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MIPS: Improve register allocation for Lithium representation changes on ARM

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Port r10538 (21c5dc1).

MIPS-specific changes:
-moved MacroAssembler::SmiTagCheckOverflow definition to macro-assembler-mips.cc from the header
-added optimized 3-argument version of said function
-removed the related, completely unused TrySmiTag function

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/9296045
Patch from Daniel Kalmar <kalmard@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10567 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
danno@chromium.org 2012-01-31 12:33:46 +00:00
parent 5dc4859fa4
commit ab5d47ef21
4 changed files with 55 additions and 42 deletions
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48
src/mips/lithium-codegen-mips.cc
View File

@ -3714,13 +3714,12 @@ void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
LNumberTagI* instr_;
};
LOperand* input = instr->InputAt(0);
ASSERT(input->IsRegister() && input->Equals(instr->result()));
Register reg = ToRegister(input);
Register src = ToRegister(instr->InputAt(0));
Register dst = ToRegister(instr->result());
Register overflow = scratch0();
DeferredNumberTagI* deferred = new DeferredNumberTagI(this, instr);
__ SmiTagCheckOverflow(reg, overflow);
__ SmiTagCheckOverflow(dst, src, overflow);
__ BranchOnOverflow(deferred->entry(), overflow);
__ bind(deferred->exit());
}
@ -3728,7 +3727,8 @@ void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
void LCodeGen::DoDeferredNumberTagI(LNumberTagI* instr) {
Label slow;
Register reg = ToRegister(instr->InputAt(0));
Register src = ToRegister(instr->InputAt(0));
Register dst = ToRegister(instr->result());
FPURegister dbl_scratch = double_scratch0();
// Preserve the value of all registers.
@ -3738,14 +3738,16 @@ void LCodeGen::DoDeferredNumberTagI(LNumberTagI* instr) {
// disagree. Try to allocate a heap number in new space and store
// the value in there. If that fails, call the runtime system.
Label done;
__ SmiUntag(reg);
__ Xor(reg, reg, Operand(0x80000000));
__ mtc1(reg, dbl_scratch);
if (dst.is(src)) {
__ SmiUntag(src, dst);
__ Xor(src, src, Operand(0x80000000));
}
__ mtc1(src, dbl_scratch);
__ cvt_d_w(dbl_scratch, dbl_scratch);
if (FLAG_inline_new) {
__ LoadRoot(t2, Heap::kHeapNumberMapRootIndex);
__ AllocateHeapNumber(t1, a3, t0, t2, &slow);
if (!reg.is(t1)) __ mov(reg, t1);
__ Move(dst, t1);
__ Branch(&done);
}
@ -3755,15 +3757,16 @@ void LCodeGen::DoDeferredNumberTagI(LNumberTagI* instr) {
// TODO(3095996): Put a valid pointer value in the stack slot where the result
// register is stored, as this register is in the pointer map, but contains an
// integer value.
__ StoreToSafepointRegisterSlot(zero_reg, reg);
__ StoreToSafepointRegisterSlot(zero_reg, src);
__ StoreToSafepointRegisterSlot(zero_reg, dst);
CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
if (!reg.is(v0)) __ mov(reg, v0);
__ Move(dst, v0);
// Done. Put the value in dbl_scratch into the value of the allocated heap
// number.
__ bind(&done);
__ sdc1(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
__ StoreToSafepointRegisterSlot(reg, reg);
__ sdc1(dbl_scratch, FieldMemOperand(dst, HeapNumber::kValueOffset));
__ StoreToSafepointRegisterSlot(dst, dst);
}
@ -3810,25 +3813,23 @@ void LCodeGen::DoDeferredNumberTagD(LNumberTagD* instr) {
void LCodeGen::DoSmiTag(LSmiTag* instr) {
LOperand* input = instr->InputAt(0);
ASSERT(input->IsRegister() && input->Equals(instr->result()));
ASSERT(!instr->hydrogen_value()->CheckFlag(HValue::kCanOverflow));
__ SmiTag(ToRegister(input));
__ SmiTag(ToRegister(instr->result()), ToRegister(instr->InputAt(0)));
}
void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
Register scratch = scratch0();
LOperand* input = instr->InputAt(0);
ASSERT(input->IsRegister() && input->Equals(instr->result()));
Register input = ToRegister(instr->InputAt(0));
Register result = ToRegister(instr->result());
if (instr->needs_check()) {
STATIC_ASSERT(kHeapObjectTag == 1);
// If the input is a HeapObject, value of scratch won't be zero.
__ And(scratch, ToRegister(input), Operand(kHeapObjectTag));
__ SmiUntag(ToRegister(input));
__ And(scratch, input, Operand(kHeapObjectTag));
__ SmiUntag(result, input);
DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
} else {
__ SmiUntag(ToRegister(input));
__ SmiUntag(result, input);
}
}
@ -3876,10 +3877,9 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
// Smi to double register conversion
__ bind(&load_smi);
__ SmiUntag(input_reg); // Untag smi before converting to float.
__ mtc1(input_reg, result_reg);
__ SmiUntag(scratch, input_reg); // Untag smi before converting to float.
__ mtc1(scratch, result_reg);
__ cvt_d_w(result_reg, result_reg);
__ SmiTag(input_reg); // Retag smi.
__ bind(&done);
}

10
src/mips/lithium-mips.cc
View File

@ -1628,11 +1628,11 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
return AssignEnvironment(DefineAsRegister(res));
} else {
ASSERT(to.IsInteger32());
LOperand* value = UseRegister(instr->value());
LOperand* value = UseRegisterAtStart(instr->value());
bool needs_check = !instr->value()->type().IsSmi();
LInstruction* res = NULL;
if (!needs_check) {
res = DefineSameAsFirst(new LSmiUntag(value, needs_check));
res = DefineAsRegister(new LSmiUntag(value, needs_check));
} else {
LOperand* temp1 = TempRegister();
LOperand* temp2 = instr->CanTruncateToInt32() ? TempRegister()
@ -1668,12 +1668,12 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
} else if (from.IsInteger32()) {
if (to.IsTagged()) {
HValue* val = instr->value();
LOperand* value = UseRegister(val);
LOperand* value = UseRegisterAtStart(val);
if (val->HasRange() && val->range()->IsInSmiRange()) {
return DefineSameAsFirst(new LSmiTag(value));
return DefineAsRegister(new LSmiTag(value));
} else {
LNumberTagI* result = new LNumberTagI(value);
return AssignEnvironment(AssignPointerMap(DefineSameAsFirst(result)));
return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
}
} else {
ASSERT(to.IsDouble());

24
src/mips/macro-assembler-mips.cc
View File

@ -4517,6 +4517,30 @@ void MacroAssembler::JumpIfNotPowerOfTwoOrZero(
}
void MacroAssembler::SmiTagCheckOverflow(Register reg, Register overflow) {
ASSERT(!reg.is(overflow));
mov(overflow, reg); // Save original value.
SmiTag(reg);
xor_(overflow, overflow, reg); // Overflow if (value ^ 2 * value) < 0.
}
void MacroAssembler::SmiTagCheckOverflow(Register dst,
Register src,
Register overflow) {
if (dst.is(src)) {
// Fall back to slower case.
SmiTagCheckOverflow(dst, overflow);
} else {
ASSERT(!dst.is(src));
ASSERT(!dst.is(overflow));
ASSERT(!src.is(overflow));
SmiTag(dst, src);
xor_(overflow, dst, src); // Overflow if (value ^ 2 * value) < 0.
}
}
void MacroAssembler::JumpIfNotBothSmi(Register reg1,
Register reg2,
Label* on_not_both_smi) {

15
src/mips/macro-assembler-mips.h
View File

@ -1222,24 +1222,13 @@ class MacroAssembler: public Assembler {
// -------------------------------------------------------------------------
// Smi utilities.
// Try to convert int32 to smi. If the value is to large, preserve
// the original value and jump to not_a_smi. Destroys scratch and
// sets flags.
// This is only used by crankshaft atm so it is unimplemented on MIPS.
void TrySmiTag(Register reg, Label* not_a_smi, Register scratch) {
UNIMPLEMENTED_MIPS();
}
void SmiTag(Register reg) {
Addu(reg, reg, reg);
}
// Test for overflow < 0: use BranchOnOverflow() or BranchOnNoOverflow().
void SmiTagCheckOverflow(Register reg, Register overflow) {
mov(overflow, reg); // Save original value.
addu(reg, reg, reg);
xor_(overflow, overflow, reg); // Overflow if (value ^ 2 * value) < 0.
}
void SmiTagCheckOverflow(Register reg, Register overflow);
void SmiTagCheckOverflow(Register dst, Register src, Register overflow);
void SmiTag(Register dst, Register src) {
Addu(dst, src, src);