--- old/src/cpu/x86/vm/vm_version_x86.cpp	2015-04-06 14:41:07.712471400 -0700
+++ new/src/cpu/x86/vm/vm_version_x86.cpp	2015-04-06 14:41:07.519452100 -0700
@@ -35,7 +35,7 @@
 int VM_Version::_cpu;
 int VM_Version::_model;
 int VM_Version::_stepping;
-int VM_Version::_cpuFeatures;
+uint64_t VM_Version::_cpuFeatures;
 const char*           VM_Version::_features_str = "";
 VM_Version::CpuidInfo VM_Version::_cpuid_info   = { 0, };
 
@@ -470,6 +470,29 @@
   if (UseSSE < 1)
     _cpuFeatures &= ~CPU_SSE;
 
+  // first try initial setting and detect what we can support
+  if (UseAVX > 0) {
+    if (UseAVX > 2 && supports_evex()) {
+      UseAVX = 3;
+    } else if (UseAVX > 1 && supports_avx2()) {
+      UseAVX = 2;
+    } else if (UseAVX > 0 && supports_avx()) {
+      UseAVX = 1;
+    } else {
+      UseAVX = 0;
+    }
+  } else if (UseAVX < 0) {
+    UseAVX = 0;
+  }
+
+  if (UseAVX < 3) {
+    _cpuFeatures &= ~CPU_AVX512F;
+    _cpuFeatures &= ~CPU_AVX512DQ;
+    _cpuFeatures &= ~CPU_AVX512CD;
+    _cpuFeatures &= ~CPU_AVX512BW;
+    _cpuFeatures &= ~CPU_AVX512VL;
+  }
+
   if (UseAVX < 2)
     _cpuFeatures &= ~CPU_AVX2;
 
@@ -485,7 +508,7 @@
   }
 
   char buf[256];
-  jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+  jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
                cores_per_cpu(), threads_per_core(),
                cpu_family(), _model, _stepping,
                (supports_cmov() ? ", cmov" : ""),
@@ -515,7 +538,8 @@
                (supports_tscinv() ? ", tscinv": ""),
                (supports_bmi1() ? ", bmi1" : ""),
                (supports_bmi2() ? ", bmi2" : ""),
-               (supports_adx() ? ", adx" : ""));
+               (supports_adx() ? ", adx" : ""),
+               (supports_evex() ? ", evex" : ""));
   _features_str = os::strdup(buf);
 
   // UseSSE is set to the smaller of what hardware supports and what
@@ -532,13 +556,6 @@
   if (!supports_sse ()) // Drop to 0 if no SSE  support
     UseSSE = 0;
 
-  if (UseAVX > 2) UseAVX=2;
-  if (UseAVX < 0) UseAVX=0;
-  if (!supports_avx2()) // Drop to 1 if no AVX2 support
-    UseAVX = MIN2((intx)1,UseAVX);
-  if (!supports_avx ()) // Drop to 0 if no AVX  support
-    UseAVX = 0;
-
   // Use AES instructions if available.
   if (supports_aes()) {
     if (FLAG_IS_DEFAULT(UseAES)) {
@@ -609,7 +626,8 @@
       if ((_model == CPU_MODEL_HASWELL_E3) ||
           (_model == CPU_MODEL_HASWELL_E7 && _stepping < 3) ||
           (_model == CPU_MODEL_BROADWELL  && _stepping < 4)) {
-        if (!UnlockExperimentalVMOptions) {
+        // currently a collision between SKL and HSW_E3
+        if (!UnlockExperimentalVMOptions && UseAVX < 3) {
           vm_exit_during_initialization("UseRTMLocking is only available as experimental option on this platform. It must be enabled via -XX:+UnlockExperimentalVMOptions flag.");
         } else {
           warning("UseRTMLocking is only available as experimental option on this platform.");
@@ -662,10 +680,10 @@
   if (MaxVectorSize > 0) {
     if (!is_power_of_2(MaxVectorSize)) {
       warning("MaxVectorSize must be a power of 2");
-      FLAG_SET_DEFAULT(MaxVectorSize, 32);
+      FLAG_SET_DEFAULT(MaxVectorSize, 64);
     }
-    if (MaxVectorSize > 32) {
-      FLAG_SET_DEFAULT(MaxVectorSize, 32);
+    if (MaxVectorSize > 64) {
+      FLAG_SET_DEFAULT(MaxVectorSize, 64);
     }
     if (MaxVectorSize > 16 && (UseAVX == 0 || !os_supports_avx_vectors())) {
       // 32 bytes vectors (in YMM) are only supported with AVX+