[PATCH, testsuite]: Introduce check_avx_os_support_available

[Uros Bizjak]

Hello!

This is the same functionality as recently added to glibc [1].

2011-07-21  Uros Bizjak  <ubizjak@gmail.com>

	* lib/target-supports.exp (check_avx_os_support_available): New.
	(check_effective_target_avx_runtime): Use it.

Tested on x86_64-pc-linux-gnu {,-m32} AVX and non-AVX targets,
ommitted to mainline SVN.
The patch will be backported to release branches.

[1] http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=5644ef5461b5d3ff266206d8ee70d4b575ea6658

Uros.
-------------- next part --------------
Index: lib/target-supports.exp
===================================================================
--- lib/target-supports.exp	(revision 176571)
+++ lib/target-supports.exp	(working copy)
@@ -1070,8 +1070,8 @@
 	    check_runtime_nocache sse_os_support_available {
 		int main ()
 		{
-		    __asm__ volatile ("movaps %xmm0,%xmm0");
-		    return 0;
+		  asm volatile ("movaps %xmm0,%xmm0");
+		  return 0;
 		}
 	    } "-msse"
 	} else {
@@ -1080,6 +1080,29 @@
     }]
 }
 
+# Return 1 if the target OS supports running AVX executables, 0
+# otherwise.  Cache the result.
+
+proc check_avx_os_support_available { } {
+    return [check_cached_effective_target avx_os_support_available {
+	# If this is not the right target then we can skip the test.
+	if { !([istarget x86_64-*-*] || [istarget i?86-*-*]) } {
+	    expr 0
+	} else {
+	    # Check that OS has AVX and SSE saving enabled.
+	    check_runtime_nocache avx_os_support_available {
+		int main ()
+		{
+		  unsigned int eax, edx;
+
+		  asm ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (0));
+		  return (eax & 6) != 6;
+		}
+	    } ""
+	}
+    }]
+}
+
 # Return 1 if the target supports executing SSE instructions, 0
 # otherwise.  Cache the result.
 
@@ -1176,7 +1199,8 @@
 
 proc check_effective_target_avx_runtime { } {
     if { [check_effective_target_avx]
-	 && [check_avx_hw_available] } {
+	 && [check_avx_hw_available]
+	 && [check_avx_os_support_available] } {
 	return 1
     }
     return 0