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//===--- ScopedAddressUtils.cpp -------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "swift/SIL/ScopedAddressUtils.h"
#include "swift/SIL/OwnershipUtils.h"
#include "swift/SIL/PrunedLiveness.h"
#include "swift/SIL/SILArgument.h"
#include "swift/SIL/SILBuilder.h"
#include "swift/SIL/SILInstruction.h"
#include "swift/SIL/Test.h"
#include "swift/SILOptimizer/Utils/InstructionDeleter.h"
#include "swift/SILOptimizer/Utils/OwnershipOptUtils.h"
using namespace swift;
void ScopedAddressValueKind::print(llvm::raw_ostream &os) const {
switch (value) {
case ScopedAddressValueKind::Invalid:
llvm_unreachable("Using invalid case?!");
case ScopedAddressValueKind::StoreBorrow:
os << "StoreBorrow";
return;
case ScopedAddressValueKind::BeginAccess:
os << "BeginAccess";
return;
}
llvm_unreachable("Covered switch isn't covered?!");
}
llvm::raw_ostream &swift::operator<<(llvm::raw_ostream &os,
ScopedAddressValueKind kind) {
kind.print(os);
return os;
}
bool ScopedAddressValue::isScopeEndingUse(Operand *op) const {
switch (kind) {
case ScopedAddressValueKind::Invalid:
llvm_unreachable("Using invalid case?!");
case ScopedAddressValueKind::StoreBorrow: {
if (auto *endBorrow = dyn_cast<EndBorrowInst>(op->getUser())) {
return endBorrow->getOperand() == value;
}
return false;
}
case ScopedAddressValueKind::BeginAccess: {
if (auto *endAccess = dyn_cast<EndAccessInst>(op->getUser())) {
return endAccess->getOperand() == value;
}
return false;
}
}
}
bool ScopedAddressValue::visitScopeEndingUses(
function_ref<bool(Operand *)> visitor) const {
switch (kind) {
case ScopedAddressValueKind::Invalid:
llvm_unreachable("Using invalid case?!");
case ScopedAddressValueKind::StoreBorrow: {
for (auto *use : value->getUses()) {
if (isa<EndBorrowInst>(use->getUser())) {
if (!visitor(use))
return false;
}
}
return true;
}
case ScopedAddressValueKind::BeginAccess: {
for (auto *use : value->getUses()) {
if (isa<EndAccessInst>(use->getUser())) {
if (!visitor(use))
return false;
}
}
return true;
}
}
}
// Note: This is used to fixup an incomplete address scope, so cannot assume the
// scope's lifetime is already complete. Therefore, it needs to transitively
// process all address uses.
//
// FIXME: users of this should use the standard recursive lifetime completion
// utility. Otherwise dealing with nested incomplete lifetimes becomes
// expensive and complex. e.g.
//
// %storeBorrow = store_borrow %_ to %adr
// %loadBorrow = load_borrow %storeBorrow
// apply %f(%loadBorrow) : $@convention(thin) (...) -> Never
// unreachable
//
AddressUseKind ScopedAddressValue::computeTransitiveLiveness(
SSAPrunedLiveness &liveness) const {
liveness.initializeDef(value);
return updateTransitiveLiveness(liveness);
}
namespace swift::test {
// Arguments:
// - SILValue: value to a analyze
// Dumps:
// - the liveness result and boundary
static FunctionTest ScopedAddressLivenessTest(
"scoped-address-liveness", [](auto &function, auto &arguments, auto &test) {
auto value = arguments.takeValue();
assert(!arguments.hasUntaken());
llvm::outs() << "Scoped address analysis: " << value;
ScopedAddressValue scopedAddress(value);
assert(scopedAddress);
SmallVector<SILBasicBlock *, 8> discoveredBlocks;
SSAPrunedLiveness liveness(value->getFunction(), &discoveredBlocks);
scopedAddress.computeTransitiveLiveness(liveness);
liveness.print(llvm::outs());
PrunedLivenessBoundary boundary;
liveness.computeBoundary(boundary);
boundary.print(llvm::outs());
});
} // end namespace swift::test
AddressUseKind ScopedAddressValue::updateTransitiveLiveness(
SSAPrunedLiveness &liveness) const {
SmallVector<Operand *, 4> uses;
// Collect all uses that need to be enclosed by the scope.
auto addressKind = findTransitiveUsesForAddress(value, &uses);
for (auto *use : uses) {
if (isScopeEndingUse(use))
continue;
// Update all collected uses as non-lifetime ending.
liveness.updateForUse(use->getUser(), /* lifetimeEnding */ false);
}
visitScopeEndingUses([&](Operand *endOp) {
liveness.updateForUse(endOp->getUser(), /* isLifetimeEnding */ true);
return true;
});
return addressKind;
}
void ScopedAddressValue::createScopeEnd(SILBasicBlock::iterator insertPt,
SILLocation loc) const {
switch (kind) {
case ScopedAddressValueKind::StoreBorrow: {
SILBuilderWithScope(insertPt).createEndBorrow(loc, value);
return;
}
case ScopedAddressValueKind::BeginAccess: {
SILBuilderWithScope(insertPt).createEndAccess(loc, value, false);
return;
}
case ScopedAddressValueKind::Invalid:
llvm_unreachable("Using invalid case?!");
}
}
void ScopedAddressValue::endScopeAtLivenessBoundary(
SSAPrunedLiveness *liveness) const {
// If no users exist, create scope ending instruction immediately after the
// scoped address value.
if (liveness->empty()) {
createScopeEnd(value->getNextInstruction()->getIterator(),
RegularLocation::getAutoGeneratedLocation());
return;
}
PrunedLivenessBoundary scopedAddressBoundary;
liveness->computeBoundary(scopedAddressBoundary);
// Go over the boundary and create scope ending instructions.
scopedAddressBoundary.visitInsertionPoints(
[&](SILBasicBlock::iterator insertPt) {
createScopeEnd(insertPt, RegularLocation::getAutoGeneratedLocation());
});
}
bool swift::hasOtherStoreBorrowsInLifetime(StoreBorrowInst *storeBorrow,
SSAPrunedLiveness *liveness,
DeadEndBlocks *deadEndBlocks) {
SmallVector<StoreBorrowInst *, 4> otherStoreBorrows;
// Collect all other store_borrows to the destination of \p storeBorrow
for (auto *destUse : storeBorrow->getDest()->getUses()) {
if (auto *user = dyn_cast<StoreBorrowInst>(destUse->getUser())) {
if (user == storeBorrow) {
continue;
}
otherStoreBorrows.push_back(user);
}
}
for (auto *otherStoreBorrow : otherStoreBorrows) {
// Return true, if otherStoreBorrow was in \p storeBorrow's scope
if (liveness->isWithinBoundary(otherStoreBorrow)) {
return true;
}
}
return false;
}
void ScopedAddressValue::print(llvm::raw_ostream &os) const {
os << "ScopedAddressIntroducingValue:\n"
"Kind: "
<< kind
<< "\n"
"Value: "
<< value;
}
llvm::raw_ostream &swift::operator<<(llvm::raw_ostream &os,
const ScopedAddressValue &value) {
value.print(os);
return os;
}
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