https://gcc.gnu.org/g:192c1c656b8b9a5e88c201c0a1c9a689fb35fd55
commit r16-478-g192c1c656b8b9a5e88c201c0a1c9a689fb35fd55
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Mon Apr 21 23:22:02 2025 -0700
gimple-fold: Don't replace `bool_var != 0` with `bool_var` inside
GIMPLE_COND
Since match and simplify will simplify `bool_var != 0` to just `bool_var`
and
this is inside a GIMPLE_COND, fold_stmt will return true but nothing has
changed.
So let's just reject the replacement if we are replacing with the same
simplification
inside replace_stmt_with_simplification. This can speed up things slightly
because
now fold_stmt won't return true on all GIMPLE_COND with `bool_var != 0` in
it.
gcc/ChangeLog:
* gimple-fold.cc (replace_stmt_with_simplification): Return false
if replacing `bool_var != 0` with `bool_var` in GIMPLE_COND.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/gimple-fold.cc | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index fd52b58905c0..f801e8b6d419 100644
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -6246,8 +6246,16 @@ replace_stmt_with_simplification (gimple_stmt_iterator
*gsi,
false, NULL_TREE)))
gimple_cond_set_condition (cond_stmt, code, ops[0], ops[1]);
else if (code == SSA_NAME)
- gimple_cond_set_condition (cond_stmt, NE_EXPR, ops[0],
- build_zero_cst (TREE_TYPE (ops[0])));
+ {
+ /* If setting the gimple cond to the same thing,
+ return false as nothing changed. */
+ if (gimple_cond_code (cond_stmt) == NE_EXPR
+ && operand_equal_p (gimple_cond_lhs (cond_stmt), ops[0])
+ && integer_zerop (gimple_cond_rhs (cond_stmt)))
+ return false;
+ gimple_cond_set_condition (cond_stmt, NE_EXPR, ops[0],
+ build_zero_cst (TREE_TYPE (ops[0])));
+ }
else if (code == INTEGER_CST)
{
if (integer_zerop (ops[0]))
