[Bug c++/23835] New: case where gcc 4.1.0 -O3 compile takes 4 times longer than gcc 3.4.3, on ia64

[jaffe at broad dot mit dot edu]

We observe that on ia64,
   gcc -On -c test.ii (n = 1,2,3)
is several times slower under gcc 4.1.0 than gcc 3.4.3:

Compile time in seconds

         -O0     -O1    -O2     -O3

3.4.3   5.659   9.515  13.811  14.779
4.1.0   8.417  44.652  56.176  60.204

This is typical of what we observe for compiles of long files.

Hardware: IA-64 (Itanium 2), 1600 MHz, running Linux 2.6.12.2n.

% gcc -v
Reading specs from /util/bin/../lib/gcc/ia64-unknown-linux-gnu/3.4.3/specs
Configured with: ../gcc-3.4.3/configure --prefix=/mnt/util/ia64
Thread model: posix
gcc version 3.4.3

% gcc -v
Using built-in specs.
Target: ia64-unknown-linux-gnu
Configured with: ../configure --prefix=/wga1/gcc
Thread model: posix
gcc version 4.1.0 20050730 (experimental)

-- 
           Summary: case where gcc 4.1.0 -O3 compile takes 4 times longer
                    than gcc 3.4.3, on ia64
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jaffe at broad dot mit dot edu
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: ia64-unknown-linux-gnu
  GCC host triplet: ia64-unknown-linux-gnu
GCC target triplet: ia64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23835