From c1bf6692beb662e5749e5680e0ebd15af2cd032a Mon Sep 17 00:00:00 2001 From: Chuck Atkins Date: Tue, 28 Jun 2016 15:50:47 -0400 Subject: swr: Refactor checks for compiler feature flags 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. v2: Pass preprocessor-check argument as true-state instead of false-state for clarity. v3: Reduce AVX2 define test to just __AVX2__. Additional defines suchas __FMA__, __BMI2__, and __F16C__ appear to be inconsistently defined w.r.t thier availability. v4: Fix C++11 flags being added globally and add more logic to swr_require_cxx_feature_flags Cc: Reviewed-by: Tim Rowley Tested-by: Tim Rowley Signed-off-by: Chuck Atkins --- configure.ac | 73 +++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 50 insertions(+), 23 deletions(-) (limited to 'configure.ac') diff --git a/configure.ac b/configure.ac index cc9bc47..8321e8e 100644 --- a/configure.ac +++ b/configure.ac @@ -2330,6 +2330,45 @@ swr_llvm_check() { fi } +swr_require_cxx_feature_flags() { + feature_name="$1" + preprocessor_test="$2" + option_list="$3" + output_var="$4" + + AC_MSG_CHECKING([whether $CXX supports $feature_name]) + AC_LANG_PUSH([C++]) + save_CXXFLAGS="$CXXFLAGS" + save_IFS="$IFS" + IFS="," + found=0 + for opts in $option_list + do + unset IFS + CXXFLAGS="$opts $save_CXXFLAGS" + AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [ #if !($preprocessor_test) + #error + #endif + ])], + [found=1; break], + []) + IFS="," + done + IFS="$save_IFS" + CXXFLAGS="$save_CXXFLAGS" + AC_LANG_POP([C++]) + if test $found -eq 1; then + AC_MSG_RESULT([$opts]) + eval "$output_var=\$opts" + return 0 + fi + AC_MSG_RESULT([no]) + AC_MSG_ERROR([swr requires $feature_name support]) + return 1 +} + dnl Duplicates in GALLIUM_DRIVERS_DIRS are removed by sorting it after this block if test -n "$with_gallium_drivers"; then gallium_drivers=`IFS=', '; echo $with_gallium_drivers` @@ -2399,31 +2438,19 @@ if test -n "$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++]) + swr_require_cxx_feature_flags "C++11" "__cplusplus >= 201103L" \ + ",-std=c++11" \ + SWR_CXX11_CXXFLAGS + AC_SUBST([SWR_CXX11_CXXFLAGS]) + swr_require_cxx_feature_flags "AVX" "defined(__AVX__)" \ + ",-mavx,-march=core-avx" \ + SWR_AVX_CXXFLAGS AC_SUBST([SWR_AVX_CXXFLAGS]) + + swr_require_cxx_feature_flags "AVX2" "defined(__AVX2__)" \ + ",-mavx2 -mfma -mbmi2 -mf16c,-march=core-avx2" \ + SWR_AVX2_CXXFLAGS AC_SUBST([SWR_AVX2_CXXFLAGS]) HAVE_GALLIUM_SWR=yes -- cgit v1.1