Make sure that we don't generate floating point code that would cause illegal...

Make sure that we don't generate floating point code that would cause illegal instruction exceptions on older processors, unless someone passes --enable-ssemath to configure.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403281

configure.in

@@ -394,6 +394,30 @@ AC_HELP_STRING([--enable-sse2], [use SSE2 assembly routines [[default=yes]]]),
         fi
     fi
 
+    # Make sure that we don't generate floating point code that would
+    # cause illegal instruction exceptions on older processors
+    case "$host" in
+        *-*-darwin*)
+            # Don't need to worry about Apple hardware, it's all SSE capable
+            default_ssemath=yes
+            ;;
+        *64-*-*)
+            # x86 64-bit architectures all have SSE instructions
+            default_ssemath=yes
+            ;;
+	*)
+            default_ssemath=no
+            ;;
+    esac
+    AC_ARG_ENABLE(ssemath,
+AC_HELP_STRING([--enable-ssemath], [Allow GCC to use SSE floating point math [[default=no]]]),
+                  , enable_ssemath=$default_ssemath)
+    if test x$enable_ssemath = xno; then
+        if test x$have_gcc_sse = xyes -o x$have_gcc_sse2 = xyes; then
+            EXTRA_CFLAGS="$EXTRA_CFLAGS -mfpmath=387"
+        fi
+    fi
+
     AC_ARG_ENABLE(altivec,
 AC_HELP_STRING([--enable-altivec], [use Altivec assembly routines [[default=yes]]]),
                   , enable_altivec=yes)