[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2005-10-04 06:26 -------
Oh, this is -ftracer being too late in the game problem.


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2005-07-04 22:23:06         |2005-10-04 06:26:03
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2005-11-02 17:16 -------
All P1 enhancements not targeted towards 4.1, moving to P5.


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P1                          |P5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[pinskia at gcc dot gnu dot org]

------- Comment #8 from pinskia at gcc dot gnu dot org  2006-06-08 05:00 -------
Yara is worse as it uses the CTR register.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[pinskia at gcc dot gnu dot org]

------- Comment #9 from pinskia at gcc dot gnu dot org  2008-09-14 04:08 -------
This was fixed for real for 4.3.0, I think by DF.
In .csa:
(insn 132 131 99 16 t.c:40 (set (reg/v:DF 33 1 [orig:126 x ] [126])
        (mem/c:DF (plus:DI (reg/f:DI 1 1)
                (const_int -16 [0xfffffffffffffff0])) [0 S8 A8])) 336
{*movdf_hardfloat64} (nil))

(insn 99 132 136 16 t.c:42 (use (reg/i:DF 33 1 [ <result> ])) -1 (nil))

(jump_insn 136 99 135 16 t.c:42 (return) -1 (nil))


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-11-11 08:49 -------
Subject: Bug 16796

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	nathan@gcc.gnu.org	2004-11-11 08:49:17

Modified files:
	gcc            : ChangeLog 
	gcc/config/rs6000: rs6000.md 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: ppc-mov-1.c 

Log message:
	.:
	PR target/16796
	* config/rs6000/rs6000.md: Add DF & SF reg move peepholes.
	testsuite:
	PR target/16796
	* gcc.dg/ppc-mov-1.c: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6272&r2=2.6273
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/config/rs6000/rs6000.md.diff?cvsroot=gcc&r1=1.332&r2=1.333
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4575&r2=1.4576
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/ppc-mov-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[nathan at gcc dot gnu dot org]

------- Additional Comments From nathan at gcc dot gnu dot org  2004-11-11 08:47 -------
2004-11-11  Nathan Sidwell  <nathan@codesourcery.com>

	PR target/16796
	* config/rs6000/rs6000.md: Add DF & SF reg move peepholes.

partial fix. Now we need a better reg-alloc

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           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |18427
         AssignedTo|nathan at gcc dot gnu dot   |unassigned at gcc dot gnu
                   |org                         |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[nathan at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |nathan at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[nathan at gcc dot gnu dot org]

------- Additional Comments From nathan at gcc dot gnu dot org  2004-11-10 11:01 -------
The fault is not the register allocator, is is a problem introduced by flow2 and
the existance of conditional returns on PPC.  During register allocation
there is one exit block.  The returns are 'x, x, x+x & x', thus the global
allocator sets the exit block to copy 'x' to the return register.  flow2
replaces some of those branches to the exit block with conditional returns,
because 'x' resides in both DF:33 and DF:32.  The remaining use of the exit
is the load from the union into DF:32, the location of 'x' during the function.



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-10-08 13:11 -------
Confirmed, the problem is related to the register allocator.

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           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-10-08 13:11:12
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796

[Bug rtl-optimization/16796] PowerPC - Unnecessary Floating Point Register Copy

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |rtl-optimization
           Keywords|                            |missed-optimization


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16796