diff options
| author | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 1997-03-16 22:50:56 +0000 |
|---|---|---|
| committer | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 1997-03-16 22:50:56 +0000 |
| commit | b20c4d57d9ac284c6c6ba61b12efe4f9488313ac (patch) | |
| tree | 35f10784c5bc49520b0e58b68ed1f84ee4481035 /gcc/loop.c | |
| parent | d584d9cd40e4961c673a83a94154364015f6feb6 (diff) | |
| download | ppe42-gcc-b20c4d57d9ac284c6c6ba61b12efe4f9488313ac.tar.gz ppe42-gcc-b20c4d57d9ac284c6c6ba61b12efe4f9488313ac.zip | |
* loop.c (strength_reduce): Adjust BENEFIT appropriately if an
autoincrement memory reference will eliminate add insns.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@13717 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/loop.c')
| -rw-r--r-- | gcc/loop.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/gcc/loop.c b/gcc/loop.c index 0ea4f202616..3e7bb58e3e3 100644 --- a/gcc/loop.c +++ b/gcc/loop.c @@ -3850,9 +3850,23 @@ strength_reduce (scan_start, end, loop_top, insn_count, unchanged (recompute it from the biv each time it is used). This decision can be made independently for each giv. */ - /* ??? Perhaps attempt to guess whether autoincrement will handle - some of the new add insns; if so, can increase BENEFIT - (undo the subtraction of add_cost that was done above). */ +#ifdef AUTO_INC_DEC + /* Attempt to guess whether autoincrement will handle some of the + new add insns; if so, increase BENEFIT (undo the subtraction of + add_cost that was done above). */ + if (v->giv_type == DEST_ADDR + && GET_CODE (v->mult_val) == CONST_INT) + { +#if defined (HAVE_POST_INCREMENT) || defined (HAVE_PRE_INCREMENT) + if (INTVAL (v->mult_val) == GET_MODE_SIZE (v->mem_mode)) + benefit += add_cost * bl->biv_count; +#endif +#if defined (HAVE_POST_DECREMENT) || defined (HAVE_PRE_DECREMENT) + if (-INTVAL (v->mult_val) == GET_MODE_SIZE (v->mem_mode)) + benefit += add_cost * bl->biv_count; +#endif + } +#endif /* If an insn is not to be strength reduced, then set its ignore flag, and clear all_reduced. */ |
