Updates refactoring of CPU feature detection

runtime/vm/cpuinfo_linux.cc

Index: runtime/vm/cpuinfo_linux.cc
===================================================================
--- runtime/vm/cpuinfo_linux.cc	(revision 0)
+++ runtime/vm/cpuinfo_linux.cc	(revision 0)
@@ -0,0 +1,126 @@
+// Copyright (c) 2012, 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_LINUX)
+
+#include "vm/cpuinfo.h"
+#include "vm/cpuid.h"
+#include "vm/proccpuinfo.h"
+
+#include "platform/assert.h"
+
+// As with Windows, on IA32 and X64, we use the cpuid instruction.
+// The analogous instruction is privileged on ARM and MIPS, so we resort to
+// reading from /proc/cpuinfo.
+
+namespace dart {
+
+CpuInfoMethod CpuInfo::method_ = kCpuInfoDefault;
+const char* CpuInfo::fields_[kCpuInfoMax] = {0};
+
+void CpuInfo::InitOnce(CpuInfoMethod method) {
+  // The default on Linux is kCpuInfoCpuId.
+  method_ =
+      ((method == kCpuInfoDefault) || (method == kCpuInfoCpuId)) ?
+      kCpuInfoCpuId : kCpuInfoSystem;
+
+#if defined(HOST_ARCH_IA32) || defined(HOST_ARCH_X64)
+  fields_[kCpuInfoProcessor] = "vendor_id";
+  fields_[kCpuInfoModel] = "model name";
+  fields_[kCpuInfoHardware] = "model name";
+  fields_[kCpuInfoFeatures] = "flags";
+#elif defined(HOST_ARCH_ARM)
+  ASSERT(method_ != kCpuInfoCpuId);  // Method does not exist.
+  fields_[kCpuInfoProcessor] = "Processor";
+  fields_[kCpuInfoModel] = "model name";
+  fields_[kCpuInfoHardware] = "Hardware";
+  fields_[kCpuInfoFeatures] = "Features";
+#elif defined(HOST_ARCH_MIPS)
+  ASSERT(method_ != kCpuInfoCpuId);  // Method does not exist.
+  fields_[kCpuInfoProcessor] = "system type";
+  fields_[kCpuInfoModel] = "cpu model";
+  fields_[kCpuInfoHardware] = "cpu model";
+  fields_[kCpuInfoFeatures] = "ASEs implemented";
+#else
+#error Unrecognized target architecture
+#endif
+
+  if (method_ == kCpuInfoCpuId) {
+    CpuId::InitOnce();
+  } else {
+    ASSERT(method_ == kCpuInfoSystem);
+    ProcCpuInfo::InitOnce();
+  }

[siva, 2014/02/21 19:28:55]

As discussed offline we could enforce either CpuId::InitOnce or
ProcCpuInfo::InitOnce based on the architecture.

[zra, 2014/02/21 21:51:55]

Done.

+}
+
+
+bool CpuInfo::FieldContains(CpuInfoIndices idx, const char* search_string) {
+  if (method_ == kCpuInfoCpuId) {
+    return strstr(CpuId::field(idx), search_string);
+  } else {
+    ASSERT(method_ == kCpuInfoSystem);
+    return ProcCpuInfo::FieldContains(FieldName(idx), search_string);
+  }
+}
+
+
+bool CpuInfo::FieldContainsByString(const char* field,
+                                    const char* search_string) {
+  if (method_ == kCpuInfoCpuId) {
+    for (int i = 0; i < kCpuInfoMax; i++) {
+      if (strcmp(field, fields_[i]) == 0) {
+        return FieldContains(static_cast<CpuInfoIndices>(i), search_string);
+      }
+    }
+    UNIMPLEMENTED();
+    return false;
+  } else {
+    ASSERT(method_ == kCpuInfoSystem);
+    return ProcCpuInfo::FieldContains(field, search_string);
+  }
+}
+
+
+const char* CpuInfo::ExtractField(CpuInfoIndices idx) {
+  if (method_ == kCpuInfoCpuId) {
+    return CpuId::field(idx);
+  } else {
+    ASSERT(method_ == kCpuInfoSystem);
+    return ProcCpuInfo::ExtractField(FieldName(idx));
+  }
+}
+
+
+const char* CpuInfo::ExtractFieldByString(const char* field) {
+  if (method_ == kCpuInfoCpuId) {
+    for (int i = 0; i < kCpuInfoMax; i++) {
+      if (strcmp(field, fields_[i]) == 0) {
+        return ExtractField(static_cast<CpuInfoIndices>(i));
+      }
+    }
+    UNIMPLEMENTED();
+    return NULL;
+  } else {
+    ASSERT(method_ == kCpuInfoSystem);
+    return ProcCpuInfo::ExtractField(field);
+  }
+}
+
+
+bool CpuInfo::HasField(const char* field) {
+  if (method_ == kCpuInfoCpuId) {
+    return (strcmp(field, fields_[kCpuInfoProcessor]) == 0) ||
+           (strcmp(field, fields_[kCpuInfoModel]) == 0) ||
+           (strcmp(field, fields_[kCpuInfoHardware]) == 0) ||
+           (strcmp(field, fields_[kCpuInfoFeatures]) == 0);
+  } else {
+    ASSERT(method_ == kCpuInfoSystem);
+    return ProcCpuInfo::HasField(field);
+  }
+}
+
+}  // namespace dart
+
+#endif  // defined(TARGET_OS_LINUX)