[Bug target/27707] New: g++.dg/tree-ssa/ivopts-1.C fails

[Bug target/27707] New: g++.dg/tree-ssa/ivopts-1.C fails

[jsm28 at gcc dot gnu dot org]

FAIL: g++.dg/tree-ssa/ivopts-1.C scan-tree-dump-not &x\[5\]
FAIL: g++.dg/tree-ssa/ivopts-1.C scan-tree-dump-not offset: -4B

appeared on mainline on hppa2.0w-hp-hpux11.11 and hppa64-hp-hpux11.11 when the
test was added.


-- 
           Summary: g++.dg/tree-ssa/ivopts-1.C fails
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jsm28 at gcc dot gnu dot org
GCC target triplet: hppa*-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug target/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2006-05-22 09:05 -------
Mine.  I'll add an XFAIL as for x86_64/i?86 - looks like hppa is another target
with weird costs.


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rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-05-22 09:05:49
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2006-05-22 09:20 -------
Fixed.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |testsuite
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2006-05-22 09:21 -------
Subject: Bug 27707

Author: rguenth
Date: Mon May 22 09:20:46 2006
New Revision: 113972

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113972
Log:
2006-05-22  Richard Guenther  <rguenther@suse.de>

        PR testsuite/27707
        * g++.dg/tree-ssa/ivopts-1.C: XFAIL for hppa*-*-*.

Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/tree-ssa/ivopts-1.C


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2006-06-09 10:24 -------
Fixed.


-- 

rguenth at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[danglin at gcc dot gnu dot org]

------- Comment #5 from danglin at gcc dot gnu dot org  2006-09-09 18:25 -------
I would like to request that this bug to be reopened.

First, the test never failed on hppa*-*-linux*, so we now have two
XPASS's on this target.  Second, between 15 and 17 August, the second
xfail for hppa*-*-* changed to an XPASS on hppa*-*-hpux*.  Third,
there's no PR for the "-4B" offset that's still present on hppa*-*-hpux*.

PR 26726, which added the testcase, points to PR target/24669 as
the remaining issue for that issue.  This is characterized as being
a target specific problem, namely that the a more complicated addressing
mode is cheaper than a simpler mode, leading ivopts to prefer the it.
The puzzle in my mind is that there is no obvious difference between
costs for hpux and linux in the PA backend.


-- 

danglin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |danglin at gcc dot gnu dot
                   |                            |org
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2006-09-09 18:34 -------
I don't know what should be the difference between hpux and linux PA, though
this is an issue of IVOPTs and rtl costs.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu dot
                   |                            |org
         AssignedTo|rguenth at gcc dot gnu dot  |unassigned at gcc dot gnu
                   |org                         |dot org
             Status|REOPENED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[dave at hiauly1 dot hia dot nrc dot ca]

------- Comment #7 from dave at hiauly1 dot hia dot nrc dot ca  2006-09-09 18:45 -------
Subject: Re:  g++.dg/tree-ssa/ivopts-1.C fails

> I don't know what should be the difference between hpux and linux PA, though
> this is an issue of IVOPTs and rtl costs.

I've the dump files for hppa-unknown-linux-gnu and hppa2.0w-hp-hpux11.11.

Dave


------- Comment #8 from dave at hiauly1 dot hia dot nrc dot ca  2006-09-09 18:45 -------
Created an attachment (id=12213)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12213&action=view)


------- Comment #9 from dave at hiauly1 dot hia dot nrc dot ca  2006-09-09 18:45 -------
Created an attachment (id=12214)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12214&action=view)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenther at suse dot de]

------- Comment #10 from rguenther at suse dot de  2006-09-09 20:37 -------
Subject: Re:  g++.dg/tree-ssa/ivopts-1.C fails

On Sat, 9 Sep 2006, dave at hiauly1 dot hia dot nrc dot ca wrote:

> ------- Comment #7 from dave at hiauly1 dot hia dot nrc dot ca  2006-09-09 18:45 -------
> Subject: Re:  g++.dg/tree-ssa/ivopts-1.C fails
> 
> > I don't know what should be the difference between hpux and linux PA, though
> > this is an issue of IVOPTs and rtl costs.
> 
> I've the dump files for hppa-unknown-linux-gnu and hppa2.0w-hp-hpux11.11.

It confirms that it is the same problem as on i?86, but it doesn't tell
why.  I don't see an obvious difference in config/pa/

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[dave at hiauly1 dot hia dot nrc dot ca]

------- Comment #11 from dave at hiauly1 dot hia dot nrc dot ca  2006-09-10 00:02 -------
Subject: Re:  g++.dg/tree-ssa/ivopts-1.C fails

> It confirms that it is the same problem as on i?86, but it doesn't tell
> why.  I don't see an obvious difference in config/pa/

Yes, it does seem to be the same problem.  The hpux assembler
output has a -4 offset:

        stw %r2,-20(%r30)
L$CFI0000
        ldi 1,%r19
        ldo 128(%r30),%r30
L$CFI0001
        ldo -116(%r30),%r28
        ldo -100(%r30),%r20
        stw %r19,-4(%r28)
L$0008:
        ldo 4(%r28),%r28
        comb,<>,n %r20,%r28,L$0008
        stw %r19,-4(%r28)
        .CALL ARGW0=GR
        bl _Z3fooR3Foo,%r2
        ldo -120(%r30),%r26

The linux output doesn't have the -4 offset:

       ldi 1,%r28
       stw %r2,-20(%r30)
.LCFI0:
       copy %r28,%r21
       ldo 128(%r30),%r30
.LCFI1:
       ldi 4,%r19
       stw %r28,-120(%r30)
       ldo -120(%r30),%r26
       ldi 16,%r20
.L2:
       addl %r19,%r26,%r28
       ldo 4(%r19),%r19
       comb,<> %r20,%r19,.L2
       stw %r21,0(%r28)
       bl _Z3fooR3Foo,%r2
       nop

Offhand, then hpux code appears better optimized.

Dave


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[dave at hiauly1 dot hia dot nrc dot ca]

------- Comment #12 from dave at hiauly1 dot hia dot nrc dot ca  2006-09-10 18:39 -------
Subject: Re:  g++.dg/tree-ssa/ivopts-1.C fails

> The linux output doesn't have the -4 offset:
> 
>        ldi 1,%r28
>        stw %r2,-20(%r30)
> .LCFI0:
>        copy %r28,%r21
>        ldo 128(%r30),%r30
> .LCFI1:
>        ldi 4,%r19
>        stw %r28,-120(%r30)
>        ldo -120(%r30),%r26
>        ldi 16,%r20
> .L2:
>        addl %r19,%r26,%r28
>        ldo 4(%r19),%r19
>        comb,<> %r20,%r19,.L2
>        stw %r21,0(%r28)
>        bl _Z3fooR3Foo,%r2
>        nop

It seems like the code generated for the hppa-unknown-linux-gnu target
has been getting worse in each release since 4.0.0.  Here is the 4.0.0
assembler code:

        stw %r2,-20(%r30)
.LCFI0:
        ldi 1,%r19
        ldo 128(%r30),%r30
.LCFI1:
        ldo -120(%r30),%r28
        ldo -104(%r30),%r20
        stw %r19,0(%r28)
.L8:
        ldo 4(%r28),%r28
        comb,<>,n %r28,%r20,.L8
        stw %r19,0(%r28)
        bl _Z3fooR3Foo,%r2
        ldo -120(%r30),%r26

In this code, the function prologue and loop setup are only six instructions.
The loop is three instructions.  The delay slot for the call to _Z3fooR3Foo
is filled.  The value loaded into r26 is the same as loaded into r28 before
the loop.  I would say this code is close to optimal aside from unrolling
loop completely.

Here is the code generated by Debian 4.1.1-13:

        stw %r2,-20(%r30)
.LCFI0:
        ldi 0,%r19
        ldo 128(%r30),%r30
.LCFI1:
        ldi 1,%r21
        ldo -120(%r30),%r26
        ldi 16,%r20
.L2:
        addl %r19,%r26,%r28
        ldo 4(%r19),%r19
        comb,<> %r20,%r19,.L2
        stw %r21,0(%r28)
        bl _Z3fooR3Foo,%r2
        nop

The prologue and loop setup are still six instructions.  However,
the loop is now four instructions per iteration and we iterate one
more time.  Thus, we have a significant performance regression
relative to 4.0.0 in the handling of this loop.

Possibly, this results from the compiler trying to avoid loading the
address "-120(%r30)" twice.  However, the cost for loading small offsets
is the same as doing a register copy.  A register copy is just a ldo
instruction with an offset of 0.

The 4.2.0 code is worse than the 4.1.1 code in that the prologue and
loop setup have now grown to eight instructions.  However, we are
back to three iterations.  It seems like the compiler may be trying
to avoid non-zero offsets.  I don't know why this would be.
hppa_address_cost is pretty simple.

As far as the the difference between linux and hpux goes, the main
difference is that long doubles are 64 bits on linux and 128 bits
on hpux.  This would affect the sizes of the cost arrays in expmed.c.
I'm wondering if somehow some of the values in these tables are
getting corrupted.

There's one puzzling difference in the linux and hpux tree dumps.
In the hpux dump, some variables are "long unsigned int" whereas in
the linux dump they are "unsigned int".

Dave


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[mmitchel at gcc dot gnu dot org]

------- Comment #13 from mmitchel at gcc dot gnu dot org  2007-05-14 22:26 -------
Will not be fixed in 4.2.0; retargeting at 4.2.1.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.0                       |4.2.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.1                       |4.2.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[mmitchel at gcc dot gnu dot org]

------- Comment #14 from mmitchel at gcc dot gnu dot org  2007-10-09 19:21 -------
Change target milestone to 4.2.3, as 4.2.2 has been released.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.2                       |4.2.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[jsm28 at gcc dot gnu dot org]

------- Comment #15 from jsm28 at gcc dot gnu dot org  2008-02-01 16:52 -------
4.2.3 is being released now, changing milestones of open bugs to 4.2.4.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.3                       |4.2.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenth at gcc dot gnu dot org]

------- Comment #16 from rguenth at gcc dot gnu dot org  2008-02-01 16:58 -------
Dave, is this test still failing on hppa?  On the branch and trunk?


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[dave at hiauly1 dot hia dot nrc dot ca]

------- Comment #17 from dave at hiauly1 dot hia dot nrc dot ca  2008-02-01 18:08 -------
Subject: Re:  g++.dg/tree-ssa/ivopts-1.C fails

> Dave, is this test still failing on hppa?  On the branch and trunk?

It is not failing on either 4.2 or trunk.  Checked hppa-unknown-linux-gnu,
hppa2.0w-hp-hpux11.11 and hppa64-hp-hpux11.11.

Dave


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[rguenth at gcc dot gnu dot org]

------- Comment #18 from rguenth at gcc dot gnu dot org  2008-02-01 18:13 -------
Thus fixed.


-- 

rguenth at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707

[Bug testsuite/27707] g++.dg/tree-ssa/ivopts-1.C fails

[dave at hiauly1 dot hia dot nrc dot ca]

------- Comment #19 from dave at hiauly1 dot hia dot nrc dot ca  2008-02-01 18:23 -------
Subject: Re:  g++.dg/tree-ssa/ivopts-1.C fails

> Thus fixed.

The test needs adjustment.

Dave


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27707