[runtime] Introduce dedicated JSBoundFunction to represent bound functions.

src/arm/builtins-arm.cc

Index: src/arm/builtins-arm.cc
diff --git a/src/arm/builtins-arm.cc b/src/arm/builtins-arm.cc
index 60ad24e7879b30ec64f542fbad790b7b3024eaa4..c24b6fb036adf29cff8f38905e6ae2045ab6a4eb 100644
--- a/src/arm/builtins-arm.cc
+++ b/src/arm/builtins-arm.cc
@@ -1894,6 +1894,90 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
 
 // static
+void Builtins::Generate_CallBoundFunction(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- r0 : the number of arguments (not including the receiver)
+  //  -- r1 : the function to call (checked to be a JSBoundFunction)
+  // -----------------------------------
+  __ AssertBoundFunction(r1);
+
+  // Patch the receiver to [[BoundThis]].
+  {
+    __ ldr(ip, FieldMemOperand(r1, JSBoundFunction::kBoundThisOffset));
+    __ str(ip, MemOperand(sp, r0, LSL, kPointerSizeLog2));
+  }
+
+  // Load [[BoundArguments]] into r2 and length of that into r4.
+  __ ldr(r2, FieldMemOperand(r1, JSBoundFunction::kBoundArgumentsOffset));
+  __ ldr(r4, FieldMemOperand(r2, FixedArray::kLengthOffset));
+  __ SmiUntag(r4);
+
+  // ----------- S t a t e -------------
+  //  -- r0 : the number of arguments (not including the receiver)
+  //  -- r1 : the function to call (checked to be a JSBoundFunction)
+  //  -- r2 : the [[BoundArguments]] (implemented as FixedArray)
+  //  -- r4 : the number of [[BoundArguments]]
+  // -----------------------------------
+
+  // Reserve stack space for the [[BoundArguments]].
+  {
+    Label done;
+    __ sub(sp, sp, Operand(r4, LSL, kPointerSizeLog2));
+    // Check the stack for overflow. We are not trying to catch interruptions
+    // (i.e. debug break and preemption) here, so check the "real stack limit".
+    __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+    __ b(gt, &done);  // Signed comparison.
+    // Restore the stack pointer.
+    __ add(sp, sp, Operand(r4, LSL, kPointerSizeLog2));
+    {
+      FrameScope scope(masm, StackFrame::MANUAL);
+      __ EnterFrame(StackFrame::INTERNAL);
+      __ CallRuntime(Runtime::kThrowStackOverflow, 0);
+    }
+    __ bind(&done);
+  }
+
+  // Relocate arguments down the stack.
+  {
+    Label loop, done_loop;
+    __ mov(r5, Operand(0));
+    __ bind(&loop);
+    __ cmp(r5, r0);
+    __ b(gt, &done_loop);
+    __ ldr(ip, MemOperand(sp, r4, LSL, kPointerSizeLog2));
+    __ str(ip, MemOperand(sp, r5, LSL, kPointerSizeLog2));
+    __ add(r4, r4, Operand(1));
+    __ add(r5, r5, Operand(1));
+    __ b(&loop);
+    __ bind(&done_loop);
+  }
+
+  // Copy [[BoundArguments]] to the stack (below the arguments).
+  {
+    Label loop, done_loop;
+    __ ldr(r4, FieldMemOperand(r2, FixedArray::kLengthOffset));
+    __ SmiUntag(r4);
+    __ add(r2, r2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+    __ bind(&loop);
+    __ sub(r4, r4, Operand(1), SetCC);
+    __ b(lt, &done_loop);
+    __ ldr(ip, MemOperand(r2, r4, LSL, kPointerSizeLog2));
+    __ str(ip, MemOperand(sp, r0, LSL, kPointerSizeLog2));
+    __ add(r0, r0, Operand(1));
+    __ b(&loop);
+    __ bind(&done_loop);
+  }
+
+  // Call the [[BoundTargetFunction]] via the Call builtin.
+  __ ldr(r1, FieldMemOperand(r1, JSBoundFunction::kBoundTargetFunctionOffset));
+  __ mov(ip, Operand(ExternalReference(Builtins::kCall_ReceiverIsAny,
+                                       masm->isolate())));
+  __ ldr(ip, MemOperand(ip));
+  __ add(pc, ip, Operand(Code::kHeaderSize - kHeapObjectTag));
+}
+
+
+// static
 void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
   // ----------- S t a t e -------------
   //  -- r0 : the number of arguments (not including the receiver)
@@ -1906,6 +1990,9 @@ void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
   __ CompareObjectType(r1, r4, r5, JS_FUNCTION_TYPE);
   __ Jump(masm->isolate()->builtins()->CallFunction(mode),
           RelocInfo::CODE_TARGET, eq);
+  __ cmp(r5, Operand(JS_BOUND_FUNCTION_TYPE));
+  __ Jump(masm->isolate()->builtins()->CallBoundFunction(),
+          RelocInfo::CODE_TARGET, eq);
   __ cmp(r5, Operand(JS_PROXY_TYPE));
   __ b(ne, &non_function);
 
@@ -1965,6 +2052,92 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
 
 // static
+void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- r0 : the number of arguments (not including the receiver)
+  //  -- r1 : the function to call (checked to be a JSBoundFunction)
+  //  -- r3 : the new target (checked to be a constructor)
+  // -----------------------------------
+  __ AssertBoundFunction(r1);
+
+  // Load [[BoundArguments]] into r2 and length of that into r4.
+  __ ldr(r2, FieldMemOperand(r1, JSBoundFunction::kBoundArgumentsOffset));
+  __ ldr(r4, FieldMemOperand(r2, FixedArray::kLengthOffset));
+  __ SmiUntag(r4);
+
+  // ----------- S t a t e -------------
+  //  -- r0 : the number of arguments (not including the receiver)
+  //  -- r1 : the function to call (checked to be a JSBoundFunction)
+  //  -- r2 : the [[BoundArguments]] (implemented as FixedArray)
+  //  -- r3 : the new target (checked to be a constructor)
+  //  -- r4 : the number of [[BoundArguments]]
+  // -----------------------------------
+
+  // Reserve stack space for the [[BoundArguments]].
+  {
+    Label done;
+    __ sub(sp, sp, Operand(r4, LSL, kPointerSizeLog2));
+    // Check the stack for overflow. We are not trying to catch interruptions
+    // (i.e. debug break and preemption) here, so check the "real stack limit".
+    __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+    __ b(gt, &done);  // Signed comparison.
+    // Restore the stack pointer.
+    __ add(sp, sp, Operand(r4, LSL, kPointerSizeLog2));
+    {
+      FrameScope scope(masm, StackFrame::MANUAL);
+      __ EnterFrame(StackFrame::INTERNAL);
+      __ CallRuntime(Runtime::kThrowStackOverflow, 0);
+    }
+    __ bind(&done);
+  }
+
+  // Relocate arguments down the stack.
+  {
+    Label loop, done_loop;
+    __ mov(r5, Operand(0));
+    __ bind(&loop);
+    __ cmp(r5, r0);
+    __ b(ge, &done_loop);
+    __ ldr(ip, MemOperand(sp, r4, LSL, kPointerSizeLog2));
+    __ str(ip, MemOperand(sp, r5, LSL, kPointerSizeLog2));
+    __ add(r4, r4, Operand(1));
+    __ add(r5, r5, Operand(1));
+    __ b(&loop);
+    __ bind(&done_loop);
+  }
+
+  // Copy [[BoundArguments]] to the stack (below the arguments).
+  {
+    Label loop, done_loop;
+    __ ldr(r4, FieldMemOperand(r2, FixedArray::kLengthOffset));
+    __ SmiUntag(r4);
+    __ add(r2, r2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+    __ bind(&loop);
+    __ sub(r4, r4, Operand(1), SetCC);
+    __ b(lt, &done_loop);
+    __ ldr(ip, MemOperand(r2, r4, LSL, kPointerSizeLog2));
+    __ str(ip, MemOperand(sp, r0, LSL, kPointerSizeLog2));
+    __ add(r0, r0, Operand(1));
+    __ b(&loop);
+    __ bind(&done_loop);
+  }
+
+  // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
+  {
+    __ cmp(r1, r3);
+    __ ldr(r3, FieldMemOperand(r1, JSBoundFunction::kBoundTargetFunctionOffset),
+           eq);
+  }
+
+  // Construct the [[BoundTargetFunction]] via the Construct builtin.
+  __ ldr(r1, FieldMemOperand(r1, JSBoundFunction::kBoundTargetFunctionOffset));
+  __ mov(ip, Operand(ExternalReference(Builtins::kConstruct, masm->isolate())));
+  __ ldr(ip, MemOperand(ip));
+  __ add(pc, ip, Operand(Code::kHeaderSize - kHeapObjectTag));
+}
+
+
+// static
 void Builtins::Generate_ConstructProxy(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0 : the number of arguments (not including the receiver)
@@ -2007,6 +2180,12 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
   __ tst(r2, Operand(1 << Map::kIsConstructor));
   __ b(eq, &non_constructor);
 
+  // Only dispatch to bound functions after checking whether they are
+  // constructors.
+  __ cmp(r5, Operand(JS_BOUND_FUNCTION_TYPE));
+  __ Jump(masm->isolate()->builtins()->ConstructBoundFunction(),
+          RelocInfo::CODE_TARGET, eq);
+
   // Only dispatch to proxies after checking whether they are constructors.
   __ cmp(r5, Operand(JS_PROXY_TYPE));
   __ Jump(masm->isolate()->builtins()->ConstructProxy(), RelocInfo::CODE_TARGET,