Operand::Operand(Register rm, ShiftOp shift_op, int shift_imm) {
ASSERT(is_uint5(shift_imm));
- ASSERT(shift_op != NO_SHIFT);
rm_ = rm;
rs_ = no_reg;
Operand::Operand(Register rm, ShiftOp shift_op, Register rs) {
- ASSERT((shift_op != RRX) && (shift_op != NO_SHIFT));
+ ASSERT(shift_op != RRX);
rm_ = rm;
rs_ = no_reg;
shift_op_ = shift_op;
// If this returns true then you have to use the rotate_imm and immed_8
// that it returns, because it may have already changed the instruction
// to match them!
-bool fits_shifter(uint32_t imm32,
- uint32_t* rotate_imm,
- uint32_t* immed_8,
- Instr* instr) {
+static bool fits_shifter(uint32_t imm32,
+ uint32_t* rotate_imm,
+ uint32_t* immed_8,
+ Instr* instr) {
// imm32 must be unsigned.
for (int rot = 0; rot < 16; rot++) {
uint32_t imm8 = (imm32 << 2*rot) | (imm32 >> (32 - 2*rot));
if ((imm8 <= 0xff)) {
- if (rotate_imm != NULL) *rotate_imm = rot;
- if (immed_8 != NULL) *immed_8 = imm8;
+ *rotate_imm = rot;
+ *immed_8 = imm8;
return true;
}
}
if (imm32 < 0x10000) {
*instr ^= kMovwLeaveCCFlip;
*instr |= EncodeMovwImmediate(imm32);
- if (rotate_imm != NULL) *rotate_imm = 0; // Not used for movw.
- if (immed_8 != NULL) *immed_8 = 0; // Not used for movw.
+ *rotate_imm = *immed_8 = 0; // Not used for movw.
return true;
}
}
};
-bool fits_shifter(uint32_t imm32, uint32_t* rotate_imm,
- uint32_t* immed_8, Instr* instr);
-
-
class EnsureSpace BASE_EMBEDDED {
public:
explicit EnsureSpace(Assembler* assembler) {
// as an argument, and will never actually be encoded. The Assembler will
// detect it and emit the correct ROR shift operand with shift_imm == 0.
RRX = -1,
- NO_SHIFT = -2,
kNumberOfShifts = 4
};
}
-HBitwiseBinaryOperation* LChunkBuilder::CanTransformToShiftedOp(HValue* val,
- HValue** left) {
- if (!val->representation().IsInteger32()) return NULL;
- if (!(val->IsBitwise() || val->IsAdd() || val->IsSub())) return NULL;
-
- HBinaryOperation* hinstr = HBinaryOperation::cast(val);
- HValue* hleft = hinstr->left();
- HValue* hright = hinstr->right();
- ASSERT(hleft->representation().Equals(hinstr->representation()));
- ASSERT(hright->representation().Equals(hinstr->representation()));
-
- if ((hright->IsConstant() &&
- LikelyFitsImmField(hinstr, HConstant::cast(hright)->Integer32Value())) ||
- (hinstr->IsCommutative() && hleft->IsConstant() &&
- LikelyFitsImmField(hinstr, HConstant::cast(hleft)->Integer32Value()))) {
- // The constant operand will likely fit in the immediate field. We are
- // better off with
- // mov r1, r2 LSL #imm
- // add r0, r1, #imm2
- // than with
- // mov r5, #imm2
- // add r0, r5, r2 LSL #imm
- return NULL;
- }
-
- HBitwiseBinaryOperation* shift = NULL;
- // TODO(aleram): We will miss situations where a shift operation is used by
- // different instructions both as a left and right operands.
- if (hright->IsBitwiseBinaryShift() &&
- HBitwiseBinaryOperation::cast(hright)->right()->IsConstant()) {
- shift = HBitwiseBinaryOperation::cast(hright);
- if (left != NULL) {
- *left = hleft;
- }
- } else if (hinstr->IsCommutative() &&
- hleft->IsBitwiseBinaryShift() &&
- HBitwiseBinaryOperation::cast(hleft)->right()->IsConstant()) {
- shift = HBitwiseBinaryOperation::cast(hleft);
- if (left != NULL) {
- *left = hright;
- }
- } else {
- return NULL;
- }
-
- if ((JSShiftAmountFromHConstant(shift->right()) == 0) && shift->IsShr()) {
- // Logical shifts right by zero can deoptimize.
- return NULL;
- }
-
- return shift;
-}
-
-
-bool LChunkBuilder::ShiftCanBeOptimizedAway(HBitwiseBinaryOperation* shift) {
- if (!shift->representation().IsInteger32()) {
- return false;
- }
- for (HUseIterator it(shift->uses()); !it.Done(); it.Advance()) {
- if (shift != CanTransformToShiftedOp(it.value())) {
- return false;
- }
- }
- return true;
-}
-
-
-LInstruction* LChunkBuilder::TryDoOpWithShiftedRightOperand(
- HBinaryOperation* instr) {
- HValue* left;
- HBitwiseBinaryOperation* shift = CanTransformToShiftedOp(instr, &left);
-
- if ((shift != NULL) && ShiftCanBeOptimizedAway(shift)) {
- return DoShiftedBinaryOp(instr, left, shift);
- }
- return NULL;
-}
-
-
-LInstruction* LChunkBuilder::DoShiftedBinaryOp(
- HBinaryOperation* hinstr, HValue* hleft, HBitwiseBinaryOperation* hshift) {
- ASSERT(hshift->IsBitwiseBinaryShift());
- ASSERT(!hshift->IsShr() || (JSShiftAmountFromHConstant(hshift->right()) > 0));
-
- LTemplateResultInstruction<1>* res;
- LOperand* left = UseRegisterAtStart(hleft);
- LOperand* right = UseRegisterAtStart(hshift->left());
- LOperand* shift_amount = UseConstant(hshift->right());
- ShiftOp shift_op;
- switch (hshift->opcode()) {
- case HValue::kShl: shift_op = LSL; break;
- case HValue::kShr: shift_op = LSR; break;
- case HValue::kSar: shift_op = ASR; break;
- default: UNREACHABLE(); shift_op = NO_SHIFT;
- }
-
- if (hinstr->IsBitwise()) {
- res = new(zone()) LBitI(left, right, shift_op, shift_amount);
- } else if (hinstr->IsAdd()) {
- res = new(zone()) LAddI(left, right, shift_op, shift_amount);
- } else {
- ASSERT(hinstr->IsSub());
- res = new(zone()) LSubI(left, right, shift_op, shift_amount);
- }
- if (hinstr->CheckFlag(HValue::kCanOverflow)) {
- AssignEnvironment(res);
- }
- return DefineAsRegister(res);
-}
-
-
LInstruction* LChunkBuilder::DoShift(Token::Value op,
HBitwiseBinaryOperation* instr) {
if (instr->representation().IsSmiOrInteger32()) {
ASSERT(instr->left()->representation().Equals(instr->representation()));
ASSERT(instr->right()->representation().Equals(instr->representation()));
-
- if (ShiftCanBeOptimizedAway(instr)) {
- return NULL;
- }
-
LOperand* left = UseRegisterAtStart(instr->left());
HValue* right_value = instr->right();
if (right_value->IsConstant()) {
HConstant* constant = HConstant::cast(right_value);
right = chunk_->DefineConstantOperand(constant);
- constant_value = JSShiftAmountFromHConstant(constant);
+ constant_value = constant->Integer32Value() & 0x1f;
// Left shifts can deoptimize if we shift by > 0 and the result cannot be
// truncated to smi.
if (instr->representation().IsSmi() && constant_value > 0) {
ASSERT(instr->right()->representation().Equals(instr->representation()));
ASSERT(instr->CheckFlag(HValue::kTruncatingToInt32));
- LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
- if (shifted_operation != NULL) {
- return shifted_operation;
- }
-
LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand());
LOperand* right = UseOrConstantAtStart(instr->BetterRightOperand());
return DefineAsRegister(new(zone()) LBitI(left, right));
ASSERT(instr->left()->representation().Equals(instr->representation()));
ASSERT(instr->right()->representation().Equals(instr->representation()));
- LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
- if (shifted_operation != NULL) {
- return shifted_operation;
- }
-
if (instr->left()->IsConstant()) {
// If lhs is constant, do reverse subtraction instead.
return DoRSub(instr);
if (instr->representation().IsSmiOrInteger32()) {
ASSERT(instr->left()->representation().Equals(instr->representation()));
ASSERT(instr->right()->representation().Equals(instr->representation()));
-
- LInstruction* shifted_operation = TryDoOpWithShiftedRightOperand(instr);
- if (shifted_operation != NULL) {
- return shifted_operation;
- }
-
LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand());
LOperand* right = UseOrConstantAtStart(instr->BetterRightOperand());
LAddI* add = new(zone()) LAddI(left, right);
class LBitI V8_FINAL : public LTemplateInstruction<1, 2, 0> {
public:
- LBitI(LOperand* left, LOperand* right)
- : shift_(NO_SHIFT), shift_amount_(0) {
- inputs_[0] = left;
- inputs_[1] = right;
- }
-
- LBitI(LOperand* left, LOperand* right, ShiftOp shift, LOperand* shift_amount)
- : shift_(shift), shift_amount_(shift_amount) {
+ LBitI(LOperand* left, LOperand* right) {
inputs_[0] = left;
inputs_[1] = right;
}
LOperand* left() { return inputs_[0]; }
LOperand* right() { return inputs_[1]; }
- ShiftOp shift() const { return shift_; }
- LOperand* shift_amount() const { return shift_amount_; }
-
Token::Value op() const { return hydrogen()->op(); }
DECLARE_CONCRETE_INSTRUCTION(BitI, "bit-i")
DECLARE_HYDROGEN_ACCESSOR(Bitwise)
-
- protected:
- ShiftOp shift_;
- LOperand* shift_amount_;
};
class LSubI V8_FINAL : public LTemplateInstruction<1, 2, 0> {
public:
- LSubI(LOperand* left, LOperand* right)
- : shift_(NO_SHIFT), shift_amount_(0) {
- inputs_[0] = left;
- inputs_[1] = right;
- }
-
- LSubI(LOperand* left, LOperand* right, ShiftOp shift, LOperand* shift_amount)
- : shift_(shift), shift_amount_(shift_amount) {
+ LSubI(LOperand* left, LOperand* right) {
inputs_[0] = left;
inputs_[1] = right;
}
- ShiftOp shift() const { return shift_; }
- LOperand* shift_amount() const { return shift_amount_; }
-
LOperand* left() { return inputs_[0]; }
LOperand* right() { return inputs_[1]; }
DECLARE_CONCRETE_INSTRUCTION(SubI, "sub-i")
DECLARE_HYDROGEN_ACCESSOR(Sub)
-
- protected:
- ShiftOp shift_;
- LOperand* shift_amount_;
};
class LAddI V8_FINAL : public LTemplateInstruction<1, 2, 0> {
public:
- LAddI(LOperand* left, LOperand* right)
- : shift_(NO_SHIFT), shift_amount_(0) {
- inputs_[0] = left;
- inputs_[1] = right;
- }
-
- LAddI(LOperand* left, LOperand* right, ShiftOp shift, LOperand* shift_amount)
- : shift_(shift), shift_amount_(shift_amount) {
+ LAddI(LOperand* left, LOperand* right) {
inputs_[0] = left;
inputs_[1] = right;
}
LOperand* left() { return inputs_[0]; }
LOperand* right() { return inputs_[1]; }
- ShiftOp shift() const { return shift_; }
- LOperand* shift_amount() const { return shift_amount_; }
-
DECLARE_CONCRETE_INSTRUCTION(AddI, "add-i")
DECLARE_HYDROGEN_ACCESSOR(Add)
-
- protected:
- ShiftOp shift_;
- LOperand* shift_amount_;
};
void AddInstruction(LInstruction* instr, HInstruction* current);
void DoBasicBlock(HBasicBlock* block, HBasicBlock* next_block);
-
- int JSShiftAmountFromHConstant(HValue* constant) {
- return HConstant::cast(constant)->Integer32Value() & 0x1f;
- }
- bool LikelyFitsImmField(HInstruction* instr, int imm) {
- Instr instr_bits;
- // All arithmetic and logical operations accept the same range of
- // immediates. In some cases though, the operation itself can be changed to
- // get a wider effective range of immediates.
- if (instr->IsAdd() || instr->IsSub()) {
- // ADD and SUB can be exchanged with a negate immediate.
- instr_bits = ADD;
- } else if (HBitwise::cast(instr)->op() == Token::BIT_AND) {
- ASSERT(instr->IsBitwise());
- // AND and BIC can be exchanged with an inverted immediate.
- instr_bits = AND;
- } else {
- ASSERT(instr->IsBitwise());
- // Use ORR for all other operations, since fits_shifter() can't adapt ORR.
- instr_bits = ORR;
- }
- return fits_shifter(imm, NULL, NULL, &instr_bits);
- }
-
- // Indicates if a sequence of the form
- // mov r1, r2 LSL #imm
- // add r0, r5, r1
- // can be replaced with:
- // add r0, r5, r2 LSL #imm
- // If this is not possible, the function returns NULL. Otherwise it returns a
- // pointer to the shift instruction that would be optimized away.
- HBitwiseBinaryOperation* CanTransformToShiftedOp(HValue* val,
- HValue** left = NULL);
- // Checks if all uses of the shift operation can optimize it away.
- bool ShiftCanBeOptimizedAway(HBitwiseBinaryOperation* shift);
- // Attempts to merge the binary operation and a previous shift operation into
- // a single operation. Returns the merged instruction on success, and NULL
- // otherwise.
- LInstruction* TryDoOpWithShiftedRightOperand(HBinaryOperation* op);
- LInstruction* DoShiftedBinaryOp(HBinaryOperation* instr,
- HValue* left,
- HBitwiseBinaryOperation* shift);
-
LInstruction* DoShift(Token::Value op, HBitwiseBinaryOperation* instr);
LInstruction* DoArithmeticD(Token::Value op,
HArithmeticBinaryOperation* instr);
}
-template<class LI>
-Operand LCodeGen::ToShiftedRightOperand(LOperand* right, LI* shift_info) {
- if (shift_info->shift() == NO_SHIFT) {
- return ToOperand(right);
- } else {
- return Operand(
- ToRegister(right),
- shift_info->shift(),
- JSShiftAmountFromLConstant(shift_info->shift_amount()));
- }
-}
-
-
bool LCodeGen::IsSmi(LConstantOperand* op) const {
return chunk_->LookupLiteralRepresentation(op).IsSmi();
}
Register result = ToRegister(instr->result());
Operand right(no_reg);
- ASSERT(right_op->IsRegister() || (instr->shift() == NO_SHIFT));
-
if (right_op->IsStackSlot()) {
right = Operand(EmitLoadRegister(right_op, ip));
} else {
ASSERT(right_op->IsRegister() || right_op->IsConstantOperand());
- right = ToShiftedRightOperand(right_op, instr);
+ right = ToOperand(right_op);
}
switch (instr->op()) {
break;
}
} else {
- int shift_count = JSShiftAmountFromLConstant(right_op);
+ // Mask the right_op operand.
+ int value = ToInteger32(LConstantOperand::cast(right_op));
+ uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
switch (instr->op()) {
case Token::ROR:
if (shift_count != 0) {
bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
SBit set_cond = can_overflow ? SetCC : LeaveCC;
- ASSERT(right->IsRegister() || (instr->shift() == NO_SHIFT));
-
if (right->IsStackSlot()) {
Register right_reg = EmitLoadRegister(right, ip);
__ sub(ToRegister(result), ToRegister(left), Operand(right_reg), set_cond);
} else {
ASSERT(right->IsRegister() || right->IsConstantOperand());
- __ sub(ToRegister(result), ToRegister(left),
- ToShiftedRightOperand(right, instr), set_cond);
+ __ sub(ToRegister(result), ToRegister(left), ToOperand(right), set_cond);
}
if (can_overflow) {
bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
SBit set_cond = can_overflow ? SetCC : LeaveCC;
- ASSERT(right->IsRegister() || (instr->shift() == NO_SHIFT));
-
if (right->IsStackSlot()) {
Register right_reg = EmitLoadRegister(right, ip);
__ add(ToRegister(result), ToRegister(left), Operand(right_reg), set_cond);
} else {
ASSERT(right->IsRegister() || right->IsConstantOperand());
- __ add(ToRegister(result), ToRegister(left),
- ToShiftedRightOperand(right, instr), set_cond);
+ __ add(ToRegister(result), ToRegister(left), ToOperand(right), set_cond);
}
if (can_overflow) {
// Returns a MemOperand pointing to the high word of a DoubleStackSlot.
MemOperand ToHighMemOperand(LOperand* op) const;
- template<class LI>
- Operand ToShiftedRightOperand(LOperand* right, LI* shift_info);
-
- int JSShiftAmountFromLConstant(LOperand* constant) {
- return ToInteger32(LConstantOperand::cast(constant)) & 0x1f;
- }
-
bool IsInteger32(LConstantOperand* op) const;
bool IsSmi(LConstantOperand* op) const;
Handle<Object> ToHandle(LConstantOperand* op) const;
projects / platform / upstream / v8.git / commitdiff