[Bug c/16834] New: huge compilation time increase from 3.2.3 to 3.3.2

[Bug c/16834] New: huge compilation time increase from 3.2.3 to 3.3.2

[jozef dot kruger at philips dot com]

I noticed that moving from gcc 3.2.3 to gcc 3.3.2 made compilation time of files
with huge expressions increase by a lot.
What we compile here are simulators for our processors and those programs can
include huge expressions. Attached to this email you'll find a file that
contains a number of expressions of almost 80.000 characters. (it has been
preprocessed and can be easily compiled with: gcc -c -xc toplevel.s.i )

The problem is that with 3.2.3 compilation takes 32 seconds:
  time gcc -c -xc toplevel.s.i 
    gcc -c -xc toplevel.s.i  31.17s user 0.66s system 99% cpu 32.001 total
With 3.3.2 it takes 38 minutes:
  time ggcc -c -xc toplevel.s.i
    gcc -c -xc toplevel.s.i  2269.29s user 4.87s system 99% cpu 38:04.19 total

The system was an Intel(R) Xeon(TM) CPU 2.80GHz with 4gb memory...

I gzipped the file because the src was 4.7M, the gzipped one is only 112k :)
gcc -v:
Reading specs from /cadappl/gcc/3.3.2/lib/gcc-lib/i686-pc-linux-gnu/3.3.2/specs
Configured with: /home/hooft/Level/Work/gcc/gcc-3.3.2/gcc-3.3.2/configure
--prefix=/cadappl/gcc/3.3.2 --enable-shared --enable-languages=c,c++,f77
--enable-__cxa_atexit --with-as=/cadappl/binutils/2.13.2/bin/as
--with-ld=/cadappl/binutils/2.13.2/bin/ld
--with-as=/cadappl/binutils/2.13.2/bin/as --with-ld=/cadappl/binutils/2.13.2/bin/ld
Thread model: posix
gcc version 3.3.2

-- 
           Summary: huge compilation time increase from 3.2.3 to 3.3.2
           Product: gcc
           Version: 3.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jozef dot kruger at philips dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] huge compilation time increase from 3.2.3 to 3.3.2

[jozef dot kruger at philips dot com]

------- Additional Comments From jozef dot kruger at philips dot com  2004-07-30 14:32 -------
Created an attachment (id=6856)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=6856&action=view)
gzipped version of source file that shows the bug

gzipped because original was 4.7M, this one is 112k

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3 Regression] huge compilation time increase from 3.2.3 to 3.3.2

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |compile-time-hog
            Summary|huge compilation time       |[3.3 Regression] huge
                   |increase from 3.2.3 to 3.3.2|compilation time increase
                   |                            |from 3.2.3 to 3.3.2
   Target Milestone|---                         |3.3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3 Regression] huge compilation time increase from 3.2.3 to 3.3.2

[gdr at integrable-solutions dot net]

------- Additional Comments From gdr at integrable-solutions dot net  2004-08-03 07:48 -------
Subject: Re:  [3.3 Regression] huge compilation time increase from 3.2.3 to 3.3.2

"pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> writes:

| -- 
|            What    |Removed                     |Added
| ----------------------------------------------------------------------------
|            Keywords|                            |compile-time-hog
|             Summary|huge compilation time       |[3.3 Regression] huge
|                    |increase from 3.2.3 to 3.3.2|compilation time increase
|                    |                            |from 3.2.3 to 3.3.2
|    Target Milestone|---                         |3.3.5

I don't think anyone wants to touch the C front-end on
gcc-3_3-branch at this point.  So, let's just recognize we're faulty
and say  we won't fix it for 3.3.x.

-- Gaby



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3 Regression] huge compilation time increase from 3.2.3 to 3.3.2

[jozef dot kruger at philips dot com]

------- Additional Comments From jozef dot kruger at philips dot com  2004-08-03 08:56 -------
The same behaviour is also shown by gcc 3.4.1.
There it takes 26 minutes.
Also, when adding the -O1 option, it only takes 12 minutes.
On 3.3.2 the difference was even bigger, adding -O1 decreased compilation time 
to 1.30 minutes.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3/3.4/3.5? Regression] huge compilation time increase from 3.2.3 to 3.3.2

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gdr at gcc dot gnu dot org
            Summary|[3.3 Regression] huge       |[3.3/3.4/3.5? Regression]
                   |compilation time increase   |huge compilation time
                   |from 3.2.3 to 3.3.2         |increase from 3.2.3 to 3.3.2
   Target Milestone|3.3.5                       |3.4.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3/3.4/3.5? Regression] huge compilation time increase from 3.2.3 to 3.3.2

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2004-08-29 18:47 -------
Postponed until GCC 3.4.3.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4.2                       |3.4.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3/3.4/4.0? Regression] huge compilation time increase from 3.2.3 to 3.3.2

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[3.3/3.4/3.5? Regression]   |[3.3/3.4/4.0? Regression]
                   |huge compilation time       |huge compilation time
                   |increase from 3.2.3 to 3.3.2|increase from 3.2.3 to 3.3.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3/3.4/4.0? Regression] huge compilation time increase from 3.2.3 to 3.3.2

[rth at gcc dot gnu dot org]

------- Additional Comments From rth at gcc dot gnu dot org  2004-10-12 21:26 -------
This is essentially a duplicate of pr17503.  I'm backporting the patch from
that PR from mainline to the 3.4 branch.  With that, compilation time for
the testcase is 1 minute instead of 30.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rth at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-10-12 21:26:20
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834

[Bug c/16834] [3.3/3.4 Regression] huge compilation time increase from 3.2.3 to 3.3.2

[rth at gcc dot gnu dot org]

------- Additional Comments From rth at gcc dot gnu dot org  2004-10-13 16:59 -------
Patch committed for 3.4.3.

I did try the patch against 3.3 branch, but it doesn't do much good.  In that
case there are other reload related bits that are snarfing up time:

  %   cumulative   self              self     total
 time   seconds   seconds    calls   s/call   s/call  name
 36.00    227.89   227.89   102804     0.00     0.01  find_equiv_reg
 26.39    394.97   167.08 703271664     0.00     0.00  single_set_2
 23.97    546.71   151.74 1749021956     0.00     0.00  true_regnum
  3.01    565.78    19.07 162045491     0.00     0.00  subreg_regno_offset

I'm not planning to look into this further.

*** This bug has been marked as a duplicate of 17503 ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
          Component|rtl-optimization            |c
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16834