Index: gcc.dg/vect/vect.exp
===================================================================
--- gcc.dg/vect/vect.exp	(revision 133085)
+++ gcc.dg/vect/vect.exp	(working copy)
@@ -1,4 +1,4 @@
-# Copyright (C) 1997, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+# Copyright (C) 1997, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -63,7 +63,11 @@
    set dg-do-what-default run
 } elseif { [istarget "i?86-*-*"] || [istarget "x86_64-*-*"] } {
     lappend DEFAULT_VECTCFLAGS "-msse2"
-    set dg-do-what-default run
+    if [check_sse2_hw_available] {
+	set dg-do-what-default run
+    } else {
+	set dg-do-what-default compile
+    }
 } elseif { [istarget "mips*-*-*"]
 	   && [check_effective_target_mpaired_single]
 	   && [check_effective_target_nomips16] } {
Index: lib/target-supports.exp
===================================================================
--- lib/target-supports.exp	(revision 133085)
+++ lib/target-supports.exp	(working copy)
@@ -1,4 +1,4 @@
-#   Copyright (C) 1999, 2001, 2003, 2004, 2005, 2006, 2007
+#   Copyright (C) 1999, 2001, 2003, 2004, 2005, 2006, 2007, 2008
 #    Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
@@ -1194,6 +1194,20 @@
     } "-mfpu=neon -mfloat-abi=softfp"]
 }
 
+# Return 1 if the target supports executing MMX instructions, 0
+# otherwise.  Cache the result.
+
+proc check_sse2_hw_available { } {
+    return [check_runtime x86_sse2_hw_available {
+	int
+	main (void)
+	{
+	  asm volatile ("paddq  %xmm0,%xmm0");
+	  return 0;
+	}
+    } "-msse2"]
+}
+
 # Return 1 if this is a PowerPC target with floating-point registers.
 
 proc check_effective_target_powerpc_fprs { } {