Refactors CPU feature detection.

runtime/vm/cpu_arm.cc

Index: runtime/vm/cpu_arm.cc
===================================================================
--- runtime/vm/cpu_arm.cc	(revision 32467)
+++ runtime/vm/cpu_arm.cc	(working copy)
@@ -6,13 +6,15 @@
 
 #if defined(TARGET_ARCH_ARM)
 
+#include "vm/cpu.h"
+#include "vm/cpuinfo.h"
+#include "vm/simulator.h"
+
 #if defined(HOST_ARCH_ARM)
 #include <sys/syscall.h>  /* NOLINT */
 #include <unistd.h>  /* NOLINT */
 #endif
 
-#include "vm/cpu.h"
-
 namespace dart {
 
 void CPU::FlushICache(uword start, uword size) {
@@ -48,6 +50,53 @@
   "arm";
 }
 
+
+bool HostCPUFeatures::integer_division_supported_ = false;
+bool HostCPUFeatures::neon_supported_ = false;
+char* HostCPUFeatures::hardware_ = NULL;
+#if defined(DEBUG)
+bool HostCPUFeatures::initialized_ = false;
+#endif
+
+
+#if defined(HOST_ARCH_ARM)
+void HostCPUFeatures::InitOnce() {
+  CpuInfo::InitOnce();
+  hardware_ = CpuInfo::GetCpuModel();
+  // Implements ARMv7.
+  ASSERT(CpuInfo::FieldContainsById(CpuInfo::kCpuInfoProcessor, "ARMv7"));
+  // Has floating point unit.
+  ASSERT(CpuInfo::FieldContainsById(CpuInfo::kCpuInfoFeatures, "vfp"));
+  // Has integer division.
+  bool is_krait =
+      CpuInfo::FieldContainsById(CpuInfo::kCpuInfoModel, "QCT APQ8064");
+  if (is_krait) {
+    // Special case for Qualcomm Krait CPUs in Nexus 4 and 7.
+    integer_division_supported_ = true;
+  } else {
+    integer_division_supported_ =
+        CpuInfo::FieldContainsById(CpuInfo::kCpuInfoFeatures, "idiva");
+  }
+  neon_supported_ =
+      CpuInfo::FieldContainsById(CpuInfo::kCpuInfoFeatures, "neon");
+#if defined(DEBUG)
+  initialized_ = true;
+#endif
+}
+
+#else
+
+void HostCPUFeatures::InitOnce() {
+  CpuInfo::InitOnce();
+  hardware_ = CpuInfo::GetCpuModel();
+  integer_division_supported_ = true;
+  neon_supported_ = true;
+#if defined(DEBUG)
+  initialized_ = true;
+#endif
+}
+#endif  // defined(HOST_ARCH_ARM)
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM