>From bc21c0d454e944e2e9be3a464adb8f3219ed0257 Mon Sep 17 00:00:00 2001
From: Kael Andrew Alonzo Franco <[email protected]>
Date: Sun, 19 Jul 2026 18:47:54 -0400
Subject: [PATCH] match: Combine two patterns into for neeq (ne eq) and
fix typo. [PR64992]
This simplify r13-2048 and fix typo on C being zero_one_valued_p to
X being zero_one_valued_p.
Bootstrapped and regtested on x86_64-pc-linux-gnu.
PR tree-optimization/64992
gcc/ChangeLog:
* match.pd: Combine two patterns into for neeq (ne eq) and fix typo.
Signed-off-by: Kael Andrew Franco <[email protected]>
---
gcc/match.pd | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index b3738fdde1d..8b156212c1c 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2680,25 +2680,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& (TYPE_UNSIGNED (type) || TYPE_PRECISION (type) > 1))
(mult (convert @1) (convert @2))))
-/* (X << C) != 0 can be simplified to X, when C is zero_one_valued_p.
+/* (X << C) != 0 can be simplified to X, when X is zero_one_valued_p.
+ (X << C) == 0 can be simplified to X == 0, when X is zero_one_valued_p.
Check that the shift is well-defined (C is less than TYPE_PRECISION)
as some targets (such as x86's SSE) may return zero for larger C. */
-(simplify
- (ne (lshift zero_one_valued_p@0 INTEGER_CST@1) integer_zerop@2)
- (if (tree_fits_shwi_p (@1)
- && tree_to_shwi (@1) > 0
- && tree_to_shwi (@1) < TYPE_PRECISION (TREE_TYPE (@0)))
- (convert @0)))
-
-/* (X << C) == 0 can be simplified to X == 0, when C is zero_one_valued_p.
- Check that the shift is well-defined (C is less than TYPE_PRECISION)
- as some targets (such as x86's SSE) may return zero for larger C. */
-(simplify
- (eq (lshift zero_one_valued_p@0 INTEGER_CST@1) integer_zerop@2)
- (if (tree_fits_shwi_p (@1)
- && tree_to_shwi (@1) > 0
- && tree_to_shwi (@1) < TYPE_PRECISION (TREE_TYPE (@0)))
- (eq @0 @2)))
+(for neeq (ne eq)
+ (simplify
+ (neeq (lshift zero_one_valued_p@0 INTEGER_CST@1) integer_zerop@2)
+ (if (tree_fits_shwi_p (@1)
+ && tree_to_shwi (@1) > 0
+ && tree_to_shwi (@1) < TYPE_PRECISION (TREE_TYPE (@0)))
+ (if (neeq == NE_EXPR)
+ (convert @0)
+ (eq @0 @2)))))
/* PR110010: (A >> C) != (B >> C) -> (A ^ B) >= (1 << C)
and likewise (A >> C) == (B >> C) -> (A ^ B) < (1 << C).
--
2.55.0
