--- a/hotspot/src/cpu/x86/vm/vm_version_x86.hpp	Sat Apr 09 22:55:25 2011 -0700
+++ b/hotspot/src/cpu/x86/vm/vm_version_x86.hpp	Mon Apr 11 15:30:31 2011 -0700
@@ -188,7 +188,8 @@
      CPU_FXSR   = (1 << 2),
      CPU_HT     = (1 << 3),
      CPU_MMX    = (1 << 4),
-     CPU_3DNOW  = (1 << 5), // 3DNow comes from cpuid 0x80000001 (EDX)
+     CPU_3DNOW_PREFETCH  = (1 << 5), // Processor supports 3dnow prefetch and prefetchw instructions
+                                     // may not necessarily support other 3dnow instructions
      CPU_SSE    = (1 << 6),
      CPU_SSE2   = (1 << 7),
      CPU_SSE3   = (1 << 8), // SSE3 comes from cpuid 1 (ECX)
@@ -328,8 +329,9 @@
 
     // AMD features.
     if (is_amd()) {
-      if (_cpuid_info.ext_cpuid1_edx.bits.tdnow != 0)
-        result |= CPU_3DNOW;
+      if ((_cpuid_info.ext_cpuid1_edx.bits.tdnow != 0) ||
+          (_cpuid_info.ext_cpuid1_ecx.bits.prefetchw != 0))
+        result |= CPU_3DNOW_PREFETCH;
       if (_cpuid_info.ext_cpuid1_ecx.bits.lzcnt != 0)
         result |= CPU_LZCNT;
       if (_cpuid_info.ext_cpuid1_ecx.bits.sse4a != 0)
@@ -446,9 +448,8 @@
   //
   // AMD features
   //
-  static bool supports_3dnow()    { return (_cpuFeatures & CPU_3DNOW) != 0; }
+  static bool supports_3dnow_prefetch()    { return (_cpuFeatures & CPU_3DNOW_PREFETCH) != 0; }
   static bool supports_mmx_ext()  { return is_amd() && _cpuid_info.ext_cpuid1_edx.bits.mmx_amd != 0; }
-  static bool supports_3dnow2()   { return is_amd() && _cpuid_info.ext_cpuid1_edx.bits.tdnow2 != 0; }
   static bool supports_lzcnt()    { return (_cpuFeatures & CPU_LZCNT) != 0; }
   static bool supports_sse4a()    { return (_cpuFeatures & CPU_SSE4A) != 0; }