> On Jun 28, 2016, at 8:24 AM, Chuck Atkins <[email protected]> wrote: > > Encapsulate the test for which flags are needed to get a compiler to > support certain features. Along with this, give various options to try > for AVX and AVX2 support. Ideally we want to use specific instruction > set feature flags, like -mavx2 for instance instead of -march=haswell, > but the flags required for certain compilers are different. This > allows, for AVX2 for instance, GCC to use -mavx2 -mfma -mbmi2 -mf16c > while the Intel compiler which doesn't support those flags can fall > back to using -march=core-avx2. > > This addresses a bug where the Intel compiler will silently ignore the > AVX2 instruction feature flags and then potentially fail to build. > > Cc: Tim Rowley <[email protected]> > Signed-off-by: Chuck Atkins <[email protected]> > --- > configure.ac | 86 +++++++++++++++++++++++++++++++++++++++++++----------------- > 1 file changed, 62 insertions(+), 24 deletions(-) > > diff --git a/configure.ac b/configure.ac > index cc9bc47..806850e 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -2330,6 +2330,39 @@ swr_llvm_check() { > fi > } > > +swr_cxx_feature_flags_check() { > + ifndef_test=$1 > + option_list="$2" > + unset SWR_CXX_FEATURE_FLAGS > + AC_LANG_PUSH([C++]) > + save_CXXFLAGS="$CXXFLAGS" > + save_IFS="$IFS" > + IFS="," > + found=0 > + for opts in $option_list > + do > + unset IFS > + CXXFLAGS="$opts $save_CXXFLAGS" > + AC_COMPILE_IFELSE( > + [AC_LANG_PROGRAM( > + [ $ifndef_test > + #error > + #endif > + ])], > + [found=1; break], > + []) > + IFS="," > + done > + IFS="$save_IFS" > + CXXFLAGS="$save_CXXFLAGS" > + AC_LANG_POP([C++]) > + if test $found -eq 1; then > + SWR_CXX_FEATURE_FLAGS="$opts" > + return 0 > + fi > + return 1 > +} > + > dnl Duplicates in GALLIUM_DRIVERS_DIRS are removed by sorting it after this > block > if test -n "$with_gallium_drivers"; then > gallium_drivers=`IFS=', '; echo $with_gallium_drivers` > @@ -2399,31 +2432,36 @@ if test -n "$with_gallium_drivers"; then > xswr) > swr_llvm_check "swr" > > - AC_MSG_CHECKING([whether $CXX supports c++11/AVX/AVX2]) > - SWR_AVX_CXXFLAGS="-mavx" > - SWR_AVX2_CXXFLAGS="-mavx2 -mfma -mbmi2 -mf16c" > - > - AC_LANG_PUSH([C++]) > - save_CXXFLAGS="$CXXFLAGS" > - CXXFLAGS="-std=c++11 $CXXFLAGS" > - AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],[], > - [AC_MSG_ERROR([c++11 compiler support not > detected])]) > - CXXFLAGS="$save_CXXFLAGS" > - > - save_CXXFLAGS="$CXXFLAGS" > - CXXFLAGS="$SWR_AVX_CXXFLAGS $CXXFLAGS" > - AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],[], > - [AC_MSG_ERROR([AVX compiler support not > detected])]) > - CXXFLAGS="$save_CXXFLAGS" > - > - save_CFLAGS="$CXXFLAGS" > - CXXFLAGS="$SWR_AVX2_CXXFLAGS $CXXFLAGS" > - AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],[], > - [AC_MSG_ERROR([AVX2 compiler support not > detected])]) > - CXXFLAGS="$save_CXXFLAGS" > - AC_LANG_POP([C++]) > - > + AC_MSG_CHECKING([whether $CXX supports c++11]) > + if ! swr_cxx_feature_flags_check \ > + "#if __cplusplus < 201103L" \ > + ",-std=c++11"; then > + AC_MSG_RESULT([no]) > + AC_MSG_ERROR([swr requires C++11 support]) > + fi > + AC_MSG_RESULT([$SWR_CXX_FEATURE_FLAGS]) > + CXXFLAGS="$SWR_CXX_FEATURE_FLAGS $CXXFLAGS”
We don’t want to globally override CXXFLAGS; AC_SUBST on a SWR_CXXFLAGS and using that in swr’s Makefile.am would be better. > + > + AC_MSG_CHECKING([whether $CXX supports AVX]) > + if ! swr_cxx_feature_flags_check \ > + "#ifndef __AVX__" \ > + ",-mavx,-march=core-avx"; then > + AC_MSG_RESULT([no]) > + AC_MSG_ERROR([swr requires AVX compiler support]) > + fi > + AC_MSG_RESULT([$SWR_CXX_FEATURE_FLAGS]) > + SWR_AVX_CXXFLAGS="$SWR_CXX_FEATURE_FLAGS" > AC_SUBST([SWR_AVX_CXXFLAGS]) > + > + AC_MSG_CHECKING([whether $CXX supports AVX2]) > + if ! swr_cxx_feature_flags_check \ > + "#if > !(defined(__AVX2__)&&defined(__FMA__)&&defined(__BMI2__)&&defined(__F16C__))” > \ Is there any standard that says these are defined if the compiler supports them? With icc 16.0.3, the test falls into the #error path when it tries the fallback test of -march=core-avx2. > + ",-mavx2 -mfma -mbmi2 -mf16c,-march=core-avx2"; then > + AC_MSG_RESULT([no]) > + AC_MSG_ERROR([swr requires AVX2 compiler support]) > + fi > + AC_MSG_RESULT([$SWR_CXX_FEATURE_FLAGS]) > + SWR_AVX2_CXXFLAGS="$SWR_CXX_FEATURE_FLAGS" > AC_SUBST([SWR_AVX2_CXXFLAGS]) > > HAVE_GALLIUM_SWR=yes > -- > 2.5.5 > _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
