From 399de24e29d7a083b388e7c05d8b4cffe5733dc3 Mon Sep 17 00:00:00 2001
From: Loic Dachary <loic@dachary.org>
Date: Sat, 29 Mar 2014 10:34:29 +0100
Subject: [PATCH] erasure-code: do not attempt to compile SSE4 on i386

SSE4 are only not availabe on older CPUs. Although the compiler could
probably generate the code, there is no point in doing so. The SSE4.1,
SSE4.2 and PCLMUL cpu features are only tested if the target CPU is
AMD64 or x86_64.

Signed-off-by: Loic Dachary <loic@dachary.org>
---
 m4/ax_intel.m4 | 116 ++++++++++++++++++++++++++-----------------------
 1 file changed, 62 insertions(+), 54 deletions(-)

diff --git a/m4/ax_intel.m4 b/m4/ax_intel.m4
index 3bcde6b0cace8..831e438890267 100644
--- a/m4/ax_intel.m4
+++ b/m4/ax_intel.m4
@@ -2,61 +2,69 @@ AC_DEFUN([AX_INTEL_FEATURES],
 [
   AC_REQUIRE([AC_CANONICAL_HOST])
 
-  AX_CHECK_COMPILE_FLAG(-msse, ax_cv_support_sse_ext=yes, [])
-  if test x"$ax_cv_support_sse_ext" = x"yes"; then
-    INTEL_SSE_FLAGS="-msse -DINTEL_SSE"
-    AC_SUBST(INTEL_SSE_FLAGS)
-    INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE_FLAGS"
-    AC_DEFINE(HAVE_SSE,,[Support SSE (Streaming SIMD Extensions) instructions])
-  fi
+  case $target_cpu in 
+    i[[3456]]86*|x86_64*|amd64*)
+      AX_CHECK_COMPILE_FLAG(-msse, ax_cv_support_sse_ext=yes, [])
+      if test x"$ax_cv_support_sse_ext" = x"yes"; then
+        INTEL_SSE_FLAGS="-msse -DINTEL_SSE"
+        AC_SUBST(INTEL_SSE_FLAGS)
+        INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE_FLAGS"
+        AC_DEFINE(HAVE_SSE,,[Support SSE (Streaming SIMD Extensions) instructions])
+      fi
+    
+      AX_CHECK_COMPILE_FLAG(-msse2, ax_cv_support_sse2_ext=yes, [])
+      if test x"$ax_cv_support_sse2_ext" = x"yes"; then
+        INTEL_SSE2_FLAGS="-msse2 -DINTEL_SSE2"
+        AC_SUBST(INTEL_SSE2_FLAGS)
+        INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE2_FLAGS"
+        AC_DEFINE(HAVE_SSE2,,[Support SSE2 (Streaming SIMD Extensions 2) instructions])
+      fi
+    
+      AX_CHECK_COMPILE_FLAG(-msse3, ax_cv_support_sse3_ext=yes, [])
+      if test x"$ax_cv_support_sse3_ext" = x"yes"; then
+        INTEL_SSE3_FLAGS="-mssse3 -DINTEL_SSE3"
+        AC_SUBST(INTEL_SSE3_FLAGS)
+        INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE3_FLAGS"
+        AC_DEFINE(HAVE_SSE3,,[Support SSE3 (Streaming SIMD Extensions 3) instructions])
+      fi
+    
+      AX_CHECK_COMPILE_FLAG(-mssse3, ax_cv_support_ssse3_ext=yes, [])
+      if test x"$ax_cv_support_ssse3_ext" = x"yes"; then
+        INTEL_SSSE3_FLAGS="-mssse3 -DINTEL_SSSE3"
+        AC_SUBST(INTEL_SSSE3_FLAGS)
+        INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSSE3_FLAGS"
+        AC_DEFINE(HAVE_SSSE3,,[Support SSSE3 (Supplemental Streaming SIMD Extensions 3) instructions])
+      fi
+    ;;
+  esac
 
-  AX_CHECK_COMPILE_FLAG(-msse2, ax_cv_support_sse2_ext=yes, [])
-  if test x"$ax_cv_support_sse2_ext" = x"yes"; then
-    INTEL_SSE2_FLAGS="-msse2 -DINTEL_SSE2"
-    AC_SUBST(INTEL_SSE2_FLAGS)
-    INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE2_FLAGS"
-    AC_DEFINE(HAVE_SSE2,,[Support SSE2 (Streaming SIMD Extensions 2) instructions])
-  fi
-
-  AX_CHECK_COMPILE_FLAG(-msse3, ax_cv_support_sse3_ext=yes, [])
-  if test x"$ax_cv_support_sse3_ext" = x"yes"; then
-    INTEL_SSE3_FLAGS="-mssse3 -DINTEL_SSE3"
-    AC_SUBST(INTEL_SSE3_FLAGS)
-    INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE3_FLAGS"
-    AC_DEFINE(HAVE_SSE3,,[Support SSE3 (Streaming SIMD Extensions 3) instructions])
-  fi
-
-  AX_CHECK_COMPILE_FLAG(-mpclmul, ax_cv_support_pclmuldq_ext=yes, [])
-  if test x"$ax_cv_support_pclmuldq_ext" = x"yes"; then
-    INTEL_PCLMUL_FLAGS="-mpclmul -DINTEL_SSE4_PCLMUL"
-    AC_SUBST(INTEL_PCLMUL_FLAGS)
-    INTEL_FLAGS="$INTEL_FLAGS $INTEL_PCLMUL_FLAGS"
-    AC_DEFINE(HAVE_PCLMUL,,[Support (PCLMUL) Carry-Free Muliplication])
-  fi
-
-  AX_CHECK_COMPILE_FLAG(-mssse3, ax_cv_support_ssse3_ext=yes, [])
-  if test x"$ax_cv_support_ssse3_ext" = x"yes"; then
-    INTEL_SSSE3_FLAGS="-mssse3 -DINTEL_SSSE3"
-    AC_SUBST(INTEL_SSSE3_FLAGS)
-    INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSSE3_FLAGS"
-    AC_DEFINE(HAVE_SSSE3,,[Support SSSE3 (Supplemental Streaming SIMD Extensions 3) instructions])
-  fi
-
-  AX_CHECK_COMPILE_FLAG(-msse4.1, ax_cv_support_sse41_ext=yes, [])
-  if test x"$ax_cv_support_sse41_ext" = x"yes"; then
-    INTEL_SSE4_1_FLAGS="-msse4.1 -DINTEL_SSE4"
-    AC_SUBST(INTEL_SSE4_1_FLAGS)
-    INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE4_1_FLAGS"
-    AC_DEFINE(HAVE_SSE4_1,,[Support SSE4.1 (Streaming SIMD Extensions 4.1) instructions])
-  fi
-
-  AX_CHECK_COMPILE_FLAG(-msse4.2, ax_cv_support_sse42_ext=yes, [])
-  if test x"$ax_cv_support_sse42_ext" = x"yes"; then
-    INTEL_SSE4_2_FLAGS="-msse4.2 -DINTEL_SSE4"
-    AC_SUBST(INTEL_SSE4_2_FLAGS)
-    INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE4_2_FLAGS"
-    AC_DEFINE(HAVE_SSE4_2,,[Support SSE4.2 (Streaming SIMD Extensions 4.2) instructions])
-  fi
+  case $target_cpu in
+  x86_64*|amd64*)
+      AX_CHECK_COMPILE_FLAG(-mpclmul, ax_cv_support_pclmuldq_ext=yes, [])
+      if test x"$ax_cv_support_pclmuldq_ext" = x"yes"; then
+        INTEL_PCLMUL_FLAGS="-mpclmul -DINTEL_SSE4_PCLMUL"
+        AC_SUBST(INTEL_PCLMUL_FLAGS)
+        INTEL_FLAGS="$INTEL_FLAGS $INTEL_PCLMUL_FLAGS"
+        AC_DEFINE(HAVE_PCLMUL,,[Support (PCLMUL) Carry-Free Muliplication])
+      fi
+    
+      AX_CHECK_COMPILE_FLAG(-msse4.1, ax_cv_support_sse41_ext=yes, [])
+      if test x"$ax_cv_support_sse41_ext" = x"yes"; then
+        INTEL_SSE4_1_FLAGS="-msse4.1 -DINTEL_SSE4"
+        AC_SUBST(INTEL_SSE4_1_FLAGS)
+        INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE4_1_FLAGS"
+        AC_DEFINE(HAVE_SSE4_1,,[Support SSE4.1 (Streaming SIMD Extensions 4.1) instructions])
+      fi
+    
+      AX_CHECK_COMPILE_FLAG(-msse4.2, ax_cv_support_sse42_ext=yes, [])
+      if test x"$ax_cv_support_sse42_ext" = x"yes"; then
+        INTEL_SSE4_2_FLAGS="-msse4.2 -DINTEL_SSE4"
+        AC_SUBST(INTEL_SSE4_2_FLAGS)
+        INTEL_FLAGS="$INTEL_FLAGS $INTEL_SSE4_2_FLAGS"
+        AC_DEFINE(HAVE_SSE4_2,,[Support SSE4.2 (Streaming SIMD Extensions 4.2) instructions])
+      fi
+    ;;
+  esac
 
   AC_SUBST(INTEL_FLAGS)
 ])
-- 
2.39.5