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129 lines
4.1 KiB
C++
129 lines
4.1 KiB
C++
//===--- LoopInfo.cpp - SIL Loop Analysis ---------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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#include "swift/SIL/LoopInfo.h"
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#include "swift/SIL/SILBasicBlock.h"
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#include "swift/SIL/Dominance.h"
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#include "swift/SIL/SILFunction.h"
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#include "swift/SIL/CFG.h"
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#include "llvm/Analysis/LoopInfoImpl.h"
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#include "llvm/Support/Debug.h"
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using namespace swift;
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// Instantiate template members.
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template class llvm::LoopBase<SILBasicBlock, SILLoop>;
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template class llvm::LoopInfoBase<SILBasicBlock, SILLoop>;
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void SILLoop::dump() const {
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#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
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print(llvm::dbgs());
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#endif
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}
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SILLoopInfo::SILLoopInfo(SILFunction *F, DominanceInfo *DT) : Dominance(DT) {
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LI.analyze(*Dominance);
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}
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bool SILLoop::canDuplicate(SILInstruction *I) const {
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// The deallocation of a stack allocation must be in the loop, otherwise the
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// deallocation will be fed by a phi node of two allocations.
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if (I->isAllocatingStack()) {
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for (auto *UI : cast<SingleValueInstruction>(I)->getUses()) {
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if (UI->getUser()->isDeallocatingStack()) {
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if (!contains(UI->getUser()->getParent()))
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return false;
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}
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}
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return true;
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}
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if (I->isDeallocatingStack()) {
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SILInstruction *alloc = nullptr;
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if (auto *dealloc = dyn_cast<DeallocStackInst>(I)) {
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SILValue address = dealloc->getOperand();
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if (isa<AllocStackInst>(address) || isa<PartialApplyInst>(address))
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alloc = cast<SingleValueInstruction>(address);
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}
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if (auto *dealloc = dyn_cast<DeallocRefInst>(I))
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alloc = dyn_cast<AllocRefInst>(dealloc->getOperand());
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return alloc && contains(alloc);
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}
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// CodeGen can't build ssa for objc methods.
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if (auto *Method = dyn_cast<MethodInst>(I)) {
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if (Method->getMember().isForeign) {
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for (auto *UI : Method->getUses()) {
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if (!contains(UI->getUser()))
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return false;
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}
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}
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return true;
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}
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// We can't have a phi of two openexistential instructions of different UUID.
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if (isa<OpenExistentialAddrInst>(I) || isa<OpenExistentialRefInst>(I) ||
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isa<OpenExistentialMetatypeInst>(I) ||
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isa<OpenExistentialValueInst>(I) || isa<OpenExistentialBoxInst>(I) ||
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isa<OpenExistentialBoxValueInst>(I)) {
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SingleValueInstruction *OI = cast<SingleValueInstruction>(I);
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for (auto *UI : OI->getUses())
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if (!contains(UI->getUser()))
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return false;
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return true;
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}
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if (isa<ThrowInst>(I))
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return false;
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// The entire access must be within the loop.
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if (auto BAI = dyn_cast<BeginAccessInst>(I)) {
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for (auto *UI : BAI->getUses()) {
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if (!contains(UI->getUser()))
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return false;
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}
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return true;
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}
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// The entire coroutine execution must be within the loop.
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// Note that we don't have to worry about the reverse --- a loop which
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// contains an end_apply or abort_apply of an external begin_apply ---
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// because that wouldn't be structurally valid in the first place.
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if (auto BAI = dyn_cast<BeginApplyInst>(I)) {
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for (auto UI : BAI->getTokenResult()->getUses()) {
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auto User = UI->getUser();
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assert(isa<EndApplyInst>(User) || isa<AbortApplyInst>(User));
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if (!contains(User))
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return false;
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}
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return true;
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}
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if (isa<DynamicMethodBranchInst>(I))
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return false;
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// Can't duplicate get/await_async_continuation.
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if (isa<AwaitAsyncContinuationInst>(I) ||
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isa<GetAsyncContinuationAddrInst>(I) || isa<GetAsyncContinuationInst>(I))
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return false;
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// Some special cases above that aren't considered isTriviallyDuplicatable
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// return true early.
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assert(I->isTriviallyDuplicatable() &&
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"Code here must match isTriviallyDuplicatable in SILInstruction");
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return true;
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}
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void SILLoopInfo::verify() const {
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LI.verify(*Dominance);
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}
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