http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52272
Bug #: 52272
Summary: [4.7 regression] Performance regresswion of 410.bwaves
on x86.
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: regression
AssignedTo: [email protected]
ReportedBy: [email protected]
Created attachment 26671
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26671
Reduced testcase
Commit
2012-02-06 Richard Guenther <[email protected]>
PR tree-optimization/50955
* tree-ssa-loop-ivopts.c (get_computation_cost_at): Artificially
raise cost of expressions that replace an address with an
expression based on a different pointer.
causes performance regression on 410.bwaves
base: -2.33%
peak: -3.82%
I attached a reduced testcase and dumps of compilers before and after commit.
Command line to reproduce
gfortran -w -g -m32 -static -S t.s -O3 -funroll-loops -msse2 -mfpmath=sse
-ffast-math -march=corei7 t.f
