Fix the CPU feature detection.

src/platform-linux.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 62 matching lines @@
 
 
 namespace v8 {
 namespace internal {
 
 
 static Mutex* limit_mutex = NULL;
 
 
 #ifdef __arm__
-static bool CPUInfoContainsString(const char * search_string) {
-  const char* file_name = "/proc/cpuinfo";
-  // This is written as a straight shot one pass parser
-  // and not using STL string and ifstream because,
-  // on Linux, it's reading from a (non-mmap-able)
-  // character special device.
-  FILE* f = NULL;
-  const char* what = search_string;
-
-  if (NULL == (f = fopen(file_name, "r"))) {
-    OS::PrintError("Failed to open /proc/cpuinfo\n");
-    return false;
-  }
-
-  int k;
-  while (EOF != (k = fgetc(f))) {
-    if (k == *what) {
-      ++what;
-      while ((*what != '\0') && (*what == fgetc(f))) {
-        ++what;
-      }
-      if (*what == '\0') {
-        fclose(f);
-        return true;
-      } else {
-        what = search_string;
-      }
-    }
-  }
-  fclose(f);
-
-  // Did not find string in the proc file.
-  return false;
-}
-
-
-bool OS::ArmCpuHasFeature(CpuFeature feature) {
-  const char* search_string = NULL;
-  // Simple detection of VFP at runtime for Linux.
-  // It is based on /proc/cpuinfo, which reveals hardware configuration
-  // to user-space applications.  According to ARM (mid 2009), no similar
-  // facility is universally available on the ARM architectures,
-  // so it's up to individual OSes to provide such.
-  switch (feature) {
-    case VFP3:
-      search_string = "vfpv3";
-      break;
-    case NEON:
-      search_string = "neon";
-      break;
-    case ARMv7:
-      search_string = "ARMv7";
-      break;
-    case SUDIV:
-      search_string = "idiva";
-      break;
-    case VFP32DREGS:
-      // This case is handled specially below.
-      break;
-    default:
-      UNREACHABLE();
-  }
-
-  if (feature == VFP32DREGS) {
-    return ArmCpuHasFeature(VFP3) && !CPUInfoContainsString("d16");
-  }
-
-  if (CPUInfoContainsString(search_string)) {
-    return true;
-  }
-
-  if (feature == VFP3) {
-    // Some old kernels will report vfp not vfpv3. Here we make a last attempt
-    // to detect vfpv3 by checking for vfp *and* neon, since neon is only
-    // available on architectures with vfpv3.
-    // Checking neon on its own is not enough as it is possible to have neon
-    // without vfp.
-    if (CPUInfoContainsString("vfp") && CPUInfoContainsString("neon")) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-
-CpuImplementer OS::GetCpuImplementer() {
-  static bool use_cached_value = false;
-  static CpuImplementer cached_value = UNKNOWN_IMPLEMENTER;
-  if (use_cached_value) {
-    return cached_value;
-  }
-  if (CPUInfoContainsString("CPU implementer\t: 0x41")) {
-    cached_value = ARM_IMPLEMENTER;
-  } else if (CPUInfoContainsString("CPU implementer\t: 0x51")) {
-    cached_value = QUALCOMM_IMPLEMENTER;
-  } else {
-    cached_value = UNKNOWN_IMPLEMENTER;
-  }
-  use_cached_value = true;
-  return cached_value;
-}
-
-
-CpuPart OS::GetCpuPart(CpuImplementer implementer) {
-  static bool use_cached_value = false;
-  static CpuPart cached_value = CPU_UNKNOWN;
-  if (use_cached_value) {
-    return cached_value;
-  }
-  if (implementer == ARM_IMPLEMENTER) {
-    if (CPUInfoContainsString("CPU part\t: 0xc0f")) {
-      cached_value = CORTEX_A15;
-    } else if (CPUInfoContainsString("CPU part\t: 0xc0c")) {
-      cached_value = CORTEX_A12;
-    } else if (CPUInfoContainsString("CPU part\t: 0xc09")) {
-      cached_value = CORTEX_A9;
-    } else if (CPUInfoContainsString("CPU part\t: 0xc08")) {
-      cached_value = CORTEX_A8;
-    } else if (CPUInfoContainsString("CPU part\t: 0xc07")) {
-      cached_value = CORTEX_A7;
-    } else if (CPUInfoContainsString("CPU part\t: 0xc05")) {
-      cached_value = CORTEX_A5;
-    } else {
-      cached_value = CPU_UNKNOWN;
-    }
-  } else {
-    cached_value = CPU_UNKNOWN;
-  }
-  use_cached_value = true;
-  return cached_value;
-}
-
 
 bool OS::ArmUsingHardFloat() {
   // GCC versions 4.6 and above define __ARM_PCS or __ARM_PCS_VFP to specify
   // the Floating Point ABI used (PCS stands for Procedure Call Standard).
   // We use these as well as a couple of other defines to statically determine
   // what FP ABI used.
   // GCC versions 4.4 and below don't support hard-fp.
   // GCC versions 4.5 may support hard-fp without defining __ARM_PCS or
   // __ARM_PCS_VFP.
 
@@ skipping 22 matching lines @@
        "http://code.google.com/p/v8/issues/detail?id=2140"
 
 #endif
 #endif
 #undef GCC_VERSION
 }
 
 #endif  // def __arm__
 
 
-#ifdef __mips__
-bool OS::MipsCpuHasFeature(CpuFeature feature) {
-  const char* search_string = NULL;
-  const char* file_name = "/proc/cpuinfo";
-  // Simple detection of FPU at runtime for Linux.
-  // It is based on /proc/cpuinfo, which reveals hardware configuration
-  // to user-space applications.  According to MIPS (early 2010), no similar
-  // facility is universally available on the MIPS architectures,
-  // so it's up to individual OSes to provide such.
-  //
-  // This is written as a straight shot one pass parser
-  // and not using STL string and ifstream because,
-  // on Linux, it's reading from a (non-mmap-able)
-  // character special device.
-
-  switch (feature) {
-    case FPU:
-      search_string = "FPU";
-      break;
-    default:
-      UNREACHABLE();
-  }
-
-  FILE* f = NULL;
-  const char* what = search_string;
-
-  if (NULL == (f = fopen(file_name, "r"))) {
-    OS::PrintError("Failed to open /proc/cpuinfo\n");
-    return false;
-  }
-
-  int k;
-  while (EOF != (k = fgetc(f))) {
-    if (k == *what) {
-      ++what;
-      while ((*what != '\0') && (*what == fgetc(f))) {
-        ++what;
-      }
-      if (*what == '\0') {
-        fclose(f);
-        return true;
-      } else {
-        what = search_string;
-      }
-    }
-  }
-  fclose(f);
-
-  // Did not find string in the proc file.
-  return false;
-}
-#endif  // def __mips__
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));
   struct tm* t = localtime(&tv);
   if (NULL == t) return "";
   return t->tm_zone;
 }
 
 
 double OS::LocalTimeOffset() {
@@ skipping 439 matching lines @@
   limit_mutex = CreateMutex();
 }
 
 
 void OS::TearDown() {
   delete limit_mutex;
 }
 
 
 } }  // namespace v8::internal