[Bug rtl-optimization/8361] [3.4/4.0/4.1 regression] C++ compile-time performance regression

[Bug rtl-optimization/8361] [3.4/4.0/4.1 regression] C++ compile-time performance regression

[ian at airs dot com]

------- Comment #56 from ian at airs dot com  2005-10-12 05:26 -------
Is this PR really a 4.0 regression?  The timings which I see in the comments
suggest that 4.0 is just as fast as earlier releases.

That is, the PR may have become a 4.1 regression, but I don't see that it is a
4.0 regression.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug rtl-optimization/8361] [3.4/4.0/4.1 regression] C++ compile-time performance regression

[pinskia at gcc dot gnu dot org]

------- Comment #57 from pinskia at gcc dot gnu dot org  2005-10-13 03:34 -------
A semi recent 4.1 (the 10th) gives:
 tree PTA              :   1.60 ( 6%) usr   0.02 ( 1%) sys   1.73 ( 6%) wall  
10338 kB ( 1%) ggc
 tree alias analysis   :   1.32 ( 5%) usr   0.19 (10%) sys   1.48 ( 5%) wall  
18910 kB ( 3%) ggc

while 4.0 gave:
 tree PTA              :   0.50 ( 2%) usr   0.00 ( 0%) sys   0.48 ( 2%) wall
 tree alias analysis   :   0.73 ( 3%) usr   0.00 ( 0%) sys   0.76 ( 3%) wall

So this is definitely a 4.1 regression.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

Re: [Bug rtl-optimization/8361] [3.4/4.0/4.1 regression] C++ compile-time performance regression

[Daniel Berlin]

On Thu, 2005-10-13 at 03:34 +0000, pinskia at gcc dot gnu dot org wrote:
> 
> ------- Comment #57 from pinskia at gcc dot gnu dot org  2005-10-13 03:34 -------
> A semi recent 4.1 (the 10th) gives:
>  tree PTA              :   1.60 ( 6%) usr   0.02 ( 1%) sys   1.73 ( 6%) wall  
> 10338 kB ( 1%) ggc
>  tree alias analysis   :   1.32 ( 5%) usr   0.19 (10%) sys   1.48 ( 5%) wall  
> 18910 kB ( 3%) ggc
> 
> while 4.0 gave:
>  tree PTA              :   0.50 ( 2%) usr   0.00 ( 0%) sys   0.48 ( 2%) wall
>  tree alias analysis   :   0.73 ( 3%) usr   0.00 ( 0%) sys   0.76 ( 3%) wall
> 
> So this is definitely a 4.1 regression.
> 
> 

I'm pretty sure we run PTA more times in 4.1 than 4.0
Maybe i'm wrong.
Can you oprofile this and give me some kind of hotspot to look into in
PTA?

[Bug rtl-optimization/8361] [3.4/4.0/4.1 regression] C++ compile-time performance regression

[dberlin at dberlin dot org]

------- Comment #58 from dberlin at gcc dot gnu dot org  2005-10-13 04:07 -------
Subject: Re:  [3.4/4.0/4.1 regression] C++
        compile-time performance regression

On Thu, 2005-10-13 at 03:34 +0000, pinskia at gcc dot gnu dot org wrote:
> 
> ------- Comment #57 from pinskia at gcc dot gnu dot org  2005-10-13 03:34 -------
> A semi recent 4.1 (the 10th) gives:
>  tree PTA              :   1.60 ( 6%) usr   0.02 ( 1%) sys   1.73 ( 6%) wall  
> 10338 kB ( 1%) ggc
>  tree alias analysis   :   1.32 ( 5%) usr   0.19 (10%) sys   1.48 ( 5%) wall  
> 18910 kB ( 3%) ggc
> 
> while 4.0 gave:
>  tree PTA              :   0.50 ( 2%) usr   0.00 ( 0%) sys   0.48 ( 2%) wall
>  tree alias analysis   :   0.73 ( 3%) usr   0.00 ( 0%) sys   0.76 ( 3%) wall
> 
> So this is definitely a 4.1 regression.
> 
> 

I'm pretty sure we run PTA more times in 4.1 than 4.0
Maybe i'm wrong.
Can you oprofile this and give me some kind of hotspot to look into in
PTA?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug rtl-optimization/8361] [4.1 regression] C++ compile-time performance regression

[ian at airs dot com]

------- Comment #59 from ian at airs dot com  2005-10-13 04:13 -------
I'm going to mark this as just a 4.1 regression.  As far as I can see, 4.0 was
OK.  And there is zero chance that we are going to address any of these issues
in 3.4, except perhaps coincidentally.


-- 

ian at airs dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|3.3.3 3.4.0 4.0.0           |4.1.0
      Known to work|3.0.4 2.95.3                |3.0.4 2.95.3 4.0.0
            Summary|[3.4/4.0/4.1 regression] C++|[4.1 regression] C++
                   |compile-time performance    |compile-time performance
                   |regression                  |regression


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1 regression] C++ compile-time performance regression

[mmitchel at gcc dot gnu dot org]

------- Comment #60 from mmitchel at gcc dot gnu dot org  2005-10-30 21:45 -------
I'd like to fix this for 4.1, but not at the expense of destabilizing things,
or losing performance.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1 regression] C++ compile-time performance regression

[pinskia at gcc dot gnu dot org]

------- Comment #61 from pinskia at gcc dot gnu dot org  2005-10-30 23:38 -------
(In reply to comment #60)
> I'd like to fix this for 4.1, but not at the expense of destabilizing things,
> or losing performance.

Does this controdict what you wrote in PR 15678:
> However, in the meanwhile, I've downgraded this to P4.  A small compile-time
> increase isn't going to block the upcoming releases.

This is a small increase really about 2-3 seconds.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[steven at gcc dot gnu dot org]

------- Comment #62 from steven at gcc dot gnu dot org  2006-02-11 15:46 -------
Compile times for generate-3.4.ii
All compilers bootstrapped, with checking disabled.

Flags: -O2

GCC 4.0 (release branch today):
real    0m22.795s       0m22.727s       0m22.760s
user    0m22.481s       0m22.297s       0m22.357s
sys     0m0.316s        0m0.412s        0m0.404s

GCC 4.1 (release branch today):
real    0m29.888s       0m28.450s       0m28.420s
user    0m28.154s       0m27.906s       0m27.894s
sys     0m0.496s        0m0.544s        0m0.524s

GCC 4.2 (trunk today):
real    0m33.715s       0m31.524s       0m31.483s
user    0m31.466s       0m31.034s       0m31.022s
sys     0m0.424s        0m0.492s        0m0.460s



Flags: -O3

GCC 4.0 (release branch today):
real    0m24.412s       0m25.000s       0m24.771s
user    0m23.921s       0m24.430s       0m24.210s
sys     0m0.368s        0m0.408s        0m0.420s

GCC 4.1 (release branch today):
real    0m33.260s       0m33.140s       0m33.188s
user    0m32.602s       0m32.522s       0m32.554s
sys     0m0.556s        0m0.544s        0m0.600s

GCC 4.2 (trunk today):
real    0m36.544s       0m36.614s       0m36.492s
user    0m35.950s       0m35.942s       0m35.994s
sys     0m0.544s        0m0.600s        0m0.464s


Significant compile time sinks in GCC 4.1 that don't appear in GCC 4.0:
 tree PTA              :   2.31 ( 7%) usr
 tree SSA incremental  :   2.14 ( 6%) usr
 expand                :   1.71 ( 5%) usr

The same passes cost the most time in GCC 4.2.  The expand cost has increades. 
The other two are not new, they just run very often or didn't have their own
time vars before.  The overall problem seems to be that we just run too many
passes too often, nothing really stands out.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

Re: [Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[Daniel Berlin]

> Flags: -O3
> 
> GCC 4.0 (release branch today):
> real    0m24.412s       0m25.000s       0m24.771s
> user    0m23.921s       0m24.430s       0m24.210s
> sys     0m0.368s        0m0.408s        0m0.420s
> 
> GCC 4.1 (release branch today):
> real    0m33.260s       0m33.140s       0m33.188s
> user    0m32.602s       0m32.522s       0m32.554s
> sys     0m0.556s        0m0.544s        0m0.600s
> 
> GCC 4.2 (trunk today):
> real    0m36.544s       0m36.614s       0m36.492s
> user    0m35.950s       0m35.942s       0m35.994s
> sys     0m0.544s        0m0.600s        0m0.464s
> 
> 
> Significant compile time sinks in GCC 4.1 that don't appear in GCC 4.0:
>  tree PTA              :   2.31 ( 7%) usr
>  tree SSA incremental  :   2.14 ( 6%) usr
>  expand                :   1.71 ( 5%) usr
> 

So, could you do me a favor if you get a chance, and change the macro
DONT_PROPAGATE_WITH_ANYTHING to 1 in tree-ssa-structalias.c, and see if
it speeds it up at all?

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[dberlin at dberlin dot org]

------- Comment #63 from dberlin at gcc dot gnu dot org  2006-02-11 16:02 -------
Subject: Re:  [4.1/4.2 regression] C++
        compile-time performance regression


> Flags: -O3
> 
> GCC 4.0 (release branch today):
> real    0m24.412s       0m25.000s       0m24.771s
> user    0m23.921s       0m24.430s       0m24.210s
> sys     0m0.368s        0m0.408s        0m0.420s
> 
> GCC 4.1 (release branch today):
> real    0m33.260s       0m33.140s       0m33.188s
> user    0m32.602s       0m32.522s       0m32.554s
> sys     0m0.556s        0m0.544s        0m0.600s
> 
> GCC 4.2 (trunk today):
> real    0m36.544s       0m36.614s       0m36.492s
> user    0m35.950s       0m35.942s       0m35.994s
> sys     0m0.544s        0m0.600s        0m0.464s
> 
> 
> Significant compile time sinks in GCC 4.1 that don't appear in GCC 4.0:
>  tree PTA              :   2.31 ( 7%) usr
>  tree SSA incremental  :   2.14 ( 6%) usr
>  expand                :   1.71 ( 5%) usr
> 

So, could you do me a favor if you get a chance, and change the macro
DONT_PROPAGATE_WITH_ANYTHING to 1 in tree-ssa-structalias.c, and see if
it speeds it up at all?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[steven at gcc dot gnu dot org]

------- Comment #64 from steven at gcc dot gnu dot org  2006-02-12 01:17 -------
DONT_PROPAGATE_WITH_ANYTHING only exists on the trunk.  With that flag, the
timings are:

Flags: -O2

GCC 4.2 (trunk today):
real    0m31.704s
user    0m31.094s
sys     0m0.584s


Flags: -O3

GCC 4.2 (trunk today):
real    0m36.206s
user    0m35.718s
sys     0m0.484s

So, no it doesn't help.

Again, the problem seems to be more that we just run so many passes, not that
one or two specific passes are to blame for most of the compile time.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[mmitchel at gcc dot gnu dot org]

------- Comment #65 from mmitchel at gcc dot gnu dot org  2006-02-24 00:25 -------
This issue will not be resolved in GCC 4.1.0; retargeted at GCC 4.1.1.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.0                       |4.1.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[mmitchel at gcc dot gnu dot org]

------- Comment #66 from mmitchel at gcc dot gnu dot org  2006-05-25 02:31 -------
Will not be fixed in 4.1.1; adjust target milestone to 4.1.2.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.1                       |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[pinskia at gcc dot gnu dot org]

------- Comment #67 from pinskia at gcc dot gnu dot org  2006-07-05 09:06 -------
Does anyone have new numbers for this, Richard G.'s recent memory patches have
an effect on the compile time also I noticed between 7% and 10% on at least
CSiBE.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[steven at gcc dot gnu dot org]

------- Comment #68 from steven at gcc dot gnu dot org  2006-07-25 22:31 -------
New timings.  These were taken on the same box as those of comment #62 and
comment #64 (Intel x86_64 3.20GHz, 1GB ram).  Times are usr times 

Invokation: time g++ -S -fpermissive -Ox -m64 generate-3.4.ii
GC params for cc1plus: --param ggc-min-expand=98 --param
ggc-min-heapsize=127550

version         ID              -O2             -O3
GCC 3.4         3.4.6           0m23.673s       0m24.362s
GCC 4.0         4.0.4 20060725  0m23.009s       0m23.849s
GCC 4.1         4.1.2 20060725  0m24.018s       0m25.294s
GCC 4.2         4.2.0 20060724  0m25.214s       0m26.242s


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[steven at gcc dot gnu dot org]

------- Comment #69 from steven at gcc dot gnu dot org  2006-07-25 22:35 -------
Re. comment #68, I should have added that all compilers were built with "gcc
(GCC) 4.0.2 20050901 (prerelease) (SUSE Linux)" with CFLAGS="-O2 -g".


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8361

[Bug tree-optimization/8361] [4.1/4.2 regression] C++ compile-time performance regression

[steven at gcc dot gnu dot org]

------- Comment #70 from steven at gcc dot gnu dot org  2006-09-03 10:39 -------
Based on my numbers of comment #69, I'm declaring this fixed once more.


-- 

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=8361