Refactors CPU feature detection.

runtime/vm/cpu_x64.cc

Index: runtime/vm/cpu_x64.cc
===================================================================
--- runtime/vm/cpu_x64.cc	(revision 32467)
+++ runtime/vm/cpu_x64.cc	(working copy)
@@ -8,13 +8,18 @@
 
 #include "vm/cpu.h"
 
+#include "vm/assembler.h"
 #include "vm/constants_x64.h"
+#include "vm/cpuinfo.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 
 namespace dart {
 
+DEFINE_FLAG(bool, use_sse41, true, "Use SSE 4.1 if available");
+
+
 void CPU::FlushICache(uword start, uword size) {
   // Nothing to be done here.
 }
@@ -24,6 +29,29 @@
   return "x64";
 }
 
+
+bool HostCPUFeatures::sse2_supported_ = true;
+bool HostCPUFeatures::sse4_1_supported_ = false;
+char* HostCPUFeatures::hardware_ = NULL;
+#ifdef DEBUG
+bool HostCPUFeatures::initialized_ = false;
+#endif
+
+
+#define __ assembler.
+void HostCPUFeatures::InitOnce() {
+  CpuInfo::InitOnce();
+  hardware_ = CpuInfo::GetCpuModel();
+  sse4_1_supported_ =
+      CpuInfo::FieldContainsById(CpuInfo::kCpuInfoFeatures, "sse4_1") ||
+      CpuInfo::FieldContainsById(CpuInfo::kCpuInfoFeatures, "sse4.1");
+
+#ifdef DEBUG
+  initialized_ = true;
+#endif
+}
+#undef __
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64