Reorder SIMD tests so that most specific is tried first and later tests are not done

The intel compiler warns that each flag is superceded by previous one, so just use the most specific, note this also means that GCC will only see one flag.


Former-commit-id: b7ae1ae756dec010b97826833768a67197292444

m4/ax_ext.m4

@@ -31,6 +31,10 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
+#   SWIFT modifications. Intel compilers accept these flags, but warn about
+#   the order of the flags when more than one is used. Given that reverse
+#   the check order and break on the highest accepted.
+
 #serial 13
 
 AC_DEFUN([AX_EXT],
@@ -156,83 +160,92 @@ AC_DEFUN([AX_EXT],
         fi
       fi
 
-      if test "$ax_cv_have_mmx_ext" = yes; then
-        AX_CHECK_COMPILE_FLAG(-mmmx, ax_cv_support_mmx_ext=yes, [])
-        if test x"$ax_cv_support_mmx_ext" = x"yes"; then
-          SIMD_FLAGS="$SIMD_FLAGS -mmmx"
-          AC_DEFINE(HAVE_MMX,,[Support mmx instructions])
-        else
-          AC_MSG_WARN([Your processor supports mmx instructions but not your compiler, can you try another compiler?])
-        fi
-      fi
+      checkmore=yes
 
-      if test "$ax_cv_have_sse_ext" = yes; then
-        AX_CHECK_COMPILE_FLAG(-msse, ax_cv_support_sse_ext=yes, [])
-        if test x"$ax_cv_support_sse_ext" = x"yes"; then
-          SIMD_FLAGS="$SIMD_FLAGS -msse"
-          AC_DEFINE(HAVE_SSE,,[Support SSE (Streaming SIMD Extensions) instructions])
+      if test "$ax_cv_have_avx_ext" = yes; then
+        AX_CHECK_COMPILE_FLAG(-mavx, ax_cv_support_avx_ext=yes, [])
+        if test x"$ax_cv_support_avx_ext" = x"yes"; then
+          SIMD_FLAGS="$SIMD_FLAGS -mavx"
+          AC_DEFINE(HAVE_AVX,,[Support AVX (Advanced Vector Extensions) instructions])
+          checkmore=no
         else
-          AC_MSG_WARN([Your processor supports sse instructions but not your compiler, can you try another compiler?])
+          AC_MSG_WARN([Your processor supports avx instructions but not your compiler, can you try another compiler?])
         fi
       fi
 
-      if test "$ax_cv_have_sse2_ext" = yes; then
-        AX_CHECK_COMPILE_FLAG(-msse2, ax_cv_support_sse2_ext=yes, [])
-        if test x"$ax_cv_support_sse2_ext" = x"yes"; then
-          SIMD_FLAGS="$SIMD_FLAGS -msse2"
-          AC_DEFINE(HAVE_SSE2,,[Support SSE2 (Streaming SIMD Extensions 2) instructions])
+      if test $checkmore = yes -a "$ax_cv_have_sse42_ext" = yes; then
+        AX_CHECK_COMPILE_FLAG(-msse4.2, ax_cv_support_sse42_ext=yes, [])
+        if test x"$ax_cv_support_sse42_ext" = x"yes"; then
+          SIMD_FLAGS="$SIMD_FLAGS -msse4.2"
+          AC_DEFINE(HAVE_SSE4_2,,[Support SSSE4.2 (Streaming SIMD Extensions 4.2) instructions])
+          checkmore=no
         else
-          AC_MSG_WARN([Your processor supports sse2 instructions but not your compiler, can you try another compiler?])
+          AC_MSG_WARN([Your processor supports sse4.2 instructions but not your compiler, can you try another compiler?])
         fi
       fi
 
-      if test "$ax_cv_have_sse3_ext" = yes; then
-        AX_CHECK_COMPILE_FLAG(-msse3, ax_cv_support_sse3_ext=yes, [])
-        if test x"$ax_cv_support_sse3_ext" = x"yes"; then
-          SIMD_FLAGS="$SIMD_FLAGS -msse3"
-          AC_DEFINE(HAVE_SSE3,,[Support SSE3 (Streaming SIMD Extensions 3) instructions])
+      if test $checkmore = yes -a "$ax_cv_have_sse41_ext" = yes; then
+        AX_CHECK_COMPILE_FLAG(-msse4.1, ax_cv_support_sse41_ext=yes, [])
+        if test x"$ax_cv_support_sse41_ext" = x"yes"; then
+          SIMD_FLAGS="$SIMD_FLAGS -msse4.1"
+          AC_DEFINE(HAVE_SSE4_1,,[Support SSSE4.1 (Streaming SIMD Extensions 4.1) instructions])
+          checkmore=no
         else
-          AC_MSG_WARN([Your processor supports sse3 instructions but not your compiler, can you try another compiler?])
+          AC_MSG_WARN([Your processor supports sse4.1 instructions but not your compiler, can you try another compiler?])
         fi
       fi
 
-      if test "$ax_cv_have_ssse3_ext" = yes; then
+      if test $checkmore = yes -a "$ax_cv_have_ssse3_ext" = yes; then
         AX_CHECK_COMPILE_FLAG(-mssse3, ax_cv_support_ssse3_ext=yes, [])
         if test x"$ax_cv_support_ssse3_ext" = x"yes"; then
           SIMD_FLAGS="$SIMD_FLAGS -mssse3"
           AC_DEFINE(HAVE_SSSE3,,[Support SSSE3 (Supplemental Streaming SIMD Extensions 3) instructions])
+          checkmore=no
         else
           AC_MSG_WARN([Your processor supports ssse3 instructions but not your compiler, can you try another compiler?])
         fi
       fi
 
-      if test "$ax_cv_have_sse41_ext" = yes; then
-        AX_CHECK_COMPILE_FLAG(-msse4.1, ax_cv_support_sse41_ext=yes, [])
-        if test x"$ax_cv_support_sse41_ext" = x"yes"; then
-          SIMD_FLAGS="$SIMD_FLAGS -msse4.1"
-          AC_DEFINE(HAVE_SSE4_1,,[Support SSSE4.1 (Streaming SIMD Extensions 4.1) instructions])
+      if test $checkmore = yes -a "$ax_cv_have_sse3_ext" = yes; then
+        AX_CHECK_COMPILE_FLAG(-msse3, ax_cv_support_sse3_ext=yes, [])
+        if test x"$ax_cv_support_sse3_ext" = x"yes"; then
+          SIMD_FLAGS="$SIMD_FLAGS -msse3"
+          AC_DEFINE(HAVE_SSE3,,[Support SSE3 (Streaming SIMD Extensions 3) instructions])
+          checkmore=no
         else
-          AC_MSG_WARN([Your processor supports sse4.1 instructions but not your compiler, can you try another compiler?])
+          AC_MSG_WARN([Your processor supports sse3 instructions but not your compiler, can you try another compiler?])
         fi
       fi
 
-      if test "$ax_cv_have_sse42_ext" = yes; then
-        AX_CHECK_COMPILE_FLAG(-msse4.2, ax_cv_support_sse42_ext=yes, [])
-        if test x"$ax_cv_support_sse42_ext" = x"yes"; then
-          SIMD_FLAGS="$SIMD_FLAGS -msse4.2"
-          AC_DEFINE(HAVE_SSE4_2,,[Support SSSE4.2 (Streaming SIMD Extensions 4.2) instructions])
+      if test $checkmore = yes -a "$ax_cv_have_sse2_ext" = yes; then
+        AX_CHECK_COMPILE_FLAG(-msse2, ax_cv_support_sse2_ext=yes, [])
+        if test x"$ax_cv_support_sse2_ext" = x"yes"; then
+          SIMD_FLAGS="$SIMD_FLAGS -msse2"
+          AC_DEFINE(HAVE_SSE2,,[Support SSE2 (Streaming SIMD Extensions 2) instructions])
+          checkmore=no
         else
-          AC_MSG_WARN([Your processor supports sse4.2 instructions but not your compiler, can you try another compiler?])
+          AC_MSG_WARN([Your processor supports sse2 instructions but not your compiler, can you try another compiler?])
         fi
       fi
 
-      if test "$ax_cv_have_avx_ext" = yes; then
-        AX_CHECK_COMPILE_FLAG(-mavx, ax_cv_support_avx_ext=yes, [])
-        if test x"$ax_cv_support_avx_ext" = x"yes"; then
-          SIMD_FLAGS="$SIMD_FLAGS -mavx"
-          AC_DEFINE(HAVE_AVX,,[Support AVX (Advanced Vector Extensions) instructions])
+      if test $checkmore = yes -a "$ax_cv_have_sse_ext" = yes; then
+        AX_CHECK_COMPILE_FLAG(-msse, ax_cv_support_sse_ext=yes, [])
+        if test x"$ax_cv_support_sse_ext" = x"yes"; then
+          SIMD_FLAGS="$SIMD_FLAGS -msse"
+          AC_DEFINE(HAVE_SSE,,[Support SSE (Streaming SIMD Extensions) instructions])
+          checkmore=no
         else
-          AC_MSG_WARN([Your processor supports avx instructions but not your compiler, can you try another compiler?])
+          AC_MSG_WARN([Your processor supports sse instructions but not your compiler, can you try another compiler?])
+        fi
+      fi
+
+      if test $checkmore = yes -a "$ax_cv_have_mmx_ext" = yes; then
+        AX_CHECK_COMPILE_FLAG(-mmmx, ax_cv_support_mmx_ext=yes, [])
+        if test x"$ax_cv_support_mmx_ext" = x"yes"; then
+          SIMD_FLAGS="$SIMD_FLAGS -mmmx"
+          AC_DEFINE(HAVE_MMX,,[Support mmx instructions])
+        else
+          AC_MSG_WARN([Your processor supports mmx instructions but not your compiler, can you try another compiler?])
         fi
       fi