[Bug c/30610] New: huge memory consumption with -O3

[Bug c/30610] New: huge memory consumption with -O3

[kcwu at csie dot org]

Happen with gcc43 snapshot 20070105 (experimental).
gcc configured with: ./..//gcc-4.3-20070105/configure --disable-nls
--with-system-zlib --with-libiconv-prefix=/usr/local --with-gmp=/usr/local
--program-suffix=43 --libdir=/usr/local/lib/gcc-4.3.0
--with-gxx-include-dir=/usr/local/lib/gcc-4.3.0/include/c++/
--infodir=/usr/local/info/gcc43 --disable-libgcj --prefix=/usr/local
x86_64-portbld-freebsd6.2

$ time gcc43 -O3 -c f5.c -Wall
user    8m0.834s
max memory usage 1321 MB.

It takes too long time and huge memory to compile, compared to gcc4.2 or -O2:
$ time gcc42 -O3 -c f5.c
user    0m0.575s
$ time gcc43 -O2 -c f5.c -finline-functions -funswitch-loops
-fgcse-after-reload                 
user    0m0.602s
And the memory usage is less than 10 MB.


-- 
           Summary: huge memory consumption with -O3
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kcwu at csie dot org
 GCC build triplet: x86_64-portbld-freebsd6.2
  GCC host triplet: x86_64-portbld-freebsd6.2
GCC target triplet: x86_64-portbld-freebsd6.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30610

[Bug c/30610] huge memory consumption with -O3

[kcwu at csie dot org]

------- Comment #1 from kcwu at csie dot org  2007-01-27 16:26 -------
Created an attachment (id=12970)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12970&action=view)
eats 1321MB memory and 8minutes to compile


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30610

[Bug c/30610] huge memory consumption with -O3

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2007-01-27 16:51 -------
All time is suck up in PRE:

 tree PRE              :  36.36 (93%) usr   0.40 (95%) sys  36.85 (93%) wall  
88918 kB (96%) ggc
 TOTAL                 :  39.03             0.42            39.74             
92276 kB

though it uses only 512MB for me (and 36s) using a release-checking enabled
build from 20070113.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dberlin at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30610

[Bug c/30610] huge memory consumption with -O3

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2007-01-27 17:07 -------
It's of course caused by the new partial-antic stuff, but still something is
out of a reasonable bound here (we're just iterating 2 times to solve partial
antic).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30610

[Bug middle-end/30610] huge memory consumption with -O3

[dberlin at gcc dot gnu dot org]

------- Comment #4 from dberlin at gcc dot gnu dot org  2007-08-13 12:06 -------
It takes 2 iterations, but it has come up with 144 thousand expressions


-- 

dberlin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |dberlin at gcc dot gnu dot
                   |dot org                     |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30610

[Bug middle-end/30610] huge memory consumption with -O3

[kcwu at csie dot org]

------- Comment #5 from kcwu at csie dot org  2008-02-23 16:21 -------
this issue is resolved in gcc 4.3 20080221 snapshot.

$ time gcc43 -O3 -c f5.c -Wall
user    0m0.418s
And the memory usage is less than 10 MB.


-- 

kcwu at csie dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30610