[Bug c++/39860] New: extremely long compile time

[Bug c++/39860] New: extremely long compile time

[pletzer at txcorp dot com]

The attached code takes 20 mins to compile on a Linux/Fedora 9 box when using
-O optimization, but only 21 seconds when using -O0

[pletzer@quartic cxxps]$ time g++ -O -ftime-report -fmem-report -c cxxps.cpp >&
stat.txt

real    21m41.494s
user    16m24.774s
sys     0m19.713s

[pletzer@quartic cxxps]$ time g++ -O0 -ftime-report -fmem-report -c cxxps.cpp
>& stat.txt

real    0m21.391s
user    0m17.666s
sys     0m2.453s


-- 
           Summary: extremely long compile time
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pletzer at txcorp dot com
 GCC build triplet: Configured with: ../configure --prefix=/usr --
                    mandir=/usr/share/
  GCC host triplet: Linux quartic.txcorp.com 2.6.25.14-108.fc9.x86_64 #1 SMP
                    Mon Aug
GCC target triplet: x86_64-redhat-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39860

[Bug c++/39860] extremely long compile time

[pletzer at txcorp dot com]

------- Comment #1 from pletzer at txcorp dot com  2009-04-23 04:38 -------
Created an attachment (id=17681)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17681&action=view)
source code reproducing problem

I apologize but I cannot produce *.i files with -save-temps:

[pletzer@localhost test]$ g++ -c -save-temps cxxps.cpp
[pletzer@localhost test]$ ls
ccps_base.h  cxxps.cpp  cxxps.o                                  f77name.h
ccps.h       cxxps.h    cxxps.tmp.localhost.localdomain.10206.s  multiarray.h


 so I'm sending the source and headers as a bz2 compressed file. To reproduce
the problem of very long compile time, type

tar xvfj cxxps.bz2
g++ -c -O cxxps.cpp


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39860

[Bug c++/39860] extremely long compile time

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2009-04-23 09:34 -------
 tree memory partitioning:  51.43 (20%) usr   0.26 ( 9%) sys  51.80 (20%) wall 
    19 kB ( 0%) ggc
 tree operand scan     : 149.30 (58%) usr   1.20 (43%) sys 151.17 (57%) wall  
18536 kB ( 4%) ggc

4.4 uses

 tree memory partitioning:  42.43 (26%) usr   0.33 (14%) sys  42.84 (26%) wall 
    13 kB ( 0%) ggc
 tree operand scan     :  71.91 (45%) usr   0.59 (25%) sys  72.88 (44%) wall  
14670 kB ( 3%) ggc

trunk does not have the above on the radar at all.

thus ...

*** This bug has been marked as a duplicate of 33237 ***


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39860