ARM: Remove some spill scopes

src/arm/codegen-arm.cc

 // Copyright 2010 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 4546 matching lines @@
   Label need_conversion_;
   Label index_out_of_range_;
 
   StringCharCodeAtGenerator char_code_at_generator_;
 };
 
 
 // This generates code that performs a String.prototype.charCodeAt() call
 // or returns a smi in order to trigger conversion.
 void CodeGenerator::GenerateStringCharCodeAt(ZoneList<Expression*>* args) {
-  VirtualFrame::SpilledScope spilled_scope(frame_);
   Comment(masm_, "[ GenerateStringCharCodeAt");
   ASSERT(args->length() == 2);
 
   Load(args->at(0));
   Load(args->at(1));
 
-  Register index = r1;
-  Register object = r2;
-
-  frame_->EmitPop(r1);
-  frame_->EmitPop(r2);
+  Register index = frame_->PopToRegister();
+  Register object = frame_->PopToRegister(index);
 
   // We need two extra registers.
-  Register scratch = r3;
-  Register result = r0;
+  Register scratch = VirtualFrame::scratch0();
+  Register result = VirtualFrame::scratch1();
 
   DeferredStringCharCodeAt* deferred =
       new DeferredStringCharCodeAt(object,
                                    index,
                                    scratch,
                                    result);
   deferred->fast_case_generator()->GenerateFast(masm_);
   deferred->BindExit();
   frame_->EmitPush(result);
 }
@@ skipping 14 matching lines @@
     char_from_code_generator_.GenerateSlow(masm(), call_helper);
   }
 
  private:
   StringCharFromCodeGenerator char_from_code_generator_;
 };
 
 
 // Generates code for creating a one-char string from a char code.
 void CodeGenerator::GenerateStringCharFromCode(ZoneList<Expression*>* args) {
-  VirtualFrame::SpilledScope spilled_scope(frame_);
   Comment(masm_, "[ GenerateStringCharFromCode");
   ASSERT(args->length() == 1);
 
   Load(args->at(0));
 
-  Register code = r1;
-  Register result = r0;
-
-  frame_->EmitPop(code);
+  Register result = frame_->GetTOSRegister();
+  Register code = frame_->PopToRegister(result);
 
   DeferredStringCharFromCode* deferred = new DeferredStringCharFromCode(
       code, result);
   deferred->fast_case_generator()->GenerateFast(masm_);
   deferred->BindExit();
   frame_->EmitPush(result);
 }
 
 
 class DeferredStringCharAt : public DeferredCode {
@@ skipping 41 matching lines @@
   Label need_conversion_;
   Label index_out_of_range_;
 
   StringCharAtGenerator char_at_generator_;
 };
 
 
 // This generates code that performs a String.prototype.charAt() call
 // or returns a smi in order to trigger conversion.
 void CodeGenerator::GenerateStringCharAt(ZoneList<Expression*>* args) {
-  VirtualFrame::SpilledScope spilled_scope(frame_);
   Comment(masm_, "[ GenerateStringCharAt");
   ASSERT(args->length() == 2);
 
   Load(args->at(0));
   Load(args->at(1));
 
-  Register index = r1;
-  Register object = r2;
-
-  frame_->EmitPop(r1);
-  frame_->EmitPop(r2);
+  Register index = frame_->PopToRegister();
+  Register object = frame_->PopToRegister(index);
 
   // We need three extra registers.
-  Register scratch1 = r3;
-  Register scratch2 = r4;
-  Register result = r0;
+  Register scratch1 = VirtualFrame::scratch0();
+  Register scratch2 = VirtualFrame::scratch1();
+  // Use r6 without notifying the virtual frame.
+  Register result = r6;
 
   DeferredStringCharAt* deferred =
       new DeferredStringCharAt(object,
                                index,
                                scratch1,
                                scratch2,
                                result);
   deferred->fast_case_generator()->GenerateFast(masm_);
   deferred->BindExit();
   frame_->EmitPush(result);
@@ skipping 158 matching lines @@
   // adaptor frame.
   __ ldr(tos,
          MemOperand(scratch0, ArgumentsAdaptorFrameConstants::kLengthOffset),
          eq);
 
   frame_->EmitPush(tos);
 }
 
 
 void CodeGenerator::GenerateArguments(ZoneList<Expression*>* args) {
-  VirtualFrame::SpilledScope spilled_scope(frame_);
   ASSERT(args->length() == 1);
 
   // Satisfy contract with ArgumentsAccessStub:
   // Load the key into r1 and the formal parameters count into r0.
   Load(args->at(0));
-  frame_->EmitPop(r1);
+  frame_->PopToR1();
+  frame_->SpillAll();
   __ mov(r0, Operand(Smi::FromInt(scope()->num_parameters())));
 
   // Call the shared stub to get to arguments[key].
   ArgumentsAccessStub stub(ArgumentsAccessStub::READ_ELEMENT);
   frame_->CallStub(&stub, 0);
   frame_->EmitPush(r0);
 }
 
 
 void CodeGenerator::GenerateRandomHeapNumber(
@@ skipping 207 matching lines @@
   virtual void Generate();
 
  private:
   Register dst_, cache_, key_;
 };
 
 
 void DeferredSearchCache::Generate() {
   __ Push(cache_, key_);
   __ CallRuntime(Runtime::kGetFromCache, 2);
-  if (!dst_.is(r0)) {
-    __ mov(dst_, r0);
-  }
+  __ Move(dst_, r0);
 }
 
 
 void CodeGenerator::GenerateGetFromCache(ZoneList<Expression*>* args) {
   ASSERT_EQ(2, args->length());
 
   ASSERT_NE(NULL, args->at(0)->AsLiteral());
   int cache_id = Smi::cast(*(args->at(0)->AsLiteral()->handle()))->value();
 
   Handle<FixedArray> jsfunction_result_caches(
       Top::global_context()->jsfunction_result_caches());
   if (jsfunction_result_caches->length() <= cache_id) {
     __ Abort("Attempt to use undefined cache.");
     frame_->EmitPushRoot(Heap::kUndefinedValueRootIndex);
     return;
   }
 
   Load(args->at(1));
 
-  VirtualFrame::SpilledScope spilled_scope(frame_);
+  frame_->PopToR1();
+  frame_->SpillAll();
+  Register key = r1;  // Just poped to r1
+  Register result = r0;  // Free, as frame has just been spilled.
+  Register scratch1 = VirtualFrame::scratch0();
+  Register scratch2 = VirtualFrame::scratch1();
 
-  frame_->EmitPop(r2);
+  __ ldr(scratch1, ContextOperand(cp, Context::GLOBAL_INDEX));
+  __ ldr(scratch1,
+         FieldMemOperand(scratch1, GlobalObject::kGlobalContextOffset));
+  __ ldr(scratch1,
+         ContextOperand(scratch1, Context::JSFUNCTION_RESULT_CACHES_INDEX));
+  __ ldr(scratch1,
+         FieldMemOperand(scratch1, FixedArray::OffsetOfElementAt(cache_id)));
 
-  __ ldr(r1, ContextOperand(cp, Context::GLOBAL_INDEX));
-  __ ldr(r1, FieldMemOperand(r1, GlobalObject::kGlobalContextOffset));
-  __ ldr(r1, ContextOperand(r1, Context::JSFUNCTION_RESULT_CACHES_INDEX));
-  __ ldr(r1, FieldMemOperand(r1, FixedArray::OffsetOfElementAt(cache_id)));
-
-  DeferredSearchCache* deferred = new DeferredSearchCache(r0, r1, r2);
+  DeferredSearchCache* deferred =
+      new DeferredSearchCache(result, scratch1, key);
 
   const int kFingerOffset =
       FixedArray::OffsetOfElementAt(JSFunctionResultCache::kFingerIndex);
   STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize == 1);
-  __ ldr(r0, FieldMemOperand(r1, kFingerOffset));
-  // r0 now holds finger offset as a smi.
-  __ add(r3, r1, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  // r3 now points to the start of fixed array elements.
-  __ ldr(r0, MemOperand(r3, r0, LSL, kPointerSizeLog2 - kSmiTagSize, PreIndex));
-  // Note side effect of PreIndex: r3 now points to the key of the pair.
-  __ cmp(r2, r0);
+  __ ldr(result, FieldMemOperand(scratch1, kFingerOffset));
+  // result now holds finger offset as a smi.
+  __ add(scratch2, scratch1, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  // scratch2 now points to the start of fixed array elements.
+  __ ldr(result,
+         MemOperand(
+             scratch2, result, LSL, kPointerSizeLog2 - kSmiTagSize, PreIndex));
+  // Note side effect of PreIndex: scratch2 now points to the key of the pair.
+  __ cmp(key, result);
   deferred->Branch(ne);
 
-  __ ldr(r0, MemOperand(r3, kPointerSize));
+  __ ldr(result, MemOperand(scratch2, kPointerSize));
 
   deferred->BindExit();
-  frame_->EmitPush(r0);
+  frame_->EmitPush(result);
 }
 
 
 void CodeGenerator::GenerateNumberToString(ZoneList<Expression*>* args) {
   ASSERT_EQ(args->length(), 1);
 
   // Load the argument on the stack and jump to the runtime.
   Load(args->at(0));
 
   NumberToStringStub stub;
@@ skipping 5272 matching lines @@
   call_helper.BeforeCall(masm);
   __ Push(object_, index_);
   __ push(index_);  // Consumed by runtime conversion function.
   if (index_flags_ == STRING_INDEX_IS_NUMBER) {
     __ CallRuntime(Runtime::kNumberToIntegerMapMinusZero, 1);
   } else {
     ASSERT(index_flags_ == STRING_INDEX_IS_ARRAY_INDEX);
     // NumberToSmi discards numbers that are not exact integers.
     __ CallRuntime(Runtime::kNumberToSmi, 1);
   }
-  if (!scratch_.is(r0)) {
-    // Save the conversion result before the pop instructions below
-    // have a chance to overwrite it.
-    __ mov(scratch_, r0);
-  }
+  // Save the conversion result before the pop instructions below
+  // have a chance to overwrite it.
+  __ Move(scratch_, r0);
   __ pop(index_);
   __ pop(object_);
   // Reload the instance type.
   __ ldr(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
   __ ldrb(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
   call_helper.AfterCall(masm);
   // If index is still not a smi, it must be out of range.
   __ BranchOnNotSmi(scratch_, index_out_of_range_);
   // Otherwise, return to the fast path.
   __ jmp(&got_smi_index_);
 
   // Call runtime. We get here when the receiver is a string and the
   // index is a number, but the code of getting the actual character
   // is too complex (e.g., when the string needs to be flattened).
   __ bind(&call_runtime_);
   call_helper.BeforeCall(masm);
   __ Push(object_, index_);
   __ CallRuntime(Runtime::kStringCharCodeAt, 2);
-  if (!result_.is(r0)) {
-    __ mov(result_, r0);
-  }
+  __ Move(result_, r0);
   call_helper.AfterCall(masm);
   __ jmp(&exit_);
 
   __ Abort("Unexpected fallthrough from CharCodeAt slow case");
 }
 
 
 // -------------------------------------------------------------------------
 // StringCharFromCodeGenerator
 
@@ skipping 20 matching lines @@
 
 
 void StringCharFromCodeGenerator::GenerateSlow(
     MacroAssembler* masm, const RuntimeCallHelper& call_helper) {
   __ Abort("Unexpected fallthrough to CharFromCode slow case");
 
   __ bind(&slow_case_);
   call_helper.BeforeCall(masm);
   __ push(code_);
   __ CallRuntime(Runtime::kCharFromCode, 1);
-  if (!result_.is(r0)) {
-    __ mov(result_, r0);
-  }
+  __ Move(result_, r0);
   call_helper.AfterCall(masm);
   __ jmp(&exit_);
 
   __ Abort("Unexpected fallthrough from CharFromCode slow case");
 }
 
 
 // -------------------------------------------------------------------------
 // StringCharAtGenerator
 
@@ skipping 908 matching lines @@
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM