[PATCH] tree-optimization/121754 - ICE with vect_reduc_type and nested cycle

[Richard Biener]

The reduction guard isn't correct, STMT_VINFO_REDUC_DEF also exists
for nested cycles not part of reductions but there's no reduction
info for them.

Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.

        PR tree-optimization/121754
        * tree-vectorizer.h (vect_reduc_type): Simplify to not ICE
        on nested cycles.

        * gcc.dg/vect/pr121754.c: New testcase.
        * gcc.target/aarch64/vect-pr121754.c: Likewise.
---
 gcc/testsuite/gcc.dg/vect/pr121754.c             | 13 +++++++++++++
 gcc/testsuite/gcc.target/aarch64/vect-pr121754.c | 14 ++++++++++++++
 gcc/tree-vectorizer.h                            | 10 +++-------
 3 files changed, 30 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/vect/pr121754.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/vect-pr121754.c

diff --git a/gcc/testsuite/gcc.dg/vect/pr121754.c 
b/gcc/testsuite/gcc.dg/vect/pr121754.c
new file mode 100644
index 00000000000..775abda76c5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr121754.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+float a;
+void
+fn1 (int b)
+{
+  for (; b < 10; b++)
+    {
+      a = 01.;
+      for (int c = 0; c < 2000; c++)
+        a *= 0.99;
+    }
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/vect-pr121754.c 
b/gcc/testsuite/gcc.target/aarch64/vect-pr121754.c
new file mode 100644
index 00000000000..8b6a757780d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/vect-pr121754.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-vectorize -mcpu=neoverse-v2" } */
+
+float a;
+void
+fn1 (int b)
+{
+  for (; b < 10; b++)
+    {
+      a = 01.;
+      for (int c = 0; c < 2000; c++)
+        a *= 0.99;
+    }
+}
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index 260cb2ddd3e..5d0c71c5604 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -2923,13 +2923,9 @@ vect_reduc_type (vec_info *vinfo, slp_tree node)
 {
   if (loop_vec_info loop_vinfo = dyn_cast<loop_vec_info> (vinfo))
     {
-      stmt_vec_info stmt_info = SLP_TREE_REPRESENTATIVE (node);
-      if (STMT_VINFO_REDUC_DEF (stmt_info))
-       {
-         vect_reduc_info reduc_info
-           = info_for_reduction (loop_vinfo, node);
-         return int (VECT_REDUC_INFO_TYPE (reduc_info));
-       }
+      vect_reduc_info reduc_info = info_for_reduction (loop_vinfo, node);
+      if (reduc_info)
+       return int (VECT_REDUC_INFO_TYPE (reduc_info));
     }
   return -1;
 }
-- 
2.43.0