Avoid jumping to the runtime for ForInFilter

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

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 1064 matching lines @@
 
   // Generate code for doing the condition check.
   __ bind(&loop);
   SetExpressionAsStatementPosition(stmt->each());
 
   // Load the current count to r0, load the length to r1.
   __ Ldrd(r0, r1, MemOperand(sp, 0 * kPointerSize));
   __ cmp(r0, r1);  // Compare to the array length.
   __ b(hs, loop_statement.break_label());
 
-  // Get the current entry of the array into register r3.
+  // Get the current entry of the array into register r0.
   __ ldr(r2, MemOperand(sp, 2 * kPointerSize));
   __ add(r2, r2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  __ ldr(r3, MemOperand::PointerAddressFromSmiKey(r2, r0));
+  __ ldr(r0, MemOperand::PointerAddressFromSmiKey(r2, r0));
 
   // Get the expected map from the stack or a smi in the
   // permanent slow case into register r2.
   __ ldr(r2, MemOperand(sp, 3 * kPointerSize));
 
   // Check if the expected map still matches that of the enumerable.
   // If not, we may have to filter the key.
   Label update_each;
   __ ldr(r1, MemOperand(sp, 4 * kPointerSize));
   __ ldr(r4, FieldMemOperand(r1, HeapObject::kMapOffset));
   __ cmp(r4, Operand(r2));
   __ b(eq, &update_each);
 
   // We need to filter the key, record slow-path here.
   int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(r0);
+  __ EmitLoadTypeFeedbackVector(r3);
   __ mov(r2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ str(r2, FieldMemOperand(r0, FixedArray::OffsetOfElementAt(vector_index)));
+  __ str(r2, FieldMemOperand(r3, FixedArray::OffsetOfElementAt(vector_index)));
 
-  // Convert the entry to a string or (smi) 0 if it isn't a property
-  // any more. If the property has been removed while iterating, we
-  // just skip it.
-  __ push(r1);  // Enumerable.
-  __ push(r3);  // Current entry.
-  __ CallRuntime(Runtime::kForInFilter);
+  // r0 contains the key. The receiver in r1 is the second argument to the
+  // ForInFilterStub. ForInFilter returns undefined if the receiver doesn't
+  // have the key or returns the name-converted key.
+  ForInFilterStub filter_stub(isolate());
+  __ CallStub(&filter_stub);
+  RestoreContext();
   PrepareForBailoutForId(stmt->FilterId(), BailoutState::TOS_REGISTER);
-  __ mov(r3, Operand(r0));
-  __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
-  __ cmp(r0, ip);
+  __ CompareRoot(result_register(), Heap::kUndefinedValueRootIndex);
   __ b(eq, loop_statement.continue_label());
 
   // Update the 'each' property or variable from the possibly filtered
-  // entry in register r3.
+  // entry in register r0.
   __ bind(&update_each);
-  __ mov(result_register(), r3);
+
   // Perform the assignment as if via '='.
   { EffectContext context(this);
     EmitAssignment(stmt->each(), stmt->EachFeedbackSlot());
     PrepareForBailoutForId(stmt->AssignmentId(), BailoutState::NO_REGISTERS);
   }
 
   // Both Crankshaft and Turbofan expect BodyId to be right before stmt->body().
   PrepareForBailoutForId(stmt->BodyId(), BailoutState::NO_REGISTERS);
   // Generate code for the body of the loop.
   Visit(stmt->body());
@@ skipping 2712 matching lines @@
   DCHECK(interrupt_address ==
          isolate->builtins()->OnStackReplacement()->entry());
   return ON_STACK_REPLACEMENT;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM