Revision: 21311
Author: [email protected]
Date: Wed May 14 14:01:29 2014 UTC
Log: A number of small changes:
- Change ConstantD for +/-zero constants to use the fp_zero register.
- Use Bfi in DoConstructDouble.
- Use Tbz for positive dividend check in mod by constant.
- Optimize some deoptimize checks.
- Fix a couple of style/consistency issues.
BUG=
[email protected]
Review URL: https://codereview.chromium.org/272183003
http://code.google.com/p/v8/source/detail?r=21311
Modified:
/branches/bleeding_edge/src/arm64/lithium-arm64.cc
/branches/bleeding_edge/src/arm64/lithium-arm64.h
/branches/bleeding_edge/src/arm64/lithium-codegen-arm64.cc
/branches/bleeding_edge/src/arm64/macro-assembler-arm64.cc
/branches/bleeding_edge/src/arm64/macro-assembler-arm64.h
=======================================
--- /branches/bleeding_edge/src/arm64/lithium-arm64.cc Fri May 9 08:28:25
2014 UTC
+++ /branches/bleeding_edge/src/arm64/lithium-arm64.cc Wed May 14 14:01:29
2014 UTC
@@ -2009,10 +2009,9 @@
LInstruction* LChunkBuilder::DoConstructDouble(HConstructDouble* instr) {
- LOperand* lo = UseRegister(instr->lo());
+ LOperand* lo = UseRegisterAndClobber(instr->lo());
LOperand* hi = UseRegister(instr->hi());
- LOperand* temp = TempRegister();
- return DefineAsRegister(new(zone()) LConstructDouble(hi, lo, temp));
+ return DefineAsRegister(new(zone()) LConstructDouble(hi, lo));
}
=======================================
--- /branches/bleeding_edge/src/arm64/lithium-arm64.h Fri May 9 12:59:24
2014 UTC
+++ /branches/bleeding_edge/src/arm64/lithium-arm64.h Wed May 14 14:01:29
2014 UTC
@@ -1041,17 +1041,15 @@
};
-class LConstructDouble V8_FINAL : public LTemplateInstruction<1, 2, 1> {
+class LConstructDouble V8_FINAL : public LTemplateInstruction<1, 2, 0> {
public:
- LConstructDouble(LOperand* hi, LOperand* lo, LOperand* temp) {
+ LConstructDouble(LOperand* hi, LOperand* lo) {
inputs_[0] = hi;
inputs_[1] = lo;
- temps_[0] = temp;
}
LOperand* hi() { return inputs_[0]; }
LOperand* lo() { return inputs_[1]; }
- LOperand* temp() { return temps_[0]; }
DECLARE_CONCRETE_INSTRUCTION(ConstructDouble, "construct-double")
};
=======================================
--- /branches/bleeding_edge/src/arm64/lithium-codegen-arm64.cc Mon May 12
13:47:01 2014 UTC
+++ /branches/bleeding_edge/src/arm64/lithium-codegen-arm64.cc Wed May 14
14:01:29 2014 UTC
@@ -2290,7 +2290,7 @@
Register result_reg = ToRegister(instr->result());
if (instr->hydrogen()->bits() == HDoubleBits::HIGH) {
__ Fmov(result_reg, value_reg);
- __ Mov(result_reg, Operand(result_reg, LSR, 32));
+ __ Lsr(result_reg, result_reg, 32);
} else {
__ Fmov(result_reg.W(), value_reg.S());
}
@@ -2300,12 +2300,12 @@
void LCodeGen::DoConstructDouble(LConstructDouble* instr) {
Register hi_reg = ToRegister(instr->hi());
Register lo_reg = ToRegister(instr->lo());
- Register temp = ToRegister(instr->temp());
DoubleRegister result_reg = ToDoubleRegister(instr->result());
- __ And(temp, lo_reg, Operand(0xffffffff));
- __ Orr(temp, temp, Operand(hi_reg, LSL, 32));
- __ Fmov(result_reg, temp);
+ // Insert the least significant 32 bits of hi_reg into the most
significant
+ // 32 bits of lo_reg, and move to a floating point register.
+ __ Bfi(lo_reg, hi_reg, 32, 32);
+ __ Fmov(result_reg, lo_reg);
}
@@ -2415,8 +2415,8 @@
Register value = ToRegister(instr->value());
__ CheckMap(value, scratch, Heap::kHeapNumberMapRootIndex,
instr->FalseLabel(chunk()), DO_SMI_CHECK);
- __ Ldr(double_scratch(), FieldMemOperand(value,
HeapNumber::kValueOffset));
- __ JumpIfMinusZero(double_scratch(), instr->TrueLabel(chunk()));
+ __ Ldr(scratch, FieldMemOperand(value, HeapNumber::kValueOffset));
+ __ JumpIfMinusZero(scratch, instr->TrueLabel(chunk()));
}
EmitGoto(instr->FalseDestination(chunk()));
}
@@ -2524,7 +2524,15 @@
void LCodeGen::DoConstantD(LConstantD* instr) {
ASSERT(instr->result()->IsDoubleRegister());
DoubleRegister result = ToDoubleRegister(instr->result());
- __ Fmov(result, instr->value());
+ if (instr->value() == 0) {
+ if (copysign(1.0, instr->value()) == 1.0) {
+ __ Fmov(result, fp_zero);
+ } else {
+ __ Fneg(result, fp_zero);
+ }
+ } else {
+ __ Fmov(result, instr->value());
+ }
}
@@ -2663,13 +2671,14 @@
// Check for (0 / -x) that will produce negative zero.
HDiv* hdiv = instr->hydrogen();
if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
- __ Cmp(dividend, 0);
- DeoptimizeIf(eq, instr->environment());
+ DeoptimizeIfZero(dividend, instr->environment());
}
// Check for (kMinInt / -1).
if (hdiv->CheckFlag(HValue::kCanOverflow) && divisor == -1) {
- __ Cmp(dividend, kMinInt);
- DeoptimizeIf(eq, instr->environment());
+ // Test dividend for kMinInt by subtracting one (cmp) and checking for
+ // overflow.
+ __ Cmp(dividend, 1);
+ DeoptimizeIf(vs, instr->environment());
}
// Deoptimize if remainder will not be 0.
if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) &&
@@ -3922,8 +3931,7 @@
// Check for (0 / -x) that will produce negative zero.
HMathFloorOfDiv* hdiv = instr->hydrogen();
if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
- __ Cmp(dividend, 0);
- DeoptimizeIf(eq, instr->environment());
+ DeoptimizeIfZero(dividend, instr->environment());
}
// Easy case: We need no dynamic check for the dividend and the flooring
@@ -3945,12 +3953,12 @@
__ TruncatingDiv(result, dividend, Abs(divisor));
if (divisor < 0) __ Neg(result, result);
__ B(&done);
- __ bind(&needs_adjustment);
+ __ Bind(&needs_adjustment);
__ Add(temp, dividend, Operand(divisor > 0 ? 1 : -1));
__ TruncatingDiv(result, temp, Abs(divisor));
if (divisor < 0) __ Neg(result, result);
__ Sub(result, result, Operand(1));
- __ bind(&done);
+ __ Bind(&done);
}
@@ -4217,8 +4225,7 @@
int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
Label dividend_is_not_negative, done;
if (hmod->CheckFlag(HValue::kLeftCanBeNegative)) {
- __ Cmp(dividend, 0);
- __ B(pl, ÷nd_is_not_negative);
+ __ Tbz(dividend, kWSignBit, ÷nd_is_not_negative);
// Note that this is correct even for kMinInt operands.
__ Neg(dividend, dividend);
__ And(dividend, dividend, mask);
=======================================
--- /branches/bleeding_edge/src/arm64/macro-assembler-arm64.cc Mon May 12
15:44:21 2014 UTC
+++ /branches/bleeding_edge/src/arm64/macro-assembler-arm64.cc Wed May 14
14:01:29 2014 UTC
@@ -2341,6 +2341,16 @@
TestForMinusZero(input);
B(vs, on_negative_zero);
}
+
+
+void MacroAssembler::JumpIfMinusZero(Register input,
+ Label* on_negative_zero) {
+ ASSERT(input.Is64Bits());
+ // Floating point value is in an integer register. Detect -0.0 by
subtracting
+ // 1 (cmp), which will cause overflow.
+ Cmp(input, 1);
+ B(vs, on_negative_zero);
+}
void MacroAssembler::ClampInt32ToUint8(Register output, Register input) {
=======================================
--- /branches/bleeding_edge/src/arm64/macro-assembler-arm64.h Mon May 12
15:44:21 2014 UTC
+++ /branches/bleeding_edge/src/arm64/macro-assembler-arm64.h Wed May 14
14:01:29 2014 UTC
@@ -919,6 +919,10 @@
// Jump to label if the input double register contains -0.0.
void JumpIfMinusZero(DoubleRegister input, Label* on_negative_zero);
+ // Jump to label if the input integer register contains the double
precision
+ // floating point representation of -0.0.
+ void JumpIfMinusZero(Register input, Label* on_negative_zero);
+
// Generate code to do a lookup in the number string cache. If the
number in
// the register object is found in the cache the generated code falls
through
// with the result in the result register. The object and the result
register
--
--
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