Refactors CPU feature detection.

runtime/vm/cpu_arm.cc

 // 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_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) {
 #if defined(HOST_ARCH_ARM)
   // Nothing to do. Flushing no instructions.
   if (size == 0) {
     return;
   }
 
   // ARM recommends using the gcc intrinsic __clear_cache on Linux, and the
@@ skipping 15 matching lines @@
 
 
 const char* CPU::Id() {
   return
 #if !defined(HOST_ARCH_ARM)
   "sim"
 #endif  // !defined(HOST_ARCH_ARM)
   "arm";
 }
 
+
+bool CPUFeatures::integer_division_supported_ = false;
+bool CPUFeatures::neon_supported_ = false;
+char CPUFeatures::hardware_[HARDWARE_LEN] = {0};
+#if defined(DEBUG)
+bool CPUFeatures::initialized_ = false;
+#endif
+
+
+bool CPUFeatures::integer_division_supported() {
+  DEBUG_ASSERT(initialized_);
+  return integer_division_supported_;
+}
+
+
+bool CPUFeatures::neon_supported() {
+  DEBUG_ASSERT(initialized_);
+  return neon_supported_;
+}
+
+
+char* CPUFeatures::hardware() {
+  DEBUG_ASSERT(initialized_);
+  return hardware_;
+}
+
+// If we are using the simulator, allow tests to enable/disable support for
+// integer division.
+#if defined(USING_SIMULATOR)
+void CPUFeatures::set_integer_division_supported(bool supported) {
+  integer_division_supported_ = supported;
+}
+
+
+void CPUFeatures::set_neon_supported(bool supported) {
+  neon_supported_ = supported;
+}
+#endif
+
+
+void CPUFeatures::InitOnce() {
+  CpuInfo::Read();
+  CpuInfo::GetCpuModel(hardware_, HARDWARE_LEN);
+#if defined(USING_SIMULATOR)
+  integer_division_supported_ = true;
+  neon_supported_ = true;
+#else
+  ASSERT(CpuInfo::FieldContains("Processor", "ARMv7"));  // Implements ARMv7.
+  // Has floating point unit.
+  ASSERT(CpuInfo::FieldContains("Features", "vfp"));
+  // Has integer division.
+  if (CpuInfo::FieldContains("Hardware", "QCT APQ8064")) {
+    // Special case for Qualcomm Krait CPUs in Nexus 4 and 7.
+    integer_division_supported_ = true;
+  } else {
+    integer_division_supported_ = CpuInfo::FieldContains("Features", "idiva");
+  }
+  neon_supported_ = CpuInfo::FieldContains("Features", "neon");
+#endif  // defined(USING_SIMULATOR)
+#if defined(DEBUG)
+  initialized_ = true;
+#endif
+}
+
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM