1246 lines
34 KiB
C
1246 lines
34 KiB
C
/* Implement looping actions for CHILL.
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Copyright (C) 1992, 93, 1994 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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#include <stdio.h>
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#include <limits.h>
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#include "config.h"
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#include "tree.h"
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#include "ch-tree.h"
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#include "lex.h"
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#include "flags.h"
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#include "actions.h"
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#include "input.h"
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#include "obstack.h"
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#include "assert.h"
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#include "rtl.h"
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/* if the user codes '-flocal-loop-counter' on the command line,
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ch-actions.c (lang_decode_option) will set this flag. */
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int flag_local_loop_counter = 0;
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extern tree chill_truthvalue_conversion PROTO((tree));
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extern rtx emit_line_note PROTO((char *, int));
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extern void error PROTO((char *, ...));
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extern rtx expand_assignment PROTO((tree, tree, int, int));
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extern void save_expr_under_name PROTO((tree, tree));
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extern void stamp_nesting_label PROTO((tree));
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extern int int_fits_type_p PROTO((tree, tree));
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extern void warning PROTO((char *, ...));
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/* forward declarations */
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static int classify_loop PROTO((void));
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static int declare_temps PROTO((void));
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static int initialize_iter_var PROTO((void));
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static int maybe_skip_loop PROTO((void));
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static int top_loop_end_check PROTO((void));
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static int bottom_loop_end_check PROTO((void));
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static int increment_temps PROTO((void));
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static tree build_temporary_variable PROTO((char *, tree));
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static tree maybe_make_for_temp PROTO((tree, char *, tree));
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static tree chill_unsigned_type PROTO((tree));
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/* In terms of the parameters passed to build_loop_iterator,
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* there are several types of loops. They are encoded by
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* the ITER_TYPE enumeration.
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*
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* 1) DO FOR EVER; ... OD
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* indicated by a NULL_TREE start_exp, step_exp and end_exp,
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* condition == NULL, in_flag = 0, and ever_flag == 1 in the
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* first ITERATOR.
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*
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* 2) DO WHILE cond; ... OD
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* indicated by NULL_TREE start_exp, step_exp and end_exp,
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* in_flag = 0, and condition != NULL.
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*
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* 3) DO; ... OD
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* indicated by NULL_TREEs in start_exp, step_exp and end_exp,
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* condition != NULL, in_flag == 0 and ever_flag == 0. This
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* is not really a loop, but a compound statement.
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*
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* 4) DO FOR user_var := start_exp
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* [DOWN] TO end_exp BY step_exp; ... DO
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* indicated by non-NULL_TREE start_exp, step_exp and end_exp.
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*
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* 5) DO FOR user_var [DOWN] IN discrete_mode; ... OD
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* indicated by in_flag == 1. start_exp is a non-NULL_TREE
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* discrete mode, with an optional down_flag.
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*
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* 6) DO FOR user_var [DOWN] IN powerset_expr; ... OD
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* indicated by in_flag == 1. start_exp is a non-NULL_TREE
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* powerset mode, with an optional down_flag.
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*
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* 7) DO FOR user_var [DOWN] IN location; ... OD
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* indicated by in_flag == 1. start_exp is a non-NULL_TREE
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* location mode, with an optional down_flag.
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*/
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typedef enum
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{
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DO_UNUSED,
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DO_FOREVER,
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DO_WHILE,
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DO_OD,
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DO_STEP,
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DO_RANGE,
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DO_POWERSET,
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DO_LOC,
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DO_LOC_VARYING
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} ITER_TYPE;
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typedef struct iterator
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{
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/* These variables only have meaning in the first ITERATOR structure. */
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ITER_TYPE itype; /* type of this iterator */
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int error_flag; /* TRUE if no loop was started due to
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user error */
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tree condition; /* WHILE condition expression */
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int down_flag; /* TRUE if DOWN was coded */
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/* These variables have meaning in every ITERATOR structure. */
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tree user_var; /* user's explicit iteration variable */
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tree start_exp; /* user's start expression
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or IN expression of a FOR .. IN*/
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tree step_exp; /* user's step expression */
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tree end_exp; /* user's end expression */
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tree start_temp; /* temp holding evaluated start_exp */
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tree end_temp; /* temp holding evaluated end_exp */
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tree step_temp; /* temp holding evaluated step_exp */
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tree powerset_temp; /* temp holding user's initial powerset expression */
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tree loc_ptr_temp; /* temp holding count for LOC enumeration ptr */
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tree iter_var; /* hidden variable for the loop */
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tree iter_type; /* hidden variable's type */
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tree base_type; /* LOC enumeration base type */
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struct iterator *next; /* ptr to next iterator for this loop */
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} ITERATOR;
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/*
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* There's an entry like this for each nested DO loop.
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* The list is maintained by push_loop_block
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* and pop_loop_block.
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*/
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typedef struct loop {
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struct loop *nxt_level; /* pointer to enclosing loop */
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ITERATOR *iter_list; /* iterators for the current loop */
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} LOOP;
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static LOOP *loop_stack = (LOOP *)0;
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#if 0
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Here is a CHILL DO FOR statement:
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DO FOR user_var := start_exp BY step_exp [DOWN] TO end_exp
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WHILE condition;
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For this loop to be 'safe', like a Pascal FOR loop, the start,
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end, and increment expressions are computed once, before the
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assignment to the iteration variable and saved in temporaries,
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before the first assignment of the iteration variable, so the
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following works:
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FOR i := (i+1) TO (i+10) DO
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To prevent changes to the start/end/step expressions from
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effecting the loop''s termination, and to make the loop end-check
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as simple as possible, we evaluate the step expression into
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a temporary and compute a hidden iteration count before entering
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the loop''s body. User code cannot effect the counter, and the
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end-loop check simply decrements the counter and checks for zero.
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The whole phrase FOR iter := ... TO end_exp can be repeated
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multiple times, with different user-iteration variables. This
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is discussed later.
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The loop counter calculations need careful design since a loop
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from MININT TO MAXINT must work, in the precision of integers.
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Here''s how it works, in C:
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0) The DO ... OD loop is simply a block with
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its own scope.
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1) The DO FOR EVER is simply implemented:
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loop_top:
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.
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. body of loop
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.
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goto loop_top
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end_loop:
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2) The DO WHILE is also simple:
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loop_top:
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if (!condition) goto end_loop
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.
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. body of loop
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.
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goto loop_top
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end_loop:
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3) The DO FOR [while condition] loop (no DOWN)
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push a new scope,
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decl iter_var
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step_temp = step_exp
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start_temp = start_exp
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end_temp = end_exp
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if (end_exp < start_exp) goto end_loop
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/* following line is all unsigned arithmetic */
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iter_var = (end_exp - start_exp + step_exp) / step_exp
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user_var = start_temp
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loop_top:
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if (!condition) goto end_loop
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.
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. body of loop
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.
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iter_var--
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if (iter_var == 0) goto end_loop
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user_var += step_temp
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goto loop_top
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end_loop:
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pop scope
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4) The proposed CHILL for [while condition] loop (with DOWN)
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push a new scope,
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decl iter
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step_temp = step_exp
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start_temp = start_exp
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end_temp = end_exp
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if (end_exp > start_exp) goto end_loop
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/* following line is all unsigned arithmetic */
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iter_var = (start_exp - end_exp + step_exp) / step_exp
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user_var = start_temp
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loop_top:
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if (!condition) goto end_loop
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.
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. body of loop
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.
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iter_var--
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if (iter_var == 0) goto end_loop
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user_var -= step_temp
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goto loop_top
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end_loop:
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pop scope
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5) The range loop, which iterates over a mode''s possible
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values, works just like the above step loops, but with
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the start and end values taken from the mode''s lower
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and upper domain values.
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6) The FOR IN loop, where a location enumeration is
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specified (see spec on page 81 of Z.200, bottom
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of page 186):
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push a new scope,
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decl iter_var as an unsigned integer
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loc_ptr_temp as pointer to a composite base type
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if array is varying
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iter_var = array''s length field
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else
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iter_var = sizeof array / sizeof base_type
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loc_ptr_temp = &of highest or lowest indexable entry
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loop_top:
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if (!condition) goto end_loop
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.
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. body of loop
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.
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iter_var--
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if (iter_var == 0) goto end_loop
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loc_ptr_temp +/-= sizeof array base_type
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goto loop_top
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end_loop:
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pop scope
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7) The DO FOR (DOWN) IN powerset_exp
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push a new scope,
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decl powerset_temp
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decl iterator as basetype of powerset
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powerset_temp := start_exp
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loop_top:
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/* if DOWN */
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if (__flsetclrpowerset () == 0) goto end_loop;
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/* not DOWN */
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if (__ffsetclrpowerset () == 0) goto end_loop;
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if (!condition) goto end_loop
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.
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. body of loop
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.
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goto loop_top
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end_loop:
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pop scope
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So, here''s the general DO FOR schema, as implemented here:
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classify_loop -- what type of loop have we?
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-- build_iterator does some of this, also
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expand_start_loop -- start the loop''s control scope
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-- start scope for synthesized loop variables
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declare_temps -- create, initialize temporary variables
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maybe_skip_loop -- skip loop if end conditions unsatisfiable
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initialize_iter_var -- initialize the iteration counter
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-- initialize user''s loop variable
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expand_start_loop -- generate top-of-loop label
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top_loop_end_check -- generate while code and/or
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powerset find-a-bit function call
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.
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.
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. user''s loop body code
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.
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.
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bottom_loop_end_check -- exit if counter has become zero
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increment_temps -- update temps for next iteration
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expand_end_loop -- generate jump back to top of loop
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expand_end_cond -- generate label for end of conditional
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-- end of scope for synthesized loop variables
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free_iterators -- free up iterator space
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When there are two or more iterator phrases, each of the
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above loop steps must act upon all iterators. For example,
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the 'increment_temps' step must increment all temporaries
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(associated with all iterators).
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NOTE: Z.200, section 10.1 says that a block is ...
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"the actions statement list in a do action, including any
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loop counter and while control". This means that an exp-
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ression in a WHILE control can include references to the
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loop counters created for the loop''s exclusive use.
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Example:
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DCL a (1:10) INT;
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DCL j INT;
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DO FOR j IN a WHILE j > 0;
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...
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OD;
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The 'j' referenced in the while is the loc-identity 'j'
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created inside the loop''s scope, and NOT the 'j' declared
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before the loop.
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#endif
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/*
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* The following routines are called directly by the
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* CHILL parser.
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*/
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void
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push_loop_block ()
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{
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LOOP *temp = (LOOP *)xmalloc (sizeof (LOOP));
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/* push a new loop onto the stack */
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temp->nxt_level = loop_stack;
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temp->iter_list = (ITERATOR *)0;
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loop_stack = temp;
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}
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||
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void
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||
pop_loop_block ()
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||
{
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LOOP *do_temp = loop_stack;
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ITERATOR *ip;
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||
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/* pop loop block off the list */
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||
loop_stack = do_temp->nxt_level;
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||
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||
/* free the loop's iterator blocks */
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||
ip = do_temp->iter_list;
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||
while (ip != NULL)
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{
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ITERATOR *temp = ip->next;
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||
free (ip);
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ip = temp;
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||
}
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||
free (do_temp);
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}
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void
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||
begin_loop_scope ()
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||
{
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||
ITERATOR *firstp = loop_stack->iter_list;
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||
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||
if (pass < 2)
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return;
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||
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||
/*
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||
* We need to classify the loop and declare its temporaries
|
||
* here, so as to define them before the WHILE condition
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||
* (if any) is parsed. The WHILE expression may refer to
|
||
* a temporary.
|
||
*/
|
||
if (classify_loop ())
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||
return;
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||
|
||
if (firstp->itype != DO_OD)
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||
declare_temps ();
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||
|
||
clear_last_expr ();
|
||
push_momentary ();
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||
expand_start_bindings (0);
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||
}
|
||
|
||
|
||
void
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||
end_loop_scope (opt_label)
|
||
tree opt_label;
|
||
{
|
||
if (opt_label)
|
||
possibly_define_exit_label (opt_label);
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||
poplevel (0, 0, 0);
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||
|
||
if (pass < 2)
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||
return;
|
||
|
||
expand_end_bindings (getdecls (), kept_level_p (), 0);
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||
pop_momentary ();
|
||
}
|
||
|
||
/* The iterator structure records all aspects of a
|
||
* 'FOR i := start [DOWN] TO end' clause or
|
||
* 'FOR i IN modename' or 'FOR i IN powerset' clause.
|
||
* It's saved on the iter_list of the current LOOP.
|
||
*/
|
||
void
|
||
build_loop_iterator (user_var, start_exp, step_exp, end_exp,
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||
down_flag, in_flag, ever_flag)
|
||
tree user_var, start_exp, step_exp, end_exp;
|
||
int down_flag, in_flag, ever_flag;
|
||
{
|
||
ITERATOR *ip = (ITERATOR *)xmalloc (sizeof (ITERATOR));
|
||
|
||
/* chain this iterator onto the current loop */
|
||
if (loop_stack->iter_list == NULL)
|
||
loop_stack->iter_list = ip;
|
||
else
|
||
{
|
||
ITERATOR *temp = loop_stack->iter_list;
|
||
while (temp->next != NULL)
|
||
temp = temp->next;
|
||
temp->next = ip;
|
||
}
|
||
|
||
ip->itype = DO_UNUSED;
|
||
ip->user_var = user_var;
|
||
ip->start_exp = start_exp;
|
||
ip->step_exp = step_exp;
|
||
ip->end_exp = end_exp;
|
||
ip->condition = NULL_TREE;
|
||
ip->start_temp = NULL_TREE;
|
||
ip->end_temp = NULL_TREE;
|
||
ip->step_temp = NULL_TREE;
|
||
ip->down_flag = down_flag;
|
||
ip->powerset_temp = NULL_TREE;
|
||
ip->iter_var = NULL_TREE;
|
||
ip->iter_type = NULL_TREE;
|
||
ip->loc_ptr_temp = NULL_TREE;
|
||
ip->error_flag = 1; /* assume error will be found */
|
||
ip->next = (ITERATOR *)0;
|
||
|
||
if (ever_flag)
|
||
ip->itype = DO_FOREVER;
|
||
else if (in_flag && start_exp != NULL_TREE)
|
||
{
|
||
if (TREE_CODE (start_exp) == ERROR_MARK)
|
||
return;
|
||
if (TREE_CODE (TREE_TYPE (start_exp)) == SET_TYPE)
|
||
ip->itype = DO_POWERSET;
|
||
else if (discrete_type_p (TREE_TYPE (ip->start_exp)))
|
||
ip->itype = DO_RANGE;
|
||
else if (TREE_CODE (TREE_TYPE (ip->start_exp)) == ARRAY_TYPE)
|
||
ip->itype = DO_LOC;
|
||
else if (chill_varying_type_p (TREE_TYPE (ip->start_exp)))
|
||
ip->itype = DO_LOC_VARYING;
|
||
else
|
||
{
|
||
error ("Loop's IN expression is not a composite object");
|
||
return;
|
||
}
|
||
}
|
||
else if (start_exp == NULL_TREE && end_exp == NULL_TREE
|
||
&& step_exp == NULL_TREE && !down_flag)
|
||
ip->itype = DO_OD;
|
||
else
|
||
{
|
||
/* FIXME: Move this to the lexer? */
|
||
#define CST_FITS_INT(NODE) (TREE_CODE(NODE) == INTEGER_CST &&\
|
||
int_fits_type_p (NODE, integer_type_node))
|
||
|
||
tree max_prec_type = integer_type_node;
|
||
|
||
if (! discrete_type_p (TREE_TYPE (ip->start_exp)))
|
||
{
|
||
error ("start expr must have discrete mode");
|
||
return;
|
||
}
|
||
if (TREE_CODE (TREE_TYPE (ip->start_exp)) == ENUMERAL_TYPE
|
||
&& CH_ENUM_IS_NUMBERED (TREE_TYPE (ip->start_exp)))
|
||
{
|
||
error ("DO FOR start expression is a numbered SET");
|
||
return;
|
||
}
|
||
if (TREE_CODE (TREE_TYPE (ip->end_exp)) == ENUMERAL_TYPE
|
||
&& CH_ENUM_IS_NUMBERED (TREE_TYPE (ip->end_exp)))
|
||
{
|
||
error ("TO expression is a numbered SET");
|
||
return;
|
||
}
|
||
/* Convert all three expressions to a common precision,
|
||
which is the largest precision they exhibit, but
|
||
INTEGER_CST nodes are built in the lexer as
|
||
long_integer_type nodes. We'll treat convert them to
|
||
integer_type_nodes if possible, for faster loop times. */
|
||
|
||
if (TYPE_PRECISION (max_prec_type) <
|
||
TYPE_PRECISION (TREE_TYPE (ip->start_exp))
|
||
&& !CST_FITS_INT (ip->start_exp))
|
||
max_prec_type = TREE_TYPE (ip->start_exp);
|
||
if (! discrete_type_p (TREE_TYPE (ip->end_exp)))
|
||
{
|
||
error ("TO expr must have discrete mode");
|
||
return;
|
||
}
|
||
if (! CH_COMPATIBLE (ip->start_exp,
|
||
TREE_TYPE (ip->end_exp)))
|
||
{
|
||
error ("start expr and TO expr must be compatible");
|
||
return;
|
||
}
|
||
if (TYPE_PRECISION (max_prec_type) <
|
||
TYPE_PRECISION (TREE_TYPE (ip->end_exp))
|
||
&& !CST_FITS_INT (ip->end_exp))
|
||
max_prec_type = TREE_TYPE (ip->end_exp);
|
||
if (ip->step_exp != NULL_TREE)
|
||
{
|
||
/* assure that default 'BY 1' gets a useful type */
|
||
if (ip->step_exp == integer_one_node)
|
||
ip->step_exp = convert (TREE_TYPE (ip->start_exp),
|
||
ip->step_exp);
|
||
if (! discrete_type_p (TREE_TYPE (ip->step_exp)))
|
||
{
|
||
error ("BY expr must have discrete mode");
|
||
return;
|
||
}
|
||
if (! CH_COMPATIBLE (ip->start_exp,
|
||
TREE_TYPE (ip->step_exp)))
|
||
{
|
||
error ("start expr and BY expr must be compatible");
|
||
return;
|
||
}
|
||
if (TYPE_PRECISION (max_prec_type) <
|
||
TYPE_PRECISION (TREE_TYPE (ip->step_exp))
|
||
&& !CST_FITS_INT (ip->step_exp))
|
||
max_prec_type = TREE_TYPE (ip->step_exp);
|
||
}
|
||
if (TREE_CODE (ip->start_exp) == INTEGER_CST
|
||
&& TREE_CODE (ip->end_exp) == INTEGER_CST
|
||
&& compare_int_csts (ip->down_flag ? LT_EXPR : GT_EXPR,
|
||
ip->start_exp, ip->end_exp))
|
||
warning ("body of DO FOR will never execute");
|
||
|
||
ip->start_exp =
|
||
convert (max_prec_type, ip->start_exp);
|
||
ip->end_exp =
|
||
convert (max_prec_type, ip->end_exp);
|
||
|
||
if (ip->step_exp != NULL_TREE)
|
||
{
|
||
ip->step_exp =
|
||
convert (max_prec_type, ip->step_exp);
|
||
|
||
if (TREE_CODE (ip->step_exp) != INTEGER_CST)
|
||
{
|
||
/* generate runtime check for negative BY expr */
|
||
ip->step_exp =
|
||
check_range (ip->step_exp, ip->step_exp,
|
||
integer_zero_node, NULL_TREE);
|
||
}
|
||
else if (compare_int_csts (LE_EXPR, ip->step_exp, integer_zero_node))
|
||
{
|
||
error ("BY expression is negative or zero");
|
||
return;
|
||
}
|
||
}
|
||
ip->itype = DO_STEP;
|
||
}
|
||
|
||
ip->error_flag = 0; /* no errors! */
|
||
}
|
||
|
||
void
|
||
build_loop_start (while_control, start_label)
|
||
tree while_control, start_label;
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list;
|
||
|
||
firstp->condition = while_control;
|
||
|
||
if (firstp->error_flag)
|
||
return;
|
||
|
||
/* We didn't know at begin_loop_scope time about the condition;
|
||
adjust iterator type now. */
|
||
if (firstp->itype == DO_OD && firstp->condition)
|
||
firstp->itype = DO_WHILE;
|
||
|
||
if (initialize_iter_var ())
|
||
return;
|
||
|
||
if (maybe_skip_loop ())
|
||
return;
|
||
|
||
/* use the label as an 'exit' label,
|
||
'goto' needs another sort of label */
|
||
expand_start_loop (start_label != NULL_TREE);
|
||
|
||
if (top_loop_end_check ())
|
||
return;
|
||
emit_line_note (input_filename, lineno);
|
||
}
|
||
|
||
/*
|
||
* Called after the last action of the loop body
|
||
* has been parsed.
|
||
*/
|
||
void
|
||
build_loop_end ()
|
||
{
|
||
ITERATOR *ip = loop_stack->iter_list;
|
||
|
||
emit_line_note (input_filename, lineno);
|
||
|
||
if (ip->error_flag)
|
||
return;
|
||
|
||
if (bottom_loop_end_check ())
|
||
return;
|
||
|
||
if (increment_temps ())
|
||
return;
|
||
|
||
if (ip->itype != DO_OD)
|
||
{
|
||
expand_end_loop ();
|
||
|
||
for (; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_LOC_VARYING:
|
||
case DO_STEP:
|
||
expand_end_cond ();
|
||
break;
|
||
default:
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/*
|
||
* The rest of the routines in this file are called from
|
||
* the above three routines.
|
||
*/
|
||
static int
|
||
classify_loop ()
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list, *ip;
|
||
|
||
firstp->error_flag = 0;
|
||
if (firstp->itype == DO_UNUSED || firstp->itype == DO_OD)
|
||
{
|
||
/* if we have just DO .. OD, do nothing - this is just a
|
||
BEGIN .. END without creating a new scope, and no looping */
|
||
if (firstp->condition != NULL_TREE)
|
||
firstp->itype = DO_WHILE;
|
||
else
|
||
firstp->itype = DO_OD;
|
||
}
|
||
|
||
/* Issue a warning if the any loop counter is mentioned more
|
||
than once in the iterator list. */
|
||
for (ip = firstp; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_FOREVER:
|
||
case DO_WHILE:
|
||
break;
|
||
case DO_STEP:
|
||
case DO_RANGE:
|
||
case DO_POWERSET:
|
||
case DO_LOC:
|
||
case DO_LOC_VARYING:
|
||
/* FIXME: check for name uniqueness */
|
||
break;
|
||
default:
|
||
;
|
||
}
|
||
}
|
||
return firstp->error_flag;
|
||
}
|
||
|
||
/*
|
||
* Reserve space for any loop-control temporaries, initialize them
|
||
*/
|
||
static int
|
||
declare_temps ()
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list, *ip;
|
||
tree start_ptr;
|
||
|
||
for (ip = firstp; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_FOREVER:
|
||
case DO_WHILE:
|
||
break;
|
||
case DO_STEP:
|
||
ip->iter_type = chill_unsigned_type (TREE_TYPE (ip->start_exp));
|
||
|
||
/* create, initialize temporaries if expressions aren't constant */
|
||
ip->start_temp = maybe_make_for_temp (ip->start_exp, "for_start",
|
||
ip->iter_type);
|
||
ip->end_temp = maybe_make_for_temp (ip->end_exp, "for_end",
|
||
ip->iter_type);
|
||
/* this is just the step-expression */
|
||
ip->step_temp = maybe_make_for_temp (ip->step_exp, "for_step",
|
||
ip->iter_type);
|
||
goto do_step_range;
|
||
|
||
case DO_RANGE:
|
||
ip->iter_type = chill_unsigned_type_node;
|
||
|
||
ip->start_temp =
|
||
(ip->down_flag ? build_chill_upper : build_chill_lower)(TREE_TYPE (ip->start_exp));
|
||
ip->end_temp =
|
||
(ip->down_flag ? build_chill_lower : build_chill_upper)(TREE_TYPE (ip->start_exp));
|
||
|
||
ip->step_temp = integer_one_node;
|
||
|
||
do_step_range:
|
||
if (flag_local_loop_counter)
|
||
{
|
||
/* (re-)declare the user's iteration variable in the
|
||
loop's scope. */
|
||
tree id_node = ip->user_var;
|
||
IDENTIFIER_LOCAL_VALUE (id_node) = ip->user_var =
|
||
decl_temp1 (id_node, ip->iter_type, 0, NULL_TREE,
|
||
0, 0);
|
||
}
|
||
else
|
||
{
|
||
/* in this case, it's a previously-declared
|
||
VAR_DECL node, checked in build_loop_iterator. */
|
||
if (TREE_CODE (ip->user_var) == IDENTIFIER_NODE)
|
||
ip->user_var = lookup_name (ip->user_var);
|
||
if (ip->user_var == NULL_TREE)
|
||
{
|
||
error ("loop identifier undeclared");
|
||
ip->error_flag = 1;
|
||
return 1;
|
||
}
|
||
}
|
||
ip->iter_var =
|
||
decl_temp1 (get_unique_identifier ("iter_var"),
|
||
ip->iter_type, 0, NULL_TREE, 0, 0);
|
||
break;
|
||
|
||
case DO_POWERSET:
|
||
ip->iter_type = chill_unsigned_type (
|
||
TYPE_DOMAIN (TREE_TYPE (ip->start_exp)));
|
||
if (flag_local_loop_counter)
|
||
{
|
||
/* declare the user's iteration variable in the loop's scope. */
|
||
/* in this case, it's just an IDENTIFIER_NODE */
|
||
ip->user_var =
|
||
decl_temp1 (ip->user_var, ip->iter_type, 0, NULL_TREE, 0, 0);
|
||
}
|
||
else
|
||
{
|
||
/* in this case, it's a previously-declared VAR_DECL node */
|
||
ip->user_var = lookup_name (ip->user_var);
|
||
}
|
||
/* the user's powerset-expression, evaluated and saved in a temp */
|
||
ip->powerset_temp = maybe_make_for_temp (ip->start_exp, "for_set",
|
||
TREE_TYPE (ip->start_exp));
|
||
mark_addressable (ip->powerset_temp);
|
||
break;
|
||
|
||
case DO_LOC:
|
||
case DO_LOC_VARYING:
|
||
ip->iter_type = chill_unsigned_type_node;
|
||
/* create the counter temp */
|
||
ip->iter_var =
|
||
build_temporary_variable ("iter_var", ip->iter_type);
|
||
|
||
if (!CH_LOCATION_P (ip->start_exp))
|
||
ip->start_exp
|
||
= decl_temp1 (get_unique_identifier ("iter_loc"),
|
||
TREE_TYPE (ip->start_exp), 0,
|
||
ip->start_exp, 0, 0);
|
||
|
||
if (ip->itype == DO_LOC)
|
||
{
|
||
tree array_type = TREE_TYPE (ip->start_exp);
|
||
tree ptr_type;
|
||
tree temp;
|
||
|
||
if (TREE_CODE (TREE_TYPE (array_type)) == BOOLEAN_TYPE)
|
||
{
|
||
error ("Can't iterate through array of BOOL");
|
||
ip->error_flag = 1;
|
||
return ip->error_flag;
|
||
}
|
||
|
||
/* FIXME: check for array type in ip->start_exp */
|
||
|
||
/* create pointer temporary */
|
||
ip->base_type = TREE_TYPE (array_type);
|
||
ptr_type = build_pointer_type (ip->base_type);
|
||
ip->loc_ptr_temp =
|
||
build_temporary_variable ("loc_ptr_tmp", ptr_type);
|
||
|
||
/* declare the user's iteration variable in
|
||
the loop's scope, as an expression, to be
|
||
passed to build_component_ref later */
|
||
save_expr_under_name (ip->user_var,
|
||
build1 (INDIRECT_REF, ip->base_type,
|
||
ip->loc_ptr_temp));
|
||
|
||
/* FIXME: see stor_layout */
|
||
ip->step_temp = size_in_bytes (ip->base_type);
|
||
|
||
temp = TYPE_DOMAIN (array_type);
|
||
|
||
/* pointer to first array entry to look at */
|
||
start_ptr = build1 (ADDR_EXPR, ptr_type, ip->start_exp);
|
||
mark_addressable (ip->start_exp);
|
||
ip->start_temp = ip->down_flag ?
|
||
fold (build (PLUS_EXPR, ptr_type,
|
||
start_ptr,
|
||
fold (build (MULT_EXPR, integer_type_node, ip->step_temp,
|
||
fold (build (MINUS_EXPR, integer_type_node,
|
||
TYPE_MAX_VALUE (temp),
|
||
TYPE_MIN_VALUE (temp)))))))
|
||
: start_ptr;
|
||
}
|
||
else
|
||
{
|
||
tree array_length =
|
||
convert (integer_type_node,
|
||
build_component_ref (ip->start_exp, var_length_id));
|
||
tree array_type = TREE_TYPE (TREE_CHAIN (
|
||
TYPE_FIELDS (TREE_TYPE (ip->start_exp))));
|
||
tree array_data_ptr =
|
||
build_component_ref (ip->start_exp, var_data_id);
|
||
tree ptr_type;
|
||
|
||
if (TREE_CODE (TREE_TYPE (array_type)) == BOOLEAN_TYPE)
|
||
{
|
||
error ("Can't iterate through array of BOOL");
|
||
firstp->error_flag = 1;
|
||
return firstp->error_flag;
|
||
}
|
||
|
||
/* create pointer temporary */
|
||
ip->base_type = TREE_TYPE (array_type);
|
||
ptr_type = build_pointer_type (ip->base_type);
|
||
ip->loc_ptr_temp =
|
||
build_temporary_variable ("loc_ptr_temp", ptr_type);
|
||
|
||
|
||
/* declare the user's iteration variable in
|
||
the loop's scope, as an expression, to be
|
||
passed to build_component_ref later */
|
||
save_expr_under_name (ip->user_var,
|
||
build1 (INDIRECT_REF, ip->base_type,
|
||
ip->loc_ptr_temp));
|
||
|
||
/* FIXME: see stor_layout */
|
||
ip->step_temp = size_in_bytes (ip->base_type);
|
||
|
||
/* pointer to first array entry to look at */
|
||
start_ptr = build1 (ADDR_EXPR, ptr_type, array_data_ptr);
|
||
mark_addressable (array_data_ptr);
|
||
ip->start_temp = ip->down_flag ?
|
||
fold (build (PLUS_EXPR, ptr_type,
|
||
start_ptr,
|
||
fold (build (MULT_EXPR, integer_type_node, ip->step_temp,
|
||
fold (build (MINUS_EXPR, integer_type_node,
|
||
array_length,
|
||
integer_one_node))))))
|
||
: start_ptr;
|
||
}
|
||
default:
|
||
;
|
||
}
|
||
}
|
||
return firstp->error_flag;
|
||
}
|
||
|
||
/*
|
||
* Initialize the hidden iteration-control variables,
|
||
* and the user's explicit loop variable.
|
||
*/
|
||
static int
|
||
initialize_iter_var ()
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list, *ip;
|
||
|
||
for (ip = firstp; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_FOREVER:
|
||
case DO_WHILE:
|
||
break;
|
||
case DO_STEP:
|
||
case DO_RANGE:
|
||
{
|
||
tree count =
|
||
fold (build (PLUS_EXPR, ip->iter_type, integer_one_node,
|
||
fold (build (TRUNC_DIV_EXPR, ip->iter_type,
|
||
convert (ip->iter_type,
|
||
fold (build (MINUS_EXPR, ip->iter_type,
|
||
ip->down_flag ? ip->start_temp : ip->end_temp,
|
||
ip->down_flag ? ip->end_temp : ip->start_temp))),
|
||
ip->step_temp))));
|
||
/* initialize the loop's hidden counter variable */
|
||
expand_expr_stmt (
|
||
build_chill_modify_expr (ip->iter_var, count));
|
||
|
||
/* initialize user's variable */
|
||
expand_expr_stmt (
|
||
build_chill_modify_expr (ip->user_var, ip->start_temp));
|
||
}
|
||
break;
|
||
case DO_POWERSET:
|
||
break;
|
||
case DO_LOC:
|
||
{
|
||
tree array_type = TREE_TYPE (ip->start_exp);
|
||
tree array_length =
|
||
fold (build (TRUNC_DIV_EXPR, integer_type_node,
|
||
size_in_bytes (array_type),
|
||
size_in_bytes (TREE_TYPE (array_type))));
|
||
|
||
expand_expr_stmt (
|
||
build_chill_modify_expr (ip->iter_var, array_length));
|
||
goto do_loc_common;
|
||
}
|
||
|
||
case DO_LOC_VARYING:
|
||
expand_expr_stmt (
|
||
build_chill_modify_expr (ip->iter_var,
|
||
convert (integer_type_node,
|
||
build_component_ref (ip->start_exp, var_length_id))));
|
||
|
||
do_loc_common:
|
||
expand_expr_stmt (
|
||
build_chill_modify_expr (ip->loc_ptr_temp,
|
||
ip->start_temp));
|
||
break;
|
||
|
||
default:
|
||
;
|
||
}
|
||
}
|
||
return firstp->error_flag;
|
||
}
|
||
|
||
/* Generate code to skip the whole loop, if start expression not
|
||
* <= end expression (or >= for DOWN loops). This comparison must
|
||
* *NOT* be done in unsigned mode, or it will fail.
|
||
* Also, skip processing an empty VARYING array.
|
||
*/
|
||
static int
|
||
maybe_skip_loop ()
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list, *ip;
|
||
|
||
for (ip = firstp; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_STEP:
|
||
expand_start_cond (
|
||
build (ip->down_flag ? GE_EXPR : LE_EXPR,
|
||
TREE_TYPE (ip->start_exp),
|
||
ip->start_exp, ip->end_exp), 0);
|
||
break;
|
||
|
||
case DO_LOC_VARYING:
|
||
{ tree array_length =
|
||
convert (integer_type_node,
|
||
build_component_ref (ip->start_exp, var_length_id));
|
||
expand_start_cond (
|
||
build (NE_EXPR, TREE_TYPE (array_length),
|
||
array_length, integer_zero_node), 0);
|
||
break;
|
||
}
|
||
default:
|
||
break;
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/*
|
||
* Check at the top of the loop for a termination
|
||
*/
|
||
static int
|
||
top_loop_end_check ()
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list, *ip;
|
||
|
||
/* now, exit the loop if the condition isn't TRUE. */
|
||
if (firstp->condition)
|
||
{
|
||
expand_exit_loop_if_false (0,
|
||
chill_truthvalue_conversion (firstp->condition));
|
||
}
|
||
|
||
for (ip = firstp; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_FOREVER:
|
||
case DO_WHILE:
|
||
case DO_STEP:
|
||
case DO_RANGE:
|
||
break;
|
||
case DO_POWERSET:
|
||
{
|
||
tree temp1;
|
||
char *func_name;
|
||
|
||
if (ip->down_flag)
|
||
func_name = "__flsetclrpowerset";
|
||
else
|
||
func_name = "__ffsetclrpowerset";
|
||
|
||
temp1 = TYPE_MIN_VALUE
|
||
(TYPE_DOMAIN (TREE_TYPE (ip->powerset_temp)));
|
||
expand_exit_loop_if_false (0,
|
||
build_chill_function_call (lookup_name (get_identifier (func_name)),
|
||
tree_cons (NULL_TREE, force_addr_of (ip->powerset_temp),
|
||
tree_cons (NULL_TREE, powersetlen (ip->powerset_temp),
|
||
tree_cons (NULL_TREE, force_addr_of (ip->user_var),
|
||
tree_cons (NULL_TREE, size_in_bytes (TREE_TYPE (ip->user_var)),
|
||
tree_cons (NULL_TREE,
|
||
convert (long_integer_type_node, temp1),
|
||
NULL_TREE)))))));
|
||
}
|
||
break;
|
||
case DO_LOC:
|
||
case DO_LOC_VARYING:
|
||
break;
|
||
default:
|
||
;
|
||
}
|
||
}
|
||
return firstp->error_flag;
|
||
}
|
||
|
||
/*
|
||
* Check generated temporaries for loop's end
|
||
*/
|
||
static int
|
||
bottom_loop_end_check ()
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list, *ip;
|
||
|
||
emit_line_note (input_filename, lineno);
|
||
|
||
/* now, generate code to check each loop counter for termination */
|
||
for (ip = firstp; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_FOREVER:
|
||
case DO_WHILE:
|
||
break;
|
||
case DO_STEP:
|
||
case DO_RANGE:
|
||
case DO_LOC:
|
||
case DO_LOC_VARYING:
|
||
/* decrement iteration counter by one */
|
||
chill_expand_assignment (ip->iter_var, MINUS_EXPR, integer_one_node);
|
||
/* exit if it's zero */
|
||
expand_exit_loop_if_false (0,
|
||
build (NE_EXPR, boolean_type_node,
|
||
ip->iter_var,
|
||
integer_zero_node));
|
||
break;
|
||
case DO_POWERSET:
|
||
break;
|
||
default:
|
||
;
|
||
}
|
||
}
|
||
|
||
return firstp->error_flag;
|
||
}
|
||
|
||
/*
|
||
* increment the loop-control variables.
|
||
*/
|
||
static int
|
||
increment_temps ()
|
||
{
|
||
ITERATOR *firstp = loop_stack->iter_list, *ip;
|
||
|
||
for (ip = firstp; ip != NULL; ip = ip->next)
|
||
{
|
||
switch (ip->itype)
|
||
{
|
||
case DO_FOREVER:
|
||
case DO_WHILE:
|
||
break;
|
||
case DO_STEP:
|
||
case DO_RANGE:
|
||
{
|
||
tree delta =
|
||
fold (build (ip->down_flag ? MINUS_EXPR : PLUS_EXPR,
|
||
TREE_TYPE (ip->user_var), ip->user_var,
|
||
ip->step_temp));
|
||
expand_expr_stmt (
|
||
build_chill_modify_expr (ip->user_var, delta));
|
||
}
|
||
break;
|
||
case DO_LOC:
|
||
case DO_LOC_VARYING:
|
||
/* This statement uses the C semantics, so that
|
||
the pointer is actually incremented by the
|
||
length of the object pointed to. */
|
||
#if 1
|
||
expand_expr_stmt (
|
||
build_modify_expr (ip->loc_ptr_temp,
|
||
ip->down_flag ? MINUS_EXPR : PLUS_EXPR,
|
||
integer_one_node));
|
||
#else
|
||
{
|
||
enum tree_code op = ip->down_flag ? MINUS_EXPR : PLUS_EXPR;
|
||
tree el_type = TREE_TYPE (TREE_TYPE (ip->loc_ptr_temp));
|
||
chill_expand_assignment (ip->loc_ptr_temp, NOP_EXPR,
|
||
build (op,
|
||
TREE_TYPE (ip->loc_ptr_temp),
|
||
ip->loc_ptr_temp,
|
||
size_in_bytes (el_type)));
|
||
}
|
||
#endif
|
||
break;
|
||
case DO_POWERSET:
|
||
break;
|
||
default:
|
||
;
|
||
}
|
||
}
|
||
return firstp->error_flag;
|
||
}
|
||
|
||
/*
|
||
* Generate a (temporary) unique identifier_node of
|
||
* the form "__tmp_%s_%d"
|
||
*/
|
||
tree
|
||
get_unique_identifier (lead)
|
||
char *lead;
|
||
{
|
||
char idbuf [256];
|
||
static int idcount = 0;
|
||
|
||
sprintf (idbuf, "__tmp_%s_%d", lead ? lead : "", idcount++);
|
||
return get_identifier (idbuf);
|
||
}
|
||
|
||
/*
|
||
* build a temporary variable, given its NAME and TYPE.
|
||
* The name will have a number appended to assure uniqueness.
|
||
* return its DECL node.
|
||
*/
|
||
static tree
|
||
build_temporary_variable (name, type)
|
||
char *name;
|
||
tree type;
|
||
{
|
||
return decl_temp1 (get_unique_identifier (name), type, 0, NULL_TREE, 0, 0);
|
||
}
|
||
|
||
|
||
/*
|
||
* If the given expression isn't a constant, build a temp for it
|
||
* and evaluate the expression into the temp. Return the tree
|
||
* representing either the original constant expression or the
|
||
* temp which now contains the expression's value.
|
||
*/
|
||
static tree
|
||
maybe_make_for_temp (exp, temp_name, exp_type)
|
||
tree exp;
|
||
char *temp_name;
|
||
tree exp_type;
|
||
{
|
||
tree result = exp;
|
||
|
||
if (exp != NULL_TREE)
|
||
{
|
||
/* if exp isn't constant, create a temporary for its value */
|
||
if (TREE_CONSTANT (exp))
|
||
{
|
||
/* FIXME: assure that TREE_TYPE (result) == ip->exp_type */
|
||
result = convert (exp_type, exp);
|
||
}
|
||
else {
|
||
/* build temp, assign the value */
|
||
result = decl_temp1 (get_unique_identifier (temp_name), exp_type, 0,
|
||
exp, 0, 0);
|
||
}
|
||
}
|
||
return result;
|
||
}
|
||
|
||
|
||
/*
|
||
* Adapt the C unsigned_type function to CHILL - we need to
|
||
* account for any CHILL-specific integer types here. So far,
|
||
* the 16-bit integer type is the only one.
|
||
*/
|
||
static tree
|
||
chill_unsigned_type (type)
|
||
tree type;
|
||
{
|
||
extern tree chill_unsigned_type_node;
|
||
tree type1 = TYPE_MAIN_VARIANT (type);
|
||
|
||
if (type1 == chill_integer_type_node)
|
||
return chill_unsigned_type_node;
|
||
else
|
||
return unsigned_type (type);
|
||
}
|