[gcc r15-9787] tree-optimization/120357 - ICE with early break vectorization

[Richard Biener via Gcc-cvs]

https://gcc.gnu.org/g:8cb0127dfd3d01d4549f3139b087d1a5966844ee

commit r15-9787-g8cb0127dfd3d01d4549f3139b087d1a5966844ee
Author: Richard Biener <rguent...@suse.de>
Date:   Fri May 30 14:11:47 2025 +0200

    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.
    
    (cherry picked from commit dce4da51ab66c3abb84448326910cd42f6fe2499)

Diff:
---
 gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c | 13 +++++++++++++
 gcc/tree-vect-loop.cc                                     |  3 ++-
 2 files changed, 15 insertions(+), 1 deletion(-)

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 000000000000..8a51cfc46a5d
--- /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 2d35fa128864..c824b5abaaff 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -6189,7 +6189,8 @@ 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);