FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Debian > Debian GCC

 
 
LinkBack Thread Tools
 
Old 07-09-2012, 10:02 AM
Ondrej Bilka
 
Default Bug#680776: gcc-4.7: does not use aligned load

Package: gcc-4.7
Version: 4.7.1-2
Severity: normal
Tags: upstream

Gcc uses unaligned load instruction movdqu even if aligned load movdqa
was requested and data are aligned.

An example follows

#include <emmintrin.h>
__m128i x(char *s){
__m128i sz,z,mvec;
s-=((unsigned long) s)%16;
sz=_mm_load_si128(s);
return sz;
}

and output of gcc -O3 -S

.file "int.c"
.text
.p2align 4,,15
.globl x
.type x, @function
x:
.LFB517:
.cfi_startproc
movq %rdi, %rax
andl $15, %eax
negq %rax
movdqu (%rdi,%rax), %xmm0
ret
.cfi_endproc
.LFE517:
.size x, .-x
.ident "GCC: (Debian 4.7.1-2) 4.7.1"
.section .note.GNU-stack,"",@progbits


-- System Information:
Debian Release: wheezy/sid
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF8, LC_CTYPE=en_US.UTF8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages gcc-4.7 depends on:
ii binutils 2.21.52.20110606-2 The GNU assembler, linker and bina
ii cpp-4.7 4.7.1-2 GNU C preprocessor
ii gcc-4.7-base 4.7.1-2 GCC, the GNU Compiler Collection (
ii libc6 2.13-33 Embedded GNU C Library: Shared lib
ii libgcc1 1:4.7.1-2 GCC support library
ii libgmp10 2:5.0.5+dfsg-2 Multiprecision arithmetic library
ii libgomp1 4.7.1-2 GCC OpenMP (GOMP) support library
ii libitm1 4.7.1-2 GNU Transactional Memory Library
ii libmpc2 0.9-4 multiple precision complex floatin
ii libmpfr4 3.1.0-5 multiple precision floating-point
ii libquadmath0 4.7.1-2 GCC Quad-Precision Math Library
ii zlib1g 1:1.2.6.dfsg-2 compression library - runtime

Versions of packages gcc-4.7 recommends:
ii libc6-dev 2.13-33 Embedded GNU C Library: Developmen

Versions of packages gcc-4.7 suggests:
pn binutils-gold <none> (no description available)
pn gcc-4.7-doc <none> (no description available)
pn gcc-4.7-locales <none> (no description available)
pn gcc-4.7-multilib <none> (no description available)
pn libgcc1-dbg <none> (no description available)
pn libgomp1-dbg <none> (no description available)
pn libitm1-dbg <none> (no description available)
pn libmudflap0-4.7-dev <none> (no description available)
pn libmudflap0-dbg <none> (no description available)
pn libquadmath0-dbg <none> (no description available)

-- no debconf information



--
To UNSUBSCRIBE, email to debian-gcc-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: http://lists.debian.org/20120709100259.24918.7443.reportbug@domone
 
Old 08-27-2012, 09:53 AM
Matthias Klose
 
Default Bug#680776: gcc-4.7: does not use aligned load

tags 680776 + moreinfo
thanks

On 09.07.2012 12:02, Ondrej Bilka wrote:
> Package: gcc-4.7
> Version: 4.7.1-2
> Severity: normal
> Tags: upstream
>
> Gcc uses unaligned load instruction movdqu even if aligned load movdqa
> was requested and data are aligned.
>
> An example follows

please check with 4.6 and trunk (gcc-snapshot) and open an upstream report if
there isn't one already.


--
To UNSUBSCRIBE, email to debian-gcc-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: 503B439F.6000502@debian.org">http://lists.debian.org/503B439F.6000502@debian.org
 
Old 08-27-2012, 11:09 AM
Ondřej Bílka
 
Default Bug#680776: gcc-4.7: does not use aligned load

On Mon, Aug 27, 2012 at 11:53:35AM +0200, Matthias Klose wrote:
> tags 680776 + moreinfo
> thanks
>
> On 09.07.2012 12:02, Ondrej Bilka wrote:
> > Package: gcc-4.7
> > Version: 4.7.1-2
> > Severity: normal
> > Tags: upstream
> >
> > Gcc uses unaligned load instruction movdqu even if aligned load movdqa
> > was requested and data are aligned.
> >
> > An example follows
>
> please check with 4.6 and trunk (gcc-snapshot) and open an upstream report if
> there isn't one already.
>
already reported to upstream.


--
To UNSUBSCRIBE, email to debian-gcc-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: 20120827110941.GA29594@domone.kolej.mff.cuni.cz">h ttp://lists.debian.org/20120827110941.GA29594@domone.kolej.mff.cuni.cz
 

Thread Tools




All times are GMT. The time now is 02:16 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org