[Bug c++/67291] New: error: 'asm' operand has impossible constraints when compiling gromacs 5.1 testsuite on PPC64 and PPC64LE with VSX SIMD

[dominik at greysector dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67291

            Bug ID: 67291
           Summary: error: 'asm' operand has impossible constraints when
                    compiling gromacs 5.1 testsuite on PPC64 and PPC64LE
                    with VSX SIMD
           Product: gcc
           Version: 5.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dominik at greysector dot net
  Target Milestone: ---

When gromacs-5.1 is configured for double precision, I get the following
compilation error when building the internal tests (make check):
[...]
[ 94%] Building CXX object
src/gromacs/simd/tests/CMakeFiles/simd-test.dir/simd_integer.cpp.o
cd /builddir/build/BUILD/gromacs-5.1/openmpi_d/src/gromacs/simd/tests &&
/usr/bin/c++   -DGMX_DOUBLE -DGTEST_USE_OWN_TR1_TUPLE=1 -DHAVE_CONFIG_H
-DTEST_DATA_PATH=\"src/gromacs/simd/tests\"
-DTEST_TEMP_PATH=\"/builddir/build/BUILD/gromacs-5.1/openmpi_d/src/gromacs/simd/tests/Testing/Temporary\"
-mvsx   -std=c++0x -O2
-g -pipe -Wall -Werror=format-security -Wp
,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong
--param=ssp-buffer-size=4 -grecord-gcc-switches
-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64  -Wundef
-Wextra -Wno-missing-field-initializers -Wpointer-arith -Wall
-Wno-unused-function   -funroll-all-loops -fexcess-precision=fast 
-Wno-array-bounds  -isystem
/builddir/build/BUILD/gromacs-5.1/src/external/gmock-1.7.0/gtest/include
-isystem /builddir/build/BUILD/gromacs-5.1/src/external/gmock-1.7.0/include
-I/builddir/build/BUILD/gromacs-5.1/openmpi_d/src/external/tng_io/include
-I/builddir/build/BUILD/gromacs-5.1/src/external/tng_io/include
-I/builddir/build/BUILD/gromacs-5.1/openmpi_d/src
-I/builddir/build/BUILD/gromacs-5.1/src/external/thread_mpi/include
-I/builddir/build/BUILD/gromacs-5.1/src
-I/usr/include/openmpi-ppc64    -Wno-unused-variable -o
CMakeFiles/simd-test.dir/simd_integer.cpp.o -c
/builddir/build/BUILD/gromacs-5.1/src/gromacs/simd/tests/simd_integer.cpp
In file included from
/builddir/build/BUILD/gromacs-5.1/src/gromacs/simd/simd.h:138:0,
                 from
/builddir/build/BUILD/gromacs-5.1/src/gromacs/simd/tests/simd_integer.cpp:37:
/builddir/build/BUILD/gromacs-5.1/src/gromacs/simd/impl_ibm_vsx/impl_ibm_vsx.h:
In member function 'virtual void
gmx::test::{anonymous}::SimdIntegerTest_gmxSimdCvtI2R_Test::TestBody()':
/builddir/build/BUILD/gromacs-5.1/src/gromacs/simd/impl_ibm_vsx/impl_ibm_vsx.h:452:80:
error: 'asm' operand has impossible constraints
     __asm__ ("xvcvsxwdp %0,%1" : "=ww" (x) : "ww" ((__vector signed int)
(ix)));
                                                                               
^
/builddir/build/BUILD/gromacs-5.1/src/gromacs/simd/impl_ibm_vsx/impl_ibm_vsx.h:452:80:
error: 'asm' operand has impossible constraints
     __asm__ ("xvcvsxwdp %0,%1" : "=ww" (x) : "ww" ((__vector signed int)
(ix)));
                                                                               
^
src/gromacs/simd/tests/CMakeFiles/simd-test.dir/build.make:209: recipe for
target 'src/gromacs/simd/tests/CMakeFiles/simd-test.dir/simd_integer.cpp.o'
failed
make[3]: ***
[src/gromacs/simd/tests/CMakeFiles/simd-test.dir/simd_integer.cpp.o] Error 1
[...]

This happens on:

$ cat /proc/cpuinfo
processor       : 0
cpu             : POWER8E (raw), altivec supported
clock           : 3425.000000MHz
revision        : 2.1 (pvr 004b 0201)

processor       : 1
cpu             : POWER8E (raw), altivec supported
clock           : 3425.000000MHz
revision        : 2.1 (pvr 004b 0201)

timebase        : 512000000
platform        : pSeries
model           : IBM pSeries (emulated by qemu)
machine         : CHRP IBM pSeries (emulated by qemu)

using

$ /usr/bin/c++ -v
Using built-in specs.
COLLECT_GCC=/usr/bin/c++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ppc64-redhat-linux/5.1.1/lto-wrapper
Target: ppc64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-linker-hash-style=gnu --enable-plugin --enable-initfini-array
--disable-libgcj --with-isl --disable-libmpx --enable-gnu-indirect-function
--enable-secureplt --with-long-double-128 --build=ppc64-redhat-linux
Thread model: posix
gcc version 5.1.1 20150618 (Red Hat 5.1.1-4) (GCC) 

in Fedora rawhide (F24) chroot while building the gromacs package
(http://pkgs.fedoraproject.org/cgit/gromacs.git) under mock.
You have to remove the %ifnarch ppc64 ppc64le part in %install section
to reproduce.

More details here: http://redmine.gromacs.org/issues/1808