Follow up to PR 41137.
Using the Intel compiler, the following program takes 0s for the loops (real
time: 0.005s); however, with
gfortran -fdump-tree-original -fwhole-program -flto -ffast-math -march=native
-O3 cont.f90
GCC needs 1.142s.
Expected:
* GCC also optimizes the loops away if the variable "a" is never read (but only
set)
Removing the !! comments prevents ifort from optimizing the loops away; still
the performance is with (real time) 0.650s twice as good as the one of GCC.
--
Summary: -flto -fwhole-program: Never read variable not optimized
away
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: burnus at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44612
