diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4ba66a70b4e..d446d2cd2de 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2014-09-16  Ilya Tocar  <ilya.tocar@intel.com>
+
+	* config/i386/driver-i386.c (host_detect_local_cpu): Detect lack of
+	zmm/k regs support.
+
 2014-09-16  Alexander Ivchenko  <alexander.ivchenko@intel.com>
 	    Maxim Kuznetsov  <maxim.kuznetsov@intel.com>
 	    Anna Tikhonova  <anna.tikhonova@intel.com>
diff --git a/gcc/config/i386/driver-i386.c b/gcc/config/i386/driver-i386.c
index af3088e5b4b..4d6bf832f46 100644
--- a/gcc/config/i386/driver-i386.c
+++ b/gcc/config/i386/driver-i386.c
@@ -533,6 +533,9 @@ const char *host_detect_local_cpu (int argc, const char **argv)
 #define XSTATE_FP			0x1
 #define XSTATE_SSE			0x2
 #define XSTATE_YMM			0x4
+#define XSTATE_OPMASK			0x20
+#define XSTATE_ZMM			0x40
+#define XSTATE_HI_ZMM			0x80
   if (has_osxsave)
     asm (".byte 0x0f; .byte 0x01; .byte 0xd0"
 	 : "=a" (eax), "=d" (edx)
@@ -554,6 +557,20 @@ const char *host_detect_local_cpu (int argc, const char **argv)
       has_xsavec = 0;
     }
 
+  if (!has_osxsave
+      || (eax &
+	  (XSTATE_SSE | XSTATE_YMM | XSTATE_OPMASK | XSTATE_ZMM | XSTATE_HI_ZMM))
+	  != (XSTATE_SSE | XSTATE_YMM | XSTATE_OPMASK | XSTATE_ZMM | XSTATE_HI_ZMM))
+    {
+      has_avx512f = 0;
+      has_avx512er = 0;
+      has_avx512pf = 0;
+      has_avx512cd = 0;
+      has_avx512dq = 0;
+      has_avx512bw = 0;
+      has_avx512vl = 0;
+    }
+
   if (!arch)
     {
       if (vendor == signature_AMD_ebx
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4d3c96beee2..c3593a710c4 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2014-09-16  Ilya Tocar  <ilya.tocar@intel.com>
+
+	* gcc.target/i386/avx512f-os-support.h: Remove magic number.
+
 2014-09-16  Jakub Jelinek  <jakub@redhat.com>
 
 	PR fortran/56408
diff --git a/gcc/testsuite/gcc.target/i386/avx512f-os-support.h b/gcc/testsuite/gcc.target/i386/avx512f-os-support.h
index deefa5e1105..2f1ed03df45 100644
--- a/gcc/testsuite/gcc.target/i386/avx512f-os-support.h
+++ b/gcc/testsuite/gcc.target/i386/avx512f-os-support.h
@@ -1,10 +1,23 @@
 /* Check if the OS supports executing AVX512F instructions.  */
 
+#define XCR_XFEATURE_ENABLED_MASK	0x0
+
+#define XSTATE_FP	0x1
+#define XSTATE_SSE	0x2
+#define XSTATE_YMM	0x4
+#define XSTATE_OPMASK	0x20
+#define XSTATE_ZMM	0x40
+#define XSTATE_HI_ZMM	0x80
+
 static int
 avx512f_os_support (void)
 {
   unsigned int eax, edx;
+  unsigned int ecx = XCR_XFEATURE_ENABLED_MASK;
+  unsigned int mask = XSTATE_SSE | XSTATE_YMM | XSTATE_OPMASK
+		      | XSTATE_ZMM | XSTATE_HI_ZMM;
 
-  __asm__ ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (0));
-  return (eax & 230) == 230;
+  __asm__ ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (ecx));
+
+  return ((eax & mask) == mask);
 }