From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 14 Mar 2025 14:34:32 +0000 (+0100)
Subject: match.pd: Fix up r15-8025 simplification [PR119287]
X-Git-Tag: basepoints/gcc-16~1493
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ab0133cdba5dbcc29655593377e80586f7080472;p=thirdparty%2Fgcc.git

match.pd: Fix up r15-8025 simplification [PR119287]

The following testcase ICEs since r15-8025.
tree_nop_conversion_p doesn't imply TREE_TYPE (@0) is uselessly convertible
to type, e.g. they could be INTEGER_TYPEs with the same precision but
different TYPE_SIGN.

The following patch just adds a convert so that it creates a valid IL
even in those cases.

2025-03-14  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/119287
	* match.pd (((X >> C1) & C2) * (1 << C1) to X & (C2 << C1)): Use
	(convert @0) instead of @0 in the substitution.

	* gcc.dg/pr119287.c: New test.
---

diff --git a/gcc/match.pd b/gcc/match.pd
index 89612d1b15b..98f63737324 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5284,7 +5284,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	 || tree_int_cst_sgn (@2) >= 0)
 	&& wi::to_wide (@3) == wi::set_bit_in_zero (shift, prec))
     (with { auto mask = wide_int::from (wi::to_wide (@2), prec, UNSIGNED); }
-     (bit_and @0 { wide_int_to_tree (type, mask << shift); }))))))
+     (bit_and (convert @0) { wide_int_to_tree (type, mask << shift); }))))))
 
 /* ~(~X >> Y) -> X >> Y (for arithmetic shift).  */
 (simplify
diff --git a/gcc/testsuite/gcc.dg/pr119287.c b/gcc/testsuite/gcc.dg/pr119287.c
new file mode 100644
index 00000000000..b4b29afab91
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr119287.c
@@ -0,0 +1,16 @@
+/* PR tree-optimization/119287 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fwrapv" } */
+
+unsigned a;
+int b;
+signed char c, d;
+
+void
+foo (void)
+{
+  c = a >> 14 & 1;
+  for (; d;)
+    c = 1;
+  b = c << 14;
+}