MIPS: port Merge arguments branch to bleeding edge (second try).

src/mips/code-stubs-mips.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4057 matching lines @@
   __ Ret();
 
   // Slow-case: Handle non-smi or out-of-bounds access to arguments
   // by calling the runtime system.
   __ bind(&slow);
   __ push(a1);
   __ TailCallRuntime(Runtime::kGetArgumentsProperty, 1, 1);
 }
 
 
-void ArgumentsAccessStub::GenerateNewObject(MacroAssembler* masm) {
+void ArgumentsAccessStub::GenerateNewNonStrictSlow(MacroAssembler* masm) {
   // sp[0] : number of parameters
   // sp[4] : receiver displacement
   // sp[8] : function
-
+  // Check if the calling frame is an arguments adaptor frame.
+  Label runtime;
+  __ lw(a3, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a2, MemOperand(a3, StandardFrameConstants::kContextOffset));
+  __ Branch(&runtime, ne,
+            a2, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+
+  // Patch the arguments.length and the parameters pointer in the current frame.
+  __ lw(a2, MemOperand(a3, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ sw(a2, MemOperand(sp, 0 * kPointerSize));
+  __ sll(t3, a2, 1);
+  __ Addu(a3, a3, Operand(t3));
+  __ addiu(a3, a3, StandardFrameConstants::kCallerSPOffset);
+  __ sw(a3, MemOperand(sp, 1 * kPointerSize));
+
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewArgumentsFast, 3, 1);
+}
+
+
+void ArgumentsAccessStub::GenerateNewNonStrictFast(MacroAssembler* masm) {
+  // Stack layout:
+  //  sp[0] : number of parameters (tagged)
+  //  sp[4] : address of receiver argument
+  //  sp[8] : function
+  // Registers used over whole function:
+  //  t2 : allocated object (tagged)
+  //  t5 : mapped parameter count (tagged)
+
+  __ lw(a1, MemOperand(sp, 0 * kPointerSize));
+  // a1 = parameter count (tagged)
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label runtime;
+  Label adaptor_frame, try_allocate;
+  __ lw(a3, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a2, MemOperand(a3, StandardFrameConstants::kContextOffset));
+  __ Branch(&adaptor_frame, eq, a2,
+            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+
+  // No adaptor, parameter count = argument count.
+  __ mov(a2, a1);
+  __ b(&try_allocate);

[Søren Thygesen Gjesse, 2011/06/21 07:46:40]

Is there no unconditional Branch macro which automatically protects the branch
delay slot?

+  __ nop();   // Branch delay slot nop.
+
+  // We have an adaptor frame. Patch the parameters pointer.
+  __ bind(&adaptor_frame);
+  __ lw(a2, MemOperand(a3, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ sll(t6, a2, 1);
+  __ Addu(a3, a3, Operand(t6));
+  __ Addu(a3, a3, Operand(StandardFrameConstants::kCallerSPOffset));
+  __ sw(a3, MemOperand(sp, 1 * kPointerSize));
+
+  // a1 = parameter count (tagged)
+  // a2 = argument count (tagged)
+  // Compute the mapped parameter count = min(a1, a2) in a1.
+  Label skip_min;
+  __ Branch(&skip_min, lt, a1, Operand(a2));
+  __ mov(a1, a2);
+  __ bind(&skip_min);
+
+  __ bind(&try_allocate);
+
+  // Compute the sizes of backing store, parameter map, and arguments object.
+  // 1. Parameter map, has 2 extra words containing context and backing store.
+  const int kParameterMapHeaderSize =
+      FixedArray::kHeaderSize + 2 * kPointerSize;
+  // If there are no mapped parameters, we do not need the parameter_map.
+  Label param_map_size;
+  ASSERT_EQ(0, Smi::FromInt(0));
+  __ Branch(USE_DELAY_SLOT, &param_map_size, eq, a1, Operand(zero_reg));
+  __ mov(t5, zero_reg);  // In delay slot: param map size = 0 when a1 == 0.
+  __ sll(t5, a1, 1);
+  __ addiu(t5, t5, kParameterMapHeaderSize);
+  __ bind(&param_map_size);
+
+  // 2. Backing store.
+  __ sll(t6, a2, 1);
+  __ Addu(t5, t5, Operand(t6));
+  __ Addu(t5, t5, Operand(FixedArray::kHeaderSize));
+
+  // 3. Arguments object.
+  __ Addu(t5, t5, Operand(Heap::kArgumentsObjectSize));
+
+  // Do the allocation of all three objects in one go.
+  __ AllocateInNewSpace(t5, v0, a3, t0, &runtime, TAG_OBJECT);
+
+  // v0 = address of new object(s) (tagged)
+  // a2 = argument count (tagged)
+  // Get the arguments boilerplate from the current (global) context into t0.
+  const int kNormalOffset =
+      Context::SlotOffset(Context::ARGUMENTS_BOILERPLATE_INDEX);
+  const int kAliasedOffset =
+      Context::SlotOffset(Context::ALIASED_ARGUMENTS_BOILERPLATE_INDEX);
+
+  __ lw(t0, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  __ lw(t0, FieldMemOperand(t0, GlobalObject::kGlobalContextOffset));
+  Label skip2_ne, skip2_eq;
+  __ Branch(&skip2_ne, ne, a1, Operand(zero_reg));
+  __ lw(t0, MemOperand(t0, kNormalOffset));
+  __ bind(&skip2_ne);
+
+  __ Branch(&skip2_eq, eq, a1, Operand(zero_reg));
+  __ lw(t0, MemOperand(t0, kAliasedOffset));
+  __ bind(&skip2_eq);
+
+  // v0 = address of new object (tagged)
+  // a1 = mapped parameter count (tagged)
+  // a2 = argument count (tagged)
+  // t0 = address of boilerplate object (tagged)
+  // Copy the JS object part.
+  for (int i = 0; i < JSObject::kHeaderSize; i += kPointerSize) {
+    __ lw(a3, FieldMemOperand(t0, i));
+    __ sw(a3, FieldMemOperand(v0, i));
+  }
+
+  // Setup the callee in-object property.
+  STATIC_ASSERT(Heap::kArgumentsCalleeIndex == 1);
+  __ lw(a3, MemOperand(sp, 2 * kPointerSize));
+  const int kCalleeOffset = JSObject::kHeaderSize +
+      Heap::kArgumentsCalleeIndex * kPointerSize;
+  __ sw(a3, FieldMemOperand(v0, kCalleeOffset));
+
+  // Use the length (smi tagged) and set that as an in-object property too.
+  STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
+  const int kLengthOffset = JSObject::kHeaderSize +
+      Heap::kArgumentsLengthIndex * kPointerSize;
+  __ sw(a2, FieldMemOperand(v0, kLengthOffset));
+
+  // Setup the elements pointer in the allocated arguments object.
+  // If we allocated a parameter map, t0 will point there, otherwise
+  // it will point to the backing store.
+  __ Addu(t0, v0, Operand(Heap::kArgumentsObjectSize));
+  __ sw(t0, FieldMemOperand(v0, JSObject::kElementsOffset));
+
+  // v0 = address of new object (tagged)
+  // a1 = mapped parameter count (tagged)
+  // a2 = argument count (tagged)
+  // t0 = address of parameter map or backing store (tagged)
+  // Initialize parameter map. If there are no mapped arguments, we're done.
+  Label skip_parameter_map;
+  Label skip3;
+  __ Branch(&skip3, ne, a1, Operand(Smi::FromInt(0)));
+  // Move backing store address to a3, because it is
+  // expected there when filling in the unmapped arguments.
+  __ mov(a3, t0);
+  __ bind(&skip3);
+
+  __ Branch(&skip_parameter_map, eq, a1, Operand(Smi::FromInt(0)));
+
+  __ LoadRoot(t2, Heap::kNonStrictArgumentsElementsMapRootIndex);
+  __ sw(t2, FieldMemOperand(t0, FixedArray::kMapOffset));
+  __ Addu(t2, a1, Operand(Smi::FromInt(2)));
+  __ sw(t2, FieldMemOperand(t0, FixedArray::kLengthOffset));
+  __ sw(cp, FieldMemOperand(t0, FixedArray::kHeaderSize + 0 * kPointerSize));
+  __ sll(t6, a1, 1);
+  __ Addu(t2, t0, Operand(t6));
+  __ Addu(t2, t2, Operand(kParameterMapHeaderSize));
+  __ sw(t2, FieldMemOperand(t0, FixedArray::kHeaderSize + 1 * kPointerSize));
+
+  // Copy the parameter slots and the holes in the arguments.
+  // We need to fill in mapped_parameter_count slots. They index the context,
+  // where parameters are stored in reverse order, at
+  //   MIN_CONTEXT_SLOTS .. MIN_CONTEXT_SLOTS+parameter_count-1
+  // The mapped parameter thus need to get indices
+  //   MIN_CONTEXT_SLOTS+parameter_count-1 ..
+  //       MIN_CONTEXT_SLOTS+parameter_count-mapped_parameter_count
+  // We loop from right to left.
+  Label parameters_loop, parameters_test;
+  __ mov(t2, a1);
+  __ lw(t5, MemOperand(sp, 0 * kPointerSize));
+  __ Addu(t5, t5, Operand(Smi::FromInt(Context::MIN_CONTEXT_SLOTS)));
+  __ Subu(t5, t5, Operand(a1));
+  __ LoadRoot(t3, Heap::kTheHoleValueRootIndex);
+  __ sll(t6, t2, 1);
+  __ Addu(a3, t0, Operand(t6));
+  __ Addu(a3, a3, Operand(kParameterMapHeaderSize));
+
+  // t2 = loop variable (tagged)
+  // a1 = mapping index (tagged)
+  // a3 = address of backing store (tagged)
+  // t0 = address of parameter map (tagged)
+  // t1 = temporary scratch (a.o., for address calculation)
+  // t3 = the hole value
+  __ jmp(&parameters_test);
+
+  __ bind(&parameters_loop);
+  __ Subu(t2, t2, Operand(Smi::FromInt(1)));
+  __ sll(t1, t2, 1);
+  __ Addu(t1, t1, Operand(kParameterMapHeaderSize - kHeapObjectTag));
+  __ Addu(t6, t0, t1);
+  __ sw(t5, MemOperand(t6));
+  __ Subu(t1, t1, Operand(kParameterMapHeaderSize - FixedArray::kHeaderSize));
+  __ Addu(t6, a3, t1);
+  __ sw(t3, MemOperand(t6));
+  __ Addu(t5, t5, Operand(Smi::FromInt(1)));
+  __ bind(&parameters_test);
+  __ Branch(&parameters_loop, ne, t2, Operand(Smi::FromInt(0)));
+
+  __ bind(&skip_parameter_map);
+  // a2 = argument count (tagged)
+  // a3 = address of backing store (tagged)
+  // t1 = scratch
+  // Copy arguments header and remaining slots (if there are any).
+  __ LoadRoot(t1, Heap::kFixedArrayMapRootIndex);
+  __ sw(t1, FieldMemOperand(a3, FixedArray::kMapOffset));
+  __ sw(a2, FieldMemOperand(a3, FixedArray::kLengthOffset));
+
+  Label arguments_loop, arguments_test;
+  __ mov(t5, a1);
+  __ lw(t0, MemOperand(sp, 1 * kPointerSize));
+  __ sll(t6, t5, 1);
+  __ Subu(t0, t0, Operand(t6));
+  __ jmp(&arguments_test);
+
+  __ bind(&arguments_loop);
+  __ Subu(t0, t0, Operand(kPointerSize));
+  __ lw(t2, MemOperand(t0, 0));
+  __ sll(t6, t5, 1);
+  __ Addu(t1, a3, Operand(t6));
+  __ sw(t2, FieldMemOperand(t1, FixedArray::kHeaderSize));
+  __ Addu(t5, t5, Operand(Smi::FromInt(1)));
+
+  __ bind(&arguments_test);
+  __ Branch(&arguments_loop, lt, t5, Operand(a2));
+
+  // Return and remove the on-stack parameters.
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+  // Do the runtime call to allocate the arguments object.
+  // a2 = argument count (taggged)
+  __ bind(&runtime);
+  __ sw(a2, MemOperand(sp, 0 * kPointerSize));  // Patch argument count.
+  __ TailCallRuntime(Runtime::kNewArgumentsFast, 3, 1);
+}
+
+
+void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
+  // sp[0] : number of parameters
+  // sp[4] : receiver displacement
+  // sp[8] : function
   // Check if the calling frame is an arguments adaptor frame.
   Label adaptor_frame, try_allocate, runtime;
   __ lw(a2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   __ lw(a3, MemOperand(a2, StandardFrameConstants::kContextOffset));
   __ Branch(&adaptor_frame,
             eq,
             a3,
             Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
 
   // Get the length from the frame.
@@ skipping 12 matching lines @@
 
   // Try the new space allocation. Start out with computing the size
   // of the arguments object and the elements array in words.
   Label add_arguments_object;
   __ bind(&try_allocate);
   __ Branch(&add_arguments_object, eq, a1, Operand(zero_reg));
   __ srl(a1, a1, kSmiTagSize);
 
   __ Addu(a1, a1, Operand(FixedArray::kHeaderSize / kPointerSize));
   __ bind(&add_arguments_object);
-  __ Addu(a1, a1, Operand(GetArgumentsObjectSize() / kPointerSize));
+  __ Addu(a1, a1, Operand(Heap::kArgumentsObjectSizeStrict / kPointerSize));
 
   // Do the allocation of both objects in one go.
-  __ AllocateInNewSpace(
-      a1,
-      v0,
-      a2,
-      a3,
-      &runtime,
-      static_cast<AllocationFlags>(TAG_OBJECT | SIZE_IN_WORDS));
+  __ AllocateInNewSpace(a1,
+                        v0,
+                        a2,
+                        a3,
+                        &runtime,
+                        static_cast<AllocationFlags>(TAG_OBJECT |
+                                                     SIZE_IN_WORDS));
 
   // Get the arguments boilerplate from the current (global) context.
   __ lw(t0, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
   __ lw(t0, FieldMemOperand(t0, GlobalObject::kGlobalContextOffset));
-  __ lw(t0, MemOperand(t0,
-                       Context::SlotOffset(GetArgumentsBoilerplateIndex())));
+  __ lw(t0, MemOperand(t0, Context::SlotOffset(
+      Context::STRICT_MODE_ARGUMENTS_BOILERPLATE_INDEX)));
 
   // Copy the JS object part.
   __ CopyFields(v0, t0, a3.bit(), JSObject::kHeaderSize / kPointerSize);
 
-  if (type_ == NEW_NON_STRICT) {
-    // Setup the callee in-object property.
-    STATIC_ASSERT(Heap::kArgumentsCalleeIndex == 1);
-    __ lw(a3, MemOperand(sp, 2 * kPointerSize));
-    const int kCalleeOffset = JSObject::kHeaderSize +
-                              Heap::kArgumentsCalleeIndex * kPointerSize;
-    __ sw(a3, FieldMemOperand(v0, kCalleeOffset));
-  }
-
   // Get the length (smi tagged) and set that as an in-object property too.
   STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
   __ lw(a1, MemOperand(sp, 0 * kPointerSize));
   __ sw(a1, FieldMemOperand(v0, JSObject::kHeaderSize +
-                                Heap::kArgumentsLengthIndex * kPointerSize));
+      Heap::kArgumentsLengthIndex * kPointerSize));
 
   Label done;
   __ Branch(&done, eq, a1, Operand(zero_reg));
 
   // Get the parameters pointer from the stack.
   __ lw(a2, MemOperand(sp, 1 * kPointerSize));
 
   // Setup the elements pointer in the allocated arguments object and
   // initialize the header in the elements fixed array.
-  __ Addu(t0, v0, Operand(GetArgumentsObjectSize()));
+  __ Addu(t0, v0, Operand(Heap::kArgumentsObjectSizeStrict));
   __ sw(t0, FieldMemOperand(v0, JSObject::kElementsOffset));
   __ LoadRoot(a3, Heap::kFixedArrayMapRootIndex);
   __ sw(a3, FieldMemOperand(t0, FixedArray::kMapOffset));
   __ sw(a1, FieldMemOperand(t0, FixedArray::kLengthOffset));
-  __ srl(a1, a1, kSmiTagSize);  // Untag the length for the loop.
+  // Untag the length for the loop.
+  __ srl(a1, a1, kSmiTagSize);
 
   // Copy the fixed array slots.
   Label loop;
   // Setup t0 to point to the first array slot.
   __ Addu(t0, t0, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   __ bind(&loop);
   // Pre-decrement a2 with kPointerSize on each iteration.
   // Pre-decrement in order to skip receiver.
   __ Addu(a2, a2, Operand(-kPointerSize));
   __ lw(a3, MemOperand(a2));
   // Post-increment t0 with kPointerSize on each iteration.
   __ sw(a3, MemOperand(t0));
   __ Addu(t0, t0, Operand(kPointerSize));
   __ Subu(a1, a1, Operand(1));
   __ Branch(&loop, ne, a1, Operand(zero_reg));
 
   // Return and remove the on-stack parameters.
   __ bind(&done);
   __ Addu(sp, sp, Operand(3 * kPointerSize));
   __ Ret();
 
   // Do the runtime call to allocate the arguments object.
   __ bind(&runtime);
-  __ TailCallRuntime(Runtime::kNewArgumentsFast, 3, 1);
+  __ TailCallRuntime(Runtime::kNewStrictArgumentsFast, 3, 1);
 }
 
 
 void RegExpExecStub::Generate(MacroAssembler* masm) {
   // Just jump directly to runtime if native RegExp is not selected at compile
   // time or if regexp entry in generated code is turned off runtime switch or
   // at compilation.
 #ifdef V8_INTERPRETED_REGEXP
   __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
 #else  // V8_INTERPRETED_REGEXP
@@ skipping 2456 matching lines @@
   __ mov(result, zero_reg);
   __ Ret();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS