[stubs] Simplify the non-function case of CallConstructStub.

src/arm/code-stubs-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/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 2510 matching lines @@
   // Jump to the function-specific construct stub.
   Register jmp_reg = r4;
   __ ldr(jmp_reg, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
   __ ldr(jmp_reg, FieldMemOperand(jmp_reg,
                                   SharedFunctionInfo::kConstructStubOffset));
   __ add(pc, jmp_reg, Operand(Code::kHeaderSize - kHeapObjectTag));
 
   // r0: number of arguments
   // r1: called object
   // r5: object type
-  Label do_call;
   __ bind(&slow);
-  __ cmp(r5, Operand(JS_FUNCTION_PROXY_TYPE));
-  __ b(ne, &non_function_call);
-  __ GetBuiltinFunction(
-      r1, Context::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR_BUILTIN_INDEX);
-  __ jmp(&do_call);
+  {
+    __ cmp(r5, Operand(JS_FUNCTION_PROXY_TYPE));
+    __ b(ne, &non_function_call);
+    // TODO(neis): This doesn't match the ES6 spec for [[Construct]] on proxies.
+    __ ldr(r1, FieldMemOperand(r1, JSFunctionProxy::kConstructTrapOffset));
+    __ Jump(isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
 
-  __ bind(&non_function_call);
-  __ GetBuiltinFunction(
-      r1, Context::CALL_NON_FUNCTION_AS_CONSTRUCTOR_BUILTIN_INDEX);
-  __ bind(&do_call);
-  // Set expected number of arguments to zero (not changing r0).
-  __ mov(r2, Operand::Zero());
-  __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
-          RelocInfo::CODE_TARGET);
+    __ bind(&non_function_call);
+    {
+      // Determine the delegate for the target (if any).
+      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+      __ SmiTag(r0);
+      __ Push(r0, r1);
+      __ CallRuntime(Runtime::kGetConstructorDelegate, 1);
+      __ mov(r1, r0);
+      __ Pop(r0);
+      __ SmiUntag(r0);
+    }
+    // The delegate is always a regular function.
+    __ AssertFunction(r1);
+    __ Jump(masm->isolate()->builtins()->CallFunction(),
+            RelocInfo::CODE_TARGET);
+  }
 }
 
 
 static void EmitLoadTypeFeedbackVector(MacroAssembler* masm, Register vector) {
   __ ldr(vector, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   __ ldr(vector, FieldMemOperand(vector,
                                  JSFunction::kSharedFunctionInfoOffset));
   __ ldr(vector, FieldMemOperand(vector,
                                  SharedFunctionInfo::kFeedbackVectorOffset));
 }
@@ skipping 2990 matching lines @@
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM