// 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
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_X64_CODEGEN_X64_H_
#define V8_X64_CODEGEN_X64_H_
namespace v8 {
namespace internal {
// Forward declarations
class CompilationInfo;
class DeferredCode;
class RegisterAllocator;
class RegisterFile;
enum InitState { CONST_INIT, NOT_CONST_INIT };
enum TypeofState { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
// -------------------------------------------------------------------------
// Reference support
// A reference is a C++ stack-allocated object that puts a
// reference on the virtual frame. The reference may be consumed
// by GetValue, TakeValue, SetValue, and Codegen::UnloadReference.
// When the lifetime (scope) of a valid reference ends, it must have
// been consumed, and be in state UNLOADED.
class Reference BASE_EMBEDDED {
public:
// The values of the types is important, see size().
enum Type { UNLOADED = -2, ILLEGAL = -1, SLOT = 0, NAMED = 1, KEYED = 2 };
Reference(CodeGenerator* cgen,
Expression* expression,
bool persist_after_get = false);
~Reference();
Expression* expression() const { return expression_; }
Type type() const { return type_; }
void set_type(Type value) {
ASSERT_EQ(ILLEGAL, type_);
type_ = value;
}
void set_unloaded() {
ASSERT_NE(ILLEGAL, type_);
ASSERT_NE(UNLOADED, type_);
type_ = UNLOADED;
}
// The size the reference takes up on the stack.
int size() const {
return (type_ < SLOT) ? 0 : type_;
}
bool is_illegal() const { return type_ == ILLEGAL; }
bool is_slot() const { return type_ == SLOT; }
bool is_property() const { return type_ == NAMED || type_ == KEYED; }
bool is_unloaded() const { return type_ == UNLOADED; }
// Return the name. Only valid for named property references.
Handle<String> GetName();
// Generate code to push the value of the reference on top of the
// expression stack. The reference is expected to be already on top of
// the expression stack, and it is consumed by the call unless the
// reference is for a compound assignment.
// If the reference is not consumed, it is left in place under its value.
void GetValue();
// Like GetValue except that the slot is expected to be written to before
// being read from again. The value of the reference may be invalidated,
// causing subsequent attempts to read it to fail.
void TakeValue();
// Generate code to store the value on top of the expression stack in the
// reference. The reference is expected to be immediately below the value
// on the expression stack. The value is stored in the location specified
// by the reference, and is left on top of the stack, after the reference
// is popped from beneath it (unloaded).
void SetValue(InitState init_state);
private:
CodeGenerator* cgen_;
Expression* expression_;
Type type_;
bool persist_after_get_;
};
// -------------------------------------------------------------------------
// Control destinations.
// A control destination encapsulates a pair of jump targets and a
// flag indicating which one is the preferred fall-through. The
// preferred fall-through must be unbound, the other may be already
// bound (ie, a backward target).
//
// The true and false targets may be jumped to unconditionally or
// control may split conditionally. Unconditional jumping and
// splitting should be emitted in tail position (as the last thing
// when compiling an expression) because they can cause either label
// to be bound or the non-fall through to be jumped to leaving an
// invalid virtual frame.
//
// The labels in the control destination can be extracted and
// manipulated normally without affecting the state of the
// destination.
class ControlDestination BASE_EMBEDDED {
public:
ControlDestination(JumpTarget* true_target,
JumpTarget* false_target,
bool true_is_fall_through)
: true_target_(true_target),
false_target_(false_target),
true_is_fall_through_(true_is_fall_through),
is_used_(false) {
ASSERT(true_is_fall_through ? !true_target->is_bound()
: !false_target->is_bound());
}
// Accessors for the jump targets. Directly jumping or branching to
// or binding the targets will not update the destination's state.
JumpTarget* true_target() const { return true_target_; }
JumpTarget* false_target() const { return false_target_; }
// True if the the destination has been jumped to unconditionally or
// control has been split to both targets. This predicate does not
// test whether the targets have been extracted and manipulated as
// raw jump targets.
bool is_used() const { return is_used_; }
// True if the destination is used and the true target (respectively
// false target) was the fall through. If the target is backward,
// "fall through" included jumping unconditionally to it.
bool true_was_fall_through() const {
return is_used_ && true_is_fall_through_;
}
bool false_was_fall_through() const {
return is_used_ && !true_is_fall_through_;
}
// Emit a branch to one of the true or false targets, and bind the
// other target. Because this binds the fall-through target, it
// should be emitted in tail position (as the last thing when
// compiling an expression).
void Split(Condition cc) {
ASSERT(!is_used_);
if (true_is_fall_through_) {
false_target_->Branch(NegateCondition(cc));
true_target_->Bind();
} else {
true_target_->Branch(cc);
false_target_->Bind();
}
is_used_ = true;
}
// Emit an unconditional jump in tail position, to the true target
// (if the argument is true) or the false target. The "jump" will
// actually bind the jump target if it is forward, jump to it if it
// is backward.
void Goto(bool where) {
ASSERT(!is_used_);
JumpTarget* target = where ? true_target_ : false_target_;
if (target->is_bound()) {
target->Jump();
} else {
target->Bind();
}
is_used_ = true;
true_is_fall_through_ = where;
}
// Mark this jump target as used as if Goto had been called, but
// without generating a jump or binding a label (the control effect
// should have already happened). This is used when the left
// subexpression of the short-circuit boolean operators are
// compiled.
void Use(bool where) {
ASSERT(!is_used_);
ASSERT((where ? true_target_ : false_target_)->is_bound());
is_used_ = true;
true_is_fall_through_ = where;
}
// Swap the true and false targets but keep the same actual label as
// the fall through. This is used when compiling negated
// expressions, where we want to swap the targets but preserve the
// state.
void Invert() {
JumpTarget* temp_target = true_target_;
true_target_ = false_target_;
false_target_ = temp_target;
true_is_fall_through_ = !true_is_fall_through_;
}
private:
// True and false jump targets.
JumpTarget* true_target_;
JumpTarget* false_target_;
// Before using the destination: true if the true target is the
// preferred fall through, false if the false target is. After
// using the destination: true if the true target was actually used
// as the fall through, false if the false target was.
bool true_is_fall_through_;
// True if the Split or Goto functions have been called.
bool is_used_;
};
// -------------------------------------------------------------------------
// Code generation state
// The state is passed down the AST by the code generator (and back up, in
// the form of the state of the jump target pair). It is threaded through
// the call stack. Constructing a state implicitly pushes it on the owning
// code generator's stack of states, and destroying one implicitly pops it.
//
// The code generator state is only used for expressions, so statements have
// the initial state.
class CodeGenState BASE_EMBEDDED {
public:
// Create an initial code generator state. Destroying the initial state
// leaves the code generator with a NULL state.
explicit CodeGenState(CodeGenerator* owner);
// Create a code generator state based on a code generator's current
// state. The new state has its own control destination.
CodeGenState(CodeGenerator* owner, ControlDestination* destination);
// Destroy a code generator state and restore the owning code generator's
// previous state.
~CodeGenState();
// Accessors for the state.
ControlDestination* destination() const { return destination_; }
private:
// The owning code generator.
CodeGenerator* owner_;
// A control destination in case the expression has a control-flow
// effect.
ControlDestination* destination_;
// The previous state of the owning code generator, restored when
// this state is destroyed.
CodeGenState* previous_;
};
// -------------------------------------------------------------------------
// Arguments allocation mode
enum ArgumentsAllocationMode {
NO_ARGUMENTS_ALLOCATION,
EAGER_ARGUMENTS_ALLOCATION,
LAZY_ARGUMENTS_ALLOCATION
};
// -------------------------------------------------------------------------
// CodeGenerator
class CodeGenerator: public AstVisitor {
public:
// Takes a function literal, generates code for it. This function should only
// be called by compiler.cc.
static Handle<Code> MakeCode(CompilationInfo* info);
// Printing of AST, etc. as requested by flags.
static void MakeCodePrologue(CompilationInfo* info);
// Allocate and install the code.
static Handle<Code> MakeCodeEpilogue(MacroAssembler* masm,
Code::Flags flags,
CompilationInfo* info);
#ifdef ENABLE_LOGGING_AND_PROFILING
static bool ShouldGenerateLog(Expression* type);
#endif
static void RecordPositions(MacroAssembler* masm, int pos);
// Accessors
MacroAssembler* masm() { return masm_; }
VirtualFrame* frame() const { return frame_; }
inline Handle<Script> script();
bool has_valid_frame() const { return frame_ != NULL; }
// Set the virtual frame to be new_frame, with non-frame register
// reference counts given by non_frame_registers. The non-frame
// register reference counts of the old frame are returned in
// non_frame_registers.
void SetFrame(VirtualFrame* new_frame, RegisterFile* non_frame_registers);
void DeleteFrame();
RegisterAllocator* allocator() const { return allocator_; }
CodeGenState* state() { return state_; }
void set_state(CodeGenState* state) { state_ = state; }
void AddDeferred(DeferredCode* code) { deferred_.Add(code); }
bool in_spilled_code() const { return in_spilled_code_; }
void set_in_spilled_code(bool flag) { in_spilled_code_ = flag; }
private:
// Construction/Destruction
explicit CodeGenerator(MacroAssembler* masm);
// Accessors
inline bool is_eval();
Scope* scope();
// Generating deferred code.
void ProcessDeferred();
// State
ControlDestination* destination() const { return state_->destination(); }
// Track loop nesting level.
int loop_nesting() const { return loop_nesting_; }
void IncrementLoopNesting() { loop_nesting_++; }
void DecrementLoopNesting() { loop_nesting_--; }
// Node visitors.
void VisitStatements(ZoneList<Statement*>* statements);
#define DEF_VISIT(type) \
void Visit##type(type* node);
AST_NODE_LIST(DEF_VISIT)
#undef DEF_VISIT
// Visit a statement and then spill the virtual frame if control flow can
// reach the end of the statement (ie, it does not exit via break,
// continue, return, or throw). This function is used temporarily while
// the code generator is being transformed.
void VisitAndSpill(Statement* statement);
// Visit a list of statements and then spill the virtual frame if control
// flow can reach the end of the list.
void VisitStatementsAndSpill(ZoneList<Statement*>* statements);
// Main code generation function
void Generate(CompilationInfo* info);
// Generate the return sequence code. Should be called no more than
// once per compiled function, immediately after binding the return
// target (which can not be done more than once).
void GenerateReturnSequence(Result* return_value);
// Returns the arguments allocation mode.
ArgumentsAllocationMode ArgumentsMode();
// Store the arguments object and allocate it if necessary.
Result StoreArgumentsObject(bool initial);
// The following are used by class Reference.
void LoadReference(Reference* ref);
void UnloadReference(Reference* ref);
static Operand ContextOperand(Register context, int index) {
return Operand(context, Context::SlotOffset(index));
}
Operand SlotOperand(Slot* slot, Register tmp);
Operand ContextSlotOperandCheckExtensions(Slot* slot,
Result tmp,
JumpTarget* slow);
// Expressions
static Operand GlobalObject() {
return ContextOperand(rsi, Context::GLOBAL_INDEX);
}
void LoadCondition(Expression* x,
ControlDestination* destination,
bool force_control);
void Load(Expression* expr);
void LoadGlobal();
void LoadGlobalReceiver();
// Generate code to push the value of an expression on top of the frame
// and then spill the frame fully to memory. This function is used
// temporarily while the code generator is being transformed.
void LoadAndSpill(Expression* expression);
// Read a value from a slot and leave it on top of the expression stack.
void LoadFromSlot(Slot* slot, TypeofState typeof_state);
void LoadFromSlotCheckForArguments(Slot* slot, TypeofState state);
Result LoadFromGlobalSlotCheckExtensions(Slot* slot,
TypeofState typeof_state,
JumpTarget* slow);
// Store the value on top of the expression stack into a slot, leaving the
// value in place.
void StoreToSlot(Slot* slot, InitState init_state);
// Load a property of an object, returning it in a Result.
// The object and the property name are passed on the stack, and
// not changed.
Result EmitKeyedLoad(bool is_global);
// Special code for typeof expressions: Unfortunately, we must
// be careful when loading the expression in 'typeof'
// expressions. We are not allowed to throw reference errors for
// non-existing properties of the global object, so we must make it
// look like an explicit property access, instead of an access
// through the context chain.
void LoadTypeofExpression(Expression* x);
// Translate the value on top of the frame into control flow to the
// control destination.
void ToBoolean(ControlDestination* destination);
void GenericBinaryOperation(
Token::Value op,
StaticType* type,
OverwriteMode overwrite_mode);
// If possible, combine two constant smi values using op to produce
// a smi result, and push it on the virtual frame, all at compile time.
// Returns true if it succeeds. Otherwise it has no effect.
bool FoldConstantSmis(Token::Value op, int left, int right);
// Emit code to perform a binary operation on a constant
// smi and a likely smi. Consumes the Result *operand.
Result ConstantSmiBinaryOperation(Token::Value op,
Result* operand,
Handle<Object> constant_operand,
StaticType* type,
bool reversed,
OverwriteMode overwrite_mode);
// Emit code to perform a binary operation on two likely smis.
// The code to handle smi arguments is produced inline.
// Consumes the Results *left and *right.
Result LikelySmiBinaryOperation(Token::Value op,
Result* left,
Result* right,
OverwriteMode overwrite_mode);
void Comparison(AstNode* node,
Condition cc,
bool strict,
ControlDestination* destination);
// To prevent long attacker-controlled byte sequences, integer constants
// from the JavaScript source are loaded in two parts if they are larger
// than 16 bits.
static const int kMaxSmiInlinedBits = 16;
bool IsUnsafeSmi(Handle<Object> value);
// Load an integer constant x into a register target using
// at most 16 bits of user-controlled data per assembly operation.
void LoadUnsafeSmi(Register target, Handle<Object> value);
void CallWithArguments(ZoneList<Expression*>* arguments,
CallFunctionFlags flags,
int position);
// An optimized implementation of expressions of the form
// x.apply(y, arguments). We call x the applicand and y the receiver.
// The optimization avoids allocating an arguments object if possible.
void CallApplyLazy(Expression* applicand,
Expression* receiver,
VariableProxy* arguments,
int position);
void CheckStack();
struct InlineRuntimeLUT {
void (CodeGenerator::*method)(ZoneList<Expression*>*);
const char* name;
};
static InlineRuntimeLUT* FindInlineRuntimeLUT(Handle<String> name);
bool CheckForInlineRuntimeCall(CallRuntime* node);
static bool PatchInlineRuntimeEntry(Handle<String> name,
const InlineRuntimeLUT& new_entry,
InlineRuntimeLUT* old_entry);
void ProcessDeclarations(ZoneList<Declaration*>* declarations);
static Handle<Code> ComputeCallInitialize(int argc, InLoopFlag in_loop);
// Declare global variables and functions in the given array of
// name/value pairs.
void DeclareGlobals(Handle<FixedArray> pairs);
// Instantiate the function boilerplate.
void InstantiateBoilerplate(Handle<JSFunction> boilerplate);
// Support for type checks.
void GenerateIsSmi(ZoneList<Expression*>* args);
void GenerateIsNonNegativeSmi(ZoneList<Expression*>* args);
void GenerateIsArray(ZoneList<Expression*>* args);
void GenerateIsRegExp(ZoneList<Expression*>* args);
void GenerateIsObject(ZoneList<Expression*>* args);
void GenerateIsFunction(ZoneList<Expression*>* args);
void GenerateIsUndetectableObject(ZoneList<Expression*>* args);
// Support for construct call checks.
void GenerateIsConstructCall(ZoneList<Expression*>* args);
// Support for arguments.length and arguments[?].
void GenerateArgumentsLength(ZoneList<Expression*>* args);
void GenerateArgumentsAccess(ZoneList<Expression*>* args);
// Support for accessing the class and value fields of an object.
void GenerateClassOf(ZoneList<Expression*>* args);
void GenerateValueOf(ZoneList<Expression*>* args);
void GenerateSetValueOf(ZoneList<Expression*>* args);
// Fast support for charCodeAt(n).
void GenerateFastCharCodeAt(ZoneList<Expression*>* args);
// Fast support for object equality testing.
void GenerateObjectEquals(ZoneList<Expression*>* args);
void GenerateLog(ZoneList<Expression*>* args);
void GenerateGetFramePointer(ZoneList<Expression*>* args);
// Fast support for Math.random().
void GenerateRandomPositiveSmi(ZoneList<Expression*>* args);
// Fast support for StringAdd.
void GenerateStringAdd(ZoneList<Expression*>* args);
// Fast support for SubString.
void GenerateSubString(ZoneList<Expression*>* args);
// Fast support for StringCompare.
void GenerateStringCompare(ZoneList<Expression*>* args);
// Support for direct calls from JavaScript to native RegExp code.
void GenerateRegExpExec(ZoneList<Expression*>* args);
// Fast support for number to string.
void GenerateNumberToString(ZoneList<Expression*>* args);
// Fast call to math functions.
void GenerateMathSin(ZoneList<Expression*>* args);
void GenerateMathCos(ZoneList<Expression*>* args);
// Simple condition analysis.
enum ConditionAnalysis {
ALWAYS_TRUE,
ALWAYS_FALSE,
DONT_KNOW
};
ConditionAnalysis AnalyzeCondition(Expression* cond);
// Methods used to indicate which source code is generated for. Source
// positions are collected by the assembler and emitted with the relocation
// information.
void CodeForFunctionPosition(FunctionLiteral* fun);
void CodeForReturnPosition(FunctionLiteral* fun);
void CodeForStatementPosition(Statement* node);
void CodeForDoWhileConditionPosition(DoWhileStatement* stmt);
void CodeForSourcePosition(int pos);
#ifdef DEBUG
// True if the registers are valid for entry to a block. There should
// be no frame-external references to (non-reserved) registers.
bool HasValidEntryRegisters();
#endif
ZoneList<DeferredCode*> deferred_;
// Assembler
MacroAssembler* masm_; // to generate code
CompilationInfo* info_;
// Code generation state
VirtualFrame* frame_;
RegisterAllocator* allocator_;
CodeGenState* state_;
int loop_nesting_;
// Jump targets.
// The target of the return from the function.
BreakTarget function_return_;
// True if the function return is shadowed (ie, jumping to the target
// function_return_ does not jump to the true function return, but rather
// to some unlinking code).
bool function_return_is_shadowed_;
// True when we are in code that expects the virtual frame to be fully
// spilled. Some virtual frame function are disabled in DEBUG builds when
// called from spilled code, because they do not leave the virtual frame
// in a spilled state.
bool in_spilled_code_;
static InlineRuntimeLUT kInlineRuntimeLUT[];
friend class VirtualFrame;
friend class JumpTarget;
friend class Reference;
friend class Result;
friend class FastCodeGenerator;
friend class FullCodeGenerator;
friend class FullCodeGenSyntaxChecker;
friend class CodeGeneratorPatcher; // Used in test-log-stack-tracer.cc
DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
};
// Flag that indicates how to generate code for the stub GenericBinaryOpStub.
enum GenericBinaryFlags {
NO_GENERIC_BINARY_FLAGS = 0,
NO_SMI_CODE_IN_STUB = 1 << 0 // Omit smi code in stub.
};
class GenericBinaryOpStub: public CodeStub {
public:
GenericBinaryOpStub(Token::Value op,
OverwriteMode mode,
GenericBinaryFlags flags,
NumberInfo::Type operands_type = NumberInfo::kUnknown)
: op_(op),
mode_(mode),
flags_(flags),
args_in_registers_(false),
args_reversed_(false),
name_(NULL),
operands_type_(operands_type) {
use_sse3_ = CpuFeatures::IsSupported(SSE3);
ASSERT(OpBits::is_valid(Token::NUM_TOKENS));
}
// Generate code to call the stub with the supplied arguments. This will add
// code at the call site to prepare arguments either in registers or on the
// stack together with the actual call.
void GenerateCall(MacroAssembler* masm, Register left, Register right);
void GenerateCall(MacroAssembler* masm, Register left, Smi* right);
void GenerateCall(MacroAssembler* masm, Smi* left, Register right);
Result GenerateCall(MacroAssembler* masm,
VirtualFrame* frame,
Result* left,
Result* right);
private:
Token::Value op_;
OverwriteMode mode_;
GenericBinaryFlags flags_;
bool args_in_registers_; // Arguments passed in registers not on the stack.
bool args_reversed_; // Left and right argument are swapped.
bool use_sse3_;
char* name_;
NumberInfo::Type operands_type_;
const char* GetName();
#ifdef DEBUG
void Print() {
PrintF("GenericBinaryOpStub %d (op %s), "
"(mode %d, flags %d, registers %d, reversed %d, only_numbers %s)\n",
MinorKey(),
Token::String(op_),
static_cast<int>(mode_),
static_cast<int>(flags_),
static_cast<int>(args_in_registers_),
static_cast<int>(args_reversed_),
NumberInfo::ToString(operands_type_));
}
#endif
// Minor key encoding in 16 bits NNNFRASOOOOOOOMM.
class ModeBits: public BitField<OverwriteMode, 0, 2> {};
class OpBits: public BitField<Token::Value, 2, 7> {};
class SSE3Bits: public BitField<bool, 9, 1> {};
class ArgsInRegistersBits: public BitField<bool, 10, 1> {};
class ArgsReversedBits: public BitField<bool, 11, 1> {};
class FlagBits: public BitField<GenericBinaryFlags, 12, 1> {};
class NumberInfoBits: public BitField<NumberInfo::Type, 13, 3> {};
Major MajorKey() { return GenericBinaryOp; }
int MinorKey() {
// Encode the parameters in a unique 16 bit value.
return OpBits::encode(op_)
| ModeBits::encode(mode_)
| FlagBits::encode(flags_)
| SSE3Bits::encode(use_sse3_)
| ArgsInRegistersBits::encode(args_in_registers_)
| ArgsReversedBits::encode(args_reversed_)
| NumberInfoBits::encode(operands_type_);
}
void Generate(MacroAssembler* masm);
void GenerateSmiCode(MacroAssembler* masm, Label* slow);
void GenerateLoadArguments(MacroAssembler* masm);
void GenerateReturn(MacroAssembler* masm);
bool ArgsInRegistersSupported() {
return (op_ == Token::ADD) || (op_ == Token::SUB)
|| (op_ == Token::MUL) || (op_ == Token::DIV);
}
bool IsOperationCommutative() {
return (op_ == Token::ADD) || (op_ == Token::MUL);
}
void SetArgsInRegisters() { args_in_registers_ = true; }
void SetArgsReversed() { args_reversed_ = true; }
bool HasSmiCodeInStub() { return (flags_ & NO_SMI_CODE_IN_STUB) == 0; }
bool HasArgsInRegisters() { return args_in_registers_; }
bool HasArgsReversed() { return args_reversed_; }
};
class StringStubBase: public CodeStub {
public:
// Generate code for copying characters using a simple loop. This should only
// be used in places where the number of characters is small and the
// additional setup and checking in GenerateCopyCharactersREP adds too much
// overhead. Copying of overlapping regions is not supported.
void GenerateCopyCharacters(MacroAssembler* masm,
Register dest,
Register src,
Register count,
bool ascii);
// Generate code for copying characters using the rep movs instruction.
// Copies rcx characters from rsi to rdi. Copying of overlapping regions is
// not supported.
void GenerateCopyCharactersREP(MacroAssembler* masm,
Register dest, // Must be rdi.
Register src, // Must be rsi.
Register count, // Must be rcx.
bool ascii);
};
// Flag that indicates how to generate code for the stub StringAddStub.
enum StringAddFlags {
NO_STRING_ADD_FLAGS = 0,
NO_STRING_CHECK_IN_STUB = 1 << 0 // Omit string check in stub.
};
class StringAddStub: public StringStubBase {
public:
explicit StringAddStub(StringAddFlags flags) {
string_check_ = ((flags & NO_STRING_CHECK_IN_STUB) == 0);
}
private:
Major MajorKey() { return StringAdd; }
int MinorKey() { return string_check_ ? 0 : 1; }
void Generate(MacroAssembler* masm);
// Should the stub check whether arguments are strings?
bool string_check_;
};
class SubStringStub: public StringStubBase {
public:
SubStringStub() {}
private:
Major MajorKey() { return SubString; }
int MinorKey() { return 0; }
void Generate(MacroAssembler* masm);
};
class StringCompareStub: public CodeStub {
public:
explicit StringCompareStub() {}
// Compare two flat ascii strings and returns result in rax after popping two
// arguments from the stack.
static void GenerateCompareFlatAsciiStrings(MacroAssembler* masm,
Register left,
Register right,
Register scratch1,
Register scratch2,
Register scratch3,
Register scratch4);
private:
Major MajorKey() { return StringCompare; }
int MinorKey() { return 0; }
void Generate(MacroAssembler* masm);
};
} } // namespace v8::internal
#endif // V8_X64_CODEGEN_X64_H_