Implement function calls on ARM using the blx instruction when available. Usi...

src/arm/constants-arm.h

 // Copyright 2010 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 54 matching lines @@
 # define CAN_USE_ARMV5_INSTRUCTIONS 1
 # define CAN_USE_THUMB_INSTRUCTIONS 1
 #endif
 
 // Simulator should support ARM5 instructions.
 #if !defined(__arm__)
 # define CAN_USE_ARMV5_INSTRUCTIONS 1
 # define CAN_USE_THUMB_INSTRUCTIONS 1
 #endif
 
+// Using blx may yield better code, so use it when required or when available
+#if defined(USE_THUMB_INTERWORK) || defined(CAN_USE_ARMV5_INSTRUCTIONS)
+#define USE_BLX 1
+#endif
+
 namespace assembler {
 namespace arm {
 
 // Number of registers in normal ARM mode.
 static const int kNumRegisters = 16;
 
 // VFP support.
 static const int kNumVFPRegisters = 48;
 
 // PC is register 15.
@@ skipping 257 matching lines @@
   static const char* Name(int reg);
 
  private:
   static const char* names_[kNumVFPRegisters];
 };
 
 
 } }  // namespace assembler::arm
 
 #endif  // V8_ARM_CONSTANTS_ARM_H_