[Bug tree-optimization/26854] Inordinate compile times on large routines

["lucier at math dot purdue dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #62 from lucier at math dot purdue dot edu  2008-05-15 02:48 -------
I thought I might test the ira branch with

euler-3% /pkgs/gcc-ira/bin/gcc -v
Using built-in specs.
Target: x86_64-unknown-linux-gnu
Configured with: ../../ira/configure --enable-checking=release
--with-gmp=/pkgs/gmp-4.2.2/ --with-mpfr=/pkgs/gmp-4.2.2/ --prefix=/pkgs/gcc-ira
--enable-languages=c --enable-gather-detailed-mem-stats
Thread model: posix
gcc version 4.4.0 20080328 (experimental) [ira revision 135280] (GCC) 

The command line was

/pkgs/gcc-ira/bin/gcc -fno-ira -Wall -W -Wno-unused -O1 -fno-math-errno
-fschedule-insns2 -fno-trapping-math -fno-strict-aliasing -fwrapv
-fomit-frame-pointer -fPIC -ftime-report -fmem-report -c all.i

with -fira and with -fno-ira.

The ira branch takes a lot longer to compile this code with -fira than without
it; the relevant lines seem to be:

for -fira:

 integrated RA         : 373.36 (66%) usr   0.33 ( 2%) sys 375.87 (64%) wall  
12064 kB ( 2%) ggc
 TOTAL                 : 563.85            15.94           582.98            
763565 kB

for -fno-ira:

 local alloc           :   8.42 ( 4%) usr   0.03 ( 0%) sys   8.43 ( 4%) wall   
7073 kB ( 1%) ggc
 global alloc          :  20.91 (11%) usr   0.30 ( 2%) sys  21.23 (10%) wall   
4961 kB ( 1%) ggc
 TOTAL                 : 196.25            17.55           213.84            
766052 kB

I'll add the complete reports as the next two attachments.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26854