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authorvitalyisaev <[email protected]>2023-06-29 10:00:50 +0300
committervitalyisaev <[email protected]>2023-06-29 10:00:50 +0300
commit6ffe9e53658409f212834330e13564e4952558f6 (patch)
tree85b1e00183517648b228aafa7c8fb07f5276f419 /contrib/libs/llvm16/lib/Transforms/Utils/LoopVersioning.cpp
parent726057070f9c5a91fc10fde0d5024913d10f1ab9 (diff)
YQ Connector: support managed ClickHouse
Со стороны dqrun можно обратиться к инстансу коннектора, который работает на streaming стенде, и извлечь данные из облачного CH.
Diffstat (limited to 'contrib/libs/llvm16/lib/Transforms/Utils/LoopVersioning.cpp')
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1 files changed, 356 insertions, 0 deletions
diff --git a/contrib/libs/llvm16/lib/Transforms/Utils/LoopVersioning.cpp b/contrib/libs/llvm16/lib/Transforms/Utils/LoopVersioning.cpp
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+//===- LoopVersioning.cpp - Utility to version a loop ---------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a utility class to perform loop versioning. The versioned
+// loop speculates that otherwise may-aliasing memory accesses don't overlap and
+// emits checks to prove this.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/LoopVersioning.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/InstSimplifyFolder.h"
+#include "llvm/Analysis/LoopAccessAnalysis.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/MDBuilder.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
+
+using namespace llvm;
+
+static cl::opt<bool>
+ AnnotateNoAlias("loop-version-annotate-no-alias", cl::init(true),
+ cl::Hidden,
+ cl::desc("Add no-alias annotation for instructions that "
+ "are disambiguated by memchecks"));
+
+LoopVersioning::LoopVersioning(const LoopAccessInfo &LAI,
+ ArrayRef<RuntimePointerCheck> Checks, Loop *L,
+ LoopInfo *LI, DominatorTree *DT,
+ ScalarEvolution *SE)
+ : VersionedLoop(L), AliasChecks(Checks.begin(), Checks.end()),
+ Preds(LAI.getPSE().getPredicate()), LAI(LAI), LI(LI), DT(DT),
+ SE(SE) {
+}
+
+void LoopVersioning::versionLoop(
+ const SmallVectorImpl<Instruction *> &DefsUsedOutside) {
+ assert(VersionedLoop->getUniqueExitBlock() && "No single exit block");
+ assert(VersionedLoop->isLoopSimplifyForm() &&
+ "Loop is not in loop-simplify form");
+
+ Value *MemRuntimeCheck;
+ Value *SCEVRuntimeCheck;
+ Value *RuntimeCheck = nullptr;
+
+ // Add the memcheck in the original preheader (this is empty initially).
+ BasicBlock *RuntimeCheckBB = VersionedLoop->getLoopPreheader();
+ const auto &RtPtrChecking = *LAI.getRuntimePointerChecking();
+
+ SCEVExpander Exp2(*RtPtrChecking.getSE(),
+ VersionedLoop->getHeader()->getModule()->getDataLayout(),
+ "induction");
+ MemRuntimeCheck = addRuntimeChecks(RuntimeCheckBB->getTerminator(),
+ VersionedLoop, AliasChecks, Exp2);
+
+ SCEVExpander Exp(*SE, RuntimeCheckBB->getModule()->getDataLayout(),
+ "scev.check");
+ SCEVRuntimeCheck =
+ Exp.expandCodeForPredicate(&Preds, RuntimeCheckBB->getTerminator());
+
+ IRBuilder<InstSimplifyFolder> Builder(
+ RuntimeCheckBB->getContext(),
+ InstSimplifyFolder(RuntimeCheckBB->getModule()->getDataLayout()));
+ if (MemRuntimeCheck && SCEVRuntimeCheck) {
+ Builder.SetInsertPoint(RuntimeCheckBB->getTerminator());
+ RuntimeCheck =
+ Builder.CreateOr(MemRuntimeCheck, SCEVRuntimeCheck, "lver.safe");
+ } else
+ RuntimeCheck = MemRuntimeCheck ? MemRuntimeCheck : SCEVRuntimeCheck;
+
+ assert(RuntimeCheck && "called even though we don't need "
+ "any runtime checks");
+
+ // Rename the block to make the IR more readable.
+ RuntimeCheckBB->setName(VersionedLoop->getHeader()->getName() +
+ ".lver.check");
+
+ // Create empty preheader for the loop (and after cloning for the
+ // non-versioned loop).
+ BasicBlock *PH =
+ SplitBlock(RuntimeCheckBB, RuntimeCheckBB->getTerminator(), DT, LI,
+ nullptr, VersionedLoop->getHeader()->getName() + ".ph");
+
+ // Clone the loop including the preheader.
+ //
+ // FIXME: This does not currently preserve SimplifyLoop because the exit
+ // block is a join between the two loops.
+ SmallVector<BasicBlock *, 8> NonVersionedLoopBlocks;
+ NonVersionedLoop =
+ cloneLoopWithPreheader(PH, RuntimeCheckBB, VersionedLoop, VMap,
+ ".lver.orig", LI, DT, NonVersionedLoopBlocks);
+ remapInstructionsInBlocks(NonVersionedLoopBlocks, VMap);
+
+ // Insert the conditional branch based on the result of the memchecks.
+ Instruction *OrigTerm = RuntimeCheckBB->getTerminator();
+ Builder.SetInsertPoint(OrigTerm);
+ Builder.CreateCondBr(RuntimeCheck, NonVersionedLoop->getLoopPreheader(),
+ VersionedLoop->getLoopPreheader());
+ OrigTerm->eraseFromParent();
+
+ // The loops merge in the original exit block. This is now dominated by the
+ // memchecking block.
+ DT->changeImmediateDominator(VersionedLoop->getExitBlock(), RuntimeCheckBB);
+
+ // Adds the necessary PHI nodes for the versioned loops based on the
+ // loop-defined values used outside of the loop.
+ addPHINodes(DefsUsedOutside);
+ formDedicatedExitBlocks(NonVersionedLoop, DT, LI, nullptr, true);
+ formDedicatedExitBlocks(VersionedLoop, DT, LI, nullptr, true);
+ assert(NonVersionedLoop->isLoopSimplifyForm() &&
+ VersionedLoop->isLoopSimplifyForm() &&
+ "The versioned loops should be in simplify form.");
+}
+
+void LoopVersioning::addPHINodes(
+ const SmallVectorImpl<Instruction *> &DefsUsedOutside) {
+ BasicBlock *PHIBlock = VersionedLoop->getExitBlock();
+ assert(PHIBlock && "No single successor to loop exit block");
+ PHINode *PN;
+
+ // First add a single-operand PHI for each DefsUsedOutside if one does not
+ // exists yet.
+ for (auto *Inst : DefsUsedOutside) {
+ // See if we have a single-operand PHI with the value defined by the
+ // original loop.
+ for (auto I = PHIBlock->begin(); (PN = dyn_cast<PHINode>(I)); ++I) {
+ if (PN->getIncomingValue(0) == Inst) {
+ SE->forgetValue(PN);
+ break;
+ }
+ }
+ // If not create it.
+ if (!PN) {
+ PN = PHINode::Create(Inst->getType(), 2, Inst->getName() + ".lver",
+ &PHIBlock->front());
+ SmallVector<User*, 8> UsersToUpdate;
+ for (User *U : Inst->users())
+ if (!VersionedLoop->contains(cast<Instruction>(U)->getParent()))
+ UsersToUpdate.push_back(U);
+ for (User *U : UsersToUpdate)
+ U->replaceUsesOfWith(Inst, PN);
+ PN->addIncoming(Inst, VersionedLoop->getExitingBlock());
+ }
+ }
+
+ // Then for each PHI add the operand for the edge from the cloned loop.
+ for (auto I = PHIBlock->begin(); (PN = dyn_cast<PHINode>(I)); ++I) {
+ assert(PN->getNumOperands() == 1 &&
+ "Exit block should only have on predecessor");
+
+ // If the definition was cloned used that otherwise use the same value.
+ Value *ClonedValue = PN->getIncomingValue(0);
+ auto Mapped = VMap.find(ClonedValue);
+ if (Mapped != VMap.end())
+ ClonedValue = Mapped->second;
+
+ PN->addIncoming(ClonedValue, NonVersionedLoop->getExitingBlock());
+ }
+}
+
+void LoopVersioning::prepareNoAliasMetadata() {
+ // We need to turn the no-alias relation between pointer checking groups into
+ // no-aliasing annotations between instructions.
+ //
+ // We accomplish this by mapping each pointer checking group (a set of
+ // pointers memchecked together) to an alias scope and then also mapping each
+ // group to the list of scopes it can't alias.
+
+ const RuntimePointerChecking *RtPtrChecking = LAI.getRuntimePointerChecking();
+ LLVMContext &Context = VersionedLoop->getHeader()->getContext();
+
+ // First allocate an aliasing scope for each pointer checking group.
+ //
+ // While traversing through the checking groups in the loop, also create a
+ // reverse map from pointers to the pointer checking group they were assigned
+ // to.
+ MDBuilder MDB(Context);
+ MDNode *Domain = MDB.createAnonymousAliasScopeDomain("LVerDomain");
+
+ for (const auto &Group : RtPtrChecking->CheckingGroups) {
+ GroupToScope[&Group] = MDB.createAnonymousAliasScope(Domain);
+
+ for (unsigned PtrIdx : Group.Members)
+ PtrToGroup[RtPtrChecking->getPointerInfo(PtrIdx).PointerValue] = &Group;
+ }
+
+ // Go through the checks and for each pointer group, collect the scopes for
+ // each non-aliasing pointer group.
+ DenseMap<const RuntimeCheckingPtrGroup *, SmallVector<Metadata *, 4>>
+ GroupToNonAliasingScopes;
+
+ for (const auto &Check : AliasChecks)
+ GroupToNonAliasingScopes[Check.first].push_back(GroupToScope[Check.second]);
+
+ // Finally, transform the above to actually map to scope list which is what
+ // the metadata uses.
+
+ for (auto Pair : GroupToNonAliasingScopes)
+ GroupToNonAliasingScopeList[Pair.first] = MDNode::get(Context, Pair.second);
+}
+
+void LoopVersioning::annotateLoopWithNoAlias() {
+ if (!AnnotateNoAlias)
+ return;
+
+ // First prepare the maps.
+ prepareNoAliasMetadata();
+
+ // Add the scope and no-alias metadata to the instructions.
+ for (Instruction *I : LAI.getDepChecker().getMemoryInstructions()) {
+ annotateInstWithNoAlias(I);
+ }
+}
+
+void LoopVersioning::annotateInstWithNoAlias(Instruction *VersionedInst,
+ const Instruction *OrigInst) {
+ if (!AnnotateNoAlias)
+ return;
+
+ LLVMContext &Context = VersionedLoop->getHeader()->getContext();
+ const Value *Ptr = isa<LoadInst>(OrigInst)
+ ? cast<LoadInst>(OrigInst)->getPointerOperand()
+ : cast<StoreInst>(OrigInst)->getPointerOperand();
+
+ // Find the group for the pointer and then add the scope metadata.
+ auto Group = PtrToGroup.find(Ptr);
+ if (Group != PtrToGroup.end()) {
+ VersionedInst->setMetadata(
+ LLVMContext::MD_alias_scope,
+ MDNode::concatenate(
+ VersionedInst->getMetadata(LLVMContext::MD_alias_scope),
+ MDNode::get(Context, GroupToScope[Group->second])));
+
+ // Add the no-alias metadata.
+ auto NonAliasingScopeList = GroupToNonAliasingScopeList.find(Group->second);
+ if (NonAliasingScopeList != GroupToNonAliasingScopeList.end())
+ VersionedInst->setMetadata(
+ LLVMContext::MD_noalias,
+ MDNode::concatenate(
+ VersionedInst->getMetadata(LLVMContext::MD_noalias),
+ NonAliasingScopeList->second));
+ }
+}
+
+namespace {
+bool runImpl(LoopInfo *LI, LoopAccessInfoManager &LAIs, DominatorTree *DT,
+ ScalarEvolution *SE) {
+ // Build up a worklist of inner-loops to version. This is necessary as the
+ // act of versioning a loop creates new loops and can invalidate iterators
+ // across the loops.
+ SmallVector<Loop *, 8> Worklist;
+
+ for (Loop *TopLevelLoop : *LI)
+ for (Loop *L : depth_first(TopLevelLoop))
+ // We only handle inner-most loops.
+ if (L->isInnermost())
+ Worklist.push_back(L);
+
+ // Now walk the identified inner loops.
+ bool Changed = false;
+ for (Loop *L : Worklist) {
+ if (!L->isLoopSimplifyForm() || !L->isRotatedForm() ||
+ !L->getExitingBlock())
+ continue;
+ const LoopAccessInfo &LAI = LAIs.getInfo(*L);
+ if (!LAI.hasConvergentOp() &&
+ (LAI.getNumRuntimePointerChecks() ||
+ !LAI.getPSE().getPredicate().isAlwaysTrue())) {
+ LoopVersioning LVer(LAI, LAI.getRuntimePointerChecking()->getChecks(), L,
+ LI, DT, SE);
+ LVer.versionLoop();
+ LVer.annotateLoopWithNoAlias();
+ Changed = true;
+ LAIs.clear();
+ }
+ }
+
+ return Changed;
+}
+
+/// Also expose this is a pass. Currently this is only used for
+/// unit-testing. It adds all memchecks necessary to remove all may-aliasing
+/// array accesses from the loop.
+class LoopVersioningLegacyPass : public FunctionPass {
+public:
+ LoopVersioningLegacyPass() : FunctionPass(ID) {
+ initializeLoopVersioningLegacyPassPass(*PassRegistry::getPassRegistry());
+ }
+
+ bool runOnFunction(Function &F) override {
+ auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+ auto &LAIs = getAnalysis<LoopAccessLegacyAnalysis>().getLAIs();
+ auto *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+ auto *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+
+ return runImpl(LI, LAIs, DT, SE);
+ }
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addRequired<LoopInfoWrapperPass>();
+ AU.addPreserved<LoopInfoWrapperPass>();
+ AU.addRequired<LoopAccessLegacyAnalysis>();
+ AU.addRequired<DominatorTreeWrapperPass>();
+ AU.addPreserved<DominatorTreeWrapperPass>();
+ AU.addRequired<ScalarEvolutionWrapperPass>();
+ }
+
+ static char ID;
+};
+}
+
+#define LVER_OPTION "loop-versioning"
+#define DEBUG_TYPE LVER_OPTION
+
+char LoopVersioningLegacyPass::ID;
+static const char LVer_name[] = "Loop Versioning";
+
+INITIALIZE_PASS_BEGIN(LoopVersioningLegacyPass, LVER_OPTION, LVer_name, false,
+ false)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopAccessLegacyAnalysis)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+INITIALIZE_PASS_END(LoopVersioningLegacyPass, LVER_OPTION, LVer_name, false,
+ false)
+
+namespace llvm {
+FunctionPass *createLoopVersioningLegacyPass() {
+ return new LoopVersioningLegacyPass();
+}
+
+PreservedAnalyses LoopVersioningPass::run(Function &F,
+ FunctionAnalysisManager &AM) {
+ auto &SE = AM.getResult<ScalarEvolutionAnalysis>(F);
+ auto &LI = AM.getResult<LoopAnalysis>(F);
+ LoopAccessInfoManager &LAIs = AM.getResult<LoopAccessAnalysis>(F);
+ auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
+
+ if (runImpl(&LI, LAIs, &DT, &SE))
+ return PreservedAnalyses::none();
+ return PreservedAnalyses::all();
+}
+} // namespace llvm