[Bug c/18707] New: Performance regression at -O2 with gzip

["ebotcazou at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

GCC 4.0.0pre generates worse code than GCC 3.4.4pre at -O2 for gzip 1.2.4 on
UltraSPARC III.  I've also included Sun ONE Studio 8 as a comparison point.

32-bit GCC vs Sun ONE Studio 8 CC:

cc: "-fast -xarch=v8plusb -xchip=ultra3"
gcc: "-O2 -mcpu=ultrasparc3"

-rwxrwxr-x   1 eric     eric       72464 Nov 28 13:08 gzip33
-rwxrwxr-x   1 eric     eric       71444 Nov 28 13:09 gzip34
-rwxrwxr-x   1 eric     eric       71904 Nov 28 13:10 gzip40
-rwxrwxr-x   1 eric     eric      118316 Nov 28 13:42 gzipcc

./gzip33 gcc.tar  28.99s user 0.78s system 98% cpu 30.343 total
./gzip33 gcc.tar  29.03s user 0.64s system 98% cpu 29.989 total
./gzip33 gcc.tar  29.01s user 0.64s system 98% cpu 29.994 total

./gzip34 gcc.tar  24.24s user 0.70s system 98% cpu 25.383 total
./gzip34 gcc.tar  24.29s user 0.65s system 98% cpu 25.296 total
./gzip34 gcc.tar  24.30s user 0.64s system 98% cpu 25.231 total

./gzip40 gcc.tar  24.76s user 0.63s system 98% cpu 25.737 total
./gzip40 gcc.tar  24.75s user 0.63s system 98% cpu 25.668 total
./gzip40 gcc.tar  24.75s user 0.58s system 98% cpu 25.696 total

./gzipcc gcc.tar  24.53s user 0.99s system 95% cpu 26.663 total
./gzipcc gcc.tar  24.45s user 0.73s system 98% cpu 25.476 total
./gzipcc gcc.tar  24.51s user 0.65s system 98% cpu 25.513 total


64-bit GCC vs Sun ONE Studio 8 CC:

cc: "-fast -xarch=v9b -xchip=ultra3"
gcc: "-O2 -mcpu=ultrasparc3"

-rwxrwxr-x   1 eric     eric      109336 Nov 28 12:56 gzip33
-rwxrwxr-x   1 eric     eric      104504 Nov 28 12:57 gzip34
-rwxrwxr-x   1 eric     eric      105048 Nov 28 12:59 gzip40
-rwxrwxr-x   1 eric     eric      149120 Nov 28 13:45 gzipcc

./gzip33 gcc.tar  33.54s user 0.65s system 99% cpu 34.458 total
./gzip33 gcc.tar  33.40s user 0.64s system 99% cpu 34.154 total
./gzip33 gcc.tar  33.45s user 0.54s system 99% cpu 34.101 total

./gzip34 gcc.tar  28.54s user 0.71s system 99% cpu 29.365 total
./gzip34 gcc.tar  28.64s user 0.60s system 99% cpu 29.345 total
./gzip34 gcc.tar  28.78s user 0.43s system 99% cpu 29.295 total

./gzip40 gcc.tar  30.77s user 0.48s system 99% cpu 31.369 total
./gzip40 gcc.tar  30.51s user 0.72s system 99% cpu 31.367 total
./gzip40 gcc.tar  30.65s user 0.62s system 99% cpu 31.378 total

./gzipcc gcc.tar  26.67s user 0.83s system 98% cpu 27.840 total
./gzipcc gcc.tar  26.69s user 0.67s system 99% cpu 27.438 total
./gzipcc gcc.tar  26.58s user 0.75s system 99% cpu 27.457 total

-- 
           Summary: Performance regression at -O2 with gzip
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ebotcazou at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: sparc*-*-*
  GCC host triplet: sparc*-*-*
GCC target triplet: sparc*-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18707