From fbd8a8041292f2ec2c22be43c8d3e74b37b2bc88 Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Fri, 11 Jun 2021 13:33:17 +0200
Subject: [PATCH] tree-optimization/101026 - fix SLP re-association
Since we cannot yet encode the operation in the SLP node itself
but need a representative stmt require an existing one for now
to avoid the need to build a fake GIMPLE stmt.
2021-06-11 Richard Biener <rguenther@suse.de>
PR tree-optimization/101026
* tree-vect-slp.c (vect_build_slp_tree_2): Make sure we
have a representative for the associated chain nodes.
* gfortran.dg/pr101026.f: New testcase.
---
gcc/testsuite/gfortran.dg/pr101026.f | 11 +++++++++++
gcc/tree-vect-slp.c | 4 +++-
2 files changed, 14 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gfortran.dg/pr101026.f
diff --git a/gcc/testsuite/gfortran.dg/pr101026.f b/gcc/testsuite/gfortran.dg/pr101026.f
new file mode 100644
index 000000000000..9576d8802ca6
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr101026.f
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-Ofast -frounding-math" }
+ SUBROUTINE PASSB4 (CC,CH)
+ DIMENSION CC(IDO,4,L1), CH(IDO,L1,*)
+ DO 103 I=2,IDO,2
+ TI4 = CC0-CC(I,4,K)
+ CI4 = TI1-TI4
+ CH(I-1,K,4) = CI4
+ CH(I,K,4) = CI4
+ 103 CONTINUE
+ END
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 6237a61ffd44..897bd6f37b90 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -1860,7 +1860,9 @@ vect_build_slp_tree_2 (vec_info *vinfo, slp_tree node,
chains.quick_push (chain.copy ());
chain.truncate (0);
}
- if (chains.length () == group_size)
+ if (chains.length () == group_size
+ /* We cannot yet use SLP_TREE_CODE to communicate the operation. */
+ && op_stmt_info)
{
/* Now we have a set of chains with the same length. */
/* 1. pre-sort according to def_type and operation. */
--
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