The polyhedron test mdbx is miscompiled with revision -O2 -ftree-vectorize at
163940:
[macbook] lin/test% gfc mdbx.f90 -O2 -ftree-vectorize -v
Driving: gfc -mmacosx-version-min=10.6.4 mdbx.f90 -O2 -ftree-vectorize -v -l
gfortran -shared-libgcc
Using built-in specs.
COLLECT_GCC=gfc
COLLECT_LTO_WRAPPER=/opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/lto-wrapper
Target: x86_64-apple-darwin10.4.0
Configured with: ../work/configure --prefix=/opt/gcc/gcc4.6w
--enable-languages=c,c++,fortran,objc,obj-c++,java,lto --with-gmp=/opt/sw64
--with-libiconv-prefix=/opt/sw64 --with-system-zlib --with-cloog=/opt/sw64
Thread model: posix
gcc version 4.6.0 20100907 (experimental) [trunk revision 163940p4] (GCC)
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.6.4' '-O2' '-ftree-vectorize' '-v'
'-shared-libgcc' '-mtune=generic'
/opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/f951 mdbx.f90
-fPIC -quiet -dumpbase mdbx.f90 -mmacosx-version-min=10.6.4 -mtune=generic
-auxbase mdbx -O2 -version -ftree-vectorize -fintrinsic-modules-path
/opt/gcc/gcc4.6w/lib/gcc/x86_64-apple-darwin10.4.0/4.6.0/finclude -o
/var/folders/LW/LW1oufkMGIqlLpjYn45fBU+++TI/-Tmp-//cceUTsb5.s
GNU Fortran (GCC) version 4.6.0 20100907 (experimental) [trunk revision
163940p4] (x86_64-apple-darwin10.4.0)
compiled by GNU C version 4.6.0 20100907 (experimental) [trunk revision
163940p4], GMP version 5.0.1, MPFR version 3.0.0, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU Fortran (GCC) version 4.6.0 20100907 (experimental) [trunk revision
163940p4] (x86_64-apple-darwin10.4.0)
compiled by GNU C version 4.6.0 20100907 (experimental) [trunk revision
163940p4], GMP version 5.0.1, MPFR version 3.0.0, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.6.4' '-O2' '-ftree-vectorize' '-v'
'-shared-libgcc' '-mtune=generic'
as -arch x86_64 -force_cpusubtype_ALL -o
/var/folders/LW/LW1oufkMGIqlLpjYn45fBU+++TI/-Tmp-//ccBHSNwY.o
/var/folders/LW/LW1oufkMGIqlLpjYn45fBU+++TI/-Tmp-//cceUTsb5.s
COMPILER_PATH=/opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/:/opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/:/opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.4.0/:/opt/gcc/gcc4.6w/lib/gcc/x86_64-apple-darwin10.4.0/4.6.0/:/opt/gcc/gcc4.6w/lib/gcc/x86_64-apple-darwin10.4.0/
LIBRARY_PATH=/opt/gcc/gcc4.6w/lib/gcc/x86_64-apple-darwin10.4.0/4.6.0/:/opt/gcc/gcc4.6w/lib/gcc/x86_64-apple-darwin10.4.0/4.6.0/../../../:/usr/lib/
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.6.4' '-O2' '-ftree-vectorize' '-v'
'-shared-libgcc' '-mtune=generic'
/opt/gcc/gcc4.6w/libexec/gcc/x86_64-apple-darwin10.4.0/4.6.0/collect2 -dynamic
-arch x86_64 -macosx_version_min 10.6.4 -weak_reference_mismatches non-weak -o
a.out -lcrt1.10.5.o -L/opt/gcc/gcc4.6w/lib/gcc/x86_64-apple-darwin10.4.0/4.6.0
-L/opt/gcc/gcc4.6w/lib/gcc/x86_64-apple-darwin10.4.0/4.6.0/../../..
/var/folders/LW/LW1oufkMGIqlLpjYn45fBU+++TI/-Tmp-//ccBHSNwY.o -lgfortran
-lgcc_ext.10.5 -lgcc -no_compact_unwind -lSystem
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.6.4' '-O2' '-ftree-vectorize' '-v'
'-shared-libgcc' '-mtune=generic'
[macbook] lin/test% a.out
MDBNCH: A MOLECULAR DYNAMICS BENCHMARK, VERSION OF DECEMBER 17, 1988
Segmentation fault
Backtrace
Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: 13 at address: 0x0000000000000000
0x0000000100007d40 in centcm_ ()
(gdb) bt
#0 0x0000000100007d40 in centcm_ ()
#1 0x00000001000086f1 in mte_ ()
The Segmentation fault occurs within the loop (lines 2073 to 2080):
DO i = 1 , MOLsa
X0(1,i) = X0(1,i) - cm1
X0(2,i) = X0(2,i) - cm2
X0(3,i) = X0(3,i) - cm3
XIN(1,i) = XIN(1,i) - cm1
XIN(2,i) = XIN(2,i) - cm2
XIN(3,i) = XIN(3,i) - cm3
ENDDO
and disappears with -fbounds-check.
Revision 163913 works. It may be due to revision 163915.
--
Summary: [4.6 Regression] The polyhedron test mdbx is miscompiled
with -O2 -ftree-vectorize at revision 163940
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dominiq at lps dot ens dot fr
GCC build triplet: x86_64-apple-darwin10
GCC host triplet: x86_64-apple-darwin10
GCC target triplet: x86_64-apple-darwin10
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45578
