https://gcc.gnu.org/g:e34cda8c594b0f91e9590b589a001a1ab9aa8ed6
commit e34cda8c594b0f91e9590b589a001a1ab9aa8ed6
Author: Alexandre Oliva <ol...@gnu.org>
Date: Thu Jan 23 02:54:55 2025 -0300
[ifcombine] improve reverse checking and operand swapping
Diff:
---
gcc/gimple-fold.cc | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index 3c971a29ef04..da3f505c3fca 100644
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -8090,8 +8090,9 @@ fold_truth_andor_for_ifcombine (enum tree_code code, tree
truth_type,
return 0;
}
- /* Prepare to turn compares of signed quantities with zero into
- sign-bit tests. */
+ /* Prepare to turn compares of signed quantities with zero into sign-bit
+ tests. We need not worry about *_reversep here for these compare
+ rewrites: loads will have already been reversed before compares. */
bool lsignbit = false, rsignbit = false;
if ((lcode == LT_EXPR || lcode == GE_EXPR)
&& integer_zerop (lr_arg)
@@ -8198,10 +8199,11 @@ fold_truth_andor_for_ifcombine (enum tree_code code,
tree truth_type,
the rhs's. If one is a load and the other isn't, we have to be
conservative and avoid the optimization, otherwise we could get
SRAed fields wrong. */
- if (volatilep || ll_reversep != rl_reversep)
+ if (volatilep)
return 0;
- if (! operand_equal_p (ll_inner, rl_inner, 0))
+ if (ll_reversep != rl_reversep
+ || ! operand_equal_p (ll_inner, rl_inner, 0))
{
/* Try swapping the operands. */
if (ll_reversep != rr_reversep
