[Interpreter] Support for operator new.

src/ia32/builtins-ia32.cc

Index: src/ia32/builtins-ia32.cc
diff --git a/src/ia32/builtins-ia32.cc b/src/ia32/builtins-ia32.cc
index 4156123f28f41d29a9ef398a84736a2d2aad61a4..66a6c614c02736f1ee3f6f4ec73b8ad8fd72e03a 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -724,6 +724,22 @@ void Builtins::Generate_InterpreterExitTrampoline(MacroAssembler* masm) {
 }
 
 
+static void Generate_InterpreterPushArgs(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- ebx : Pointer to the last argument in the args array.
+  //  -- ebx : Pointer to one before the first argument in the args array.
+  // -----------------------------------
+  Label loop_header, loop_check;
+  __ jmp(&loop_check);
+  __ bind(&loop_header);
+  __ Push(Operand(ebx, 0));
+  __ sub(ebx, Immediate(kPointerSize));
+  __ bind(&loop_check);
+  __ cmp(ebx, ecx);
+  __ j(greater, &loop_header, Label::kNear);
+}
+
+
 // static
 void Builtins::Generate_InterpreterPushArgsAndCall(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ -732,6 +748,7 @@ void Builtins::Generate_InterpreterPushArgsAndCall(MacroAssembler* masm) {
   //           arguments should be consecutive above this, in the same order as
   //           they are to be pushed onto the stack.
   //  -- edi : the target to call (can be any Object).
+  // -----------------------------------
 
   // Pop return address to allow tail-call after pushing arguments.
   __ Pop(edx);
@@ -743,15 +760,7 @@ void Builtins::Generate_InterpreterPushArgsAndCall(MacroAssembler* masm) {
   __ neg(ecx);
   __ add(ecx, ebx);
 
-  // Push the arguments.
-  Label loop_header, loop_check;
-  __ jmp(&loop_check);
-  __ bind(&loop_header);
-  __ Push(Operand(ebx, 0));
-  __ sub(ebx, Immediate(kPointerSize));
-  __ bind(&loop_check);
-  __ cmp(ebx, ecx);
-  __ j(greater, &loop_header, Label::kNear);
+  Generate_InterpreterPushArgs(masm);
 
   // Call the target.
   __ Push(edx);  // Re-push return address.
@@ -759,6 +768,44 @@ void Builtins::Generate_InterpreterPushArgsAndCall(MacroAssembler* masm) {
 }
 
 
+// static
+void Builtins::Generate_InterpreterPushArgsAndConstruct(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- eax : the number of arguments (not including the receiver)
+  //  -- edx : the original constructor
+  //  -- edi : the constructor
+  //  -- ebx : the address of the first argument to be pushed. Subsequent
+  //           arguments should be consecutive above this, in the same order as
+  //           they are to be pushed onto the stack.
+  // -----------------------------------
+
+  // Save number of arguments on the stack below where arguments are pushed.

[rmcilroy, 2015/10/15 10:30:55]

nit - arguments are going to be pushed

[oth, 2015/10/15 11:16:43]

Done.

+  __ mov(ecx, eax);
+  __ neg(ecx);
+  __ mov(Operand(esp, ecx, times_pointer_size, -kPointerSize), eax);
+
+  // Pop return address to allow tail-call after pushing arguments.
+  __ Pop(eax);
+
+  // Find the address of the last argument.
+  __ shl(ecx, kPointerSizeLog2);
+  __ add(ecx, ebx);
+
+  // Push required padding.
+  __ Push(Immediate(0));
+
+  Generate_InterpreterPushArgs(masm);
+
+  // Restore number of arguments from slot on stack.
+  __ xchg(eax, ecx);

[rmcilroy, 2015/10/15 10:30:55]

optional nit - I think you could avoid the xchg if you just keep the return
address in ecx and pass stack limit in eax, with Generate_InterpreterPushArgs
taking an argument for the register holding the stack limit.

[oth, 2015/10/15 11:16:43]

Done. Also looked at stashing the stack address in that slot and subtracting esp
at the end, but it saves no instructions, but is aesthetically neater.

+  __ mov(eax, Operand(esp, -kPointerSize));
+
+  // Call the target.
+  __ Push(ecx);  // Re-push return address.
+  __ Jump(masm->isolate()->builtins()->Construct(), RelocInfo::CONSTRUCT_CALL);
+}
+
+
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   CallRuntimePassFunction(masm, Runtime::kCompileLazy);
   GenerateTailCallToReturnedCode(masm);