Merge 6168:6800 from bleeding_edge to experimental/gc branch.

src/x64/codegen-x64.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 613 matching lines @@
       : LAZY_ARGUMENTS_ALLOCATION;
 }
 
 
 Result CodeGenerator::StoreArgumentsObject(bool initial) {
   ArgumentsAllocationMode mode = ArgumentsMode();
   ASSERT(mode != NO_ARGUMENTS_ALLOCATION);
 
   Comment cmnt(masm_, "[ store arguments object");
   if (mode == LAZY_ARGUMENTS_ALLOCATION && initial) {
-    // When using lazy arguments allocation, we store the hole value
+    // When using lazy arguments allocation, we store the arguments marker value
     // as a sentinel indicating that the arguments object hasn't been
     // allocated yet.
-    frame_->Push(Factory::the_hole_value());
+    frame_->Push(Factory::arguments_marker());
   } else {
     ArgumentsAccessStub stub(ArgumentsAccessStub::NEW_OBJECT);
     frame_->PushFunction();
     frame_->PushReceiverSlotAddress();
     frame_->Push(Smi::FromInt(scope()->num_parameters()));
     Result result = frame_->CallStub(&stub, 3);
     frame_->Push(&result);
   }
 
   Variable* arguments = scope()->arguments();
   Variable* shadow = scope()->arguments_shadow();
   ASSERT(arguments != NULL && arguments->AsSlot() != NULL);
   ASSERT(shadow != NULL && shadow->AsSlot() != NULL);
   JumpTarget done;
   bool skip_arguments = false;
   if (mode == LAZY_ARGUMENTS_ALLOCATION && !initial) {
     // We have to skip storing into the arguments slot if it has
     // already been written to. This can happen if the a function
     // has a local variable named 'arguments'.
     LoadFromSlot(arguments->AsSlot(), NOT_INSIDE_TYPEOF);
     Result probe = frame_->Pop();
     if (probe.is_constant()) {
       // We have to skip updating the arguments object if it has
       // been assigned a proper value.
-      skip_arguments = !probe.handle()->IsTheHole();
+      skip_arguments = !probe.handle()->IsArgumentsMarker();
     } else {
-      __ CompareRoot(probe.reg(), Heap::kTheHoleValueRootIndex);
+      __ CompareRoot(probe.reg(), Heap::kArgumentsMarkerRootIndex);
       probe.Unuse();
       done.Branch(not_equal);
     }
   }
   if (!skip_arguments) {
     StoreToSlot(arguments->AsSlot(), NOT_CONST_INIT);
     if (mode == LAZY_ARGUMENTS_ALLOCATION) done.Bind();
   }
   StoreToSlot(shadow->AsSlot(), NOT_CONST_INIT);
   return frame_->Pop();
@@ skipping 1838 matching lines @@
   // Check if the arguments object has been lazily allocated
   // already. If so, just use that instead of copying the arguments
   // from the stack. This also deals with cases where a local variable
   // named 'arguments' has been introduced.
   frame_->Dup();
   Result probe = frame_->Pop();
   { VirtualFrame::SpilledScope spilled_scope;
     Label slow, done;
     bool try_lazy = true;
     if (probe.is_constant()) {
-      try_lazy = probe.handle()->IsTheHole();
+      try_lazy = probe.handle()->IsArgumentsMarker();
     } else {
-      __ CompareRoot(probe.reg(), Heap::kTheHoleValueRootIndex);
+      __ CompareRoot(probe.reg(), Heap::kArgumentsMarkerRootIndex);
       probe.Unuse();
       __ j(not_equal, &slow);
     }
 
     if (try_lazy) {
       Label build_args;
       // Get rid of the arguments object probe.
       frame_->Drop();  // Can be called on a spilled frame.
       // Stack now has 3 elements on it.
       // Contents of stack at this point:
@@ skipping 454 matching lines @@
 
   // Add a label for checking the size of the code used for returning.
 #ifdef DEBUG
   Label check_exit_codesize;
   masm_->bind(&check_exit_codesize);
 #endif
 
   // Leave the frame and return popping the arguments and the
   // receiver.
   frame_->Exit();
-  masm_->ret((scope()->num_parameters() + 1) * kPointerSize);
+  int arguments_bytes = (scope()->num_parameters() + 1) * kPointerSize;
+  __ Ret(arguments_bytes, rcx);
   DeleteFrame();
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // Add padding that will be overwritten by a debugger breakpoint.
-  // frame_->Exit() generates "movq rsp, rbp; pop rbp; ret k"
+  // The shortest return sequence generated is "movq rsp, rbp; pop rbp; ret k"
   // with length 7 (3 + 1 + 3).
   const int kPadding = Assembler::kJSReturnSequenceLength - 7;
   for (int i = 0; i < kPadding; ++i) {
     masm_->int3();
   }
-  // Check that the size of the code used for returning matches what is
-  // expected by the debugger.
-  ASSERT_EQ(Assembler::kJSReturnSequenceLength,
-            masm_->SizeOfCodeGeneratedSince(&check_exit_codesize));
+  // Check that the size of the code used for returning is large enough
+  // for the debugger's requirements.
+  ASSERT(Assembler::kJSReturnSequenceLength <=
+         masm_->SizeOfCodeGeneratedSince(&check_exit_codesize));
 #endif
 }
 
 
 void CodeGenerator::VisitWithEnterStatement(WithEnterStatement* node) {
   ASSERT(!in_spilled_code());
   Comment cmnt(masm_, "[ WithEnterStatement");
   CodeForStatementPosition(node);
   Load(node->expression());
   Result context;
@@ skipping 1389 matching lines @@
 
   // ... or if the slot isn't a non-parameter arguments slot.
   if (slot->type() == Slot::PARAMETER || !slot->is_arguments()) return;
 
   // Pop the loaded value from the stack.
   Result value = frame_->Pop();
 
   // If the loaded value is a constant, we know if the arguments
   // object has been lazily loaded yet.
   if (value.is_constant()) {
-    if (value.handle()->IsTheHole()) {
+    if (value.handle()->IsArgumentsMarker()) {
       Result arguments = StoreArgumentsObject(false);
       frame_->Push(&arguments);
     } else {
       frame_->Push(&value);
     }
     return;
   }
 
   // The loaded value is in a register. If it is the sentinel that
   // indicates that we haven't loaded the arguments object yet, we
   // need to do it now.
   JumpTarget exit;
-  __ CompareRoot(value.reg(), Heap::kTheHoleValueRootIndex);
+  __ CompareRoot(value.reg(), Heap::kArgumentsMarkerRootIndex);
   frame_->Push(&value);
   exit.Branch(not_equal);
   Result arguments = StoreArgumentsObject(false);
   frame_->SetElementAt(0, &arguments);
   exit.Bind();
 }
 
 
 Result CodeGenerator::LoadFromGlobalSlotCheckExtensions(
     Slot* slot,
@@ skipping 446 matching lines @@
         if (CompileTimeValue::IsCompileTimeValue(property->value())) break;
         // else fall through.
       case ObjectLiteral::Property::COMPUTED: {
         Handle<Object> key(property->key()->handle());
         if (key->IsSymbol()) {
           // Duplicate the object as the IC receiver.
           frame_->Dup();
           Load(property->value());
           if (property->emit_store()) {
             Result ignored =
-                frame_->CallStoreIC(Handle<String>::cast(key), false);
+                frame_->CallStoreIC(Handle<String>::cast(key), false,
+                                    strict_mode_flag());
             // A test rax instruction following the store IC call would
             // indicate the presence of an inlined version of the
             // store. Add a nop to indicate that there is no such
             // inlined version.
             __ nop();
           } else {
             frame_->Drop(2);
           }
           break;
         }
@@ skipping 492 matching lines @@
                                                      NOT_INSIDE_TYPEOF,
                                                      &slow);
       frame_->Push(&fun);
       if (arg_count > 0) {
         frame_->PushElementAt(arg_count);
       } else {
         frame_->Push(Factory::undefined_value());
       }
       frame_->PushParameterAt(-1);
 
+      // Push the strict mode flag.
+      frame_->Push(Smi::FromInt(strict_mode_flag()));
+
       // Resolve the call.
       result =
-          frame_->CallRuntime(Runtime::kResolvePossiblyDirectEvalNoLookup, 3);
+          frame_->CallRuntime(Runtime::kResolvePossiblyDirectEvalNoLookup, 4);
 
       done.Jump(&result);
       slow.Bind();
     }
 
     // Prepare the stack for the call to ResolvePossiblyDirectEval by
     // pushing the loaded function, the first argument to the eval
     // call and the receiver.
     frame_->PushElementAt(arg_count + 1);
     if (arg_count > 0) {
       frame_->PushElementAt(arg_count);
     } else {
       frame_->Push(Factory::undefined_value());
     }
     frame_->PushParameterAt(-1);
 
+    // Push the strict mode flag.
+    frame_->Push(Smi::FromInt(strict_mode_flag()));
+
     // Resolve the call.
-    result = frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 3);
+    result = frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 4);
 
     // If we generated fast-case code bind the jump-target where fast
     // and slow case merge.
     if (done.is_linked()) done.Bind(&result);
 
     // The runtime call returns a pair of values in rax (function) and
     // rdx (receiver). Touch up the stack with the right values.
     Result receiver = allocator_->Allocate(rdx);
     frame_->SetElementAt(arg_count + 1, &result);
     frame_->SetElementAt(arg_count, &receiver);
@@ skipping 1529 matching lines @@
   // Test for -0.5.
   // Load xmm2 with -0.5.
   __ movl(answer.reg(), Immediate(0xBF000000));
   __ movd(xmm2, answer.reg());
   __ cvtss2sd(xmm2, xmm2);
   // xmm2 now has -0.5.
   __ ucomisd(xmm2, xmm1);
   __ j(not_equal, &not_minus_half);
 
   // Calculates reciprocal of square root.
-  // Note that 1/sqrt(x) = sqrt(1/x))
-  __ divsd(xmm3, xmm0);
+  // sqrtsd returns -0 when input is -0.  ECMA spec requires +0.
+  __ xorpd(xmm1, xmm1);
+  __ addsd(xmm1, xmm0);
+  __ sqrtsd(xmm1, xmm1);
+  __ divsd(xmm3, xmm1);
   __ movsd(xmm1, xmm3);
-  __ sqrtsd(xmm1, xmm1);
   __ jmp(&allocate_return);
 
   // Test for 0.5.
   __ bind(&not_minus_half);
   // Load xmm2 with 0.5.
   // Since xmm3 is 1 and xmm2 is -0.5 this is simply xmm2 + xmm3.
   __ addsd(xmm2, xmm3);
   // xmm2 now has 0.5.
   __ ucomisd(xmm2, xmm1);
   call_runtime.Branch(not_equal);
 
   // Calculates square root.
-  __ movsd(xmm1, xmm0);
+  // sqrtsd returns -0 when input is -0.  ECMA spec requires +0.
+  __ xorpd(xmm1, xmm1);
+  __ addsd(xmm1, xmm0);
   __ sqrtsd(xmm1, xmm1);
 
   JumpTarget done;
   Label failure, success;
   __ bind(&allocate_return);
   // Make a copy of the frame to enable us to handle allocation
   // failure after the JumpTarget jump.
   VirtualFrame* clone = new VirtualFrame(frame());
   __ AllocateHeapNumber(answer.reg(), exponent.reg(), &failure);
   __ movsd(FieldOperand(answer.reg(), HeapNumber::kValueOffset), xmm1);
@@ skipping 212 matching lines @@
     destination()->Invert();
     LoadCondition(node->expression(), destination(), true);
     // Swap the labels back.
     destination()->Invert();
 
   } else if (op == Token::DELETE) {
     Property* property = node->expression()->AsProperty();
     if (property != NULL) {
       Load(property->obj());
       Load(property->key());
-      Result answer = frame_->InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION, 2);
+      frame_->Push(Smi::FromInt(strict_mode_flag()));
+      Result answer = frame_->InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION, 3);
       frame_->Push(&answer);
       return;
     }
 
     Variable* variable = node->expression()->AsVariableProxy()->AsVariable();
     if (variable != NULL) {
+      // Delete of an unqualified identifier is disallowed in strict mode
+      // so this code can only be reached in non-strict mode.
+      ASSERT(strict_mode_flag() == kNonStrictMode);
       Slot* slot = variable->AsSlot();
       if (variable->is_global()) {
         LoadGlobal();
         frame_->Push(variable->name());
+        frame_->Push(Smi::FromInt(kNonStrictMode));
         Result answer = frame_->InvokeBuiltin(Builtins::DELETE,
-                                              CALL_FUNCTION, 2);
+                                              CALL_FUNCTION, 3);
         frame_->Push(&answer);
         return;
 
       } else if (slot != NULL && slot->type() == Slot::LOOKUP) {
-        // Call the runtime to look up the context holding the named
+        // Call the runtime to delete from the context holding the named
         // variable.  Sync the virtual frame eagerly so we can push the
         // arguments directly into place.
         frame_->SyncRange(0, frame_->element_count() - 1);
         frame_->EmitPush(rsi);
         frame_->EmitPush(variable->name());
-        Result context = frame_->CallRuntime(Runtime::kLookupContext, 2);
-        ASSERT(context.is_register());
-        frame_->EmitPush(context.reg());
-        context.Unuse();
-        frame_->EmitPush(variable->name());
-        Result answer = frame_->InvokeBuiltin(Builtins::DELETE,
-                                              CALL_FUNCTION, 2);
+        Result answer = frame_->CallRuntime(Runtime::kDeleteContextSlot, 2);
         frame_->Push(&answer);
         return;
       }
 
       // Default: Result of deleting non-global, not dynamically
       // introduced variables is false.
       frame_->Push(Factory::false_value());
 
     } else {
       // Default: Result of deleting expressions is true.
@@ skipping 961 matching lines @@
 }
 
 
 Result CodeGenerator::EmitNamedStore(Handle<String> name, bool is_contextual) {
 #ifdef DEBUG
   int expected_height = frame()->height() - (is_contextual ? 1 : 2);
 #endif
 
   Result result;
   if (is_contextual || scope()->is_global_scope() || loop_nesting() == 0) {
-      result = frame()->CallStoreIC(name, is_contextual);
+      result = frame()->CallStoreIC(name, is_contextual, strict_mode_flag());
       // A test rax instruction following the call signals that the inobject
       // property case was inlined.  Ensure that there is not a test rax
       // instruction here.
       __ nop();
   } else {
     // Inline the in-object property case.
     JumpTarget slow, done;
     Label patch_site;
 
     // Get the value and receiver from the stack.
@@ skipping 82 matching lines @@
     }
     __ bind(&skip_write_barrier);
     value.Unuse();
     scratch.Unuse();
     receiver.Unuse();
     done.Jump(&result);
 
     slow.Bind(&value, &receiver);
     frame()->Push(&receiver);
     frame()->Push(&value);
-    result = frame()->CallStoreIC(name, is_contextual);
+    result = frame()->CallStoreIC(name, is_contextual, strict_mode_flag());
     // Encode the offset to the map check instruction and the offset
     // to the write barrier store address computation in a test rax
     // instruction.
     int delta_to_patch_site = masm_->SizeOfCodeGeneratedSince(&patch_site);
     __ testl(rax,
              Immediate((delta_to_record_write << 16) | delta_to_patch_site));
     done.Bind(&result);
   }
 
   ASSERT_EQ(expected_height, frame()->height());
@@ skipping 462 matching lines @@
 }
 
 #endif
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64