[Bug optimization/14063] New: conditional around vec_dss() call disappears at -O2

[Bug optimization/14063] New: conditional around vec_dss() call disappears at -O2

[leblanc at skycomputers dot com]

The problem does NOT occur at lower optimization levels.

Configured with:
    ../gnu-tool-chain/gcc/configure
    --with-cpu=7450
    --enable-altivec
    --enable-shared
    --enable-threads=posix
    --enable-languages=c,c++
    --disable-checking
    --with-system-zlib
    --enable-__cxa_atexit
    --host=ppc-sky-linux
    --target=ppc-sky-linux
    --prefix=/usr/local

Thread model: posix

Source mike.c:
#include <altivec.h>
void dstt_bug(int i, int j, char *mem)
{
    if (i == 0)
        vec_dss(1);
}

Command line:
    gcc mike.c -S -O2 -maltivec

No messages; mike.s shows bug:
        .file   "mike.c"
        .section        ".text"
        .align 2
        .globl dstt_bug
        .type   dstt_bug, @function
dstt_bug:
        stwu 1,-16(1)
        dss 1
        addi 1,1,16
        blr
        .size   dstt_bug, .-dstt_bug
        .ident  "GCC: (GNU) 3.3"

mike.i:
# 1 "mike.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "mike.c"
# 1 "/usr/local/lib/gcc-lib/ppc-sky-linux/3.3/include/altivec.h" 1 3 4
# 52 "/usr/local/lib/gcc-lib/ppc-sky-linux/3.3/include/altivec.h" 3 4
extern int __altivec_link_error_invalid_argument ();
# 2 "mike.c" 2
void dstt_bug(int i, int j, char *mem)
{
    if (i == 0)
        __builtin_altivec_dss ((1));
}

-- 
           Summary: conditional around vec_dss() call disappears at -O2
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: leblanc at skycomputers dot com
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: ppc-sky-linux
GCC target triplet: ppc-sky-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug optimization/14063] conditional around vec_dss() call disappears at -O2

[leblanc at skycomputers dot com]

------- Additional Comments From leblanc at skycomputers dot com  2004-02-07 17:26 -------
Although the bug does not occur at -O1, it does occur at "-O1 -fschedule-insns".

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug optimization/14063] conditional around vec_dss() call disappears at -O2

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-02-07 17:54 -------
Fixed for 3.4.0 by a slight rewrite.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |3.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug optimization/14063] conditional around vec_dss() call disappears at -O2

[leblanc at skycomputers dot com]

------- Additional Comments From leblanc at skycomputers dot com  2004-02-08 14:30 -------
Subject: Re:  conditional around vec_dss() call disappears at -O2

Could you please indicate what was slightly rewritten?  Would it be 
worth
the effort to try to retrofit the changes into 3.3.*?

Mike LeBlanc

On Feb 7, 2004, at 12:54 PM, pinskia at gcc dot gnu dot org wrote:

> ------- Additional Comments From pinskia at gcc dot gnu dot org  
> 2004-02-07 17:54 -------
> Fixed for 3.4.0 by a slight rewrite.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug optimization/14063] conditional around vec_dss() call disappears at -O2

[leblanc at skycomputers dot com]

------- Additional Comments From leblanc at skycomputers dot com  2004-02-08 16:24 -------
I just fetched the 3.4.0 source, snapshot 20040206, and built it.  The bug remains.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug target/14063] conditional around vec_dss() call disappears at -O2

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-02-08 20:10 -------
Confirmed, the problem is that the machine descriptions are using unspec instead of unspec_volatile.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|optimization                |target
     Ever Confirmed|                            |1
   GCC host triplet|ppc-sky-linux               |
 GCC target triplet|ppc-sky-linux               |powerpc-*-*
           Keywords|                            |wrong-code
   Last reconfirmed|0000-00-00 00:00:00         |2004-02-08 20:10:06
               date|                            |
   Target Milestone|3.4.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug target/14063] conditional around vec_dss() call disappears at -O2

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
   Last reconfirmed|2004-02-08 20:10:06         |2004-05-10 16:49:33
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug target/14063] conditional around vec_dss() call disappears at -O2

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-05-11 04:22 -------
Subject: Bug 14063

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	pinskia@gcc.gnu.org	2004-05-11 04:22:05

Modified files:
	gcc            : ChangeLog 
	gcc/config/rs6000: altivec.md 

Log message:
	2004-05-11  Andrew Pinski  <pinskia@gcc.gnu.org>
	
	PR target/14063
	* config/rs6000/altivec.md (altivec_dssall):
	Change to unspec_volatile.
	(altivec_dss): Likewise.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.3622&r2=2.3623
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/config/rs6000/altivec.md.diff?cvsroot=gcc&r1=1.19&r2=1.20



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug target/14063] conditional around vec_dss() call disappears at -O2

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-11 04:22 -------
Fixed in the mainline for 3.5.0.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063

[Bug target/14063] conditional around vec_dss() call disappears at -O2

[leblanc at skycomputers dot com]

------- Additional Comments From leblanc at skycomputers dot com  2004-05-11 14:53 -------
The same change should be appled to these instructions as well:
    dst
    dstt
    dstst
    dststt

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14063