Reviewers: ulan, jochen (OOO until March 10),
Description:
A64: Improve constraints for StoreNamedField
Improve register constraints for cases that don't need write barriers, and
remove TODOs.
BUG=
Please review this at https://codereview.chromium.org/189373006/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+48, -34 lines):
M src/a64/lithium-a64.cc
M src/a64/lithium-codegen-a64.cc
Index: src/a64/lithium-a64.cc
diff --git a/src/a64/lithium-a64.cc b/src/a64/lithium-a64.cc
index
cf89c09f5b2515d2dbc0b6cabe667b10245eb9ea..ce77209910d33131d5ea6607a585d9ccd6f05df2
100644
--- a/src/a64/lithium-a64.cc
+++ b/src/a64/lithium-a64.cc
@@ -2231,17 +2231,27 @@ LInstruction*
LChunkBuilder::DoStoreKeyedGeneric(HStoreKeyedGeneric* instr) {
LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
- // TODO(jbramley): Optimize register usage in this instruction. For now,
it
- // allocates everything that it might need because it keeps changing in
the
- // merge and keeping it valid is time-consuming.
-
// TODO(jbramley): It might be beneficial to allow value to be a
constant in
// some cases. x64 makes use of this with FLAG_track_fields, for example.
LOperand* object = UseRegister(instr->object());
- LOperand* value = UseRegisterAndClobber(instr->value());
- LOperand* temp0 = TempRegister();
- LOperand* temp1 = TempRegister();
+ LOperand* value;
+ LOperand* temp0 = NULL;
+ LOperand* temp1 = NULL;
+ if (instr->NeedsWriteBarrier()) {
+ value = UseRegisterAndClobber(instr->value());
+ temp0 = TempRegister();
+ temp1 = TempRegister();
+ } else {
+ value = UseRegister(instr->value());
+ if (!(instr->access().IsExternalMemory() ||
+ instr->field_representation().IsDouble())) {
+ temp0 = TempRegister();
+ if (instr->NeedsWriteBarrierForMap()) {
+ temp1 = TempRegister();
+ }
+ }
+ }
LStoreNamedField* result =
new(zone()) LStoreNamedField(object, value, temp0, temp1);
Index: src/a64/lithium-codegen-a64.cc
diff --git a/src/a64/lithium-codegen-a64.cc b/src/a64/lithium-codegen-a64.cc
index
ad8d742abac2cc894d292e026d7005b67933e834..aca060f75d1cae9d03f0343ea030dee6accb8696
100644
--- a/src/a64/lithium-codegen-a64.cc
+++ b/src/a64/lithium-codegen-a64.cc
@@ -5146,36 +5146,20 @@ void
LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
}
-// TODO(jbramley): Once the merge is done and we're tracking
bleeding_edge, try
-// to tidy up this function.
void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
Representation representation = instr->representation();
Register object = ToRegister(instr->object());
- Register temp0 = ToRegister(instr->temp0());
- Register temp1 = ToRegister(instr->temp1());
HObjectAccess access = instr->hydrogen()->access();
+ Handle<Map> transition = instr->transition();
int offset = access.offset();
if (access.IsExternalMemory()) {
+ ASSERT(transition.is_null());
+ ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
Register value = ToRegister(instr->value());
__ Store(value, MemOperand(object, offset), representation);
return;
- }
-
- Handle<Map> transition = instr->transition();
- SmiCheck check_needed =
- instr->hydrogen()->value()->IsHeapObject()
- ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
-
- if (representation.IsHeapObject()) {
- Register value = ToRegister(instr->value());
- if (!instr->hydrogen()->value()->type().IsHeapObject()) {
- DeoptimizeIfSmi(value, instr->environment());
-
- // We know that value is a smi now, so we can omit the check below.
- check_needed = OMIT_SMI_CHECK;
- }
} else if (representation.IsDouble()) {
ASSERT(transition.is_null());
ASSERT(access.IsInobject());
@@ -5185,9 +5169,22 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField*
instr) {
return;
}
+ Register value = ToRegister(instr->value());
+
+ SmiCheck check_needed = instr->hydrogen()->value()->IsHeapObject()
+ ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
+
+ if (representation.IsHeapObject() &&
+ !instr->hydrogen()->value()->type().IsHeapObject()) {
+ DeoptimizeIfSmi(value, instr->environment());
+
+ // We know that value is a smi now, so we can omit the check below.
+ check_needed = OMIT_SMI_CHECK;
+ }
+
if (!transition.is_null()) {
// Store the new map value.
- Register new_map_value = temp0;
+ Register new_map_value = ToRegister(instr->temp0());
__ Mov(new_map_value, Operand(transition));
__ Str(new_map_value, FieldMemOperand(object, HeapObject::kMapOffset));
if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
@@ -5195,7 +5192,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField*
instr) {
__ RecordWriteField(object,
HeapObject::kMapOffset,
new_map_value,
- temp1,
+ ToRegister(instr->temp1()),
GetLinkRegisterState(),
kSaveFPRegs,
OMIT_REMEMBERED_SET,
@@ -5204,21 +5201,28 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField*
instr) {
}
// Do the store.
- Register value = ToRegister(instr->value());
Register destination;
if (access.IsInobject()) {
destination = object;
} else {
+ Register temp0 = ToRegister(instr->temp0());
__ Ldr(temp0, FieldMemOperand(object, JSObject::kPropertiesOffset));
destination = temp0;
}
if (representation.IsSmi() &&
- instr->hydrogen()->value()->representation().IsInteger32()) {
+ instr->hydrogen()->value()->representation().IsInteger32()) {
ASSERT(instr->hydrogen()->store_mode() == STORE_TO_INITIALIZED_ENTRY);
#ifdef DEBUG
- __ Ldr(temp1, FieldMemOperand(destination, offset));
- __ AssertSmi(temp1);
+ Register temp0 = ToRegister(instr->temp0());
+ __ Ldr(temp0, FieldMemOperand(destination, offset));
+ __ AssertSmi(temp0);
+ // If destination aliased temp0, restore it to the address calculated
+ // earlier.
+ if (destination.Is(temp0)) {
+ ASSERT(!access.IsInobject());
+ __ Ldr(destination, FieldMemOperand(object,
JSObject::kPropertiesOffset));
+ }
#endif
STATIC_ASSERT(kSmiValueSize == 32 && kSmiShift == 32 && kSmiTag == 0);
__ Store(value, UntagSmiFieldMemOperand(destination, offset),
@@ -5229,8 +5233,8 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField*
instr) {
if (instr->hydrogen()->NeedsWriteBarrier()) {
__ RecordWriteField(destination,
offset,
- value, // Clobbered.
- temp1, // Clobbered.
+ value, // Clobbered.
+ ToRegister(instr->temp1()), // Clobbered.
GetLinkRegisterState(),
kSaveFPRegs,
EMIT_REMEMBERED_SET,
--
--
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