From: Richard Biener <rguenther@suse.de>
Date: Fri, 30 May 2025 12:11:47 +0000 (+0200)
Subject: tree-optimization/120357 - ICE with early break vectorization
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dce4da51ab66c3abb84448326910cd42f6fe2499;p=thirdparty%2Fgcc.git

tree-optimization/120357 - ICE with early break vectorization

When doing early break vectorization of a loop with a conditional
reduction the epilog creation code is confused as to before which exit
to insert the conditional reduction induction IV update.  The
following make sure this is done before the main IV exit.

	PR tree-optimization/120357
	* tree-vect-loop.cc (vect_create_epilog_for_reduction): Create
	the conditional reduction induction IV increment before the
	main IV exit.

	* gcc.dg/vect/vect-early-break_136-pr120357.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c
new file mode 100644
index 00000000000..8a51cfc46a5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-add-options vect_early_break } */
+/* { dg-additional-options "-O3" } */
+
+char a;
+unsigned long long t[2][22];
+int u[22];
+void f(void)
+{
+  for (int v = 0; v < 22; v++)
+    for (_Bool w = 0; w < (u[v] < 0) + 1; w = 1)
+      a *= 0 != t[w][v];
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 2d1a6883e6b..8c5761d3c55 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -6016,7 +6016,8 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo,
       /* Create an induction variable.  */
       gimple_stmt_iterator incr_gsi;
       bool insert_after;
-      vect_iv_increment_position (loop_exit, &incr_gsi, &insert_after);
+      vect_iv_increment_position (LOOP_VINFO_IV_EXIT (loop_vinfo),
+				  &incr_gsi, &insert_after);
       create_iv (series_vect, PLUS_EXPR, vec_step, NULL_TREE, loop, &incr_gsi,
 		 insert_after, &indx_before_incr, &indx_after_incr);