[gcc r15-6683] tree-optimization/118269 - SLP reduction chain and early breaks

[Richard Biener via Gcc-cvs]

https://gcc.gnu.org/g:2dd4eb15b63ca1f20a637e8b26567d5064a43a4f

commit r15-6683-g2dd4eb15b63ca1f20a637e8b26567d5064a43a4f
Author: Richard Biener <rguent...@suse.de>
Date:   Tue Jan 7 11:15:43 2025 +0100

    tree-optimization/118269 - SLP reduction chain and early breaks
    
    When we create the SLP reduction chain epilogue for the PHIs for
    the early exit we fail to properly classify the reduction as SLP
    reduction chain.  The following fixes the corresponding checks.
    
            PR tree-optimization/118269
            * tree-vect-loop.cc (vect_create_epilog_for_reduction):
            Use the correct stmt for the REDUC_GROUP_FIRST_ELEMENT lookup.
    
            * gcc.dg/vect/vect-early-break_131-pr118269.c: New testcase.

Diff:
---
 .../gcc.dg/vect/vect-early-break_131-pr118269.c         | 17 +++++++++++++++++
 gcc/tree-vect-loop.cc                                   |  8 +++++---
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_131-pr118269.c 
b/gcc/testsuite/gcc.dg/vect/vect-early-break_131-pr118269.c
new file mode 100644
index 000000000000..5f7abcee57c9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_131-pr118269.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-add-options vect_early_break } */
+/* { dg-additional-options "-O3" } */
+
+short g_113;
+int func_1_l_1273, func_1_l_1370, func_1_l_1258;
+void func_1() {
+  int l_1375;
+  for (; l_1375; l_1375--) {
+    for (; func_1_l_1370;)
+      ;
+    func_1_l_1273 &= !0;
+    func_1_l_1273 &= g_113;
+    if (func_1_l_1258)
+      break;
+  }
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 2b9d59566357..bb1138bfcfba 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -6039,7 +6039,9 @@ vect_create_epilog_for_reduction (loop_vec_info 
loop_vinfo,
      # b1 = phi <b2, b0>
      a2 = operation (a1)
      b2 = operation (b1)  */
-  bool slp_reduc = (slp_node && !REDUC_GROUP_FIRST_ELEMENT (stmt_info));
+  bool slp_reduc
+    = (slp_node
+       && !REDUC_GROUP_FIRST_ELEMENT (STMT_VINFO_REDUC_DEF (reduc_info)));
   bool direct_slp_reduc;
   tree induction_index = NULL_TREE;
 
@@ -6331,7 +6333,7 @@ vect_create_epilog_for_reduction (loop_vec_info 
loop_vinfo,
      a multiple of the SLP group size.
 
      The same is true if we couldn't use a single defuse cycle.  */
-  if (REDUC_GROUP_FIRST_ELEMENT (stmt_info)
+  if (REDUC_GROUP_FIRST_ELEMENT (STMT_VINFO_REDUC_DEF (reduc_info))
       || direct_slp_reduc
       || (slp_reduc
          && constant_multiple_p (TYPE_VECTOR_SUBPARTS (vectype), group_size))
@@ -6632,7 +6634,7 @@ vect_create_epilog_for_reduction (loop_vec_info 
loop_vinfo,
       if (slp_node)
        {
          tree initial_value = NULL_TREE;
-         if (REDUC_GROUP_FIRST_ELEMENT (stmt_info))
+         if (REDUC_GROUP_FIRST_ELEMENT (STMT_VINFO_REDUC_DEF (reduc_info)))
            initial_value = reduc_info->reduc_initial_values[0];
          neutral_op = neutral_op_for_reduction (TREE_TYPE (vectype), code,
                                                 initial_value, false);