Revision: 16576
Author: [email protected]
Date: Fri Sep 6 13:12:46 2013 UTC
Log: ARM: Improve integer multiplication.
TEST=test/mjsunit/lithium/MulI.js
[email protected]
Review URL: https://codereview.chromium.org/23452022
http://code.google.com/p/v8/source/detail?r=16576
Added:
/branches/bleeding_edge/test/mjsunit/lithium
/branches/bleeding_edge/test/mjsunit/lithium/MulI.js
Modified:
/branches/bleeding_edge/src/arm/lithium-arm.cc
/branches/bleeding_edge/src/arm/lithium-arm.h
/branches/bleeding_edge/src/arm/lithium-codegen-arm.cc
=======================================
--- /dev/null
+++ /branches/bleeding_edge/test/mjsunit/lithium/MulI.js Fri Sep 6
13:12:46 2013 UTC
@@ -0,0 +1,70 @@
+// Copyright 2013 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,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax --no-use-osr
+
+function foo_smi(a, b) {
+ var result = a * b;
+ result += a * 35;
+ result += a * -1;
+ result += a * 1;
+ result += a * 0;
+ return result * a;
+}
+
+function foo_int(a, b) {
+ var result = a * b;
+ result += a * 35;
+ result += a * -1;
+ result += a * 1;
+ result += a * 0;
+ return result * a;
+}
+
+foo_smi(10, 5);
+var r1 = foo_smi(10, 5);
+%OptimizeFunctionOnNextCall(foo_smi);
+var r2 = foo_smi(10, 5);
+
+assertEquals(r1, r2);
+
+foo_int(10, 21474800);
+var r3 = foo_int(10, 21474800);
+%OptimizeFunctionOnNextCall(foo_int);
+var r4 = foo_int(10, 21474800);
+
+assertEquals(r3, r4);
+
+// Check overflow with -1 constant.
+function foo2(value) {
+ return value * -1;
+}
+
+foo2(-2147483600);
+foo2(-2147483600);
+%OptimizeFunctionOnNextCall(foo2);
+assertEquals(2147483648, foo2(-2147483648));
=======================================
--- /branches/bleeding_edge/src/arm/lithium-arm.cc Wed Aug 28 15:00:30 2013
UTC
+++ /branches/bleeding_edge/src/arm/lithium-arm.cc Fri Sep 6 13:12:46 2013
UTC
@@ -1511,20 +1511,39 @@
if (instr->representation().IsSmiOrInteger32()) {
ASSERT(instr->left()->representation().Equals(instr->representation()));
ASSERT(instr->right()->representation().Equals(instr->representation()));
- LOperand* left;
- LOperand* right = UseOrConstant(instr->BetterRightOperand());
- LOperand* temp = NULL;
- if (instr->CheckFlag(HValue::kBailoutOnMinusZero) &&
- (instr->CheckFlag(HValue::kCanOverflow) ||
- !right->IsConstantOperand())) {
- left = UseRegister(instr->BetterLeftOperand());
- temp = TempRegister();
+ HValue* left = instr->BetterLeftOperand();
+ HValue* right = instr->BetterRightOperand();
+ LOperand* left_op;
+ LOperand* right_op;
+ bool can_overflow = instr->CheckFlag(HValue::kCanOverflow);
+ bool bailout_on_minus_zero =
instr->CheckFlag(HValue::kBailoutOnMinusZero);
+
+ if (right->IsConstant()) {
+ HConstant* constant = HConstant::cast(right);
+ int32_t constant_value = constant->Integer32Value();
+ // Constants -1, 0 and 1 can be optimized if the result can overflow.
+ // For other constants, it can be optimized only without overflow.
+ if (!can_overflow || ((constant_value >= -1) && (constant_value <=
1))) {
+ left_op = UseRegisterAtStart(left);
+ right_op = UseConstant(right);
+ } else {
+ if (bailout_on_minus_zero) {
+ left_op = UseRegister(left);
+ } else {
+ left_op = UseRegisterAtStart(left);
+ }
+ right_op = UseRegister(right);
+ }
} else {
- left = UseRegisterAtStart(instr->BetterLeftOperand());
+ if (bailout_on_minus_zero) {
+ left_op = UseRegister(left);
+ } else {
+ left_op = UseRegisterAtStart(left);
+ }
+ right_op = UseRegister(right);
}
- LMulI* mul = new(zone()) LMulI(left, right, temp);
- if (instr->CheckFlag(HValue::kCanOverflow) ||
- instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
+ LMulI* mul = new(zone()) LMulI(left_op, right_op);
+ if (can_overflow || bailout_on_minus_zero) {
AssignEnvironment(mul);
}
return DefineAsRegister(mul);
=======================================
--- /branches/bleeding_edge/src/arm/lithium-arm.h Wed Aug 28 14:16:57 2013
UTC
+++ /branches/bleeding_edge/src/arm/lithium-arm.h Fri Sep 6 13:12:46 2013
UTC
@@ -677,17 +677,15 @@
};
-class LMulI V8_FINAL : public LTemplateInstruction<1, 2, 1> {
+class LMulI V8_FINAL : public LTemplateInstruction<1, 2, 0> {
public:
- LMulI(LOperand* left, LOperand* right, LOperand* temp) {
+ LMulI(LOperand* left, LOperand* right) {
inputs_[0] = left;
inputs_[1] = right;
- temps_[0] = temp;
}
LOperand* left() { return inputs_[0]; }
LOperand* right() { return inputs_[1]; }
- LOperand* temp() { return temps_[0]; }
DECLARE_CONCRETE_INSTRUCTION(MulI, "mul-i")
DECLARE_HYDROGEN_ACCESSOR(Mul)
=======================================
--- /branches/bleeding_edge/src/arm/lithium-codegen-arm.cc Fri Aug 30
11:24:58 2013 UTC
+++ /branches/bleeding_edge/src/arm/lithium-codegen-arm.cc Fri Sep 6
13:12:46 2013 UTC
@@ -1573,17 +1573,16 @@
void LCodeGen::DoMulI(LMulI* instr) {
- Register scratch = scratch0();
Register result = ToRegister(instr->result());
// Note that result may alias left.
Register left = ToRegister(instr->left());
LOperand* right_op = instr->right();
- bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
bool bailout_on_minus_zero =
instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
+ bool overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
- if (right_op->IsConstantOperand() && !can_overflow) {
+ if (right_op->IsConstantOperand()) {
int32_t constant = ToInteger32(LConstantOperand::cast(right_op));
if (bailout_on_minus_zero && (constant < 0)) {
@@ -1595,7 +1594,12 @@
switch (constant) {
case -1:
- __ rsb(result, left, Operand::Zero());
+ if (overflow) {
+ __ rsb(result, left, Operand::Zero(), SetCC);
+ DeoptimizeIf(vs, instr->environment());
+ } else {
+ __ rsb(result, left, Operand::Zero());
+ }
break;
case 0:
if (bailout_on_minus_zero) {
@@ -1616,23 +1620,21 @@
int32_t mask = constant >> 31;
uint32_t constant_abs = (constant + mask) ^ mask;
- if (IsPowerOf2(constant_abs) ||
- IsPowerOf2(constant_abs - 1) ||
- IsPowerOf2(constant_abs + 1)) {
- if (IsPowerOf2(constant_abs)) {
- int32_t shift = WhichPowerOf2(constant_abs);
- __ mov(result, Operand(left, LSL, shift));
- } else if (IsPowerOf2(constant_abs - 1)) {
- int32_t shift = WhichPowerOf2(constant_abs - 1);
- __ add(result, left, Operand(left, LSL, shift));
- } else if (IsPowerOf2(constant_abs + 1)) {
- int32_t shift = WhichPowerOf2(constant_abs + 1);
- __ rsb(result, left, Operand(left, LSL, shift));
- }
-
+ if (IsPowerOf2(constant_abs)) {
+ int32_t shift = WhichPowerOf2(constant_abs);
+ __ mov(result, Operand(left, LSL, shift));
+ // Correct the sign of the result is the constant is negative.
+ if (constant < 0) __ rsb(result, result, Operand::Zero());
+ } else if (IsPowerOf2(constant_abs - 1)) {
+ int32_t shift = WhichPowerOf2(constant_abs - 1);
+ __ add(result, left, Operand(left, LSL, shift));
+ // Correct the sign of the result is the constant is negative.
+ if (constant < 0) __ rsb(result, result, Operand::Zero());
+ } else if (IsPowerOf2(constant_abs + 1)) {
+ int32_t shift = WhichPowerOf2(constant_abs + 1);
+ __ rsb(result, left, Operand(left, LSL, shift));
// Correct the sign of the result is the constant is negative.
if (constant < 0) __ rsb(result, result, Operand::Zero());
-
} else {
// Generate standard code.
__ mov(ip, Operand(constant));
@@ -1641,12 +1643,11 @@
}
} else {
- Register right = EmitLoadRegister(right_op, scratch);
- if (bailout_on_minus_zero) {
- __ orr(ToRegister(instr->temp()), left, right);
- }
+ ASSERT(right_op->IsRegister());
+ Register right = ToRegister(right_op);
- if (can_overflow) {
+ if (overflow) {
+ Register scratch = scratch0();
// scratch:result = left * right.
if (instr->hydrogen()->representation().IsSmi()) {
__ SmiUntag(result, left);
@@ -1666,12 +1667,12 @@
}
if (bailout_on_minus_zero) {
- // Bail out if the result is supposed to be negative zero.
Label done;
+ __ teq(left, Operand(right));
+ __ b(pl, &done);
+ // Bail out if the result is minus zero.
__ cmp(result, Operand::Zero());
- __ b(ne, &done);
- __ cmp(ToRegister(instr->temp()), Operand::Zero());
- DeoptimizeIf(mi, instr->environment());
+ DeoptimizeIf(eq, instr->environment());
__ bind(&done);
}
}
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