Hi,
I'm experiencing problems when statically linking using particular GCC supplied
with XCode 3.2.2: i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build
5659) on Mac OS X 10.6.2. Computations become incorrect.
My application consists of main in C and computational code in Fortran (NETLIB
BLAS and slightly modified LAPACK). I'm compiling Fortran code using Intel
Fortran Compiler.
If I'm linking using the particular build, then results of my computations
become completely incorrect. When I'm linking using any other build (5646 from
XCode 3.2, or even i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build
5490)) everything computes correctly for the exactly same object files.
I'm guessing that linker somehow messes constants in my code and this results
incorrect computations. I've succeed to see in my big application that constant
ONE becomes -ONE with only this linker, however cleaning up for a smaller
reproducer I've missed such a constant, but computations results in the
reproducer are still incorrect for the build.
I've tried different versions of Intel Fortran Compiler (10.1, 11.1, etc), also
tried to compile C code with GCC and with Intel C Compiler - all this doesn't
affect results. Only GCC build matters, so I assume this is a problem of
linker. However map files produced by all mentioned builds of GCC are binary
same, so the problem somewhere deeper.
I'm attaching object files of reproducer. To link say just: gcc *.o.
Resulting a.out will show correct output like:
x[0] = {1.000000, 0.000000}
x[1] = {1.000000, 0.000000}
x[2] = {1.000000, 0.000000}
TEST PASSED
or report a error like:
info = 0
x[0] = {0.856000, -0.608000} - FAIL
x[1] = {1.520000, 0.840000} - FAIL
x[2] = {0.968000, 1.176000} - FAIL
TEST FAILED!!!
Please feel free to ask for more details. I would like to help to localize the
issue, but just don't know where to look at.
Thanks,
Alexander
--
Summary: problems when linking in XCode 3.2.2 (gcc build 5659) -
static constants are messed?
Product: gcc
Version: 4.2.1
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: other
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: alexander dot v dot kobotov at intel dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43834
