[Bug tree-optimization/77848] Gimple if-conversion results in redundant comparisons

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77848

--- Comment #13 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
SPEC cpu2006 on powerpc64le-unknown-linux-gnu with the simple patch:

Geomean, integer:  +0.2%
Geomean, float:    +0.5%
Geomean, overall:  +0.4%

Notable improvements:
  454.calculix:    +3.7%
  453.povray:      +3.4%
  458.sjeng:       +1.4%
  429.mcf:         +1.2%
  445.gobmk:       +1.2%
  471.omnetpp:     +1.2%

Notable degradations:
  403.gcc:         -1.8%

Other results in noise (+/- 1.0%)

Thus, not too bad for a simple patch, though we don't like seeing 403.gcc
degrade.

I've made some progress on the outer loop vectorization issue, but haven't
completely solved it yet.  I'll try to have something to look at there in the
next couple of days.