averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

Revert "Expand the amount of unchecked_addr_casts that we can handle."

Browse Source 
This reverts commit r19272 to unblock the submission. I am going to
cherry-pick this later.

Swift SVN r19279
This commit is contained in:
Michael Gottesman
2014-06-27 00:02:05 +00:00
parent 22f0e39ef2
commit cf896976a0
4 changed files with 67 additions and 100 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
lib/SILPasses/LoadStoreOpts.cpp
View File

@@ -40,12 +40,13 @@ STATISTIC(NumForwardedLoads, "Number of loads forwarded");
/// insts and return the last such inst.
static SILValue
findExtractPathFromAddressValueToLoad(SILValue Address, SILValue StoredValue,
SILInstruction *Inst, SILValue InstOp) {
LoadInst *Load) {
// Attempt to find the projection path from Address -> Load->getOperand().
SILValue LIOp = Load->getOperand();
llvm::SmallVector<Projection, 4> ProjectionPath;
// If we failed to find the path, return an empty value early.
if (!findAddressProjectionPathBetweenValues(Address, InstOp, ProjectionPath))
if (!findAddressProjectionPathBetweenValues(Address, LIOp, ProjectionPath))
return SILValue();
// If we found a projection path, but there are no projections, then the two
@@ -56,12 +57,12 @@ findExtractPathFromAddressValueToLoad(SILValue Address, SILValue StoredValue,
// Ok, at this point we know that we can construct our aggregate projections
// from our list of address projections.
SILValue LastExtract = StoredValue;
SILBuilder Builder(Inst);
SILBuilder Builder(Load);
while (!ProjectionPath.empty()) {
auto P = ProjectionPath.pop_back_val();
if (ValueDecl *D = P.getDecl()) {
if (P.getNominalType() == Projection::NominalType::Struct) {
LastExtract = Builder.createStructExtract(Inst->getLoc(), LastExtract,
LastExtract = Builder.createStructExtract(Load->getLoc(), LastExtract,
cast<VarDecl>(D),
P.getType().getObjectType());
assert(cast<StructExtractInst>(*LastExtract).getStructDecl() &&
@@ -71,13 +72,13 @@ findExtractPathFromAddressValueToLoad(SILValue Address, SILValue StoredValue,
"Expected an enum decl here. Only other possibility is a "
"class which we do not support");
LastExtract = Builder.createUncheckedEnumData(
Inst->getLoc(), LastExtract, cast<EnumElementDecl>(D),
Load->getLoc(), LastExtract, cast<EnumElementDecl>(D),
P.getType().getObjectType());
assert(cast<UncheckedEnumDataInst>(*LastExtract).getElement() &&
"Instruction must have an enum element decl!");
}
} else {
LastExtract = Builder.createTupleExtract(Inst->getLoc(), LastExtract,
LastExtract = Builder.createTupleExtract(Load->getLoc(), LastExtract,
P.getIndex(),
P.getType().getObjectType());
assert(cast<TupleExtractInst>(*LastExtract).getTupleType() &&
@@ -238,28 +239,17 @@ void LSBBForwarder::tryToEliminateDeadStores(StoreInst *SI) {
Stores.insert(SI);
}
/// Given an unchecked_addr_cast with various address projections using it,
/// rewrite the forwarding stored value to a bitcast + the relevant extract
/// operations.
static SILValue
tryToForwardAddressValueToUncheckedAddrToLoad(SILValue Address,
SILValue StoredValue,
LoadInst *LI,
UncheckedAddrCastInst *UADCI) {
assert(LI->getOperand().stripAddressProjections() == UADCI &&
"We assume that the UADCI is the load's address stripped of "
"address projections.");
// First grab the address operand of our UADCI.
SILValue UADCIOp = UADCI->getOperand();
// Make sure that this is equal to our address. If not, bail.
if (UADCIOp != Address)
if (Address != UADCIOp)
return SILValue();
// Construct the relevant bitcast.
SILModule &Mod = UADCI->getModule();
SILType InputTy = UADCI->getOperand().getType();
SILType InputTy = UADCIOp.getType();
SILType OutputTy = UADCI->getType();
// If OutputTy is not layout compatible with InputTy, there is nothing we can
@@ -270,37 +260,27 @@ tryToForwardAddressValueToUncheckedAddrToLoad(SILValue Address,
bool InputIsTrivial = InputTy.isTrivial(Mod);
bool OutputIsTrivial = OutputTy.isTrivial(Mod);
// If one is trivial and the other is not, bail.
if (InputIsTrivial != OutputIsTrivial)
return SILValue();
// If either are generic, bail.
if (InputTy.hasArchetype() || OutputTy.hasArchetype())
return SILValue();
SILBuilder B(LI);
SILValue CastValue;
// If the output is trivial, we have a trivial bit cast.
if (InputIsTrivial || OutputIsTrivial) {
CastValue = B.createUncheckedTrivialBitCast(UADCI->getLoc(), StoredValue,
OutputTy.getObjectType());
} else {
// Otherwise, both must have some sort of reference counts on them. Insert
// the ref count cast.
CastValue = B.createUncheckedRefBitCast(UADCI->getLoc(), StoredValue,
OutputTy.getObjectType());
// If both input and output are trivial types, return an
// unchecked_trivial_bit_cast.
if (InputIsTrivial && OutputIsTrivial) {
return B.createUncheckedTrivialBitCast(UADCI->getLoc(), StoredValue,
OutputTy.getObjectType());
}
// Then try to construct an extract path from the UADCI to the Address.
SILValue ExtractPath =
findExtractPathFromAddressValueToLoad(UADCI, CastValue,
LI, LI->getOperand());
// If we can not construct the extract path, bail.
if (!ExtractPath)
return SILValue();
assert(ExtractPath.getType() == UADCIOp.getType().getObjectType() &&
"Must have same types here.");
return ExtractPath;
// Otherwise, both must have some sort of reference counts on them. Insert the
// ref count cast.
return B.createUncheckedRefBitCast(UADCI->getLoc(), StoredValue,
OutputTy.getObjectType());
}
/// Given an address \p Address and a value \p Value stored there that is then
@@ -311,15 +291,13 @@ static SILValue tryToForwardAddressValueToLoad(SILValue Address,
LoadInst *LI) {
// First if we have a store + unchecked_addr_cast + load, try to forward the
// value the store using a bitcast.
SILValue LIOpWithoutProjs = LI->getOperand().stripAddressProjections();
if (auto *UADCI = dyn_cast<UncheckedAddrCastInst>(LIOpWithoutProjs))
if (auto *UADCI = dyn_cast<UncheckedAddrCastInst>(LI->getOperand()))
return tryToForwardAddressValueToUncheckedAddrToLoad(Address, StoredValue,
LI, UADCI);
// Next, try to promote partial loads from stores. If this fails, it will
// return SILValue(), which is also our failure condition.
return findExtractPathFromAddressValueToLoad(Address, StoredValue, LI,
LI->getOperand());
return findExtractPathFromAddressValueToLoad(Address, StoredValue, LI);
}
void LSBBForwarder::tryToForwardLoad(LoadInst *LI) {