[r14-3571 Regression] FAIL: gcc.target/i386/pr52252-atom.c scan-assembler palignr on Linux/x86_64

[r14-3571 Regression] FAIL: gcc.target/i386/pr52252-atom.c scan-assembler palignr on Linux/x86_64

[Jiang, Haochen]

On Linux/x86_64,

caa7a99a052929d5970677c5b639e1fa5166e334 is the first bad commit
commit caa7a99a052929d5970677c5b639e1fa5166e334
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Aug 30 11:57:47 2023 +0200

    tree-optimization/111228 - combine two VEC_PERM_EXPRs

caused

FAIL: gcc.target/i386/pr52252-atom.c scan-assembler palignr

with GCC configured with

../../gcc/configure --prefix=/export/users/haochenj/src/gcc-bisect/master/master/r14-3571/usr --enable-clocale=gnu --with-system-zlib --with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++,fortran --enable-cet --without-isl --enable-libmpx x86_64-linux --disable-bootstrap

To reproduce:

$ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/pr52252-atom.c --target_board='unix{-m32\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/pr52252-atom.c --target_board='unix{-m64\ -march=cascadelake}'"

(For question about this report, contact me at haochen dot jiang at intel.com.)
(If you met problems with cascadelake related, disabling AVX512F in command line might save that.)
(However, please make sure that there is no potential problems with AVX512.)

Re: [r14-3571 Regression] FAIL: gcc.target/i386/pr52252-atom.c scan-assembler palignr on Linux/x86_64

[Richard Biener]

On Thu, 31 Aug 2023, Jiang, Haochen wrote:

> On Linux/x86_64,
> 
> caa7a99a052929d5970677c5b639e1fa5166e334 is the first bad commit
> commit caa7a99a052929d5970677c5b639e1fa5166e334
> Author: Richard Biener <rguenther@suse.de>
> Date:   Wed Aug 30 11:57:47 2023 +0200
> 
>     tree-optimization/111228 - combine two VEC_PERM_EXPRs
> 
> caused
> 
> FAIL: gcc.target/i386/pr52252-atom.c scan-assembler palignr
> 
> with GCC configured with
> 
> ../../gcc/configure --prefix=/export/users/haochenj/src/gcc-bisect/master/master/r14-3571/usr --enable-clocale=gnu --with-system-zlib --with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++,fortran --enable-cet --without-isl --enable-libmpx x86_64-linux --disable-bootstrap
> 
> To reproduce:
> 
> $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/pr52252-atom.c --target_board='unix{-m32\ -march=cascadelake}'"
> $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/pr52252-atom.c --target_board='unix{-m64\ -march=cascadelake}'"
> 
> (For question about this report, contact me at haochen dot jiang at intel.com.)
> (If you met problems with cascadelake related, disabling AVX512F in command line might save that.)
> (However, please make sure that there is no potential problems with AVX512.)

We are eliding 6 permutations on the testcase with the change.  The
testcase in question gcc.target/i386/pr52252-atom.c, doesn't expect
to have AVX512 enabled.

I wonder why -mtune=slm doesn't enable -mprefer-vector-width=128,
when I add that the testcase will pass again.


I'm pushing the following, tested on x86_64-unknown-linux-gnu.

Richard

From 2d24c1715a096cd069e1627864cdcbba908c807c Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Thu, 31 Aug 2023 09:06:24 +0200
Subject: [PATCH] Adjust gcc.target/i386/pr52252-{atom,core}.c
To: gcc-patches@gcc.gnu.org

The following adjusts the testcases to force 128bit vectorization
to make them more robust when for example adding -march=cascadelake

	* gcc.target/i386/pr52252-atom.c: Add -mprefer-vector-width=128.
	* gcc.target/i386/pr52252-core.c: Likewise.
---
 gcc/testsuite/gcc.target/i386/pr52252-atom.c | 2 +-
 gcc/testsuite/gcc.target/i386/pr52252-core.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/testsuite/gcc.target/i386/pr52252-atom.c b/gcc/testsuite/gcc.target/i386/pr52252-atom.c
index ee604f2189a..11f94411575 100644
--- a/gcc/testsuite/gcc.target/i386/pr52252-atom.c
+++ b/gcc/testsuite/gcc.target/i386/pr52252-atom.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -ftree-vectorize -mssse3 -mtune=slm" } */
+/* { dg-options "-O2 -ftree-vectorize -mssse3 -mtune=slm -mprefer-vector-width=128" } */
 #define byte unsigned char
 
 void
diff --git a/gcc/testsuite/gcc.target/i386/pr52252-core.c b/gcc/testsuite/gcc.target/i386/pr52252-core.c
index 65d62cfa365..897026b0997 100644
--- a/gcc/testsuite/gcc.target/i386/pr52252-core.c
+++ b/gcc/testsuite/gcc.target/i386/pr52252-core.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -ftree-vectorize -mssse3 -mtune=corei7" } */
+/* { dg-options "-O2 -ftree-vectorize -mssse3 -mtune=corei7 -mprefer-vector-width=128" } */
 #define byte unsigned char
 
 void
-- 
2.35.3