[Bug target/41156] [4.4/4.5 Regression] zlib segfault in inflate_table() compiled w/ -O -msse2 ftree-vectorize

[hjl dot tools at gmail dot com]

------- Comment #7 from hjl dot tools at gmail dot com  2009-09-01 13:20 -------
Realign the incoming stack for vectorizer has very limited impact
on performance. Here are the differences of -m32 -O3 -msse2
-mfpmath=sse -ffast-math -funroll-loops before and after my patch:

400.perlbench                    -0.384615%
401.bzip2                        0%
403.gcc                          -0.362319%
429.mcf                          -0.813008%
445.gobmk                        0.921659%
456.hmmer                        0.549451%
458.sjeng                        -0.438596%
462.libquantum                   0%
464.h264ref                      0%
471.omnetpp                      -0.478469%
473.astar                        -0.645161%
483.xalancbmk                    -0.727273%
SPECint(R)_base2006              -0.411523%
410.bwaves                       -0.406504%
416.gamess                       0%
433.milc                         -1.36986%
434.zeusmp                       -0.44843%
435.gromacs                      0%
436.cactusADM                    0%
437.leslie3d                     -0.888889%
444.namd                         1.20482%
447.dealII                       -0.350877%
450.soplex                       -0.31746%
453.povray                       0.458716%
454.calculix                     0%
459.GemsFDTD                     0%
465.tonto                        0%
470.lbm                          0%
481.wrf                          0.480769%
482.sphinx3                      0.940439%
SPECfp(R)_base2006               0%

It won't change generated code if vectorizer isn't
enabled. Its benifits outweigh its drawbacks.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41156