Fix delta computation in DoDeferredInstanceOfKnownGlobal() for ARM.

BUG=v8:2314

R=yangguo@chromium.org

Review URL: https://chromiumcodereview.appspot.com/10908195

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12478 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-codegen-arm.cc

@@ -2472,12 +2472,18 @@ void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
   Register temp = ToRegister(instr->TempAt(0));
   ASSERT(temp.is(r4));
   __ LoadHeapObject(InstanceofStub::right(), instr->function());
-  static const int kAdditionalDelta = 4;
+  static const int kAdditionalDelta = 5;
   int delta = masm_->InstructionsGeneratedSince(map_check) + kAdditionalDelta;
   Label before_push_delta;
   __ bind(&before_push_delta);
   __ BlockConstPoolFor(kAdditionalDelta);
   __ mov(temp, Operand(delta * kPointerSize));
+  // The mov above can generate one or two instructions. The delta was computed
+  // for two instructions, so we need to pad here in case of one instruction.
+  if (masm_->InstructionsGeneratedSince(&before_push_delta) != 2) {
+    ASSERT_EQ(1, masm_->InstructionsGeneratedSince(&before_push_delta));
+    __ nop();
+  }
   __ StoreToSafepointRegisterSlot(temp, temp);
   CallCodeGeneric(stub.GetCode(),
                   RelocInfo::CODE_TARGET,

test/mjsunit/mjsunit.status

@@ -86,9 +86,7 @@ array-splice: PASS || TIMEOUT
 
 # Long running test.
 string-indexof-2: PASS || TIMEOUT
-# BUG(2314): Crankshaft generates incorrect (crashing) code on ARM
-# mirror-object: PASS || TIMEOUT
-mirror-object: SKIP
+mirror-object: PASS || TIMEOUT
 
 # BUG(3251035): Timeouts in long looping crankshaft optimization
 # tests. Skipping because having them timeout takes too long on the