[es6] Make new.target work in functions

src/mips64/builtins-mips64.cc

Index: src/mips64/builtins-mips64.cc
diff --git a/src/mips64/builtins-mips64.cc b/src/mips64/builtins-mips64.cc
index c63d92d69d1d820e60454b4091e6647c757f2b7b..cd2edef6b19837b4ef15c99e9f25896873fa9d4c 100644
--- a/src/mips64/builtins-mips64.cc
+++ b/src/mips64/builtins-mips64.cc
@@ -347,6 +347,7 @@ static void Generate_Runtime_NewObject(MacroAssembler* masm,
 
 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                            bool is_api_function,
+                                           bool use_new_target,
                                            bool create_memento) {
   // ----------- S t a t e -------------
   //  -- a0     : number of arguments
@@ -381,7 +382,11 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     // Preserve the two incoming parameters on the stack.
     // Tag arguments count.
     __ dsll32(a0, a0, 0);
-    __ MultiPushReversed(a0.bit() | a1.bit());
+    if (use_new_target) {
+      __ MultiPushReversed(a0.bit() | a1.bit() | a3.bit());

[paul.l..., 2015/06/26 04:02:24]

nit: more readable as Push(a0, a1, a2); here and just below.

+    } else {
+      __ MultiPushReversed(a0.bit() | a1.bit());
+    }
 
     Label rt_call, allocated, normal_new, count_incremented;
     __ Branch(&normal_new, eq, a1, Operand(a3));
@@ -636,7 +641,8 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     __ bind(&allocated);
 
     if (create_memento) {
-      __ ld(a2, MemOperand(sp, kPointerSize * 2));
+      int offset = (use_new_target ? 3 : 2) * kPointerSize;
+      __ ld(a2, MemOperand(sp, offset));
       __ LoadRoot(t1, Heap::kUndefinedValueRootIndex);
       __ Branch(&count_incremented, eq, a2, Operand(t1));
       // a2 is an AllocationSite. We are creating a memento from it, so we
@@ -649,22 +655,24 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
       __ bind(&count_incremented);
     }
 
+    // Restore the parameters.
+    if (use_new_target) {
+      __ Pop(a3);  // new.target
+    }
     __ Pop(a1);
 
-    __ Push(t0, t0);
+    __ ld(a0, MemOperand(sp));
+    __ SmiUntag(a0);
 
-    // Reload the number of arguments from the stack.
-    // sp[0]: receiver
-    // sp[1]: receiver
-    // sp[2]: number of arguments (smi-tagged)
-    __ ld(a3, MemOperand(sp, 2 * kPointerSize));
+    if (use_new_target) {
+      __ Push(a3, t0, t0);
+    } else {
+      __ Push(t0, t0);
+    }
 
     // Set up pointer to last argument.
     __ Daddu(a2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
 

[paul.l..., 2015/06/26 04:02:24]

Move untagged argument count to a3 for loop counter.
  __ mov(a3, a0);

-    // Set up number of arguments for function call below.
-    __ SmiUntag(a0, a3);
-
     // Copy arguments and receiver to the expression stack.
     // a0: number of arguments
     // a1: constructor function
@@ -672,7 +680,8 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     // a3: number of arguments (smi-tagged)
     // sp[0]: receiver
     // sp[1]: receiver
-    // sp[2]: number of arguments (smi-tagged)
+    // sp[2]: new.target (if used)
+    // sp[2/3]: number of arguments (smi-tagged)
     Label loop, entry;
     __ SmiUntag(a3);
     __ jmp(&entry);
@@ -699,7 +708,9 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     }
 
     // Store offset of return address for deoptimizer.
-    if (!is_api_function) {
+    // TODO(arv): Remove the "!use_new_target" before supporting optimization
+    // of functions that reference new.target
+    if (!is_api_function && !use_new_target) {
       masm->isolate()->heap()->SetConstructStubDeoptPCOffset(masm->pc_offset());
     }
 
@@ -714,7 +725,8 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     // If the result is a smi, it is *not* an object in the ECMA sense.
     // v0: result
     // sp[0]: receiver (newly allocated object)
-    // sp[1]: number of arguments (smi-tagged)
+    // sp[1]: new.target (if used)
+    // sp[1/2]: number of arguments (smi-tagged)
     __ JumpIfSmi(v0, &use_receiver);
 
     // If the type of the result (stored in its map) is less than
@@ -732,8 +744,10 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     __ bind(&exit);
     // v0: result
     // sp[0]: receiver (newly allocated object)
-    // sp[1]: number of arguments (smi-tagged)
-    __ ld(a1, MemOperand(sp, kPointerSize));
+    // sp[1]: new.target (if used)
+    // sp[1/2]: number of arguments (smi-tagged)
+    int offset = (use_new_target ? 2 : 1) * kPointerSize;
+    __ ld(a1, MemOperand(sp, offset));
 
     // Leave construct frame.
   }
@@ -747,12 +761,17 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
 
 
 void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, false, FLAG_pretenuring_call_new);
+  Generate_JSConstructStubHelper(masm, false, false, FLAG_pretenuring_call_new);
 }
 
 
 void Builtins::Generate_JSConstructStubApi(MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, true, false);
+  Generate_JSConstructStubHelper(masm, true, false, false);
+}
+
+
+void Builtins::Generate_JSConstructStubNewTarget(MacroAssembler* masm) {
+  Generate_JSConstructStubHelper(masm, false, true, FLAG_pretenuring_call_new);
 }