X64 implementation: Correct kTargetAddrToReturnAddrDist value for x64.

Review URL: http://codereview.chromium.org/140063

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2240 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/x64/assembler-x64.h

@@ -413,8 +413,8 @@ class Assembler : public Malloced {
   static inline void set_target_address_at(Address pc, Address target);
 
   // Distance between the address of the code target in the call instruction
-  // and the return address
-  static const int kTargetAddrToReturnAddrDist = kPointerSize;
+  // and the return address.  Checked in the debug build.
+  static const int kTargetAddrToReturnAddrDist = 3 + kPointerSize;
 
 
   // ---------------------------------------------------------------------------

src/x64/macro-assembler-x64.cc

@@ -337,7 +337,15 @@ void MacroAssembler::Call(Handle<Code> code_object, RelocInfo::Mode rmode) {
   WriteRecordedPositions();
   ASSERT(RelocInfo::IsCodeTarget(rmode));
   movq(kScratchRegister, code_object, rmode);
+#ifdef DEBUG
+  Label target;
+  bind(&target);
+#endif
   call(kScratchRegister);
+#ifdef DEBUG
+  ASSERT_EQ(kTargetAddrToReturnAddrDist,
+            SizeOfCodeGeneratedSince(&target) + kPointerSize);
+#endif
 }