http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52525
Bug #: 52525
Summary: compiler segmentation fault when building OpenMP code
with -O3
Classification: Unclassified
Product: gcc
Version: 4.4.6
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: sin.pec...@gmail.com
An -O3 optimization seems to make gcc 4.4.x choke with a segfault while
compiling some OpenMP code. The same code compiles with -O2. Strangely enough,
it also compiles with -O2 + the additional -O3 flags listed in the 4.4.6 docs
(-finline-functions, -funswitch-loops, -fpredictive-commoning,
-fgcse-after-reload, -ftree-vectorize and -fipa-cp-clone).
The bug is not present neither in 4.3 nor 4.5, 4.6.
Marked with major severity as this code will be part of the next version of
GROMACS, the OSS HPC molecular simulation package shipped by several distros
and running on lots of machines from desktops to the largest clusters.
Tested with:
Ubuntu 10.04 x86_64, gcc-4.4 (Ubuntu 4.4.6-3lucid2) 4.4.6
Ubuntu 11.10 x86_64, gcc-4.4 (Ubuntu/Linaro 4.4.6-11ubuntu2) 4.4.6
RHEL 6.0 x86_64, gcc (GCC) 4.4.4 20100726 (Red Hat 4.4.4-13)
Attached is the input that reproduces the segfault by running:
$ gcc-4.4 -fopenmp -O3 force.i
/home/pszilard/projects/gmx/gromacs-gpu/src/mdlib/force.c: In function
‘do_force_lowlevel.omp_fn.0’:
/home/pszilard/projects/gmx/gromacs-gpu/src/mdlib/force.c:448: internal
compiler error: Segmentation fault
