From: Richard Biener <rguenther@suse.de>
Date: Mon, 21 Jul 2025 10:48:45 +0000 (+0200)
Subject: tree-optimization/121194 - check LC PHIs can be vectorized
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8ca85e95daca7f7c56d297fa7f2328e5385d446c;p=thirdparty%2Fgcc.git

tree-optimization/121194 - check LC PHIs can be vectorized

With bools we can have the usual mismatch between mask and data
use.  Catch that, like we do elsewhere.

	PR tree-optimization/121194
	* tree-vect-loop.cc (vectorizable_lc_phi): Verify
	vector types are compatible.

	* gcc.dg/torture/pr121194.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/torture/pr121194.c b/gcc/testsuite/gcc.dg/torture/pr121194.c
new file mode 100644
index 00000000000..20f5ff7184f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr121194.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+
+int a, b, c, d;
+void e() {
+  int *f = &b;
+  for (a = 0; a < 8; a++) {
+    *f = 0;
+    for (c = 0; c < 2; c++)
+      *f = *f == 0;
+  }
+}
+int main() {
+  e();
+  int *g = &b;
+  *g = *g == (d == 0);
+  return 0;
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index fe11eb72e4b..899e09dd659 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -8759,6 +8759,18 @@ vectorizable_lc_phi (loop_vec_info loop_vinfo,
 			 "incompatible vector types for invariants\n");
       return false;
     }
+
+  /* ???  This can happen with data vs. mask uses of boolean.  */
+  if (!useless_type_conversion_p (SLP_TREE_VECTYPE (slp_node),
+				  SLP_TREE_VECTYPE
+				    (SLP_TREE_CHILDREN (slp_node)[0])))
+    {
+      if (dump_enabled_p ())
+	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			 "missed mask promotion\n");
+      return false;
+    }
+
   STMT_VINFO_TYPE (stmt_info) = lc_phi_info_type;
   return true;
 }