https://gcc.gnu.org/g:3ab9eb6946f7b832834b3d808c5617935e0be727
commit r15-6992-g3ab9eb6946f7b832834b3d808c5617935e0be727
Author: Jakub Jelinek <ja...@redhat.com>
Date: Fri Jan 17 11:30:07 2025 +0100
match.pd: Fix (FTYPE) N CMP (FTYPE) M optimization for GENERIC [PR118522]
The last case of this optimization assumes that if 2 integral types
have same precision and TYPE_UNSIGNED, then they are uselessly convertible.
While that is very likely the case for GIMPLE, it is not the case for
GENERIC, so the following patch adds there a convert so that the
optimization produces also valid GENERIC. Without it we got
(int) p == b where b had _BitInt(32) type, so incompatible types.
2025-01-17 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/118522
* match.pd ((FTYPE) N CMP (FTYPE) M): Add convert, as in GENERIC
integral types with the same precision and sign might actually not
be compatible types.
* gcc.dg/bitint-120.c: New test.
Diff:
---
gcc/match.pd | 2 +-
gcc/testsuite/gcc.dg/bitint-120.c | 11 +++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index b6cbb851897d..f4359d3a005a 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -7253,7 +7253,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(icmp (convert:type2 @1) @2)
(if (TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
&& type1_signed_p == type2_signed_p)
- (icmp @1 @2))))))))))
+ (icmp @1 (convert @2)))))))))))
/* Optimize various special cases of (FTYPE) N CMP CST. */
(for cmp (lt le eq ne ge gt)
diff --git a/gcc/testsuite/gcc.dg/bitint-120.c
b/gcc/testsuite/gcc.dg/bitint-120.c
new file mode 100644
index 000000000000..51098881e140
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-120.c
@@ -0,0 +1,11 @@
+/* PR tree-optimization/118522 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-O2" } */
+
+_BitInt(32) b;
+
+int
+foo (unsigned short p)
+{
+ return p == (double) b;
+}
