[arm] Fix pushing of stale register in CallConstructStub.

src/arm64/code-stubs-arm64.cc

Index: src/arm64/code-stubs-arm64.cc
diff --git a/src/arm64/code-stubs-arm64.cc b/src/arm64/code-stubs-arm64.cc
index da6bdb75c58fa180dcf5acb069d436ed57ae307e..1703d4bcbf80127d17a094e669316bbfdb1139bb 100644
--- a/src/arm64/code-stubs-arm64.cc
+++ b/src/arm64/code-stubs-arm64.cc
@@ -2749,17 +2749,25 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
 static void CallStubInRecordCallTarget(MacroAssembler* masm, CodeStub* stub,
                                        Register argc, Register function,
                                        Register feedback_vector, Register index,
-                                       Register orig_construct) {
+                                       Register orig_construct, bool is_super) {
   FrameScope scope(masm, StackFrame::INTERNAL);
 
   // Number-of-arguments register must be smi-tagged to call out.
   __ SmiTag(argc);
-  __ Push(argc, function, feedback_vector, index, orig_construct);
+  if (is_super) {
+    __ Push(argc, function, feedback_vector, index, orig_construct);

[jbramley, 2015/07/22 07:51:36]

Why not pass orig_construct=NoReg for the !is_super case? That way you don't
need the complexity in this function (or in GenerateRecordCallTarget).

I don't think the same will work for ARM, but it's a separate Push there anyway.

[Michael Starzinger, 2015/07/22 08:07:41]

The way the 8-register push is implemented, it assumes that 5 registers are
always valid and only treats the last 3 registers as "var-args" that could be
invalid.

+  } else {
+    __ Push(argc, function, feedback_vector, index);
+  }
 
   DCHECK(feedback_vector.Is(x2) && index.Is(x3));
   __ CallStub(stub);
 
-  __ Pop(orig_construct, index, feedback_vector, function, argc);
+  if (is_super) {
+    __ Pop(orig_construct, index, feedback_vector, function, argc);
+  } else {
+    __ Pop(index, feedback_vector, function, argc);
+  }
   __ SmiUntag(argc);
 }
 
@@ -2768,7 +2776,8 @@ static void GenerateRecordCallTarget(MacroAssembler* masm, Register argc,
                                      Register function,
                                      Register feedback_vector, Register index,
                                      Register orig_construct, Register scratch1,
-                                     Register scratch2, Register scratch3) {
+                                     Register scratch2, Register scratch3,
+                                     bool is_super) {
   ASM_LOCATION("GenerateRecordCallTarget");
   DCHECK(!AreAliased(scratch1, scratch2, scratch3, argc, function,
                      feedback_vector, index, orig_construct));
@@ -2778,7 +2787,7 @@ static void GenerateRecordCallTarget(MacroAssembler* masm, Register argc,
   //  function :        the function to call
   //  feedback_vector : the feedback vector
   //  index :           slot in feedback vector (smi)
-  //  orig_construct :  original constructor
+  //  orig_construct :  original constructor (for IsSuperConstructorCall)
   Label initialize, done, miss, megamorphic, not_array_function;
 
   DCHECK_EQ(*TypeFeedbackVector::MegamorphicSentinel(masm->isolate()),
@@ -2857,7 +2866,8 @@ static void GenerateRecordCallTarget(MacroAssembler* masm, Register argc,
     // slot.
     CreateAllocationSiteStub create_stub(masm->isolate());
     CallStubInRecordCallTarget(masm, &create_stub, argc, function,
-                               feedback_vector, index, orig_construct);
+                               feedback_vector, index, orig_construct,
+                               is_super);
     __ B(&done);
 
     __ Bind(&not_array_function);
@@ -2865,7 +2875,7 @@ static void GenerateRecordCallTarget(MacroAssembler* masm, Register argc,
 
   CreateWeakCellStub create_stub(masm->isolate());
   CallStubInRecordCallTarget(masm, &create_stub, argc, function,
-                             feedback_vector, index, orig_construct);
+                             feedback_vector, index, orig_construct, is_super);
   __ Bind(&done);
 }
 
@@ -3005,7 +3015,8 @@ void CallConstructStub::Generate(MacroAssembler* masm) {
                          &slow);
 
   if (RecordCallTarget()) {
-    GenerateRecordCallTarget(masm, x0, function, x2, x3, x4, x5, x11, x12);
+    GenerateRecordCallTarget(masm, x0, function, x2, x3, x4, x5, x11, x12,
+                             IsSuperConstructorCall());
 
     __ Add(x5, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
     if (FLAG_pretenuring_call_new) {