Backport from mainline

	2016-09-29  Uros Bizjak  <ubizjak@gmail.com>

	* config/i386/driver-i386.c (host_detect_local_cpu): Check maximum
	ext_level before calling CPUID with 0x80000008.

	2016-09-29  Uros Bizjak  <ubizjak@gmail.com>

	PR target/77756
	* config/i386/cpuid.h (__get_cpuid_count): New.
	(__get_cpuid): Rename __level to __leaf.

testsuite/ChangeLog:

	Backport from mainline
	2016-09-29  Uros Bizjak  <ubizjak@gmail.com>

	PR target/77756
	* gcc.target/i386/pr77756.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-6-branch@240747 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 27 insertions, 8 deletions

diff --git a/gcc/config/i386/cpuid.h b/gcc/config/i386/cpuid.h
index 8760e60d382..4ea3f74fecd 100644
--- a/gcc/config/i386/cpuid.h
+++ b/gcc/config/i386/cpuid.h
@@ -229,21 +229,37 @@ __get_cpuid_max (unsigned int __ext, unsigned int *__sig)
   return __eax;
 }
 
-/* Return cpuid data for requested cpuid level, as found in returned
+/* Return cpuid data for requested cpuid leaf, as found in returned
    eax, ebx, ecx and edx registers.  The function checks if cpuid is
    supported and returns 1 for valid cpuid information or 0 for
-   unsupported cpuid level.  All pointers are required to be non-null.  */
+   unsupported cpuid leaf.  All pointers are required to be non-null.  */
 
 static __inline int
-__get_cpuid (unsigned int __level,
+__get_cpuid (unsigned int __leaf,
 	     unsigned int *__eax, unsigned int *__ebx,
 	     unsigned int *__ecx, unsigned int *__edx)
 {
-  unsigned int __ext = __level & 0x80000000;
+  unsigned int __ext = __leaf & 0x80000000;
 
-  if (__get_cpuid_max (__ext, 0) < __level)
+  if (__get_cpuid_max (__ext, 0) < __leaf)
     return 0;
 
-  __cpuid (__level, *__eax, *__ebx, *__ecx, *__edx);
+  __cpuid (__leaf, *__eax, *__ebx, *__ecx, *__edx);
+  return 1;
+}
+
+/* Same as above, but sub-leaf can be specified.  */
+
+static __inline int
+__get_cpuid_count (unsigned int __leaf, unsigned int __subleaf,
+		   unsigned int *__eax, unsigned int *__ebx,
+		   unsigned int *__ecx, unsigned int *__edx)
+{
+  unsigned int __ext = __leaf & 0x80000000;
+
+  if (__get_cpuid_max (__ext, 0) < __leaf)
+    return 0;
+
+  __cpuid_count (__leaf, __subleaf, *__eax, *__ebx, *__ecx, *__edx);
   return 1;
 }
diff --git a/gcc/config/i386/driver-i386.c b/gcc/config/i386/driver-i386.c
index a9d5135f678..cb59b0c5754 100644
--- a/gcc/config/i386/driver-i386.c
+++ b/gcc/config/i386/driver-i386.c
@@ -517,7 +517,7 @@ const char *host_detect_local_cpu (int argc, const char **argv)
   /* Check cpuid level of extended features.  */
   __cpuid (0x80000000, ext_level, ebx, ecx, edx);
 
-  if (ext_level > 0x80000000)
+  if (ext_level >= 0x80000001)
     {
       __cpuid (0x80000001, eax, ebx, ecx, edx);
 
@@ -535,7 +535,10 @@ const char *host_detect_local_cpu (int argc, const char **argv)
       has_3dnowp = edx & bit_3DNOWP;
       has_3dnow = edx & bit_3DNOW;
       has_mwaitx = ecx & bit_MWAITX;
+    }
 
+  if (ext_level >= 0x80000008)
+    {
       __cpuid (0x80000008, eax, ebx, ecx, edx);
       has_clzero = ebx & bit_CLZERO;
     }
@@ -603,7 +606,7 @@ const char *host_detect_local_cpu (int argc, const char **argv)
       unsigned int name;
 
       /* Detect geode processor by its processor signature.  */
-      if (ext_level > 0x80000001)
+      if (ext_level >= 0x80000002)
 	__cpuid (0x80000002, name, ebx, ecx, edx);
       else
 	name = 0;