[Bug rtl-optimization/20070] New: If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[Bug rtl-optimization/20070] New: If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

If-conversion currently lacks the ability to merge two
basic blocks that are identical except for an input register
that can be set up using a conditional move, and possibly some
different local registers.

Cross-jumping lacks the ability to recognize that two blocks are
equivalent when there are different local registers, and (for -Os)
to find opportunities where setting up input registers will allow
to do cross jumping.

The problem has been discussed here:
http://gcc.gnu.org/ml/gcc-patches/2004-01/msg03281.html
http://gcc.gnu.org/ml/gcc-patches/2005-01/msg00672.html

A patch against 4.0 20050218 has been posted here:
http://gcc.gnu.org/ml/gcc-patches/2005-02/msg01066.html

-- 
           Summary: If-conversion can't match equivalent code, and cross-
                    jumping only works for literal matches
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Keywords: missed-optimization, patch
          Severity: enhancement
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: amylaar at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
OtherBugsDependingO 17652
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-19 05:04 -------
Confirmed based on RTH's comments to the patch.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-02-19 05:04:56
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-02-21 15:44 -------
regression testing of the patch in gcc 4.0 20050218 was successful.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-02-21 16:38 -------
While merging the patch in a 3.4.3 based branch, I noticed three small issues:

- The rest_of_handle_life prototype in passes.c is not necessary.  It is a
  vestige from a previous (more intrusive) attempt to provide life
  information to if_convert.
- In passes.c:rest_of_handle_if_conversion, at the end of the
  flag_expensive_optimizations code, EXIT_BLOCK_PTR->global_live_at_start
  has to be cleared for compatibility with this patch:

  2004-05-17  J"orn Rennecke <joern.rennecke@superh.com>

        * cse.c (trivially_dead_nonlocal_regs): New variable.
        (note_dead_set): New function.
        (delete_trivially_dead_insns): If life info is available, update it.

  For completeness, we might also clear ENTRY_BLOCK_PTR->global_live_at_end.
- config/pa/pa.c:pa_commutative_p is missing the parameter list:
  (rtx x, int outer_code)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-03-02 22:06 -------
The recog.c / recog.h part of the patch has been committed as part
of another patch:
http://gcc.gnu.org/ml/gcc-patches/2005-03/msg00133.html

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-03 02:44 -------
(In reply to comment #4)
> The recog.c / recog.h part of the patch has been committed as part
> of another patch:
> http://gcc.gnu.org/ml/gcc-patches/2005-03/msg00133.html

Yes this also caused a regression on ppc-darwin (it might also be reproducable with ppc-elf and ppc-
linux).

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[joern dot rennecke at st dot com]

------- Additional Comments From joern dot rennecke at st dot com  2005-03-03 14:59 -------
Subject: Re:  If-conversion can't match equivalent code, and cross-jumping only works for literal matches

pinskia at gcc dot gnu dot org wrote:

>------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-03 02:44 -------
>(In reply to comment #4)
>  
>
>>The recog.c / recog.h part of the patch has been committed as part
>>of another patch:
>>http://gcc.gnu.org/ml/gcc-patches/2005-03/msg00133.html
>>    
>>
>
>Yes this also caused a regression on ppc-darwin (it might also be reproducable with ppc-elf and ppc-
>linux).
>
>  
>
I've tried ppc-eabisim, but can't reproduce a failure there building gcc 
or newlib.  powerpc-apple-darwin7.4.0
wants lots of include files which I don't have.  Could you send me a 
preprocessed file so that I can test my patch
against that?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-04-12 18:56 -------
PR and patch predate gcc 4.0 branch.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |17652
              nThis|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |21767


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-06-01 11:59 -------
For the purposes of PR20070, it is sufficient that PR21767 is fixed on mainline.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|21767                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-07-07 18:29 -------
An updated patch is here:
http://gcc.gnu.org/ml/gcc-patches/2005-07/msg00482.html

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-07-12 13:14 -------
An updated patch is here:
http://gcc.gnu.org/ml/gcc-patches/2005-07/msg00843.html

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-07-12 13:30 -------
Subject: Bug 20070

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	sh-elf-4_1-branch
Changes by:	amylaar@gcc.gnu.org	2005-07-12 13:29:58

Modified files:
	gcc            : ChangeLog basic-block.h cfgcleanup.c ifcvt.c 
	                 recog.c recog.h 

Log message:
	PR rtl-optimization/20070
	http://gcc.gnu.org/ml/gcc-patches/2005-07/msg00843.html
	* basic-block.h (STRUCT_EQUIV_START, STRUCT_EQUIV_RERUN): Define.
	(STRUCT_EQUIV_FINAL, STRUCT_EQUIV_MAX_LOCAL): Likewise.
	(struct struct_equiv_checkpoint, struct equiv_info): Likewise.
	(struct_equiv_block_eq): Declare.
	* cfgcleanup.c (reload.h, expr.h): #include.
	(IMPOSSIBLE_MOVE_FACTOR): Define.
	(flow_find_cross_jump): Remove.
	(assign_reg_reg_set, struct_equiv, struct_equiv_set): New functions.
	(struct_equiv_dst_mem, struct_equiv_make_checkpoint): Likewise.
	(struct_equiv_improve_checkpoint): Likewise.
	(struct_equiv_restore_checkpoint, struct_equiv_death): Likewise.
	(struct_equiv_block_eq): Likewise.
	(find_dying_inputs, resolve_input_conflict): Likewise.
	(try_crossjump_to_edge): Use struct_equiv_block_eq instead of
	flow_find_cross_jump.
	* ifcvt.c (noce_try_complex_cmove): New function.
	(noce_process_if_block): Call it.
	For flag_expensive_optimizations, update cond_exec_changed_p on
	success.
	(rest_of_handle_if_conversion): For flag_expensive_optimizations,
	provide if_convert with register lifeness info.
	
	Back out this change:
	2005-03-07  Kazu Hirata  <kazu@cs.umass.edu>
	* recog.c (verify_changes): Make it static.
	* recog.h: Remove the corresponding prototype.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=2.8142.2.17&r2=2.8142.2.18
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/basic-block.h.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=1.246.2.2&r2=1.246.2.3
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cfgcleanup.c.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=1.143.2.1&r2=1.143.2.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ifcvt.c.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=1.184.2.1&r2=1.184.2.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/recog.c.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=1.221.4.1&r2=1.221.4.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/recog.h.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=1.55.4.1&r2=1.55.4.2



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[amylaar at gcc dot gnu dot org]

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-07-15 14:07 -------
An updated patch is here:
http://gcc.gnu.org/ml/gcc-patches/2005-07/msg01041.html

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070

[Bug rtl-optimization/20070] If-conversion can't match equivalent code, and cross-jumping only works for literal matches

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-07-15 14:25 -------
Subject: Bug 20070

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	sh-elf-4_1-branch
Changes by:	amylaar@gcc.gnu.org	2005-07-15 14:25:24

Modified files:
	gcc            : cfgcleanup.c ChangeLog 

Log message:
	Update this patch:
	2005-07-14  J"orn Rennecke <joern.rennecke@st.com>
	
	PR rtl-optimization/20070
	http://gcc.gnu.org/ml/gcc-patches/2005-07/msg01041.html
	* basic-block.h (STRUCT_EQUIV_START, STRUCT_EQUIV_RERUN): Define.
	(STRUCT_EQUIV_FINAL, STRUCT_EQUIV_MAX_LOCAL): Likewise.
	(struct struct_equiv_checkpoint, struct equiv_info): Likewise.
	(struct_equiv_block_eq): Declare.
	* cfgcleanup.c (reload.h, expr.h): #include.
	(IMPOSSIBLE_MOVE_FACTOR): Define.
	(flow_find_cross_jump): Remove.
	(assign_reg_reg_set, struct_equiv, struct_equiv_set): New functions.
	(struct_equiv_dst_mem, struct_equiv_make_checkpoint): Likewise.
	(struct_equiv_improve_checkpoint): Likewise.
	(struct_equiv_restore_checkpoint, struct_equiv_death): Likewise.
	(struct_equiv_block_eq): Likewise.
	(find_dying_inputs, resolve_input_conflict): Likewise.
	(try_crossjump_to_edge): Use struct_equiv_block_eq instead of
	flow_find_cross_jump.
	* ifcvt.c (noce_try_complex_cmove): New function.
	(noce_process_if_block): Call it.
	For flag_expensive_optimizations, update cond_exec_changed_p on
	success.
	(rest_of_handle_if_conversion): For flag_expensive_optimizations,
	provide if_convert with register lifeness info.
	
	Back out this change:
	2005-03-07  Kazu Hirata  <kazu@cs.umass.edu>
	* recog.c (verify_changes): Make it static.
	* recog.h: Remove the corresponding prototype.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cfgcleanup.c.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=1.143.2.3&r2=1.143.2.4
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=sh-elf-4_1-branch&r1=2.8142.2.22&r2=2.8142.2.23



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20070