bool IRInstruction::consumesReference(int srcNo) const {
if (!consumesReferences()) {
return false;
}
// CheckType/AssertType consume a reference if we're guarding from a
// maybeCounted type to a notCounted type.
if (m_op == CheckType || m_op == AssertType) {
assert(srcNo == 0);
return src(0)->type().maybeCounted() && typeParam().notCounted();
}
// SpillStack consumes inputs 2 and onward
if (m_op == SpillStack) return srcNo >= 2;
// Call consumes inputs 3 and onward
if (m_op == Call) return srcNo >= 3;
// StRetVal only consumes input 1
if (m_op == StRetVal) return srcNo == 1;
if (m_op == StLoc || m_op == StLocNT) {
// StLoc[NT] <stkptr>, <value>
return srcNo == 1;
}
if (m_op == StProp || m_op == StPropNT || m_op == StMem || m_op == StMemNT) {
// StProp[NT]|StMem[NT] <base>, <offset>, <value>
return srcNo == 2;
}
if (m_op == ArraySet || m_op == ArraySetRef) {
// Only consumes the reference to its input array
return srcNo == 1;
}
return true;
}
bool IRInstruction::canCSE() const {
auto canCSE = opcodeHasFlags(op(), CanCSE);
// Make sure that instructions that are CSE'able can't consume reference
// counts.
assert(!canCSE || !consumesReferences());
return canCSE;
}
bool IRInstruction::canCSE() const {
auto canCSE = opcodeHasFlags(op(), CanCSE);
// Make sure that instructions that are CSE'able can't produce a reference
// count or consume reference counts. CheckType/AssertType are special
// because they can refine a maybeCounted type to a notCounted type, so they
// logically consume and produce a reference without doing any work.
assert(!canCSE || !consumesReferences() ||
m_op == CheckType || m_op == AssertType);
return canCSE && !mayReenterHelper();
}
bool IRInstruction::consumesReference(int srcNo) const {
if (!consumesReferences()) {
return false;
}
switch (op()) {
case ConcatStrStr:
case ConcatStrInt:
case ConcatCellCell:
// Call a helper that decrefs the first argument
return srcNo == 0;
case StRef:
case StClosureArg:
case StClosureCtx:
case StContArValue:
case StContArKey:
case StRetVal:
case StLoc:
case StLocNT:
// Consume the value being stored, not the thing it's being stored into
return srcNo == 1;
case StProp:
case StMem:
// StProp|StMem <base>, <offset>, <value>
return srcNo == 2;
case ArraySet:
case ArraySetRef:
// Only consumes the reference to its input array
return srcNo == 1;
case SpillStack:
// Inputs 2+ are values to store
return srcNo >= 2;
case SpillFrame:
// Consumes the $this/Class field of the ActRec
return srcNo == 3;
case Call:
// Inputs 3+ are arguments to the function
return srcNo >= 3;
case ColAddElemC:
// value at index 2
return srcNo == 2;
case ColAddNewElemC:
// value at index 1
return srcNo == 1;
case CheckNullptr:
return srcNo == 0;
case CreateAFWHFunc:
return srcNo == 1;
case CreateAFWHMeth:
return srcNo == 2;
default:
return true;
}
}
