[PATCH, i386 testsuite]: Introduce gcc.target/i386/mpx/mpx-os-support.h

[Uros Bizjak]

2017-09-04  Uros Bizjak  <ubizjak@gmail.com>

    * gcc.target/i386/mpx/mpx-os-support.h: New file.
    * gcc.target/i386/mpx/mpx-check.h: Include mpx-os-support.h.

Tested on x86_64-linux-gnu {,-m32}.

Committed to mainline SVN.

Uros.
-------------- next part --------------
Index: gcc.target/i386/mpx/mpx-check.h
===================================================================
--- gcc.target/i386/mpx/mpx-check.h	(revision 251661)
+++ gcc.target/i386/mpx/mpx-check.h	(working copy)
@@ -1,8 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <assert.h>
-
 #include "cpuid.h"
+#include "mpx-os-support.h"
 
 static int
 __attribute__ ((noinline))
@@ -16,16 +16,6 @@
 
 #define DEBUG
 
-#define XSTATE_BNDREGS (1 << 3)
-
-/* This should be an intrinsic, but isn't.  */
-static int xgetbv (unsigned x)
-{
-   unsigned eax, edx;
-   asm ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (x)); 
-   return eax;
-}
-
 static int
 check_osxsave (void)
 {
@@ -44,7 +34,7 @@
     return NORUNRES;
 
   /* Run MPX test only if host has MPX support.  */
-  if (check_osxsave () && (ebx & bit_MPX) && (xgetbv (0) & XSTATE_BNDREGS))
+  if (check_osxsave () && (ebx & bit_MPX) && mpx_os_support ())
     mpx_test (argc, argv);
   else
     {
Index: gcc.target/i386/mpx/mpx-os-support.h
===================================================================
--- gcc.target/i386/mpx/mpx-os-support.h	(nonexistent)
+++ gcc.target/i386/mpx/mpx-os-support.h	(working copy)
@@ -0,0 +1,16 @@
+/* Check if the OS supports executing MPX instructions.  */
+
+#define XCR_XFEATURE_ENABLED_MASK	0x0
+
+#define XSTATE_BNDREGS	0x8
+
+static int
+mpx_os_support (void)
+{
+  unsigned int eax, edx;
+  unsigned int ecx = XCR_XFEATURE_ENABLED_MASK;
+
+  __asm__ ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (ecx));
+
+  return (eax & XSTATE_BNDREGS) != 0;
+}