[Bug c++/28960] New: optimized bug with ia32 sse

[Bug c++/28960] New: optimized bug with ia32 sse

[zengpan at goldhuman dot com]

[root@localhost tmp]# cat a.cpp
#include <xmmintrin.h>
#include <stdio.h>

__m128 mm;

void test ( const __m128& vm, float r )
{
        mm = _mm_add_ps( mm, _mm_set_ps( 0.0f, r, r, r) );

        float vm0, vm1, vm2;
        _mm_store_ss( &vm0, vm );
        _mm_store_ss( &vm1, _mm_shuffle_ps( vm, vm, 1 ) );
        _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) );
        _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) );
        printf("In     TEST: %f %f %f\n", vm0, vm1, vm2 );
}

int main()
{
        __m128 vm = _mm_set_ps( 4.0f, 3.0f, 2.0f, 1.0f );

        float vm0, vm1, vm2;
        _mm_store_ss( &vm0, vm );
        _mm_store_ss( &vm1, _mm_shuffle_ps( vm, vm, 1 ) );
        _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) );
        printf("Before TEST: %f %f %f\n", vm0, vm1, vm2 );

        test(vm, 0.5f);

        _mm_store_ss( &vm0, vm );
        _mm_store_ss( &vm1, _mm_shuffle_ps( vm, vm, 1 ) );
        _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) );
        printf("After  TEST: %f %f %f\n", vm0, vm1, vm2 );
        return 0;
}
[root@localhost tmp]# g++ -Wall -O3 -msse a.cpp; ./a.out
Before TEST: 1.000000 2.000000 3.000000
In     TEST: nan nan nan
After  TEST: 1.000000 2.000000 3.000000
[root@localhost tmp]# g++ -Wall -O2 -msse a.cpp; ./a.out
Before TEST: 1.000000 2.000000 3.000000
In     TEST: nan nan nan
After  TEST: 1.000000 2.000000 3.000000
[root@localhost tmp]# g++ -Wall -O1 -msse a.cpp; ./a.out
Before TEST: 1.000000 2.000000 3.000000
In     TEST: nan nan nan
After  TEST: 1.000000 2.000000 3.000000
[root@localhost tmp]# g++ -Wall -O0 -msse a.cpp; ./a.out
Before TEST: 1.000000 2.000000 3.000000
In     TEST: 1.000000 2.000000 3.000000
After  TEST: 1.000000 2.000000 3.000000
[root@localhost tmp]#
[root@localhost tmp]# uname -a
Linux localhost.localdomain 2.6.17-1.2139_FC5smp #1 SMP Fri Jun 23 13:12:06 EDT
2006 i686 i686 i386 GNU/Linux
[root@localhost tmp]# gcc -v
Using built-in specs.
Target: i386-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking
=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,
fortran,ada --enable-java-awt=gtk --disable-dssi
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic
--host=i386-redhat-linux
Thread model: posix
gcc version 4.1.1 20060525 (Red Hat 4.1.1-1)
[root@localhost tmp]#

gcc3 is OK


-- 
           Summary: optimized bug with ia32 sse
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: zengpan at goldhuman dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960

[Bug target/28960] optimized bug with ia32 sse

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal
          Component|c++                         |target


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960

[Bug target/28960] [4.0/4.1 Regression] optimized bug with ia32 sse

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2006-09-06 14:23 -------
Confirmed.  With -mfpmath=sse I get

Before TEST: 1.000000 2.000000 3.000000
In     TEST: nan 2.000000 3.000000
After  TEST: 1.000000 2.000000 3.000000

with -mfpmath=sse,387

Before TEST: 1.000000 2.000000 3.000000
In     TEST: 1.000000 2.000000 nan
After  TEST: 1.000000 2.000000 3.000000


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
 GCC target triplet|                            |i?86-*-*
           Keywords|                            |wrong-code
      Known to fail|                            |4.0.3 4.1.1 4.1.2
      Known to work|                            |3.4.6 4.2.0
   Last reconfirmed|0000-00-00 00:00:00         |2006-09-06 14:23:10
               date|                            |
            Summary|optimized bug with ia32 sse |[4.0/4.1 Regression]
                   |                            |optimized bug with ia32 sse
   Target Milestone|---                         |4.0.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960

[Bug target/28960] [4.0/4.1 Regression] optimized bug with ia32 sse

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2006-10-16 10:16 -------
Differences mainline vs. 4.1.x are

@@ -8,14 +8,19 @@
 test:
        pushl   %ebp
        movl    %esp, %ebp
-       subl    $40, %esp
-       movss   12(%ebp), %xmm1
-       movaps  %xmm1, %xmm2
-       unpcklps        %xmm1, %xmm2
-       movaps  %xmm2, %xmm0
+       subl    $56, %esp
+       movd    12(%ebp), %mm1
+       movq    %mm1, %mm2
+       punpckldq       %mm2, %mm2
+       movd    %mm1, -4(%ebp)
+       movss   -4(%ebp), %xmm1
        xorps   %xmm2, %xmm2
        unpcklps        %xmm2, %xmm1
-       movlhps %xmm1, %xmm0
+       movaps  %xmm1, %xmm0
+       movq    %mm2, -16(%ebp)
+       movq2dq %mm2, %xmm1
+       movlhps %xmm0, %xmm1
+       movaps  %xmm1, %xmm0
        addps   mm, %xmm0
        movaps  %xmm0, mm
        movl    8(%ebp), %eax

i.e. 4.1.x uses MMX code here.  This is PR28825 actually, I'll do a backport.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |28825
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2006-09-06 14:23:10         |2006-10-16 10:16:09
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960

[Bug target/28960] [4.0/4.1 Regression] optimized bug with ia32 sse

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2006-10-16 11:35 -------
Subject: Bug 28960

Author: rguenth
Date: Mon Oct 16 11:34:44 2006
New Revision: 117784

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=117784
Log:
2006-10-16  Richard Guenther  <rguenther@suse.de>

        PR target/28960
        Backport from mainline:
        2006-08-23  Stuart Hastings  <stuart@apple.com>

        PR target/28825
        * gcc/config/i386/i386.c (ix86_expand_vector_init_duplicate,
        ix86_expand_vector_init_one_nonzero): Remove TARGET_SSE test.

        * gcc.target/i386/20060821-1.c: New.

Added:
    branches/gcc-4_1-branch/gcc/testsuite/gcc.target/i386/20060821-1.c
      - copied unchanged from r116356,
trunk/gcc/testsuite/gcc.target/i386/20060821-1.c
Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/config/i386/i386.c
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960

[Bug target/28960] [4.0 Regression] optimized bug with ia32 sse

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2006-10-16 11:35 -------
Fixed on the 4.1 branch.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|rguenth at gcc dot gnu dot  |unassigned at gcc dot gnu
                   |org                         |dot org
             Status|ASSIGNED                    |NEW
            Summary|[4.0/4.1 Regression]        |[4.0 Regression] optimized
                   |optimized bug with ia32 sse |bug with ia32 sse


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960

[Bug target/28960] [4.0 Regression] optimized bug with ia32 sse

[gdr at gcc dot gnu dot org]

------- Comment #5 from gdr at gcc dot gnu dot org  2007-02-03 19:43 -------
Fixed in GCC-4.1.2.


-- 

gdr at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.0.4                       |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960