http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50190
Bug #: 50190
Summary: linkpk bench of polyhedron fails during validation
with gcc trunk when it is compiled with -Ofast on
amd64.
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: venkataramanan.kumar....@gmail.com
Polyhedron benchmark linpk fails during validation when compiled with -Ofast
flag.
(Snip)
> Value= 25.114499300 Target= 23.100000000 Tolerance= 2.0000000000
FAIL <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> Value=0.27880142600E-10 Target=0.27858826400E-10 Tolerance=0.10000000000E-09
> Value=0.22204460500E-15 Target=0.22204460500E-15 Tolerance=0.10000000000E-14
> Value= 1.0000000000 Target= 1.0000000000 Tolerance=0.10000000000E-07
> Value= 1.0000000000 Target= 1.0000000000 Tolerance=0.10000000000E-07
linpk FAILED 1 fails and 4 passes
(Snip)
exact version of GCC: gcctrunk 1780539
system type: amd64
options given when GCC was configured/built: --disable-bootstrap --without-ppl
--without-cloog --enable-languages=c,c++,fortran
complete command line that triggers the bug: -Ofast
This issue does not occur when -fprotect-parens is specified with -Ofast.
Current trunk has -fno-protect-parens in -Ofast. So this seems to be a
precision issue as GCC may reorder floating point computations. But I have
reported this to bring it to the notice of community.
