target.h (htm_available): Determine vendor from __get_cpuid_max return.

	* config/x86/target.h (htm_available): Determine vendor from
	__get_cpuid_max return.  Use signature_INTEL_ebx.  Cleanup.

From-SVN: r244644

diff --git a/libitm/ChangeLog b/libitm/ChangeLog
index d50005f4d910009f8375e5a5620b1e3eb9be763a..5f44e3f1250b59e963f485a7c39a81bda1948cdb 100644 (file)
--- a/libitm/ChangeLog
+++ b/libitm/ChangeLog
@@ -1,3 +1,8 @@
+2017-01-19  Uros Bizjak  <ubizjak@gmail.com>
+
+       * config/x86/target.h (htm_available): Determine vendor from
+       __get_cpuid_max return.  Use signature_INTEL_ebx.  Cleanup.
+
 2017-01-18  Torvald Riegel  <triegel@redhat.com>
 
        * config/x86/target.h (htm_available): Add check for some processors

diff --git a/libitm/config/x86/target.h b/libitm/config/x86/target.h
index 665c7d6e986bd5a1899a613918de9e97ee99fe95..1b79dc03a67e92faaae6785b309dc00a675616c4 100644 (file)
--- a/libitm/config/x86/target.h
+++ b/libitm/config/x86/target.h
@@ -75,31 +75,32 @@ static inline bool
 htm_available ()
 {
   const unsigned cpuid_rtm = bit_RTM;
-  if (__get_cpuid_max (0, NULL) >= 7)
+  unsigned vendor;
+
+  if (__get_cpuid_max (0, &vendor) >= 7)
     {
       unsigned a, b, c, d;
-      /* TSX is broken on some processors.  This can be fixed by microcode,
+      unsigned family;
+
+      __cpuid (1, a, b, c, d);
+      family = (a >> 8) & 0x0f;
+      /* TSX is broken on some processors.  TSX can be disabled by microcode,
         but we cannot reliably detect whether the microcode has been
         updated.  Therefore, do not report availability of TSX on these
         processors.  We use the same approach here as in glibc (see
         https://sourceware.org/ml/libc-alpha/2016-12/msg00470.html).  */
-      __cpuid (0, a, b, c, d);
-      if (b == 0x756e6547 && c == 0x6c65746e && d == 0x49656e69)
+      if (vendor == signature_INTEL_ebx && family == 0x06)
        {
-         __cpuid (1, a, b, c, d);
-         if (((a >> 8) & 0x0f) == 0x06) // Family.
-           {
-             unsigned model = ((a >> 4) & 0x0f) // Model.
-                 + ((a >> 12) & 0xf0); // Extended model.
-             unsigned stepping = a & 0x0f;
-             if ((model == 0x3c)
-                 || (model == 0x45)
-                 || (model == 0x46)
-                 /* Xeon E7 v3 has correct TSX if stepping >= 4.  */
-                 || ((model == 0x3f) && (stepping < 4)))
-               return false;
-           }
+         unsigned model = ((a >> 4) & 0x0f) + ((a >> 12) & 0xf0);
+         unsigned stepping = a & 0x0f;
+         if (model == 0x3c
+             /* Xeon E7 v3 has correct TSX if stepping >= 4.  */
+             || (model == 0x3f && stepping < 4)
+             || model == 0x45
+             || model == 0x46)
+           return false;
        }
+
       __cpuid_count (7, 0, a, b, c, d);
       if (b & cpuid_rtm)
        return true;