From 172a72da368146e0fe34194020eb7a6636db4438 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 17 Nov 2023 15:09:44 +0100
Subject: [PATCH] vect: Fix check_reduction_path [PR112374]
As mentioned in the PR, the intent of the r14-5076 changes was that
it doesn't count one of the uses on the use_stmt, but what actually
got implemented is that it does this processing on any op_use_stmt,
even if it is not the use_stmt statement, which means that it
can increase count even on debug stmts (-fcompare-debug failures),
or if there would be some other use stmt with 2+ uses it could count
that as a single use. Though, because it fails whenever cnt != 1
and I believe use_stmt must be one of the uses, it would probably
fail in the latter case anyway.
The following patch fixes that by doing this extra processing only when
op_use_stmt is use_stmt, and using the normal processing otherwise
(so ignore debug stmts, and increase on any uses on the stmt).
2023-11-17 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/112374
* tree-vect-loop.cc (check_reduction_path): Perform the cond_fn_p
special case only if op_use_stmt == use_stmt, use as_a rather than
dyn_cast in that case.
* gcc.dg/pr112374-1.c: New test.
* gcc.dg/pr112374-2.c: New test.
* g++.dg/opt/pr112374.C: New test.
---
gcc/testsuite/g++.dg/opt/pr112374.C | 24 +++++++++++++++++++++
gcc/testsuite/gcc.dg/pr112374-1.c | 20 +++++++++++++++++
gcc/testsuite/gcc.dg/pr112374-2.c | 33 +++++++++++++++++++++++++++++
gcc/tree-vect-loop.cc | 4 ++--
4 files changed, 79 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/opt/pr112374.C
create mode 100644 gcc/testsuite/gcc.dg/pr112374-1.c
create mode 100644 gcc/testsuite/gcc.dg/pr112374-2.c
diff --git a/gcc/testsuite/g++.dg/opt/pr112374.C b/gcc/testsuite/g++.dg/opt/pr112374.C
new file mode 100644
index 000000000000..15d8a067754e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/pr112374.C
@@ -0,0 +1,24 @@
+// PR tree-optimization/112374
+// { dg-do compile { target c++11 } }
+// { dg-options "-fcompare-debug -gno-statement-frontiers -O2" }
+// { dg-additional-options "-march=skylake-avx512" { target i?86-*-* x86_64-*-* } }
+// { dg-additional-options "-march=armv9-a" { target aarch64*-*-* } }
+
+struct t
+{
+ long coef[1];
+ t(const unsigned long &a) : coef{(long)a} {};
+ t(const t &a);
+};
+extern void gen_int_mode(t, int);
+struct expand_vec_perm_d {
+ unsigned char perm[64];
+ int vmode;
+ unsigned char nelt;
+};
+void expand_vec_perm_blend(struct expand_vec_perm_d *d) {
+ unsigned long mask = 0;
+ for (unsigned i = 0; i < 4; ++i)
+ mask |= (d->perm[i] >= 4 ? 3 : 0) << (i * 2);
+ gen_int_mode(mask, 0);
+}
diff --git a/gcc/testsuite/gcc.dg/pr112374-1.c b/gcc/testsuite/gcc.dg/pr112374-1.c
new file mode 100644
index 000000000000..7fbd67a12883
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112374-1.c
@@ -0,0 +1,20 @@
+/* PR tree-optimization/112374 */
+/* { dg-do compile } */
+/* { dg-options "-fcompare-debug -gno-statement-frontiers -O2 -w" } */
+/* { dg-additional-options "-march=skylake-avx512" { target i?86-*-* x86_64-*-* } } */
+/* { dg-additional-options "-march=armv9-a" { target aarch64*-*-* } } */
+
+void foo (int, int);
+struct S { char s[4]; };
+int a, b, c;
+
+void
+bar ()
+{
+ struct S d;
+ long e = 0;
+ for (c = 0; c < 4; ++c)
+ e |= (d.s[c] ? 3 : 0) << c;
+ if (e)
+ foo (a, b);
+}
diff --git a/gcc/testsuite/gcc.dg/pr112374-2.c b/gcc/testsuite/gcc.dg/pr112374-2.c
new file mode 100644
index 000000000000..1598c49fc549
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112374-2.c
@@ -0,0 +1,33 @@
+/* PR tree-optimization/112374 */
+/* { dg-do compile } */
+/* { dg-options "-fcompare-debug -gno-statement-frontiers -O2" } */
+/* { dg-additional-options "-march=skylake-avx512" { target i?86-*-* x86_64-*-* } } */
+/* { dg-additional-options "-march=armv9-a" { target aarch64*-*-* } } */
+
+void foo (int, int);
+struct S { char s[64]; } *p;
+char a, b;
+unsigned char c;
+int d, e;
+
+void
+bar (void)
+{
+ unsigned i;
+ long j = 0;
+ for (i = 0; i < b; ++i)
+ j |= (p->s[i] ? 3 : 0) << i;
+ if (p->s[i + 1])
+ lab:
+ for (;;)
+ ;
+ for (i = 0; i < 4; ++i)
+ j |= p->s[i] << i;
+ for (; i; i += 2)
+ if (c + 1 != a)
+ goto lab;
+ for (; i < 8; ++i)
+ j |= p->s[i] >= 6;
+ if (j)
+ foo (d, e);
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 3f59139cb013..e8b8be5b7e1c 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -4118,9 +4118,9 @@ pop:
/* In case of a COND_OP (mask, op1, op2, op1) reduction we might have
op1 twice (once as definition, once as else) in the same operation.
Allow this. */
- if (cond_fn_p)
+ if (cond_fn_p && op_use_stmt == use_stmt)
{
- gcall *call = dyn_cast<gcall *> (use_stmt);
+ gcall *call = as_a<gcall *> (use_stmt);
unsigned else_pos
= internal_fn_else_index (internal_fn (op.code));
--
GitLab