Updates refactoring of CPU feature detection

runtime/vm/cpuid.cc

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/globals.h"
+#if !defined(TARGET_OS_MACOS)
+#include "vm/cpuid.h"
+
+#if defined(HOST_ARCH_IA32) || defined(HOST_ARCH_X64)
+// GetCpuId() on Windows, __get_cpuid() on Linux
+#if defined(TARGET_OS_WINDOWS)
+#include <intrin.h>  // NOLINT
+#else
+#include <cpuid.h>  // NOLINT
+#endif
+#endif
+
+namespace dart {
+
+bool CpuId::sse2_ = false;
+bool CpuId::sse41_ = false;
+const char* CpuId::id_string_ = NULL;
+const char* CpuId::brand_string_ = NULL;
+
+#if defined(HOST_ARCH_IA32) || defined(HOST_ARCH_X64)
+
+void CpuId::GetCpuId(int32_t level, uint32_t info[4]) {
+#if defined(TARGET_OS_WINDOWS)
+  // The documentation for __cpuid is at:
+  // http://msdn.microsoft.com/en-us/library/hskdteyh(v=vs.90).aspx
+  __cpuid(reinterpret_cast<int*>(info), level);
+#else
+  __get_cpuid(level, &info[0], &info[1], &info[2], &info[3]);
+#endif
+}
+
+
+void CpuId::InitOnce() {
+  uint32_t info[4] = {-1};
+
+  GetCpuId(0, info);
+  char* id_string = new char[3 * sizeof(int32_t)];
+  // Yes, these are supposed to be out of order.
+  *reinterpret_cast<uint32_t*>(id_string) = info[1];
+  *reinterpret_cast<uint32_t*>(id_string + 4) = info[3];
+  *reinterpret_cast<uint32_t*>(id_string + 8) = info[2];
+  CpuId::id_string_ = id_string;
+
+  GetCpuId(1, info);
+  CpuId::sse41_ = (info[2] & (1 << 19)) != 0;
+  CpuId::sse2_ = (info[3] & (1 << 26)) != 0;
+
+  char* brand_string = new char[3 * 4 * sizeof(uint32_t)];
+  for (uint32_t i = 0x80000002; i <= 0x80000004; i++) {
+    uint32_t off = (i - 0x80000002U) * 4 * sizeof(uint32_t);
+    GetCpuId(i, info);
+    *reinterpret_cast<int32_t*>(brand_string + off) = info[0];
+    *reinterpret_cast<int32_t*>(brand_string + off + 4) = info[1];
+    *reinterpret_cast<int32_t*>(brand_string + off + 8) = info[2];
+    *reinterpret_cast<int32_t*>(brand_string + off + 12) = info[3];
+  }
+  CpuId::brand_string_ = brand_string;
+}
+
+
+void CpuId::Cleanup() {
+  ASSERT(id_string_ != NULL);
+  delete[] id_string_;
+  id_string_ = NULL;
+
+  ASSERT(brand_string_ != NULL);
+  delete[] brand_string_;
+  brand_string_ = NULL;
+}
+
+
+const char* CpuId::id_string() {
+  return strdup(id_string_);
+}
+
+
+const char* CpuId::brand_string() {
+  return strdup(brand_string_);
+}
+
+
+const char* CpuId::field(CpuInfoIndices idx) {
+  switch (idx) {
+    case kCpuInfoProcessor:
+      return id_string();
+    case kCpuInfoModel:
+      return brand_string();
+    case kCpuInfoHardware:
+      return brand_string();
+    case kCpuInfoFeatures: {
+      if (sse2() && sse41()) {
+        return strdup("sse2 sse4.1");
+      } else if (sse2()) {
+        return strdup("sse2");
+      } else if (sse41()) {
+        return strdup("sse4.1");
+      } else {
+        return strdup("");
+      }
+    }
+    default: {
+      UNREACHABLE();
+      return NULL;
+    }
+  }
+}
+
+#endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64)
+}  // namespace dart
+
+#endif  // !defined(TARGET_OS_MACOS)