swr: Add arch flags to support Cray and PGI compilers

Note that the Cray flags (-target-cpu=) need to come first since the
cray programming environment uses wappers around other compilers.  By
checking the wrapper flags first, you can be sure to match the wrapper
flag instead of the underlying compiler (gcc, intel, pgi, etc.) flags.

Signed-off-by: Chuck Atkins <chuck.atkins@kitware.com>
Reviewed-by: Tim Rowley <timothy.o.rowley@intel.com>
diff --git a/configure.ac b/configure.ac
index 6302aa2..3b45baf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2511,7 +2511,7 @@
             AC_SUBST([SWR_CXX11_CXXFLAGS])
 
             swr_require_cxx_feature_flags "AVX" "defined(__AVX__)" \
-                ",-mavx,-march=core-avx" \
+                ",-target-cpu=sandybridge,-mavx,-march=core-avx,-tp=sandybridge" \
                 SWR_AVX_CXXFLAGS
             AC_SUBST([SWR_AVX_CXXFLAGS])
 
@@ -2523,21 +2523,21 @@
                     ;;
                 xavx2)
                     swr_require_cxx_feature_flags "AVX2" "defined(__AVX2__)" \
-                        ",-mavx2 -mfma -mbmi2 -mf16c,-march=core-avx2" \
+                        ",-target-cpu=haswell,-mavx2 -mfma -mbmi2 -mf16c,-march=core-avx2,-tp=haswell" \
                         SWR_AVX2_CXXFLAGS
                     AC_SUBST([SWR_AVX2_CXXFLAGS])
                     HAVE_SWR_AVX2=yes
                     ;;
                 xknl)
                     swr_require_cxx_feature_flags "KNL" "defined(__AVX512F__) && defined(__AVX512ER__)" \
-                        ",-march=knl,-xMIC-AVX512" \
+                        ",-target-cpu=mic-knl,-march=knl,-xMIC-AVX512" \
                         SWR_KNL_CXXFLAGS
                     AC_SUBST([SWR_KNL_CXXFLAGS])
                     HAVE_SWR_KNL=yes
                     ;;
                 xskx)
                     swr_require_cxx_feature_flags "SKX" "defined(__AVX512F__) && defined(__AVX512BW__)" \
-                        ",-march=skylake-avx512,-xCORE-AVX512" \
+                        ",-target-cpu=x86-skylake,-march=skylake-avx512,-xCORE-AVX512" \
                         SWR_SKX_CXXFLAGS
                     AC_SUBST([SWR_SKX_CXXFLAGS])
                     HAVE_SWR_SKX=yes