[Bug rtl-optimization/38034] New: Unnecssary register move

[Bug rtl-optimization/38034] New: Unnecssary register move

[hjl dot tools at gmail dot com]

[hjl@gnu-14 prev-gcc]$ cat /tmp/x.c
#include <ia64intrin.h>

int
foo (int *p)
{
  return __sync_lock_test_and_set (p, 0);
}
[hjl@gnu-14 prev-gcc]$ ./xgcc -B./ -O2 -S /tmp/x.c 
[hjl@gnu-14 prev-gcc]$ cat x.s
        .file   "x.c"
        .pred.safe_across_calls p1-p5,p16-p63
        .text
        .align 16
        .align 64
        .global foo#
        .type   foo#, @function
        .proc foo#
foo:
        .prologue
        .body
        .mmi
        nop 0
        mov r8 = r0
        nop 0
        ;;
        .mib
        xchg4 r8 = [r32], r8
        nop 0
        br.ret.sptk.many b0
        .endp foo#
        .ident  "GCC: (GNU) 4.4.0 20081106 (experimental) [trunk revision
141649]"
[hjl@gnu-14 prev-gcc]$ 

We don't need

mov r8 = r0

We should generate

xchg4 r8 = [r32], r0


-- 
           Summary: Unnecssary register move
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: ra
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hjl dot tools at gmail dot com
GCC target triplet: ia64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38034

[Bug rtl-optimization/38034] Unnecssary register move

[jakub at gcc dot gnu dot org]

------- Comment #1 from jakub at gcc dot gnu dot org  2008-11-06 21:41 -------
Created an attachment (id=16629)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16629&action=view)
gcc44-pr38034.patch

Untested patch to fix it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38034

[Bug rtl-optimization/38034] Unnecssary register move

[hjl dot tools at gmail dot com]

------- Comment #2 from hjl dot tools at gmail dot com  2009-02-13 21:58 -------
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00674.html


-- 

hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sje at cup dot hp dot com
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2009-
                   |                            |02/msg00674.html


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38034

[Bug rtl-optimization/38034] Unnecssary register move

[hjl at gcc dot gnu dot org]

------- Comment #3 from hjl at gcc dot gnu dot org  2009-03-27 22:28 -------
Subject: Bug 38034

Author: hjl
Date: Fri Mar 27 22:28:20 2009
New Revision: 145135

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=145135
Log:
gcc/

2009-03-27  H.J. Lu  <hongjiu.lu@intel.com>
            Jakub Jelinek  <jakub@redhat.com>

        PR target/38034
        * config/ia64/sync.md (cmpxchg_rel_<mode>): Replace input
        gr_register_operand with gr_reg_or_0_operand.
        (cmpxchg_rel_di): Likewise.
        (sync_lock_test_and_set<mode>): Likewise.

gcc/testsuite/

2009-03-27  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/38034
        * gcc.target/ia64/sync-1.c: New.

Added:
    trunk/gcc/testsuite/gcc.target/ia64/sync-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/ia64/sync.md
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38034

[Bug rtl-optimization/38034] Unnecessary register move

[sje at cup dot hp dot com]

------- Comment #4 from sje at cup dot hp dot com  2009-03-30 16:59 -------
Closing this out since it is now fixed for 4.5.


-- 

sje at cup dot hp dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
      Known to fail|                            |4.4.0
      Known to work|                            |4.5.0
         Resolution|                            |FIXED
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38034