ARM: Don't require the receiver on the stack for load IC...

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 1352 matching lines @@
   // and y the receiver.
   VirtualFrame::SpilledScope spilled_scope(frame_);
 
   ASSERT(ArgumentsMode() == LAZY_ARGUMENTS_ALLOCATION);
   ASSERT(arguments->IsArguments());
 
   // Load applicand.apply onto the stack. This will usually
   // give us a megamorphic load site. Not super, but it works.
   LoadAndSpill(applicand);
   Handle<String> name = Factory::LookupAsciiSymbol("apply");
+  frame_->Dup();
   frame_->CallLoadIC(name, RelocInfo::CODE_TARGET);
   frame_->EmitPush(r0);
 
   // Load the receiver and the existing arguments object onto the
   // expression stack. Avoid allocating the arguments object here.
   LoadAndSpill(receiver);
   LoadFromSlot(scope()->arguments()->var()->slot(), NOT_INSIDE_TYPEOF);
 
   // Emit the source position information after having loaded the
   // receiver and the arguments.
@@ skipping 1619 matching lines @@
     __ bind(&fast);
   }
 
   // Load the global object.
   LoadGlobal();
   // Setup the name register and call load IC.
   frame_->CallLoadIC(slot->var()->name(),
                      typeof_state == INSIDE_TYPEOF
                          ? RelocInfo::CODE_TARGET
                          : RelocInfo::CODE_TARGET_CONTEXT);
-  // Drop the global object. The result is in r0.
-  frame_->Drop();
 }
 
 
 void CodeGenerator::EmitDynamicLoadFromSlotFastCase(Slot* slot,
                                                     TypeofState typeof_state,
                                                     JumpTarget* slow,
                                                     JumpTarget* done) {
   // Generate fast-case code for variables that might be shadowed by
   // eval-introduced variables.  Eval is used a lot without
   // introducing variables.  In those cases, we do not want to
@@ skipping 393 matching lines @@
     // For a compound assignment the right-hand side is a binary operation
     // between the current property value and the actual right-hand side.
     if (is_trivial_receiver) {
       Load(prop->obj());
     } else if (var != NULL) {
       LoadGlobal();
     } else {
       frame_->Dup();
     }
     EmitNamedLoad(name, var != NULL);
-    frame_->Drop();  // Receiver is left on the stack.
     frame_->EmitPush(r0);
 
     // Perform the binary operation.
     Literal* literal = node->value()->AsLiteral();
     bool overwrite_value =
         (node->value()->AsBinaryOperation() != NULL &&
          node->value()->AsBinaryOperation()->ResultOverwriteAllowed());
     if (literal != NULL && literal->handle()->IsSmi()) {
       SmiOperation(node->binary_op(),
                    literal->handle(),
@@ skipping 1985 matching lines @@
     default:
       UNREACHABLE();
   }
   ASSERT((has_cc() && frame_->height() == original_height) ||
          (!has_cc() && frame_->height() == original_height + 1));
 }
 
 
 class DeferredReferenceGetNamedValue: public DeferredCode {
  public:
-  explicit DeferredReferenceGetNamedValue(Handle<String> name) : name_(name) {
+  explicit DeferredReferenceGetNamedValue(Register receiver,
+                                          Handle<String> name)
+      : receiver_(receiver), name_(name) {
     set_comment("[ DeferredReferenceGetNamedValue");
   }
 
   virtual void Generate();
 
  private:
+  Register receiver_;
   Handle<String> name_;
 };
 
 
 void DeferredReferenceGetNamedValue::Generate() {
+  ASSERT(receiver_.is(r0) || receiver_.is(r1));
+
   Register scratch1 = VirtualFrame::scratch0();
   Register scratch2 = VirtualFrame::scratch1();
   __ DecrementCounter(&Counters::named_load_inline, 1, scratch1, scratch2);
   __ IncrementCounter(&Counters::named_load_inline_miss, 1, scratch1, scratch2);
 
-  // Setup the registers and call load IC.
-  // On entry to this deferred code, r0 is assumed to already contain the
-  // receiver from the top of the stack.
+  // Ensure receiver in r0 and name in r2 to match load ic calling convention.
+  __ Move(r0, receiver_);
   __ mov(r2, Operand(name_));
 
   // The rest of the instructions in the deferred code must be together.
   { Assembler::BlockConstPoolScope block_const_pool(masm_);
     Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
     __ Call(ic, RelocInfo::CODE_TARGET);
     // The call must be followed by a nop(1) instruction to indicate that the
     // in-object has been inlined.
     __ nop(PROPERTY_ACCESS_INLINED);
 
@@ skipping 118 matching lines @@
     // having it in the instruction stream below where patching will occur.
     __ IncrementCounter(&Counters::named_load_inline, 1,
                         frame_->scratch0(), frame_->scratch1());
 
     // The following instructions are the inlined load of an in-object property.
     // Parts of this code is patched, so the exact instructions generated needs
     // to be fixed. Therefore the instruction pool is blocked when generating
     // this code
 
     // Load the receiver from the stack.
-    frame_->SpillAllButCopyTOSToR0();
+    Register receiver = frame_->PopToRegister();
+    VirtualFrame::SpilledScope spilled(frame_);
 
     DeferredReferenceGetNamedValue* deferred =
-        new DeferredReferenceGetNamedValue(name);
+        new DeferredReferenceGetNamedValue(receiver, name);
 
 #ifdef DEBUG
     int kInlinedNamedLoadInstructions = 7;
     Label check_inlined_codesize;
     masm_->bind(&check_inlined_codesize);
 #endif
 
     { Assembler::BlockConstPoolScope block_const_pool(masm_);
       // Check that the receiver is a heap object.
-      __ tst(r0, Operand(kSmiTagMask));
+      __ tst(receiver, Operand(kSmiTagMask));
       deferred->Branch(eq);
 
       // Check the map. The null map used below is patched by the inline cache
       // code.
-      __ ldr(r2, FieldMemOperand(r0, HeapObject::kMapOffset));
+      __ ldr(r2, FieldMemOperand(receiver, HeapObject::kMapOffset));
       __ mov(r3, Operand(Factory::null_value()));
       __ cmp(r2, r3);
       deferred->Branch(ne);
 
       // Initially use an invalid index. The index will be patched by the
       // inline cache code.
-      __ ldr(r0, MemOperand(r0, 0));
+      __ ldr(r0, MemOperand(receiver, 0));
 
       // Make sure that the expected number of instructions are generated.
       ASSERT_EQ(kInlinedNamedLoadInstructions,
                 masm_->InstructionsGeneratedSince(&check_inlined_codesize));
     }
 
     deferred->BindExit();
   }
 }
 
@@ skipping 228 matching lines @@
       if (!persist_after_get_) {
         cgen_->UnloadReference(this);
       }
       break;
     }
 
     case NAMED: {
       Variable* var = expression_->AsVariableProxy()->AsVariable();
       bool is_global = var != NULL;
       ASSERT(!is_global || var->is_global());
+      if (persist_after_get_) {
+        cgen_->frame()->Dup();
+      }
       cgen_->EmitNamedLoad(GetName(), is_global);
       cgen_->frame()->EmitPush(r0);
-      if (!persist_after_get_) {
-        cgen_->UnloadReference(this);
-      }
+      if (!persist_after_get_) set_unloaded();
       break;
     }
 
     case KEYED: {
+      ASSERT(property != NULL);
       if (persist_after_get_) {
         cgen_->frame()->Dup2();
       }
-      ASSERT(property != NULL);
       cgen_->EmitKeyedLoad();
       cgen_->frame()->EmitPush(r0);
       if (!persist_after_get_) set_unloaded();
       break;
     }
 
     default:
       UNREACHABLE();
   }
 }
@@ skipping 4147 matching lines @@
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM