bool
AllocationIntegrityState::checkSafepointAllocation(LInstruction* ins,
uint32_t vreg, LAllocation alloc,
bool populateSafepoints)
{
LSafepoint* safepoint = ins->safepoint();
MOZ_ASSERT(safepoint);
if (ins->isCall() && alloc.isRegister())
return true;
if (alloc.isRegister()) {
AnyRegister reg = alloc.toRegister();
if (populateSafepoints)
safepoint->addLiveRegister(reg);
MOZ_ASSERT(safepoint->liveRegs().has(reg));
}
// The |this| argument slot is implicitly included in all safepoints.
if (alloc.isArgument() && alloc.toArgument()->index() < THIS_FRAME_ARGSLOT + sizeof(Value))
return true;
LDefinition::Type type = virtualRegisters[vreg]
? virtualRegisters[vreg]->type()
: LDefinition::GENERAL;
switch (type) {
case LDefinition::OBJECT:
if (populateSafepoints) {
JitSpew(JitSpew_RegAlloc, "Safepoint object v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addGcPointer(alloc))
return false;
}
MOZ_ASSERT(safepoint->hasGcPointer(alloc));
break;
case LDefinition::SLOTS:
if (populateSafepoints) {
JitSpew(JitSpew_RegAlloc, "Safepoint slots v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addSlotsOrElementsPointer(alloc))
return false;
}
MOZ_ASSERT(safepoint->hasSlotsOrElementsPointer(alloc));
break;
#ifdef JS_NUNBOX32
// Do not assert that safepoint information for nunbox types is complete,
// as if a vreg for a value's components are copied in multiple places
// then the safepoint information may not reflect all copies. All copies
// of payloads must be reflected, however, for generational GC.
case LDefinition::TYPE:
if (populateSafepoints) {
JitSpew(JitSpew_RegAlloc, "Safepoint type v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addNunboxType(vreg, alloc))
return false;
}
break;
case LDefinition::PAYLOAD:
if (populateSafepoints) {
JitSpew(JitSpew_RegAlloc, "Safepoint payload v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addNunboxPayload(vreg, alloc))
return false;
}
MOZ_ASSERT(safepoint->hasNunboxPayload(alloc));
break;
#else
case LDefinition::BOX:
if (populateSafepoints) {
JitSpew(JitSpew_RegAlloc, "Safepoint boxed value v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addBoxedValue(alloc))
return false;
}
MOZ_ASSERT(safepoint->hasBoxedValue(alloc));
break;
#endif
default:
break;
}
return true;
}
bool
AllocationIntegrityState::check(bool populateSafepoints)
{
MOZ_ASSERT(!instructions.empty());
#ifdef DEBUG
if (JitSpewEnabled(JitSpew_RegAlloc))
dump();
for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); blockIndex++) {
LBlock* block = graph.getBlock(blockIndex);
// Check that all instruction inputs and outputs have been assigned an allocation.
for (LInstructionIterator iter = block->begin(); iter != block->end(); iter++) {
LInstruction* ins = *iter;
for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next())
MOZ_ASSERT(!alloc->isUse());
for (size_t i = 0; i < ins->numDefs(); i++) {
LDefinition* def = ins->getDef(i);
MOZ_ASSERT(!def->output()->isUse());
LDefinition oldDef = instructions[ins->id()].outputs[i];
MOZ_ASSERT_IF(oldDef.policy() == LDefinition::MUST_REUSE_INPUT,
*def->output() == *ins->getOperand(oldDef.getReusedInput()));
}
for (size_t i = 0; i < ins->numTemps(); i++) {
LDefinition* temp = ins->getTemp(i);
MOZ_ASSERT_IF(!temp->isBogusTemp(), temp->output()->isRegister());
LDefinition oldTemp = instructions[ins->id()].temps[i];
MOZ_ASSERT_IF(oldTemp.policy() == LDefinition::MUST_REUSE_INPUT,
*temp->output() == *ins->getOperand(oldTemp.getReusedInput()));
}
}
}
#endif
// Check that the register assignment and move groups preserve the original
// semantics of the virtual registers. Each virtual register has a single
// write (owing to the SSA representation), but the allocation may move the
// written value around between registers and memory locations along
// different paths through the script.
//
// For each use of an allocation, follow the physical value which is read
// backward through the script, along all paths to the value's virtual
// register's definition.
for (size_t blockIndex = 0; blockIndex < graph.numBlocks(); blockIndex++) {
LBlock* block = graph.getBlock(blockIndex);
for (LInstructionIterator iter = block->begin(); iter != block->end(); iter++) {
LInstruction* ins = *iter;
const InstructionInfo& info = instructions[ins->id()];
LSafepoint* safepoint = ins->safepoint();
if (safepoint) {
for (size_t i = 0; i < ins->numTemps(); i++) {
if (ins->getTemp(i)->isBogusTemp())
continue;
uint32_t vreg = info.temps[i].virtualRegister();
LAllocation* alloc = ins->getTemp(i)->output();
if (!checkSafepointAllocation(ins, vreg, *alloc, populateSafepoints))
return false;
}
MOZ_ASSERT_IF(ins->isCall() && !populateSafepoints,
safepoint->liveRegs().emptyFloat() &&
safepoint->liveRegs().emptyGeneral());
}
size_t inputIndex = 0;
for (LInstruction::InputIterator alloc(*ins); alloc.more(); alloc.next()) {
LAllocation oldInput = info.inputs[inputIndex++];
if (!oldInput.isUse())
continue;
uint32_t vreg = oldInput.toUse()->virtualRegister();
if (safepoint && !oldInput.toUse()->usedAtStart()) {
if (!checkSafepointAllocation(ins, vreg, **alloc, populateSafepoints))
return false;
}
// Start checking at the previous instruction, in case this
// instruction reuses its input register for an output.
LInstructionReverseIterator riter = block->rbegin(ins);
riter++;
checkIntegrity(block, *riter, vreg, **alloc, populateSafepoints);
while (!worklist.empty()) {
IntegrityItem item = worklist.popCopy();
checkIntegrity(item.block, *item.block->rbegin(), item.vreg, item.alloc, populateSafepoints);
}
}
}
}
return true;
}
bool
AllocationIntegrityState::checkSafepointAllocation(LInstruction *ins,
uint32_t vreg, LAllocation alloc,
bool populateSafepoints)
{
LSafepoint *safepoint = ins->safepoint();
JS_ASSERT(safepoint);
if (ins->isCall() && alloc.isRegister())
return true;
if (alloc.isRegister()) {
AnyRegister reg = alloc.toRegister();
if (populateSafepoints)
safepoint->addLiveRegister(reg);
JS_ASSERT(safepoint->liveRegs().has(reg));
}
LDefinition::Type type = virtualRegisters[vreg]
? virtualRegisters[vreg]->type()
: LDefinition::GENERAL;
switch (type) {
case LDefinition::OBJECT:
if (populateSafepoints) {
IonSpew(IonSpew_RegAlloc, "Safepoint object v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addGcPointer(alloc))
return false;
}
JS_ASSERT(safepoint->hasGcPointer(alloc));
break;
#ifdef JS_NUNBOX32
// Do not assert that safepoint information for nunboxes is complete,
// as if a vreg for a value's components are copied in multiple places
// then the safepoint information may not reflect all copies.
// See SafepointWriter::writeNunboxParts.
case LDefinition::TYPE:
if (populateSafepoints) {
IonSpew(IonSpew_RegAlloc, "Safepoint type v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addNunboxType(vreg, alloc))
return false;
}
break;
case LDefinition::PAYLOAD:
if (populateSafepoints) {
IonSpew(IonSpew_RegAlloc, "Safepoint payload v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addNunboxPayload(vreg, alloc))
return false;
}
break;
#else
case LDefinition::BOX:
if (populateSafepoints) {
IonSpew(IonSpew_RegAlloc, "Safepoint boxed value v%u i%u %s",
vreg, ins->id(), alloc.toString());
if (!safepoint->addBoxedValue(alloc))
return false;
}
JS_ASSERT(safepoint->hasBoxedValue(alloc));
break;
#endif
default:
break;
}
return true;
}
