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* [Bug optimization/4079] unnecessary register move on simple code
       [not found] <20010822061601.4079.mattias@virtutech.se>
@ 2003-06-08 14:07 ` pinskia@physics.uc.edu
  2003-08-06 16:06 ` pinskia at physics dot uc dot edu
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 6+ messages in thread
From: pinskia@physics.uc.edu @ 2003-06-08 14:07 UTC (permalink / raw)
  To: gcc-bugs

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4079


pinskia@physics.uc.edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|0000-00-00 00:00:00         |2003-06-08 14:07:22
               date|                            |


------- Additional Comments From pinskia@physics.uc.edu  2003-06-08 14:07 -------
It is alittle better on the mainline (20030607) but still exits though:

_mulh:
        mulhwu r2,r3,r4
        mr r3,r2
        blr


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug optimization/4079] unnecessary register move on simple code
       [not found] <20010822061601.4079.mattias@virtutech.se>
  2003-06-08 14:07 ` [Bug optimization/4079] unnecessary register move on simple code pinskia@physics.uc.edu
@ 2003-08-06 16:06 ` pinskia at physics dot uc dot edu
  2003-08-11 18:22 ` pinskia at gcc dot gnu dot org
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 6+ messages in thread
From: pinskia at physics dot uc dot edu @ 2003-08-06 16:06 UTC (permalink / raw)
  To: gcc-bugs

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4079



------- Additional Comments From pinskia at physics dot uc dot edu  2003-08-06 16:06 -------
Actually this is another libcall problem like PR11825.


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug optimization/4079] unnecessary register move on simple code
       [not found] <20010822061601.4079.mattias@virtutech.se>
  2003-06-08 14:07 ` [Bug optimization/4079] unnecessary register move on simple code pinskia@physics.uc.edu
  2003-08-06 16:06 ` pinskia at physics dot uc dot edu
@ 2003-08-11 18:22 ` pinskia at gcc dot gnu dot org
  2003-08-29 15:32 ` pinskia at gcc dot gnu dot org
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2003-08-11 18:22 UTC (permalink / raw)
  To: gcc-bugs

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4079


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug optimization/4079] unnecessary register move on simple code
       [not found] <20010822061601.4079.mattias@virtutech.se>
                   ` (2 preceding siblings ...)
  2003-08-11 18:22 ` pinskia at gcc dot gnu dot org
@ 2003-08-29 15:32 ` pinskia at gcc dot gnu dot org
  2004-03-29  5:32 ` pinskia at gcc dot gnu dot org
  2004-03-29  5:34 ` pinskia at gcc dot gnu dot org
  5 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2003-08-29 15:32 UTC (permalink / raw)
  To: gcc-bugs

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4079



------- Additional Comments From pinskia at gcc dot gnu dot org  2003-08-29 15:32 -------
Here is more information on how I say this is libcall problem:
(insn 16 12 13 0 (clobber (reg:DI 123)) -1 (nil)
    (insn_list:REG_LIBCALL 17 (nil)))

(insn 13 16 15 0 (set (subreg:SI (reg:DI 123) 4)
        (subreg:SI (reg:DI 122) 0)) 308 {*movsi_internal1} (insn_list 12 (insn_list 16 (nil)))
    (expr_list:REG_DEAD (reg:DI 122)
        (expr_list:REG_NO_CONFLICT (reg:DI 122)
            (nil))))

(insn 15 13 17 0 (set
 (subreg:SI (reg:DI 123) 0)
        (const_i
nt 0 [0x0])) 308
 
{*movsi_internal1} (insn_list 13 (nil))
    (expr_list:REG_NO_CONFLICT (reg:DI 122)
        (nil)))

(insn 17 15 23 0 (set (reg:DI 123)
        (reg:DI 123)) 331 {*movdi_internal32} (insn_list 15 (nil))
    (insn_list:REG_RETVAL 16 (expr_list:REG_EQUAL (lshiftrt:DI (reg:DI 122)
                (const_int 32 [0x20]))
            (nil))))  <--- why is this here, this is causing the problem??


Maybe the fix is to implement (lshiftrt:DI (reg:DI 122) (const_int 32 [0x20])) as an expand 
in the md file.


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug optimization/4079] unnecessary register move on simple code
       [not found] <20010822061601.4079.mattias@virtutech.se>
                   ` (3 preceding siblings ...)
  2003-08-29 15:32 ` pinskia at gcc dot gnu dot org
@ 2004-03-29  5:32 ` pinskia at gcc dot gnu dot org
  2004-03-29  5:34 ` pinskia at gcc dot gnu dot org
  5 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-03-29  5:32 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-29 05:32 -------
Using unions make the code not use a "mv" instruction:
unsigned mulh(unsigned a, unsigned b)
{
    union a{
    unsigned long long ull;
    unsigned long ul[2];
    }ullul;
    ullul.ull = ((unsigned long long)a * (unsigned long long)b);
    return ullul.ul[1];
}

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2003-11-28 07:53:38         |2004-03-29 05:32:12
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4079


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [Bug optimization/4079] unnecessary register move on simple code
       [not found] <20010822061601.4079.mattias@virtutech.se>
                   ` (4 preceding siblings ...)
  2004-03-29  5:32 ` pinskia at gcc dot gnu dot org
@ 2004-03-29  5:34 ` pinskia at gcc dot gnu dot org
  5 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-03-29  5:34 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-29 05:34 -------
I was wrong as I put the wrong array reference, it should have been [2] instead of [1].
But it still has a mr. :(

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4079


^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2004-03-29  5:34 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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     [not found] <20010822061601.4079.mattias@virtutech.se>
2003-06-08 14:07 ` [Bug optimization/4079] unnecessary register move on simple code pinskia@physics.uc.edu
2003-08-06 16:06 ` pinskia at physics dot uc dot edu
2003-08-11 18:22 ` pinskia at gcc dot gnu dot org
2003-08-29 15:32 ` pinskia at gcc dot gnu dot org
2004-03-29  5:32 ` pinskia at gcc dot gnu dot org
2004-03-29  5:34 ` pinskia at gcc dot gnu dot org

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