_HARD_REG_BIT (regstack->reg_set, i);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Now emit a pop insn for any REG_UNUSED output, or any REG_DEAD
|
||
input that the asm didn't implicitly pop. If the asm didn't
|
||
implicitly pop an input reg, that reg will still be live.
|
||
|
||
Note that we can't use find_regno_note here: the register numbers
|
||
in the death notes have already been substituted. */
|
||
|
||
for (i = 0; i < n_outputs; i++)
|
||
if (STACK_REG_P (recog_operand[i]))
|
||
{
|
||
int j;
|
||
|
||
for (j = 0; j < n_notes; j++)
|
||
if (REGNO (recog_operand[i]) == REGNO (note_reg[j])
|
||
&& note_kind[j] == REG_UNUSED)
|
||
{
|
||
insn = emit_pop_insn (insn, regstack, recog_operand[i],
|
||
emit_insn_after);
|
||
break;
|
||
}
|
||
}
|
||
|
||
for (i = n_outputs; i < n_outputs + n_inputs; i++)
|
||
if (STACK_REG_P (recog_operand[i]))
|
||
{
|
||
int j;
|
||
|
||
for (j = 0; j < n_notes; j++)
|
||
if (REGNO (recog_operand[i]) == REGNO (note_reg[j])
|
||
&& note_kind[j] == REG_DEAD
|
||
&& TEST_HARD_REG_BIT (regstack->reg_set,
|
||
REGNO (recog_operand[i])))
|
||
{
|
||
insn = emit_pop_insn (insn, regstack, recog_operand[i],
|
||
emit_insn_after);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Substitute stack hard reg numbers for stack virtual registers in
|
||
INSN. Non-stack register numbers are not changed. REGSTACK is the
|
||
current stack content. Insns may be emitted as needed to arrange the
|
||
stack for the 387 based on the contents of the insn. */
|
||
|
||
static void
|
||
subst_stack_regs (insn, regstack)
|
||
rtx insn;
|
||
stack regstack;
|
||
{
|
||
register rtx *note_link, note;
|
||
register int i;
|
||
|
||
if (GET_CODE (insn) == CALL_INSN)
|
||
{
|
||
int top = regstack->top;
|
||
|
||
/* If there are any floating point parameters to be passed in
|
||
registers for this call, make sure they are in the right
|
||
order. */
|
||
|
||
if (top >= 0)
|
||
{
|
||
straighten_stack (PREV_INSN (insn), regstack);
|
||
|
||
/* Now mark the arguments as dead after the call. */
|
||
|
||
while (regstack->top >= 0)
|
||
{
|
||
CLEAR_HARD_REG_BIT (regstack->reg_set, FIRST_STACK_REG + regstack->top);
|
||
regstack->top--;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Do the actual substitution if any stack regs are mentioned.
|
||
Since we only record whether entire insn mentions stack regs, and
|
||
subst_stack_regs_pat only works for patterns that contain stack regs,
|
||
we must check each pattern in a parallel here. A call_value_pop could
|
||
fail otherwise. */
|
||
|
||
if (stack_regs_mentioned (insn))
|
||
{
|
||
int n_operands = asm_noperands (PATTERN (insn));
|
||
if (n_operands >= 0)
|
||
{
|
||
/* This insn is an `asm' with operands. Decode the operands,
|
||
decide how many are inputs, and do register substitution.
|
||
Any REG_UNUSED notes will be handled by subst_asm_stack_regs. */
|
||
|
||
subst_asm_stack_regs (insn, regstack);
|
||
return;
|
||
}
|
||
|
||
if (GET_CODE (PATTERN (insn)) == PARALLEL)
|
||
for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
|
||
{
|
||
if (stack_regs_mentioned_p (XVECEXP (PATTERN (insn), 0, i)))
|
||
{
|
||
subst_stack_regs_pat (insn, regstack,
|
||
XVECEXP (PATTERN (insn), 0, i));
|
||
|
||
/* subst_stack_regs_pat may have deleted a no-op insn. */
|
||
if (GET_CODE (insn) == NOTE)
|
||
break;
|
||
}
|
||
}
|
||
else
|
||
subst_stack_regs_pat (insn, regstack, PATTERN (insn));
|
||
}
|
||
|
||
/* subst_stack_regs_pat may have deleted a no-op insn. If so, any
|
||
REG_UNUSED will already have been dealt with, so just return. */
|
||
|
||
if (GET_CODE (insn) == NOTE)
|
||
return;
|
||
|
||
/* If there is a REG_UNUSED note on a stack register on this insn,
|
||
the indicated reg must be popped. The REG_UNUSED note is removed,
|
||
since the form of the newly emitted pop insn references the reg,
|
||
making it no longer `unset'. */
|
||
|
||
note_link = ®_NOTES(insn);
|
||
for (note = *note_link; note; note = XEXP (note, 1))
|
||
if (REG_NOTE_KIND (note) == REG_UNUSED && STACK_REG_P (XEXP (note, 0)))
|
||
{
|
||
*note_link = XEXP (note, 1);
|
||
insn = emit_pop_insn (insn, regstack, XEXP (note, 0), emit_insn_after);
|
||
}
|
||
else
|
||
note_link = &XEXP (note, 1);
|
||
}
|
||
|
||
/* Change the organization of the stack so that it fits a new basic
|
||
block. Some registers might have to be popped, but there can never be
|
||
a register live in the new block that is not now live.
|
||
|
||
Insert any needed insns before or after INSN. WHEN is emit_insn_before
|
||
or emit_insn_after. OLD is the original stack layout, and NEW is
|
||
the desired form. OLD is updated to reflect the code emitted, ie, it
|
||
will be the same as NEW upon return.
|
||
|
||
This function will not preserve block_end[]. But that information
|
||
is no longer needed once this has executed. */
|
||
|
||
static void
|
||
change_stack (insn, old, new, when)
|
||
rtx insn;
|
||
stack old;
|
||
stack new;
|
||
rtx (*when)();
|
||
{
|
||
int reg;
|
||
|
||
/* We will be inserting new insns "backwards", by calling emit_insn_before.
|
||
If we are to insert after INSN, find the next insn, and insert before
|
||
it. */
|
||
|
||
if (when == emit_insn_after)
|
||
insn = NEXT_INSN (insn);
|
||
|
||
/* Pop any registers that are not needed in the new block. */
|
||
|
||
for (reg = old->top; reg >= 0; reg--)
|
||
if (! TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]))
|
||
emit_pop_insn (insn, old, FP_MODE_REG (old->reg[reg], DFmode),
|
||
emit_insn_before);
|
||
|
||
if (new->top == -2)
|
||
{
|
||
/* If the new block has never been processed, then it can inherit
|
||
the old stack order. */
|
||
|
||
new->top = old->top;
|
||
bcopy (old->reg, new->reg, sizeof (new->reg));
|
||
}
|
||
else
|
||
{
|
||
/* This block has been entered before, and we must match the
|
||
previously selected stack order. */
|
||
|
||
/* By now, the only difference should be the order of the stack,
|
||
not their depth or liveliness. */
|
||
|
||
GO_IF_HARD_REG_EQUAL (old->reg_set, new->reg_set, win);
|
||
|
||
abort ();
|
||
|
||
win:
|
||
|
||
if (old->top != new->top)
|
||
abort ();
|
||
|
||
/* If the stack is not empty (new->top != -1), loop here emitting
|
||
swaps until the stack is correct.
|
||
|
||
The worst case number of swaps emitted is N + 2, where N is the
|
||
depth of the stack. In some cases, the reg at the top of
|
||
stack may be correct, but swapped anyway in order to fix
|
||
other regs. But since we never swap any other reg away from
|
||
its correct slot, this algorithm will converge. */
|
||
|
||
if (new->top != -1)
|
||
do
|
||
{
|
||
/* Swap the reg at top of stack into the position it is
|
||
supposed to be in, until the correct top of stack appears. */
|
||
|
||
while (old->reg[old->top] != new->reg[new->top])
|
||
{
|
||
for (reg = new->top; reg >= 0; reg--)
|
||
if (new->reg[reg] == old->reg[old->top])
|
||
break;
|
||
|
||
if (reg == -1)
|
||
abort ();
|
||
|
||
emit_swap_insn (insn, old,
|
||
FP_MODE_REG (old->reg[reg], DFmode));
|
||
}
|
||
|
||
/* See if any regs remain incorrect. If so, bring an
|
||
incorrect reg to the top of stack, and let the while loop
|
||
above fix it. */
|
||
|
||
for (reg = new->top; reg >= 0; reg--)
|
||
if (new->reg[reg] != old->reg[reg])
|
||
{
|
||
emit_swap_insn (insn, old,
|
||
FP_MODE_REG (old->reg[reg], DFmode));
|
||
break;
|
||
}
|
||
} while (reg >= 0);
|
||
|
||
/* At this point there must be no differences. */
|
||
|
||
for (reg = old->top; reg >= 0; reg--)
|
||
if (old->reg[reg] != new->reg[reg])
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Check PAT, which points to RTL in INSN, for a LABEL_REF. If it is
|
||
found, ensure that a jump from INSN to the code_label to which the
|
||
label_ref points ends up with the same stack as that at the
|
||
code_label. Do this by inserting insns just before the code_label to
|
||
pop and rotate the stack until it is in the correct order. REGSTACK
|
||
is the order of the register stack in INSN.
|
||
|
||
Any code that is emitted here must not be later processed as part
|
||
of any block, as it will already contain hard register numbers. */
|
||
|
||
static void
|
||
goto_block_pat (insn, regstack, pat)
|
||
rtx insn;
|
||
stack regstack;
|
||
rtx pat;
|
||
{
|
||
rtx label;
|
||
rtx new_jump, new_label, new_barrier;
|
||
rtx *ref;
|
||
stack label_stack;
|
||
struct stack_def temp_stack;
|
||
int reg;
|
||
|
||
switch (GET_CODE (pat))
|
||
{
|
||
case RETURN:
|
||
straighten_stack (PREV_INSN (insn), regstack);
|
||
return;
|
||
default:
|
||
{
|
||
int i, j;
|
||
char *fmt = GET_RTX_FORMAT (GET_CODE (pat));
|
||
|
||
for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
|
||
{
|
||
if (fmt[i] == 'e')
|
||
goto_block_pat (insn, regstack, XEXP (pat, i));
|
||
if (fmt[i] == 'E')
|
||
for (j = 0; j < XVECLEN (pat, i); j++)
|
||
goto_block_pat (insn, regstack, XVECEXP (pat, i, j));
|
||
}
|
||
return;
|
||
}
|
||
case LABEL_REF:;
|
||
}
|
||
|
||
label = XEXP (pat, 0);
|
||
if (GET_CODE (label) != CODE_LABEL)
|
||
abort ();
|
||
|
||
/* First, see if in fact anything needs to be done to the stack at all. */
|
||
if (INSN_UID (label) <= 0)
|
||
return;
|
||
|
||
label_stack = &block_stack_in[BLOCK_NUM (label)];
|
||
|
||
if (label_stack->top == -2)
|
||
{
|
||
/* If the target block hasn't had a stack order selected, then
|
||
we need merely ensure that no pops are needed. */
|
||
|
||
for (reg = regstack->top; reg >= 0; reg--)
|
||
if (! TEST_HARD_REG_BIT (label_stack->reg_set, regstack->reg[reg]))
|
||
break;
|
||
|
||
if (reg == -1)
|
||
{
|
||
/* change_stack will not emit any code in this case. */
|
||
|
||
change_stack (label, regstack, label_stack, emit_insn_after);
|
||
return;
|
||
}
|
||
}
|
||
else if (label_stack->top == regstack->top)
|
||
{
|
||
for (reg = label_stack->top; reg >= 0; reg--)
|
||
if (label_stack->reg[reg] != regstack->reg[reg])
|
||
break;
|
||
|
||
if (reg == -1)
|
||
return;
|
||
}
|
||
|
||
/* At least one insn will need to be inserted before label. Insert
|
||
a jump around the code we are about to emit. Emit a label for the new
|
||
code, and point the original insn at this new label. We can't use
|
||
redirect_jump here, because we're using fld[4] of the code labels as
|
||
LABEL_REF chains, no NUSES counters. */
|
||
|
||
new_jump = emit_jump_insn_before (gen_jump (label), label);
|
||
record_label_references (new_jump, PATTERN (new_jump));
|
||
JUMP_LABEL (new_jump) = label;
|
||
|
||
new_barrier = emit_barrier_after (new_jump);
|
||
|
||
new_label = gen_label_rtx ();
|
||
emit_label_after (new_label, new_barrier);
|
||
LABEL_REFS (new_label) = new_label;
|
||
|
||
/* The old label_ref will no longer point to the code_label if now uses,
|
||
so strip the label_ref from the code_label's chain of references. */
|
||
|
||
for (ref = &LABEL_REFS (label); *ref != label; ref = &LABEL_NEXTREF (*ref))
|
||
if (*ref == pat)
|
||
break;
|
||
|
||
if (*ref == label)
|
||
abort ();
|
||
|
||
*ref = LABEL_NEXTREF (*ref);
|
||
|
||
XEXP (pat, 0) = new_label;
|
||
record_label_references (insn, PATTERN (insn));
|
||
|
||
if (JUMP_LABEL (insn) == label)
|
||
JUMP_LABEL (insn) = new_label;
|
||
|
||
/* Now emit the needed code. */
|
||
|
||
temp_stack = *regstack;
|
||
|
||
change_stack (new_label, &temp_stack, label_stack, emit_insn_after);
|
||
}
|
||
|
||
/* Traverse all basic blocks in a function, converting the register
|
||
references in each insn from the "flat" register file that gcc uses, to
|
||
the stack-like registers the 387 uses. */
|
||
|
||
static void
|
||
convert_regs ()
|
||
{
|
||
register int block, reg;
|
||
register rtx insn, next;
|
||
struct stack_def regstack;
|
||
|
||
for (block = 0; block < blocks; block++)
|
||
{
|
||
if (block_stack_in[block].top == -2)
|
||
{
|
||
/* This block has not been previously encountered. Choose a
|
||
default mapping for any stack regs live on entry */
|
||
|
||
block_stack_in[block].top = -1;
|
||
|
||
for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; reg--)
|
||
if (TEST_HARD_REG_BIT (block_stack_in[block].reg_set, reg))
|
||
block_stack_in[block].reg[++block_stack_in[block].top] = reg;
|
||
}
|
||
|
||
/* Process all insns in this block. Keep track of `next' here,
|
||
so that we don't process any insns emitted while making
|
||
substitutions in INSN. */
|
||
|
||
next = block_begin[block];
|
||
regstack = block_stack_in[block];
|
||
do
|
||
{
|
||
insn = next;
|
||
next = NEXT_INSN (insn);
|
||
|
||
/* Don't bother processing unless there is a stack reg
|
||
mentioned or if it's a CALL_INSN (register passing of
|
||
floating point values). */
|
||
|
||
if (stack_regs_mentioned (insn) || GET_CODE (insn) == CALL_INSN)
|
||
subst_stack_regs (insn, ®stack);
|
||
|
||
} while (insn != block_end[block]);
|
||
|
||
/* For all further actions, INSN needs to be the last insn in
|
||
this basic block. If subst_stack_regs inserted additional
|
||
instructions after INSN, it is no longer the last one at
|
||
this point. */
|
||
next = PREV_INSN (next);
|
||
|
||
/* If subst_stack_regs inserted something after a JUMP_INSN, that
|
||
is almost certainly a bug. */
|
||
if (GET_CODE (insn) == JUMP_INSN && insn != next)
|
||
abort ();
|
||
insn = next;
|
||
|
||
/* Something failed if the stack life doesn't match. */
|
||
|
||
GO_IF_HARD_REG_EQUAL (regstack.reg_set, block_out_reg_set[block], win);
|
||
|
||
abort ();
|
||
|
||
win:
|
||
|
||
/* Adjust the stack of this block on exit to match the stack of
|
||
the target block, or copy stack information into stack of
|
||
jump target if the target block's stack order hasn't been set
|
||
yet. */
|
||
|
||
if (GET_CODE (insn) == JUMP_INSN)
|
||
goto_block_pat (insn, ®stack, PATTERN (insn));
|
||
|
||
/* Likewise handle the case where we fall into the next block. */
|
||
|
||
if ((block < blocks - 1) && block_drops_in[block+1])
|
||
change_stack (insn, ®stack, &block_stack_in[block+1],
|
||
emit_insn_after);
|
||
}
|
||
|
||
/* If the last basic block is the end of a loop, and that loop has
|
||
regs live at its start, then the last basic block will have regs live
|
||
at its end that need to be popped before the function returns. */
|
||
|
||
{
|
||
int value_reg_low, value_reg_high;
|
||
value_reg_low = value_reg_high = -1;
|
||
{
|
||
rtx retvalue;
|
||
if ((retvalue = stack_result (current_function_decl)))
|
||
{
|
||
value_reg_low = REGNO (retvalue);
|
||
value_reg_high = value_reg_low +
|
||
HARD_REGNO_NREGS (value_reg_low, GET_MODE (retvalue)) - 1;
|
||
}
|
||
|
||
}
|
||
for (reg = regstack.top; reg >= 0; reg--)
|
||
if (regstack.reg[reg] < value_reg_low
|
||
|| regstack.reg[reg] > value_reg_high)
|
||
insn = emit_pop_insn (insn, ®stack,
|
||
FP_MODE_REG (regstack.reg[reg], DFmode),
|
||
emit_insn_after);
|
||
}
|
||
straighten_stack (insn, ®stack);
|
||
}
|
||
|
||
/* Check expression PAT, which is in INSN, for label references. if
|
||
one is found, print the block number of destination to FILE. */
|
||
|
||
static void
|
||
print_blocks (file, insn, pat)
|
||
FILE *file;
|
||
rtx insn, pat;
|
||
{
|
||
register RTX_CODE code = GET_CODE (pat);
|
||
register int i;
|
||
register char *fmt;
|
||
|
||
if (code == LABEL_REF)
|
||
{
|
||
register rtx label = XEXP (pat, 0);
|
||
|
||
if (GET_CODE (label) != CODE_LABEL)
|
||
abort ();
|
||
|
||
fprintf (file, " %d", BLOCK_NUM (label));
|
||
|
||
return;
|
||
}
|
||
|
||
fmt = GET_RTX_FORMAT (code);
|
||
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
||
{
|
||
if (fmt[i] == 'e')
|
||
print_blocks (file, insn, XEXP (pat, i));
|
||
if (fmt[i] == 'E')
|
||
{
|
||
register int j;
|
||
for (j = 0; j < XVECLEN (pat, i); j++)
|
||
print_blocks (file, insn, XVECEXP (pat, i, j));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Write information about stack registers and stack blocks into FILE.
|
||
This is part of making a debugging dump. */
|
||
|
||
static void
|
||
dump_stack_info (file)
|
||
FILE *file;
|
||
{
|
||
register int block;
|
||
|
||
fprintf (file, "\n%d stack blocks.\n", blocks);
|
||
for (block = 0; block < blocks; block++)
|
||
{
|
||
register rtx head, jump, end;
|
||
register int regno;
|
||
|
||
fprintf (file, "\nStack block %d: first insn %d, last %d.\n",
|
||
block, INSN_UID (block_begin[block]),
|
||
INSN_UID (block_end[block]));
|
||
|
||
head = block_begin[block];
|
||
|
||
fprintf (file, "Reached from blocks: ");
|
||
if (GET_CODE (head) == CODE_LABEL)
|
||
for (jump = LABEL_REFS (head);
|
||
jump != head;
|
||
jump = LABEL_NEXTREF (jump))
|
||
{
|
||
register int from_block = BLOCK_NUM (CONTAINING_INSN (jump));
|
||
fprintf (file, " %d", from_block);
|
||
}
|
||
if (block_drops_in[block])
|
||
fprintf (file, " previous");
|
||
|
||
fprintf (file, "\nlive stack registers on block entry: ");
|
||
for (regno = FIRST_STACK_REG; regno <= LAST_STACK_REG; regno++)
|
||
{
|
||
if (TEST_HARD_REG_BIT (block_stack_in[block].reg_set, regno))
|
||
fprintf (file, "%d ", regno);
|
||
}
|
||
|
||
fprintf (file, "\nlive stack registers on block exit: ");
|
||
for (regno = FIRST_STACK_REG; regno <= LAST_STACK_REG; regno++)
|
||
{
|
||
if (TEST_HARD_REG_BIT (block_out_reg_set[block], regno))
|
||
fprintf (file, "%d ", regno);
|
||
}
|
||
|
||
end = block_end[block];
|
||
|
||
fprintf (file, "\nJumps to blocks: ");
|
||
if (GET_CODE (end) == JUMP_INSN)
|
||
print_blocks (file, end, PATTERN (end));
|
||
|
||
if (block + 1 < blocks && block_drops_in[block+1])
|
||
fprintf (file, " next");
|
||
else if (block + 1 == blocks
|
||
|| (GET_CODE (end) == JUMP_INSN
|
||
&& GET_CODE (PATTERN (end)) == RETURN))
|
||
fprintf (file, " return");
|
||
|
||
fprintf (file, "\n");
|
||
}
|
||
}
|
||
#endif /* STACK_REGS */
|