[Bug target/39716] New: [cond-optab] worse MAX_EXPR expansion for Thumb

[Bug target/39716] New: [cond-optab] worse MAX_EXPR expansion for Thumb

[bonzini at gnu dot org]

/* -O1 -mthumb -march=armv6t2 -ffinite-math-only */

float repl1 (float varx)
{
  if (varx < 0.0)
    return 0.0;
    return varx;
}


-- 
           Summary: [cond-optab] worse MAX_EXPR expansion for Thumb
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bonzini at gnu dot org
OtherBugsDependingO 39714
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] [4.5 Regression][cond-optab] worse MAX_EXPR expansion for Thumb

[bonzini at gnu dot org]

-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] [4.5 Regression][cond-optab] worse MAX_EXPR expansion for Thumb

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
 GCC target triplet|                            |arm
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] [4.5 Regression][cond-optab] worse MAX_EXPR expansion for Thumb

[bonzini at gnu dot org]

------- Comment #1 from bonzini at gnu dot org  2009-07-14 20:35 -------
This fails for me with r149508 with a reload failure.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] [4.5 Regression][cond-optab] worse MAX_EXPR expansion for Thumb

[ramana at gcc dot gnu dot org]

------- Comment #2 from ramana at gcc dot gnu dot org  2009-08-19 08:59 -------
(In reply to comment #1)
> This fails for me with r149508 with a reload failure.
> 

I don't seem to have a reload failure for this with 150624.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] [4.5 Regression][cond-optab] worse MAX_EXPR expansion for Thumb

[ramana at gcc dot gnu dot org]

------- Comment #3 from ramana at gcc dot gnu dot org  2009-09-09 11:08 -------
There isn't a reload failure  with trunk as of yesterday. 

Paolo can you explain this further ?


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] suboptimal MAX_EXPR expansion for Thumb

[bonzini at gnu dot org]

------- Comment #4 from bonzini at gnu dot org  2009-09-09 15:11 -------
I don't see the reload failure anymore.

The code is:

        push    {r4, lr}
        mov     r4, r0
        mov     r1, #0
        bl      __gesf2
        cmp     r0, #0
        it      lt
        movlt   r4, #0
        mov     r0, r4
        pop     {r4, pc}

Pre-cond-optab, we generated

        push    {r4, lr}
        mov     r4, r0
        mov     r1, #0
        bl      __gesf2
        cmp     r0, #0
        mov     r0, #0      <<<<
        it      ge
        movge   r0, r4
        pop     {r4, pc}

So this is fixed.  I'm leaving this bug open as an enhancement though because
the highlighted mov is redundant.


-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|39714                       |
              nThis|                            |
           Severity|normal                      |enhancement
             Status|WAITING                     |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |missed-optimization
           Priority|P2                          |P3
   Last reconfirmed|0000-00-00 00:00:00         |2009-09-09 15:11:09
               date|                            |
            Summary|[4.5 Regression][cond-optab]|suboptimal MAX_EXPR
                   |worse MAX_EXPR expansion for|expansion for Thumb
                   |Thumb                       |
   Target Milestone|4.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] suboptimal MAX_EXPR expansion for Thumb

[steven at gcc dot gnu dot org]

------- Comment #5 from steven at gcc dot gnu dot org  2010-02-08 11:29 -------
Trunk today (r156595) produces this:

repl1:
        @ args = 0, pretend = 0, frame = 0
        @ frame_needed = 0, uses_anonymous_args = 0
        push    {r4, lr}
        mov     r4, r0
        mov     r1, #0
        bl      __gesf2
        cmp     r0, #0
        it      lt
        movlt   r4, #0
        mov     r0, r4
        pop     {r4, pc}

Regarding the redundant mov of comment #4: There is another PR about missed
implicit sets after reload, see bug 14770. I'm sure this is the same issue.

Thus, fixed.


-- 

steven at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716

[Bug target/39716] suboptimal MAX_EXPR expansion for Thumb

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39716