From: Richard Biener <rguenther@suse.de>
Date: Tue, 6 Jan 2026 13:10:38 +0000 (+0100)
Subject: tree-optimization/123316 - avoid ICE due to lack of PHI patterns
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=515dba569d138d84e8a5f7ea71d38480732ee899;p=thirdparty%2Fgcc.git

tree-optimization/123316 - avoid ICE due to lack of PHI patterns

With bools we can end up with mixed vector types in PHI nodes due
to PHIs not having pattern stmts.  Avoid this when analyzing
a nested cycle, similar to how we already to when analyzing BB
vectorization PHIs.

	PR tree-optimization/123316
	* tree-vect-loop.cc (vectorizable_reduction): Detect missing
	PHI patterns for bools.

	* gcc.dg/vect/vect-pr123316.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/vect/vect-pr123316.c b/gcc/testsuite/gcc.dg/vect/vect-pr123316.c
new file mode 100644
index 00000000000..dc3284ae7de
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-pr123316.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+
+int a;
+extern bool b[];
+void e (int c)
+{
+  for (; c; c++)
+    for (int d = 2; d < 21; d++)
+      b[c] |= a;
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 8e60a433596..a82949745e8 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -6979,6 +6979,21 @@ vectorizable_reduction (loop_vec_info loop_vinfo,
 			       "invariants\n");
 	    return false;
 	  }
+	else if (SLP_TREE_DEF_TYPE (child) == vect_internal_def
+		 && !useless_type_conversion_p (SLP_TREE_VECTYPE (slp_node),
+						SLP_TREE_VECTYPE (child)))
+	  {
+	    /* With bools we can have mask and non-mask precision vectors
+	       or different non-mask precisions.  while pattern recog is
+	       supposed to guarantee consistency here, we do not have
+	       pattern stmts for PHIs (PR123316).
+	       Deal with that here instead of ICEing later.  */
+	    if (dump_enabled_p ())
+	      dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			       "incompatible vector type setup from "
+			       "bool pattern detection\n");
+	    return false;
+	  }
       /* Analysis for double-reduction is done on the outer
 	 loop PHI, nested cycles have no further restrictions.  */
       SLP_TREE_TYPE (slp_node) = cycle_phi_info_type;