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authorRichard Guenther <rguenther@suse.de>2012-06-12 08:43:55 +0000
committerRichard Biener <rguenth@gcc.gnu.org>2012-06-12 08:43:55 +0000
commitf68396a1e0fffa1b15b8c5b732cd4f83c1b6b24b (patch)
tree011d7419e5eca6bff61d2f8643f8a7fad5e60297 /gcc/alias.c
parent891ca07d493c51f468710ba0f4af74bbe5e09fdd (diff)
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emit-rtl.c (set_mem_attributes_minus_bitpos): Remove dead code.
2012-06-12 Richard Guenther <rguenther@suse.de> * emit-rtl.c (set_mem_attributes_minus_bitpos): Remove dead code. * alias.c (ao_ref_from_mem): MEM_EXPR is conservative, MEM_OFFSET and MEM_SIZE only refines it. Reflect that and be less conservative if either of the latter is not known. From-SVN: r188429
Diffstat (limited to 'gcc/alias.c')
-rw-r--r--gcc/alias.c15
1 files changed, 6 insertions, 9 deletions
diff --git a/gcc/alias.c b/gcc/alias.c
index 88a3b7e..fbc4e10 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -326,17 +326,11 @@ ao_ref_from_mem (ao_ref *ref, const_rtx mem)
ref->ref_alias_set = MEM_ALIAS_SET (mem);
- /* If MEM_OFFSET or MEM_SIZE are unknown we have to punt.
- Keep points-to related information though. */
+ /* If MEM_OFFSET or MEM_SIZE are unknown what we got from MEM_EXPR
+ is conservative, so trust it. */
if (!MEM_OFFSET_KNOWN_P (mem)
|| !MEM_SIZE_KNOWN_P (mem))
- {
- ref->ref = NULL_TREE;
- ref->offset = 0;
- ref->size = -1;
- ref->max_size = -1;
- return true;
- }
+ return true;
/* If the base decl is a parameter we can have negative MEM_OFFSET in
case of promoted subregs on bigendian targets. Trust the MEM_EXPR
@@ -345,6 +339,9 @@ ao_ref_from_mem (ao_ref *ref, const_rtx mem)
&& (MEM_SIZE (mem) + MEM_OFFSET (mem)) * BITS_PER_UNIT == ref->size)
return true;
+ /* Otherwise continue and refine size and offset we got from analyzing
+ MEM_EXPR by using MEM_SIZE and MEM_OFFSET. */
+
ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT;
ref->size = MEM_SIZE (mem) * BITS_PER_UNIT;