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* [Bug target/54446] New: Stack needlessly aligned with AVX
@ 2012-09-01 1:22 cesarb at cesarb dot net
2012-09-01 1:24 ` [Bug target/54446] " cesarb at cesarb dot net
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: cesarb at cesarb dot net @ 2012-09-01 1:22 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54446
Bug #: 54446
Summary: Stack needlessly aligned with AVX
Classification: Unclassified
Product: gcc
Version: 4.6.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: cesarb@cesarb.net
When compiling the following small function, gcc aligns the stack, even though
the function does not store any AVX values in the stack:
bool test(__m256i *p)
{
__m256i x = _mm256_load_si256(p);
return _mm256_testz_si256(x, x);
}
The generated assembly output is:
test:
pushq %rbp
movq %rsp, %rbp
andq $-32, %rsp
addq $16, %rsp
vmovdqa (%rdi), %ymm0
vptest %ymm0, %ymm0
leave
sete %al
vzeroupper
ret
The assembly output should instead be something like:
test:
vmovdqa (%rdi), %ymm0
vptest %ymm0, %ymm0
sete %al
vzeroupper
ret
The command line is "gcc -mavx -std=c99 -O3 -Wall -Wextra -Werror -save-temps".
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.6.3/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla
--enable-bootstrap --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin
--enable-java-awt=gtk --disable-dssi
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --enable-java-maintainer-mode
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib
--with-ppl --with-cloog --with-tune=generic --with-arch_32=i686
--build=x86_64-redhat-linux
Thread model: posix
gcc version 4.6.3 20120306 (Red Hat 4.6.3-2) (GCC)
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/54446] Stack needlessly aligned with AVX
2012-09-01 1:22 [Bug target/54446] New: Stack needlessly aligned with AVX cesarb at cesarb dot net
@ 2012-09-01 1:24 ` cesarb at cesarb dot net
2012-09-01 14:30 ` hjl.tools at gmail dot com
2024-03-28 4:47 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: cesarb at cesarb dot net @ 2012-09-01 1:24 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54446
--- Comment #1 from Cesar Eduardo Barros <cesarb at cesarb dot net> 2012-09-01 01:23:48 UTC ---
Created attachment 28114
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28114
testcase
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/54446] Stack needlessly aligned with AVX
2012-09-01 1:22 [Bug target/54446] New: Stack needlessly aligned with AVX cesarb at cesarb dot net
2012-09-01 1:24 ` [Bug target/54446] " cesarb at cesarb dot net
@ 2012-09-01 14:30 ` hjl.tools at gmail dot com
2024-03-28 4:47 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: hjl.tools at gmail dot com @ 2012-09-01 14:30 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54446
--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2012-09-01 14:30:22 UTC ---
It has been fixed in GCC 4.7:
.cfi_startproc
vmovdqa (%rdi), %ymm0
vptest %ymm0, %ymm0
sete %al
ret
.cfi_endproc
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/54446] Stack needlessly aligned with AVX
2012-09-01 1:22 [Bug target/54446] New: Stack needlessly aligned with AVX cesarb at cesarb dot net
2012-09-01 1:24 ` [Bug target/54446] " cesarb at cesarb dot net
2012-09-01 14:30 ` hjl.tools at gmail dot com
@ 2024-03-28 4:47 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-28 4:47 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54446
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Target Milestone|--- |4.7.0
Resolution|--- |FIXED
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed a long time ago.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-03-28 4:47 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2012-09-01 1:22 [Bug target/54446] New: Stack needlessly aligned with AVX cesarb at cesarb dot net
2012-09-01 1:24 ` [Bug target/54446] " cesarb at cesarb dot net
2012-09-01 14:30 ` hjl.tools at gmail dot com
2024-03-28 4:47 ` pinskia at gcc dot gnu.org
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