Support fast case for-in in Crankshaft.

src/x64/full-codegen-x64.cc

 // Copyright 2012 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 883 matching lines @@
   // ignore null and undefined in contrast to the specification; see
   // ECMA-262 section 12.6.4.
   VisitForAccumulatorValue(stmt->enumerable());
   __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
   __ j(equal, &exit);
   Register null_value = rdi;
   __ LoadRoot(null_value, Heap::kNullValueRootIndex);
   __ cmpq(rax, null_value);
   __ j(equal, &exit);
 
+  PrepareForBailoutForId(stmt->PrepareId(), TOS_REG);
+
   // Convert the object to a JS object.
   Label convert, done_convert;
   __ JumpIfSmi(rax, &convert);
   __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rcx);
   __ j(above_equal, &done_convert);
   __ bind(&convert);
   __ push(rax);
   __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
   __ bind(&done_convert);
   __ push(rax);
 
   // Check for proxies.
   Label call_runtime;
   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   __ CmpObjectType(rax, LAST_JS_PROXY_TYPE, rcx);
   __ j(below_equal, &call_runtime);
 
   // Check cache validity in generated code. This is a fast case for
   // the JSObject::IsSimpleEnum cache validity checks. If we cannot
   // guarantee cache validity, call the runtime system to check cache
   // validity or get the property names in a fixed array.
-  Label next;
-  Register empty_fixed_array_value = r8;
-  __ LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
-  Register empty_descriptor_array_value = r9;
-  __ LoadRoot(empty_descriptor_array_value,
-              Heap::kEmptyDescriptorArrayRootIndex);
-  __ movq(rcx, rax);
-  __ bind(&next);
-
-  // Check that there are no elements.  Register rcx contains the
-  // current JS object we've reached through the prototype chain.
-  __ cmpq(empty_fixed_array_value,
-          FieldOperand(rcx, JSObject::kElementsOffset));
-  __ j(not_equal, &call_runtime);
-
-  // Check that instance descriptors are not empty so that we can
-  // check for an enum cache.  Leave the map in rbx for the subsequent
-  // prototype load.
-  __ movq(rbx, FieldOperand(rcx, HeapObject::kMapOffset));
-  __ movq(rdx, FieldOperand(rbx, Map::kInstanceDescriptorsOrBitField3Offset));
-  __ JumpIfSmi(rdx, &call_runtime);
-
-  // Check that there is an enum cache in the non-empty instance
-  // descriptors (rdx).  This is the case if the next enumeration
-  // index field does not contain a smi.
-  __ movq(rdx, FieldOperand(rdx, DescriptorArray::kEnumerationIndexOffset));
-  __ JumpIfSmi(rdx, &call_runtime);
-
-  // For all objects but the receiver, check that the cache is empty.
-  Label check_prototype;
-  __ cmpq(rcx, rax);
-  __ j(equal, &check_prototype, Label::kNear);
-  __ movq(rdx, FieldOperand(rdx, DescriptorArray::kEnumCacheBridgeCacheOffset));
-  __ cmpq(rdx, empty_fixed_array_value);
-  __ j(not_equal, &call_runtime);
-
-  // Load the prototype from the map and loop if non-null.
-  __ bind(&check_prototype);
-  __ movq(rcx, FieldOperand(rbx, Map::kPrototypeOffset));
-  __ cmpq(rcx, null_value);
-  __ j(not_equal, &next);
+  __ CheckEnumCache(null_value, &call_runtime);
 
   // The enum cache is valid.  Load the map of the object being
   // iterated over and use the cache for the iteration.
   Label use_cache;
   __ movq(rax, FieldOperand(rax, HeapObject::kMapOffset));
   __ jmp(&use_cache, Label::kNear);
 
   // Get the set of properties to enumerate.
   __ bind(&call_runtime);
   __ push(rax);  // Duplicate the enumerable object on the stack.
@@ skipping 31 matching lines @@
   __ j(above, &non_proxy);
   __ Move(rbx, Smi::FromInt(0));  // Zero indicates proxy
   __ bind(&non_proxy);
   __ push(rbx);  // Smi
   __ push(rax);  // Array
   __ movq(rax, FieldOperand(rax, FixedArray::kLengthOffset));
   __ push(rax);  // Fixed array length (as smi).
   __ Push(Smi::FromInt(0));  // Initial index.
 
   // Generate code for doing the condition check.
+  PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
   __ bind(&loop);
   __ movq(rax, Operand(rsp, 0 * kPointerSize));  // Get the current index.
   __ cmpq(rax, Operand(rsp, 1 * kPointerSize));  // Compare to the array length.
   __ j(above_equal, loop_statement.break_label());
 
   // Get the current entry of the array into register rbx.
   __ movq(rbx, Operand(rsp, 2 * kPointerSize));
   SmiIndex index = masm()->SmiToIndex(rax, rax, kPointerSizeLog2);
   __ movq(rbx, FieldOperand(rbx,
                             index.reg,
@@ skipping 25 matching lines @@
   __ Cmp(rax, Smi::FromInt(0));
   __ j(equal, loop_statement.continue_label());
   __ movq(rbx, rax);
 
   // Update the 'each' property or variable from the possibly filtered
   // entry in register rbx.
   __ bind(&update_each);
   __ movq(result_register(), rbx);
   // Perform the assignment as if via '='.
   { EffectContext context(this);
-    EmitAssignment(stmt->each(), stmt->AssignmentId());
+    EmitAssignment(stmt->each());
   }
 
   // Generate code for the body of the loop.
   Visit(stmt->body());
 
   // Generate code for going to the next element by incrementing the
   // index (smi) stored on top of the stack.
   __ bind(loop_statement.continue_label());
   __ SmiAddConstant(Operand(rsp, 0 * kPointerSize), Smi::FromInt(1));
 
   EmitStackCheck(stmt, &loop);
   __ jmp(&loop);
 
   // Remove the pointers stored on the stack.
   __ bind(loop_statement.break_label());
   __ addq(rsp, Immediate(5 * kPointerSize));
 
   // Exit and decrement the loop depth.
+  PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
   __ bind(&exit);
   decrement_loop_depth();
 }
 
 
 void FullCodeGenerator::EmitNewClosure(Handle<SharedFunctionInfo> info,
                                        bool pretenure) {
   // Use the fast case closure allocation code that allocates in new
   // space for nested functions that don't need literals cloning. If
   // we're running with the --always-opt or the --prepare-always-opt
@@ skipping 702 matching lines @@
                                      OverwriteMode mode) {
   __ pop(rdx);
   BinaryOpStub stub(op, mode);
   JumpPatchSite patch_site(masm_);    // unbound, signals no inlined smi code.
   __ call(stub.GetCode(), RelocInfo::CODE_TARGET, expr->id());
   patch_site.EmitPatchInfo();
   context()->Plug(rax);
 }
 
 
-void FullCodeGenerator::EmitAssignment(Expression* expr, int bailout_ast_id) {
+void FullCodeGenerator::EmitAssignment(Expression* expr) {
   // Invalid left-hand sides are rewritten to have a 'throw
   // ReferenceError' on the left-hand side.
   if (!expr->IsValidLeftHandSide()) {
     VisitForEffect(expr);
     return;
   }
 
   // Left-hand side can only be a property, a global or a (parameter or local)
   // slot.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
@@ skipping 31 matching lines @@
       __ movq(rcx, rax);
       __ pop(rdx);
       __ pop(rax);  // Restore value.
       Handle<Code> ic = is_classic_mode()
           ? isolate()->builtins()->KeyedStoreIC_Initialize()
           : isolate()->builtins()->KeyedStoreIC_Initialize_Strict();
       __ call(ic);
       break;
     }
   }
-  PrepareForBailoutForId(bailout_ast_id, TOS_REG);
   context()->Plug(rax);
 }
 
 
 void FullCodeGenerator::EmitVariableAssignment(Variable* var,
                                                Token::Value op) {
   if (var->IsUnallocated()) {
     // Global var, const, or let.
     __ Move(rcx, var->name());
     __ movq(rdx, GlobalObjectOperand());
@@ skipping 2515 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64