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* [Bug tree-optimization/23955] New: Compile time regressions with tramp3d
@ 2005-09-18 17:49 rguenth at gcc dot gnu dot org
  2005-09-18 17:54 ` [Bug tree-optimization/23955] " pinskia at gcc dot gnu dot org
                   ` (5 more replies)
  0 siblings, 6 replies; 7+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2005-09-18 17:49 UTC (permalink / raw)
  To: gcc-bugs

The tramp3d-v4.cpp testcase (attached to PR23928) shows regressions in compile
time.  For a first comparison consider compilation with leafify disabled and
 -fno-exceptions -O2 -march=pentium4 -ffast-math -fpeel-loops
compile flags.  All results with checking-disable and profile-bootstrapped
compilers from the HEAD of their branches.  Run-time for 10 iterations is
included as a reference, too.

         compile   run
gcc-3.4  1m02s     25.9s
gcc-4.0  1m43s     15.2s
gcc-4.1  2m50s      8.8s

The following measurements are with leafification enabled (patched
3.4 and 4.0, -Dleafify=flatten for 4.1):

gcc-3.4  1m20s     10.5s
gcc-4.0  2m18s      8.6s
gcc-4.1  3m2s       8.5s
gcc-4.1+ 3m8s       6.5s

gcc-4.1+ is with the tree-forwprop and array-aliasing patches.

We see that even the fair comparison (same inlining via the
leafify patch) regresses considerably from 3.4 to 4.0 and 4.1.
Given the non-existant run-time improvement from 4.0 to 4.1
the regression there is even more disappointing.

Just for the complete report, here are some -O0 -fno-exception
numbers (w/o leafify):

3.4  22.3s
4.0  15.8s
4.1  16.8s

-- 
           Summary: Compile time regressions with tramp3d
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23955


^ permalink raw reply	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2005-09-19  8:46 UTC | newest]

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2005-09-18 17:49 [Bug tree-optimization/23955] New: Compile time regressions with tramp3d rguenth at gcc dot gnu dot org
2005-09-18 17:54 ` [Bug tree-optimization/23955] " pinskia at gcc dot gnu dot org
2005-09-18 17:56 ` pinskia at gcc dot gnu dot org
2005-09-18 18:16 ` rguenth at gcc dot gnu dot org
2005-09-19  0:36 ` pinskia at gcc dot gnu dot org
2005-09-19  8:16 ` rguenth at gcc dot gnu dot org
2005-09-19  8:46 ` rguenth at gcc dot gnu dot org

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