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

src/arm/debug-arm.cc

 // Copyright 2006-2008 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 28 matching lines @@
 }
 
 
 void BreakLocationIterator::SetDebugBreakAtReturn() {
   // Patch the code changing the return from JS function sequence from
   //   mov sp, fp
   //   ldmia sp!, {fp, lr}
   //   add sp, sp, #4
   //   bx lr
   // to a call to the debug break return code.
+  // #if USE_BLX
+  //   ldr ip, [pc, #0]
+  //   blx ip
+  // #else
   //   mov lr, pc
   //   ldr pc, [pc, #-4]
+  // #endif
   //   <debug break return code entry point address>
   //   bktp 0
   CodePatcher patcher(rinfo()->pc(), 4);
+#ifdef USE_BLX
+  patcher.masm()->ldr(v8::internal::ip, MemOperand(v8::internal::pc, 0));
+  patcher.masm()->blx(v8::internal::ip);
+#else
   patcher.masm()->mov(v8::internal::lr, v8::internal::pc);
   patcher.masm()->ldr(v8::internal::pc, MemOperand(v8::internal::pc, -4));
+#endif
   patcher.Emit(Debug::debug_break_return()->entry());
   patcher.masm()->bkpt(0);
 }
 
 
 // Restore the JS frame exit code.
 void BreakLocationIterator::ClearDebugBreakAtReturn() {
   rinfo()->PatchCode(original_rinfo()->pc(),
                      Assembler::kJSReturnSequenceLength);
 }
@@ skipping 138 matching lines @@
   // -----------------------------------
   Generate_DebugBreakCallHelper(masm, 0);
 }
 
 
 #undef __
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal