Simplify stackframe of construct stub on ARM and MIPS.

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 186d06e3f095b3a11a17561b646711e8ef0ce58f..50b6bce30b7dddc4caeec098dd1e38464839d610 100644
--- a/src/arm/builtins-arm.cc
+++ b/src/arm/builtins-arm.cc
@@ -895,23 +895,15 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     // r4: JSObject
     __ bind(&allocated);
     __ push(r4);
+    __ push(r4);
 
-    // Push the function and the allocated receiver from the stack.
-    // sp[0]: receiver (newly allocated object)
-    // sp[1]: constructor function
-    // sp[2]: number of arguments (smi-tagged)
-    __ ldr(r1, MemOperand(sp, kPointerSize));
-    __ push(r1);  // Constructor function.
-    __ push(r4);  // Receiver.
-
-    // Reload the number of arguments from the stack.
-    // r1: constructor function
+    // Reload the number of arguments and the constructor from the stack.
     // sp[0]: receiver
-    // sp[1]: constructor function
-    // sp[2]: receiver
-    // sp[3]: constructor function
-    // sp[4]: number of arguments (smi-tagged)
-    __ ldr(r3, MemOperand(sp, 4 * kPointerSize));
+    // sp[1]: receiver
+    // sp[2]: constructor function
+    // sp[3]: number of arguments (smi-tagged)
+    __ ldr(r1, MemOperand(sp, 2 * kPointerSize));
+    __ ldr(r3, MemOperand(sp, 3 * kPointerSize));
 
     // Set up pointer to last argument.
     __ add(r2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
@@ -921,14 +913,13 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
 
     // Copy arguments and receiver to the expression stack.
     // r0: number of arguments
-    // r2: address of last argument (caller sp)
     // r1: constructor function
+    // r2: address of last argument (caller sp)
     // r3: number of arguments (smi-tagged)
     // sp[0]: receiver
-    // sp[1]: constructor function
-    // sp[2]: receiver
-    // sp[3]: constructor function
-    // sp[4]: number of arguments (smi-tagged)
+    // sp[1]: receiver
+    // sp[2]: constructor function
+    // sp[3]: number of arguments (smi-tagged)
     Label loop, entry;
     __ b(&entry);
     __ bind(&loop);
@@ -954,13 +945,6 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                         NullCallWrapper(), CALL_AS_METHOD);
     }
 
-    // Pop the function from the stack.
-    // sp[0]: constructor function
-    // sp[2]: receiver
-    // sp[3]: constructor function
-    // sp[4]: number of arguments (smi-tagged)
-    __ pop();
-
     // Restore context from the frame.
     // r0: result
     // sp[0]: receiver