[compiler] No need to push literal index in VisitArrayLiteral.

The literal index is being pushed onto the stack while evaluating
the non-constant subexpressions, but never used in fullcodegen (and
hence not used in the optimizing compilers).

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1471893003

Cr-Commit-Position: refs/heads/master@{#32205}

src/compiler/ast-graph-builder.cc

@@ -1929,10 +1929,9 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
   PrepareFrameState(literal, expr->CreateLiteralId(),
                     OutputFrameStateCombine::Push());
 
-  // The array and the literal index are both expected on the operand stack
-  // during computation of the element values.
+  // The array is expected on the operand stack during computation of the
+  // element values.
   environment()->Push(literal);
-  environment()->Push(literal_index);
 
   // Create nodes to evaluate all the non-constant subexpressions and to store
   // them into the newly cloned array.
@@ -1948,7 +1947,7 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
       VectorSlotPair pair = CreateVectorSlotPair(expr->LiteralFeedbackSlot());
       Node* value = environment()->Pop();
       Node* index = jsgraph()->Constant(array_index);
-      Node* literal = environment()->Peek(1);
+      Node* literal = environment()->Top();
       Node* store = BuildKeyedStore(literal, index, value, pair);
       states.AddToNode(store, expr->GetIdForElement(array_index),
                        OutputFrameStateCombine::Ignore());
@@ -1960,7 +1959,6 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
   // above. The second part is the part after the first spread expression
   // (inclusive) and these elements gets appended to the array. Note that the
   // number elements an iterable produces is unknown ahead of time.
-  environment()->Pop();  // Array literal index.
   for (; array_index < expr->values()->length(); array_index++) {
     Expression* subexpr = expr->values()->at(array_index);
     Node* result;

src/crankshaft/hydrogen.cc

@@ -6074,8 +6074,6 @@ void HOptimizedGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
   // The array is expected in the bailout environment during computation
   // of the property values and is the value of the entire expression.
   Push(literal);
-  // The literal index is on the stack, too.
-  Push(Add<HConstant>(expr->literal_index()));
 
   HInstruction* elements = NULL;
 
@@ -6117,7 +6115,6 @@ void HOptimizedGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
     Add<HSimulate>(expr->GetIdForElement(i));
   }
 
-  Drop(1);  // array literal index
   return ast_context()->ReturnValue(Pop());
 }
 

src/full-codegen/arm/full-codegen-arm.cc

@@ -1768,13 +1768,12 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
 
     if (!result_saved) {
       __ push(r0);
-      __ Push(Smi::FromInt(expr->literal_index()));
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);
 
     __ mov(StoreDescriptor::NameRegister(), Operand(Smi::FromInt(array_index)));
-    __ ldr(StoreDescriptor::ReceiverRegister(), MemOperand(sp, kPointerSize));
+    __ ldr(StoreDescriptor::ReceiverRegister(), MemOperand(sp, 0));
     EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
     Handle<Code> ic =
         CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
@@ -1789,7 +1788,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   // (inclusive) and these elements gets appended to the array. Note that the
   // number elements an iterable produces is unknown ahead of time.
   if (array_index < length && result_saved) {
-    __ pop();  // literal index
     __ Pop(r0);
     result_saved = false;
   }
@@ -1810,7 +1808,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   }
 
   if (result_saved) {
-    __ pop();  // literal index
     context()->PlugTOS();
   } else {
     context()->Plug(r0);

src/full-codegen/arm64/full-codegen-arm64.cc

@@ -1750,14 +1750,13 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
     if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
 
     if (!result_saved) {
-      __ Mov(x1, Smi::FromInt(expr->literal_index()));
-      __ Push(x0, x1);
+      __ Push(x0);
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);
 
     __ Mov(StoreDescriptor::NameRegister(), Smi::FromInt(array_index));
-    __ Peek(StoreDescriptor::ReceiverRegister(), kPointerSize);
+    __ Peek(StoreDescriptor::ReceiverRegister(), 0);
     EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
     Handle<Code> ic =
         CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
@@ -1772,7 +1771,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   // (inclusive) and these elements gets appended to the array. Note that the
   // number elements an iterable produces is unknown ahead of time.
   if (array_index < length && result_saved) {
-    __ Drop(1);  // literal index
     __ Pop(x0);
     result_saved = false;
   }
@@ -1793,7 +1791,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   }
 
   if (result_saved) {
-    __ Drop(1);   // literal index
     context()->PlugTOS();
   } else {
     context()->Plug(x0);

src/full-codegen/ia32/full-codegen-ia32.cc

@@ -1690,14 +1690,13 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
 
     if (!result_saved) {
       __ push(eax);  // array literal.
-      __ push(Immediate(Smi::FromInt(expr->literal_index())));
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);
 
     __ mov(StoreDescriptor::NameRegister(),
            Immediate(Smi::FromInt(array_index)));
-    __ mov(StoreDescriptor::ReceiverRegister(), Operand(esp, kPointerSize));
+    __ mov(StoreDescriptor::ReceiverRegister(), Operand(esp, 0));
     EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
     Handle<Code> ic =
         CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
@@ -1711,7 +1710,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   // (inclusive) and these elements gets appended to the array. Note that the
   // number elements an iterable produces is unknown ahead of time.
   if (array_index < length && result_saved) {
-    __ Drop(1);  // literal index
     __ Pop(eax);
     result_saved = false;
   }
@@ -1732,7 +1730,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   }
 
   if (result_saved) {
-    __ Drop(1);  // literal index
     context()->PlugTOS();
   } else {
     context()->Plug(eax);

src/full-codegen/mips/full-codegen-mips.cc

@@ -1764,14 +1764,13 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
 
     if (!result_saved) {
       __ push(v0);  // array literal
-      __ Push(Smi::FromInt(expr->literal_index()));
       result_saved = true;
     }
 
     VisitForAccumulatorValue(subexpr);
 
     __ li(StoreDescriptor::NameRegister(), Operand(Smi::FromInt(array_index)));
-    __ lw(StoreDescriptor::ReceiverRegister(), MemOperand(sp, kPointerSize));
+    __ lw(StoreDescriptor::ReceiverRegister(), MemOperand(sp, 0));
     __ mov(StoreDescriptor::ValueRegister(), result_register());
     EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
     Handle<Code> ic =
@@ -1787,7 +1786,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   // (inclusive) and these elements gets appended to the array. Note that the
   // number elements an iterable produces is unknown ahead of time.
   if (array_index < length && result_saved) {
-    __ Pop();  // literal index
     __ Pop(v0);
     result_saved = false;
   }
@@ -1808,7 +1806,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   }
 
   if (result_saved) {
-    __ Pop();  // literal index
     context()->PlugTOS();
   } else {
     context()->Plug(v0);

src/full-codegen/mips64/full-codegen-mips64.cc

@@ -1764,14 +1764,13 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
 
     if (!result_saved) {
       __ push(v0);  // array literal
-      __ Push(Smi::FromInt(expr->literal_index()));
       result_saved = true;
     }
 
     VisitForAccumulatorValue(subexpr);
 
     __ li(StoreDescriptor::NameRegister(), Operand(Smi::FromInt(array_index)));
-    __ ld(StoreDescriptor::ReceiverRegister(), MemOperand(sp, kPointerSize));
+    __ ld(StoreDescriptor::ReceiverRegister(), MemOperand(sp, 0));
     __ mov(StoreDescriptor::ValueRegister(), result_register());
     EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
     Handle<Code> ic =
@@ -1787,7 +1786,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   // (inclusive) and these elements gets appended to the array. Note that the
   // number elements an iterable produces is unknown ahead of time.
   if (array_index < length && result_saved) {
-    __ Pop();  // literal index
     __ Pop(v0);
     result_saved = false;
   }
@@ -1808,7 +1806,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   }
 
   if (result_saved) {
-    __ Pop();  // literal index
     context()->PlugTOS();
   } else {
     context()->Plug(v0);

src/full-codegen/x64/full-codegen-x64.cc

@@ -1715,13 +1715,12 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
 
     if (!result_saved) {
       __ Push(rax);  // array literal
-      __ Push(Smi::FromInt(expr->literal_index()));
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);
 
     __ Move(StoreDescriptor::NameRegister(), Smi::FromInt(array_index));
-    __ movp(StoreDescriptor::ReceiverRegister(), Operand(rsp, kPointerSize));
+    __ movp(StoreDescriptor::ReceiverRegister(), Operand(rsp, 0));
     EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
     Handle<Code> ic =
         CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
@@ -1736,7 +1735,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   // (inclusive) and these elements gets appended to the array. Note that the
   // number elements an iterable produces is unknown ahead of time.
   if (array_index < length && result_saved) {
-    __ Drop(1);  // literal index
     __ Pop(rax);
     result_saved = false;
   }
@@ -1757,7 +1755,6 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   }
 
   if (result_saved) {
-    __ Drop(1);  // literal index
     context()->PlugTOS();
   } else {
     context()->Plug(rax);