Optimise the deoptimisation check to improve performance on modern ARM cores....

src/arm/constants-arm.h

 // Copyright 2011 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 358 matching lines @@
   // break point
   kBreakpoint= 0x20,
   // stop
   kStopCode = 1 << 23
 };
 static const uint32_t kStopCodeMask = kStopCode - 1;
 static const uint32_t kMaxStopCode = kStopCode - 1;
 static const int32_t  kDefaultStopCode = -1;
 
 
+// -----------------------------------------------------------------------------
+// Breakpoint codes (bkpt instruction);
+enum BkptCodes {
+  kBkptDefaultCode,
+  kBkptUninitializedCode,
+  kBkptStopCode
+};
+
+
 // Type of VFP register. Determines register encoding.
 enum VFPRegPrecision {
   kSinglePrecision = 0,
   kDoublePrecision = 1
 };
 
 
 // VFP FPSCR constants.
 enum VFPConversionMode {
   kFPSCRRounding = 0,
@@ skipping 377 matching lines @@
   static int Number(const char* name, bool* is_double);
 
  private:
   static const char* names_[kNumVFPRegisters];
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_CONSTANTS_ARM_H_