#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ProfileSummaryInfo.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/ISDOpcodes.h"
-#include "llvm/CodeGen/MachineValueType.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
+#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetPassConfig.h"
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/Config/llvm-config.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MachineValueType.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/BypassSlowDivision.h"
-#include "llvm/Transforms/Utils/Cloning.h"
-#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/SimplifyLibCalls.h"
-#include "llvm/Transforms/Utils/ValueMapper.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
"of sunken Casts");
STATISTIC(NumMemoryInsts, "Number of memory instructions whose address "
"computations were sunk");
+STATISTIC(NumMemoryInstsPhiCreated,
+ "Number of phis created when address "
+ "computations were sunk to memory instructions");
+STATISTIC(NumMemoryInstsSelectCreated,
+ "Number of select created when address "
+ "computations were sunk to memory instructions");
STATISTIC(NumExtsMoved, "Number of [s|z]ext instructions combined with loads");
STATISTIC(NumExtUses, "Number of uses of [s|z]ext instructions optimized");
STATISTIC(NumAndsAdded,
STATISTIC(NumSelectsExpanded, "Number of selects turned into branches");
STATISTIC(NumStoreExtractExposed, "Number of store(extractelement) exposed");
-STATISTIC(NumMemCmpCalls, "Number of memcmp calls");
-STATISTIC(NumMemCmpNotConstant, "Number of memcmp calls without constant size");
-STATISTIC(NumMemCmpGreaterThanMax,
- "Number of memcmp calls with size greater than max size");
-STATISTIC(NumMemCmpInlined, "Number of inlined memcmp calls");
-
static cl::opt<bool> DisableBranchOpts(
"disable-cgp-branch-opts", cl::Hidden, cl::init(false),
cl::desc("Disable branch optimizations in CodeGenPrepare"));
cl::desc("Enable merging of redundant sexts when one is dominating"
" the other."), cl::init(true));
-static cl::opt<unsigned> MemCmpNumLoadsPerBlock(
- "memcmp-num-loads-per-block", cl::Hidden, cl::init(1),
- cl::desc("The number of loads per basic block for inline expansion of "
- "memcmp that is only being compared against zero."));
+static cl::opt<bool> DisableComplexAddrModes(
+ "disable-complex-addr-modes", cl::Hidden, cl::init(false),
+ cl::desc("Disables combining addressing modes with different parts "
+ "in optimizeMemoryInst."));
+
+static cl::opt<bool>
+AddrSinkNewPhis("addr-sink-new-phis", cl::Hidden, cl::init(false),
+ cl::desc("Allow creation of Phis in Address sinking."));
+
+static cl::opt<bool>
+AddrSinkNewSelects("addr-sink-new-select", cl::Hidden, cl::init(true),
+ cl::desc("Allow creation of selects in Address sinking."));
+
+static cl::opt<bool> AddrSinkCombineBaseReg(
+ "addr-sink-combine-base-reg", cl::Hidden, cl::init(true),
+ cl::desc("Allow combining of BaseReg field in Address sinking."));
+
+static cl::opt<bool> AddrSinkCombineBaseGV(
+ "addr-sink-combine-base-gv", cl::Hidden, cl::init(true),
+ cl::desc("Allow combining of BaseGV field in Address sinking."));
+
+static cl::opt<bool> AddrSinkCombineBaseOffs(
+ "addr-sink-combine-base-offs", cl::Hidden, cl::init(true),
+ cl::desc("Allow combining of BaseOffs field in Address sinking."));
+
+static cl::opt<bool> AddrSinkCombineScaledReg(
+ "addr-sink-combine-scaled-reg", cl::Hidden, cl::init(true),
+ cl::desc("Allow combining of ScaledReg field in Address sinking."));
+
+static cl::opt<bool>
+ EnableGEPOffsetSplit("cgp-split-large-offset-gep", cl::Hidden,
+ cl::init(true),
+ cl::desc("Enable splitting large offset of GEP."));
namespace {
+enum ExtType {
+ ZeroExtension, // Zero extension has been seen.
+ SignExtension, // Sign extension has been seen.
+ BothExtension // This extension type is used if we saw sext after
+ // ZeroExtension had been set, or if we saw zext after
+ // SignExtension had been set. It makes the type
+ // information of a promoted instruction invalid.
+};
+
using SetOfInstrs = SmallPtrSet<Instruction *, 16>;
-using TypeIsSExt = PointerIntPair<Type *, 1, bool>;
+using TypeIsSExt = PointerIntPair<Type *, 2, ExtType>;
using InstrToOrigTy = DenseMap<Instruction *, TypeIsSExt>;
using SExts = SmallVector<Instruction *, 16>;
using ValueToSExts = DenseMap<Value *, SExts>;
/// Keeps track of non-local addresses that have been sunk into a block.
/// This allows us to avoid inserting duplicate code for blocks with
- /// multiple load/stores of the same address.
- ValueMap<Value*, Value*> SunkAddrs;
+ /// multiple load/stores of the same address. The usage of WeakTrackingVH
+ /// enables SunkAddrs to be treated as a cache whose entries can be
+ /// invalidated if a sunken address computation has been erased.
+ ValueMap<Value*, WeakTrackingVH> SunkAddrs;
/// Keeps track of all instructions inserted for the current function.
SetOfInstrs InsertedInsts;
/// Keep track of sext chains based on their initial value.
DenseMap<Value *, Instruction *> SeenChainsForSExt;
+ /// Keep track of GEPs accessing the same data structures such as structs or
+ /// arrays that are candidates to be split later because of their large
+ /// size.
+ DenseMap<
+ AssertingVH<Value>,
+ SmallVector<std::pair<AssertingVH<GetElementPtrInst>, int64_t>, 32>>
+ LargeOffsetGEPMap;
+
+ /// Keep track of new GEP base after splitting the GEPs having large offset.
+ SmallSet<AssertingVH<Value>, 2> NewGEPBases;
+
+ /// Map serial numbers to Large offset GEPs.
+ DenseMap<AssertingVH<GetElementPtrInst>, int> LargeOffsetGEPID;
+
/// Keep track of SExt promoted.
ValueToSExts ValToSExtendedUses;
bool isPreheader);
bool optimizeBlock(BasicBlock &BB, bool &ModifiedDT);
bool optimizeInst(Instruction *I, bool &ModifiedDT);
- bool optimizeMemoryInst(Instruction *I, Value *Addr,
- Type *AccessTy, unsigned AS);
+ bool optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
+ Type *AccessTy, unsigned AddrSpace);
bool optimizeInlineAsmInst(CallInst *CS);
bool optimizeCallInst(CallInst *CI, bool &ModifiedDT);
bool optimizeExt(Instruction *&I);
bool optimizeExtUses(Instruction *I);
- bool optimizeLoadExt(LoadInst *I);
+ bool optimizeLoadExt(LoadInst *Load);
bool optimizeSelectInst(SelectInst *SI);
- bool optimizeShuffleVectorInst(ShuffleVectorInst *SI);
- bool optimizeSwitchInst(SwitchInst *CI);
+ bool optimizeShuffleVectorInst(ShuffleVectorInst *SVI);
+ bool optimizeSwitchInst(SwitchInst *SI);
bool optimizeExtractElementInst(Instruction *Inst);
bool dupRetToEnableTailCallOpts(BasicBlock *BB);
bool placeDbgValues(Function &F);
SmallVectorImpl<Instruction *> &ProfitablyMovedExts,
unsigned CreatedInstsCost = 0);
bool mergeSExts(Function &F);
+ bool splitLargeGEPOffsets();
bool performAddressTypePromotion(
Instruction *&Inst,
bool AllowPromotionWithoutCommonHeader,
SmallVectorImpl<Instruction *> &SpeculativelyMovedExts);
bool splitBranchCondition(Function &F);
bool simplifyOffsetableRelocate(Instruction &I);
- bool splitIndirectCriticalEdges(Function &F);
};
} // end anonymous namespace
// Clear per function information.
InsertedInsts.clear();
PromotedInsts.clear();
- BFI.reset();
- BPI.reset();
ModifiedDT = false;
if (auto *TPC = getAnalysisIfAvailable<TargetPassConfig>()) {
TLInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+ BPI.reset(new BranchProbabilityInfo(F, *LI));
+ BFI.reset(new BlockFrequencyInfo(F, *BPI, *LI));
OptSize = F.optForSize();
+ ProfileSummaryInfo *PSI =
+ getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
if (ProfileGuidedSectionPrefix) {
- ProfileSummaryInfo *PSI =
- getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
- if (PSI->isFunctionHotInCallGraph(&F))
+ if (PSI->isFunctionHotInCallGraph(&F, *BFI))
F.setSectionPrefix(".hot");
- else if (PSI->isFunctionColdInCallGraph(&F))
+ else if (PSI->isFunctionColdInCallGraph(&F, *BFI))
F.setSectionPrefix(".unlikely");
}
/// This optimization identifies DIV instructions that can be
/// profitably bypassed and carried out with a shorter, faster divide.
- if (!OptSize && TLI && TLI->isSlowDivBypassed()) {
+ if (!OptSize && !PSI->hasHugeWorkingSetSize() && TLI &&
+ TLI->isSlowDivBypassed()) {
const DenseMap<unsigned int, unsigned int> &BypassWidths =
TLI->getBypassSlowDivWidths();
BasicBlock* BB = &*F.begin();
// Split some critical edges where one of the sources is an indirect branch,
// to help generate sane code for PHIs involving such edges.
- EverMadeChange |= splitIndirectCriticalEdges(F);
+ EverMadeChange |= SplitIndirectBrCriticalEdges(F);
bool MadeChange = true;
while (MadeChange) {
SeenChainsForSExt.clear();
ValToSExtendedUses.clear();
RemovedInsts.clear();
+ LargeOffsetGEPMap.clear();
+ LargeOffsetGEPID.clear();
for (Function::iterator I = F.begin(); I != F.end(); ) {
BasicBlock *BB = &*I++;
bool ModifiedDTOnIteration = false;
}
if (EnableTypePromotionMerge && !ValToSExtendedUses.empty())
MadeChange |= mergeSExts(F);
+ if (!LargeOffsetGEPMap.empty())
+ MadeChange |= splitLargeGEPOffsets();
// Really free removed instructions during promotion.
for (Instruction *I : RemovedInsts)
if (!DisableBranchOpts) {
MadeChange = false;
- SmallPtrSet<BasicBlock*, 8> WorkList;
+ // Use a set vector to get deterministic iteration order. The order the
+ // blocks are removed may affect whether or not PHI nodes in successors
+ // are removed.
+ SmallSetVector<BasicBlock*, 8> WorkList;
for (BasicBlock &BB : F) {
SmallVector<BasicBlock *, 2> Successors(succ_begin(&BB), succ_end(&BB));
MadeChange |= ConstantFoldTerminator(&BB, true);
// Delete the dead blocks and any of their dead successors.
MadeChange |= !WorkList.empty();
while (!WorkList.empty()) {
- BasicBlock *BB = *WorkList.begin();
- WorkList.erase(BB);
+ BasicBlock *BB = WorkList.pop_back_val();
SmallVector<BasicBlock*, 2> Successors(succ_begin(BB), succ_end(BB));
DeleteDeadBlock(BB);
bool CodeGenPrepare::eliminateFallThrough(Function &F) {
bool Changed = false;
// Scan all of the blocks in the function, except for the entry block.
- for (Function::iterator I = std::next(F.begin()), E = F.end(); I != E;) {
- BasicBlock *BB = &*I++;
+ // Use a temporary array to avoid iterator being invalidated when
+ // deleting blocks.
+ SmallVector<WeakTrackingVH, 16> Blocks;
+ for (auto &Block : llvm::make_range(std::next(F.begin()), F.end()))
+ Blocks.push_back(&Block);
+
+ for (auto &Block : Blocks) {
+ auto *BB = cast_or_null<BasicBlock>(Block);
+ if (!BB)
+ continue;
// If the destination block has a single pred, then this is a trivial
// edge, just collapse it.
BasicBlock *SinglePred = BB->getSinglePredecessor();
BranchInst *Term = dyn_cast<BranchInst>(SinglePred->getTerminator());
if (Term && !Term->isConditional()) {
Changed = true;
- DEBUG(dbgs() << "To merge:\n"<< *SinglePred << "\n\n\n");
- // Remember if SinglePred was the entry block of the function.
- // If so, we will need to move BB back to the entry position.
- bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
- MergeBasicBlockIntoOnlyPred(BB, nullptr);
-
- if (isEntry && BB != &BB->getParent()->getEntryBlock())
- BB->moveBefore(&BB->getParent()->getEntryBlock());
+ LLVM_DEBUG(dbgs() << "To merge:\n" << *BB << "\n\n\n");
- // We have erased a block. Update the iterator.
- I = BB->getIterator();
+ // Merge BB into SinglePred and delete it.
+ MergeBlockIntoPredecessor(BB);
}
}
return Changed;
return DestBB;
}
-// Return the unique indirectbr predecessor of a block. This may return null
-// even if such a predecessor exists, if it's not useful for splitting.
-// If a predecessor is found, OtherPreds will contain all other (non-indirectbr)
-// predecessors of BB.
-static BasicBlock *
-findIBRPredecessor(BasicBlock *BB, SmallVectorImpl<BasicBlock *> &OtherPreds) {
- // If the block doesn't have any PHIs, we don't care about it, since there's
- // no point in splitting it.
- PHINode *PN = dyn_cast<PHINode>(BB->begin());
- if (!PN)
- return nullptr;
-
- // Verify we have exactly one IBR predecessor.
- // Conservatively bail out if one of the other predecessors is not a "regular"
- // terminator (that is, not a switch or a br).
- BasicBlock *IBB = nullptr;
- for (unsigned Pred = 0, E = PN->getNumIncomingValues(); Pred != E; ++Pred) {
- BasicBlock *PredBB = PN->getIncomingBlock(Pred);
- TerminatorInst *PredTerm = PredBB->getTerminator();
- switch (PredTerm->getOpcode()) {
- case Instruction::IndirectBr:
- if (IBB)
- return nullptr;
- IBB = PredBB;
- break;
- case Instruction::Br:
- case Instruction::Switch:
- OtherPreds.push_back(PredBB);
- continue;
- default:
- return nullptr;
- }
- }
-
- return IBB;
-}
-
-// Split critical edges where the source of the edge is an indirectbr
-// instruction. This isn't always possible, but we can handle some easy cases.
-// This is useful because MI is unable to split such critical edges,
-// which means it will not be able to sink instructions along those edges.
-// This is especially painful for indirect branches with many successors, where
-// we end up having to prepare all outgoing values in the origin block.
-//
-// Our normal algorithm for splitting critical edges requires us to update
-// the outgoing edges of the edge origin block, but for an indirectbr this
-// is hard, since it would require finding and updating the block addresses
-// the indirect branch uses. But if a block only has a single indirectbr
-// predecessor, with the others being regular branches, we can do it in a
-// different way.
-// Say we have A -> D, B -> D, I -> D where only I -> D is an indirectbr.
-// We can split D into D0 and D1, where D0 contains only the PHIs from D,
-// and D1 is the D block body. We can then duplicate D0 as D0A and D0B, and
-// create the following structure:
-// A -> D0A, B -> D0A, I -> D0B, D0A -> D1, D0B -> D1
-bool CodeGenPrepare::splitIndirectCriticalEdges(Function &F) {
- // Check whether the function has any indirectbrs, and collect which blocks
- // they may jump to. Since most functions don't have indirect branches,
- // this lowers the common case's overhead to O(Blocks) instead of O(Edges).
- SmallSetVector<BasicBlock *, 16> Targets;
- for (auto &BB : F) {
- auto *IBI = dyn_cast<IndirectBrInst>(BB.getTerminator());
- if (!IBI)
- continue;
-
- for (unsigned Succ = 0, E = IBI->getNumSuccessors(); Succ != E; ++Succ)
- Targets.insert(IBI->getSuccessor(Succ));
- }
-
- if (Targets.empty())
- return false;
-
- bool Changed = false;
- for (BasicBlock *Target : Targets) {
- SmallVector<BasicBlock *, 16> OtherPreds;
- BasicBlock *IBRPred = findIBRPredecessor(Target, OtherPreds);
- // If we did not found an indirectbr, or the indirectbr is the only
- // incoming edge, this isn't the kind of edge we're looking for.
- if (!IBRPred || OtherPreds.empty())
- continue;
-
- // Don't even think about ehpads/landingpads.
- Instruction *FirstNonPHI = Target->getFirstNonPHI();
- if (FirstNonPHI->isEHPad() || Target->isLandingPad())
- continue;
-
- BasicBlock *BodyBlock = Target->splitBasicBlock(FirstNonPHI, ".split");
- // It's possible Target was its own successor through an indirectbr.
- // In this case, the indirectbr now comes from BodyBlock.
- if (IBRPred == Target)
- IBRPred = BodyBlock;
-
- // At this point Target only has PHIs, and BodyBlock has the rest of the
- // block's body. Create a copy of Target that will be used by the "direct"
- // preds.
- ValueToValueMapTy VMap;
- BasicBlock *DirectSucc = CloneBasicBlock(Target, VMap, ".clone", &F);
-
- for (BasicBlock *Pred : OtherPreds) {
- // If the target is a loop to itself, then the terminator of the split
- // block needs to be updated.
- if (Pred == Target)
- BodyBlock->getTerminator()->replaceUsesOfWith(Target, DirectSucc);
- else
- Pred->getTerminator()->replaceUsesOfWith(Target, DirectSucc);
- }
-
- // Ok, now fix up the PHIs. We know the two blocks only have PHIs, and that
- // they are clones, so the number of PHIs are the same.
- // (a) Remove the edge coming from IBRPred from the "Direct" PHI
- // (b) Leave that as the only edge in the "Indirect" PHI.
- // (c) Merge the two in the body block.
- BasicBlock::iterator Indirect = Target->begin(),
- End = Target->getFirstNonPHI()->getIterator();
- BasicBlock::iterator Direct = DirectSucc->begin();
- BasicBlock::iterator MergeInsert = BodyBlock->getFirstInsertionPt();
-
- assert(&*End == Target->getTerminator() &&
- "Block was expected to only contain PHIs");
-
- while (Indirect != End) {
- PHINode *DirPHI = cast<PHINode>(Direct);
- PHINode *IndPHI = cast<PHINode>(Indirect);
-
- // Now, clean up - the direct block shouldn't get the indirect value,
- // and vice versa.
- DirPHI->removeIncomingValue(IBRPred);
- Direct++;
-
- // Advance the pointer here, to avoid invalidation issues when the old
- // PHI is erased.
- Indirect++;
-
- PHINode *NewIndPHI = PHINode::Create(IndPHI->getType(), 1, "ind", IndPHI);
- NewIndPHI->addIncoming(IndPHI->getIncomingValueForBlock(IBRPred),
- IBRPred);
-
- // Create a PHI in the body block, to merge the direct and indirect
- // predecessors.
- PHINode *MergePHI =
- PHINode::Create(IndPHI->getType(), 2, "merge", &*MergeInsert);
- MergePHI->addIncoming(NewIndPHI, Target);
- MergePHI->addIncoming(DirPHI, DirectSucc);
-
- IndPHI->replaceAllUsesWith(MergePHI);
- IndPHI->eraseFromParent();
- }
-
- Changed = true;
- }
-
- return Changed;
-}
-
/// Eliminate blocks that contain only PHI nodes, debug info directives, and an
/// unconditional branch. Passes before isel (e.g. LSR/loopsimplify) often split
/// edges in ways that are non-optimal for isel. Start by eliminating these
}
bool MadeChange = false;
+ // Copy blocks into a temporary array to avoid iterator invalidation issues
+ // as we remove them.
// Note that this intentionally skips the entry block.
- for (Function::iterator I = std::next(F.begin()), E = F.end(); I != E;) {
- BasicBlock *BB = &*I++;
+ SmallVector<WeakTrackingVH, 16> Blocks;
+ for (auto &Block : llvm::make_range(std::next(F.begin()), F.end()))
+ Blocks.push_back(&Block);
+
+ for (auto &Block : Blocks) {
+ BasicBlock *BB = cast_or_null<BasicBlock>(Block);
+ if (!BB)
+ continue;
BasicBlock *DestBB = findDestBlockOfMergeableEmptyBlock(BB);
if (!DestBB ||
!isMergingEmptyBlockProfitable(BB, DestBB, Preheaders.count(BB)))
if (DestBBPred == BB)
continue;
- bool HasAllSameValue = true;
- BasicBlock::const_iterator DestBBI = DestBB->begin();
- while (const PHINode *DestPN = dyn_cast<PHINode>(DestBBI++)) {
- if (DestPN->getIncomingValueForBlock(BB) !=
- DestPN->getIncomingValueForBlock(DestBBPred)) {
- HasAllSameValue = false;
- break;
- }
- }
- if (HasAllSameValue)
+ if (llvm::all_of(DestBB->phis(), [&](const PHINode &DestPN) {
+ return DestPN.getIncomingValueForBlock(BB) ==
+ DestPN.getIncomingValueForBlock(DestBBPred);
+ }))
SameIncomingValueBBs.insert(DestBBPred);
}
if (SameIncomingValueBBs.count(Pred))
return true;
- if (!BFI) {
- Function &F = *BB->getParent();
- LoopInfo LI{DominatorTree(F)};
- BPI.reset(new BranchProbabilityInfo(F, LI));
- BFI.reset(new BlockFrequencyInfo(F, *BPI, LI));
- }
-
BlockFrequency PredFreq = BFI->getBlockFreq(Pred);
BlockFrequency BBFreq = BFI->getBlockFreq(BB);
// We only want to eliminate blocks whose phi nodes are used by phi nodes in
// the successor. If there are more complex condition (e.g. preheaders),
// don't mess around with them.
- BasicBlock::const_iterator BBI = BB->begin();
- while (const PHINode *PN = dyn_cast<PHINode>(BBI++)) {
- for (const User *U : PN->users()) {
+ for (const PHINode &PN : BB->phis()) {
+ for (const User *U : PN.users()) {
const Instruction *UI = cast<Instruction>(U);
if (UI->getParent() != DestBB || !isa<PHINode>(UI))
return false;
for (unsigned i = 0, e = DestBBPN->getNumIncomingValues(); i != e; ++i) {
BasicBlock *Pred = DestBBPN->getIncomingBlock(i);
if (BBPreds.count(Pred)) { // Common predecessor?
- BBI = DestBB->begin();
- while (const PHINode *PN = dyn_cast<PHINode>(BBI++)) {
- const Value *V1 = PN->getIncomingValueForBlock(Pred);
- const Value *V2 = PN->getIncomingValueForBlock(BB);
+ for (const PHINode &PN : DestBB->phis()) {
+ const Value *V1 = PN.getIncomingValueForBlock(Pred);
+ const Value *V2 = PN.getIncomingValueForBlock(BB);
// If V2 is a phi node in BB, look up what the mapped value will be.
if (const PHINode *V2PN = dyn_cast<PHINode>(V2))
BranchInst *BI = cast<BranchInst>(BB->getTerminator());
BasicBlock *DestBB = BI->getSuccessor(0);
- DEBUG(dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n" << *BB << *DestBB);
+ LLVM_DEBUG(dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n"
+ << *BB << *DestBB);
// If the destination block has a single pred, then this is a trivial edge,
// just collapse it.
if (BasicBlock *SinglePred = DestBB->getSinglePredecessor()) {
if (SinglePred != DestBB) {
- // Remember if SinglePred was the entry block of the function. If so, we
- // will need to move BB back to the entry position.
- bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
- MergeBasicBlockIntoOnlyPred(DestBB, nullptr);
-
- if (isEntry && BB != &BB->getParent()->getEntryBlock())
- BB->moveBefore(&BB->getParent()->getEntryBlock());
-
- DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n");
+ assert(SinglePred == BB &&
+ "Single predecessor not the same as predecessor");
+ // Merge DestBB into SinglePred/BB and delete it.
+ MergeBlockIntoPredecessor(DestBB);
+ // Note: BB(=SinglePred) will not be deleted on this path.
+ // DestBB(=its single successor) is the one that was deleted.
+ LLVM_DEBUG(dbgs() << "AFTER:\n" << *SinglePred << "\n\n\n");
return;
}
}
// Otherwise, we have multiple predecessors of BB. Update the PHIs in DestBB
// to handle the new incoming edges it is about to have.
- PHINode *PN;
- for (BasicBlock::iterator BBI = DestBB->begin();
- (PN = dyn_cast<PHINode>(BBI)); ++BBI) {
+ for (PHINode &PN : DestBB->phis()) {
// Remove the incoming value for BB, and remember it.
- Value *InVal = PN->removeIncomingValue(BB, false);
+ Value *InVal = PN.removeIncomingValue(BB, false);
// Two options: either the InVal is a phi node defined in BB or it is some
// value that dominates BB.
if (InValPhi && InValPhi->getParent() == BB) {
// Add all of the input values of the input PHI as inputs of this phi.
for (unsigned i = 0, e = InValPhi->getNumIncomingValues(); i != e; ++i)
- PN->addIncoming(InValPhi->getIncomingValue(i),
- InValPhi->getIncomingBlock(i));
+ PN.addIncoming(InValPhi->getIncomingValue(i),
+ InValPhi->getIncomingBlock(i));
} else {
// Otherwise, add one instance of the dominating value for each edge that
// we will be adding.
if (PHINode *BBPN = dyn_cast<PHINode>(BB->begin())) {
for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; ++i)
- PN->addIncoming(InVal, BBPN->getIncomingBlock(i));
+ PN.addIncoming(InVal, BBPN->getIncomingBlock(i));
} else {
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
- PN->addIncoming(InVal, *PI);
+ PN.addIncoming(InVal, *PI);
}
}
}
BB->eraseFromParent();
++NumBlocksElim;
- DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n");
+ LLVM_DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n");
}
// Computes a map of base pointer relocation instructions to corresponding
assert(InsertPt != UserBB->end());
InsertedCast = CastInst::Create(CI->getOpcode(), CI->getOperand(0),
CI->getType(), "", &*InsertPt);
+ InsertedCast->setDebugLoc(CI->getDebugLoc());
}
// Replace a use of the cast with a use of the new cast.
// If we removed all uses, nuke the cast.
if (CI->use_empty()) {
+ salvageDebugInfo(*CI);
CI->eraseFromParent();
MadeChange = true;
}
if (!TLI.isMaskAndCmp0FoldingBeneficial(*AndI))
return false;
- DEBUG(dbgs() << "found 'and' feeding only icmp 0;\n");
- DEBUG(AndI->getParent()->dump());
+ LLVM_DEBUG(dbgs() << "found 'and' feeding only icmp 0;\n");
+ LLVM_DEBUG(AndI->getParent()->dump());
// Push the 'and' into the same block as the icmp 0. There should only be
// one (icmp (and, 0)) in each block, since CSE/GVN should have removed any
// Preincrement use iterator so we don't invalidate it.
++UI;
- DEBUG(dbgs() << "sinking 'and' use: " << *User << "\n");
+ LLVM_DEBUG(dbgs() << "sinking 'and' use: " << *User << "\n");
// Keep the 'and' in the same place if the use is already in the same block.
Instruction *InsertPt =
// Replace a use of the 'and' with a use of the new 'and'.
TheUse = InsertedAnd;
++NumAndUses;
- DEBUG(User->getParent()->dump());
+ LLVM_DEBUG(User->getParent()->dump());
}
// We removed all uses, nuke the and.
/// %x.extract.shift.1 = lshr i64 %arg1, 32
/// %x.extract.trunc = trunc i64 %x.extract.shift.1 to i16
///
-/// CodeGen will recoginze the pattern in BB2 and generate BitExtract
+/// CodeGen will recognize the pattern in BB2 and generate BitExtract
/// instruction.
/// Return true if any changes are made.
static bool OptimizeExtractBits(BinaryOperator *ShiftI, ConstantInt *CI,
// cmp i16 trunc.result, opnd2
//
if (isa<TruncInst>(User) && shiftIsLegal
- // If the type of the truncate is legal, no trucate will be
+ // If the type of the truncate is legal, no truncate will be
// introduced in other basic blocks.
&&
(!TLI.isTypeLegal(TLI.getValueType(DL, User->getType()))))
return true;
}
-namespace {
-
-// This class provides helper functions to expand a memcmp library call into an
-// inline expansion.
-class MemCmpExpansion {
- struct ResultBlock {
- BasicBlock *BB = nullptr;
- PHINode *PhiSrc1 = nullptr;
- PHINode *PhiSrc2 = nullptr;
-
- ResultBlock() = default;
- };
-
- CallInst *const CI;
- ResultBlock ResBlock;
- const unsigned Size;
- unsigned MaxLoadSize;
- unsigned NumLoadsNonOneByte;
- const unsigned NumLoadsPerBlock;
- std::vector<BasicBlock *> LoadCmpBlocks;
- BasicBlock *EndBlock;
- PHINode *PhiRes;
- const bool IsUsedForZeroCmp;
- const DataLayout &DL;
- IRBuilder<> Builder;
- // Represents the decomposition in blocks of the expansion. For example,
- // comparing 33 bytes on X86+sse can be done with 2x16-byte loads and
- // 1x1-byte load, which would be represented as [{16, 0}, {16, 16}, {32, 1}.
- // TODO(courbet): Involve the target more in this computation. On X86, 7
- // bytes can be done more efficiently with two overlaping 4-byte loads than
- // covering the interval with [{4, 0},{2, 4},{1, 6}}.
- struct LoadEntry {
- LoadEntry(unsigned LoadSize, uint64_t Offset)
- : LoadSize(LoadSize), Offset(Offset) {
- assert(Offset % LoadSize == 0 && "invalid load entry");
- }
-
- uint64_t getGEPIndex() const { return Offset / LoadSize; }
-
- // The size of the load for this block, in bytes.
- const unsigned LoadSize;
- // The offset of this load WRT the base pointer, in bytes.
- const uint64_t Offset;
- };
- SmallVector<LoadEntry, 8> LoadSequence;
-
- void createLoadCmpBlocks();
- void createResultBlock();
- void setupResultBlockPHINodes();
- void setupEndBlockPHINodes();
- Value *getCompareLoadPairs(unsigned BlockIndex, unsigned &LoadIndex);
- void emitLoadCompareBlock(unsigned BlockIndex);
- void emitLoadCompareBlockMultipleLoads(unsigned BlockIndex,
- unsigned &LoadIndex);
- void emitLoadCompareByteBlock(unsigned BlockIndex, unsigned GEPIndex);
- void emitMemCmpResultBlock();
- Value *getMemCmpExpansionZeroCase();
- Value *getMemCmpEqZeroOneBlock();
- Value *getMemCmpOneBlock();
-
- public:
- MemCmpExpansion(CallInst *CI, uint64_t Size, unsigned MaxLoadSize,
- unsigned NumLoadsPerBlock, const DataLayout &DL);
-
- unsigned getNumBlocks();
- unsigned getNumLoads() const { return LoadSequence.size(); }
-
- Value *getMemCmpExpansion();
-};
-
-} // end anonymous namespace
-
-// Initialize the basic block structure required for expansion of memcmp call
-// with given maximum load size and memcmp size parameter.
-// This structure includes:
-// 1. A list of load compare blocks - LoadCmpBlocks.
-// 2. An EndBlock, split from original instruction point, which is the block to
-// return from.
-// 3. ResultBlock, block to branch to for early exit when a
-// LoadCmpBlock finds a difference.
-MemCmpExpansion::MemCmpExpansion(CallInst *const CI, uint64_t Size,
- const unsigned MaxLoadSize,
- const unsigned LoadsPerBlock,
- const DataLayout &TheDataLayout)
- : CI(CI),
- Size(Size),
- MaxLoadSize(MaxLoadSize),
- NumLoadsNonOneByte(0),
- NumLoadsPerBlock(LoadsPerBlock),
- IsUsedForZeroCmp(isOnlyUsedInZeroEqualityComparison(CI)),
- DL(TheDataLayout),
- Builder(CI) {
- // Scale the max size down if the target can load more bytes than we need.
- while (this->MaxLoadSize > Size) {
- this->MaxLoadSize /= 2;
- }
- // Compute the decomposition.
- unsigned LoadSize = this->MaxLoadSize;
- assert(Size > 0 && "zero blocks");
- uint64_t Offset = 0;
- while (Size) {
- assert(LoadSize > 0 && "zero load size");
- const uint64_t NumLoadsForThisSize = Size / LoadSize;
- if (NumLoadsForThisSize > 0) {
- for (uint64_t I = 0; I < NumLoadsForThisSize; ++I) {
- LoadSequence.push_back({LoadSize, Offset});
- Offset += LoadSize;
- }
- if (LoadSize > 1) {
- ++NumLoadsNonOneByte;
- }
- Size = Size % LoadSize;
- }
- // FIXME: This can result in a non-native load size (e.g. X86-32+SSE can
- // load 16 and 4 but not 8), which throws the load count off (e.g. in the
- // aforementioned case, 16 bytes will count for 2 loads but will generate
- // 4).
- LoadSize /= 2;
- }
-}
-
-unsigned MemCmpExpansion::getNumBlocks() {
- if (IsUsedForZeroCmp)
- return getNumLoads() / NumLoadsPerBlock +
- (getNumLoads() % NumLoadsPerBlock != 0 ? 1 : 0);
- return getNumLoads();
-}
-
-void MemCmpExpansion::createLoadCmpBlocks() {
- for (unsigned i = 0; i < getNumBlocks(); i++) {
- BasicBlock *BB = BasicBlock::Create(CI->getContext(), "loadbb",
- EndBlock->getParent(), EndBlock);
- LoadCmpBlocks.push_back(BB);
- }
-}
-
-void MemCmpExpansion::createResultBlock() {
- ResBlock.BB = BasicBlock::Create(CI->getContext(), "res_block",
- EndBlock->getParent(), EndBlock);
-}
-
-// This function creates the IR instructions for loading and comparing 1 byte.
-// It loads 1 byte from each source of the memcmp parameters with the given
-// GEPIndex. It then subtracts the two loaded values and adds this result to the
-// final phi node for selecting the memcmp result.
-void MemCmpExpansion::emitLoadCompareByteBlock(unsigned BlockIndex,
- unsigned GEPIndex) {
- Value *Source1 = CI->getArgOperand(0);
- Value *Source2 = CI->getArgOperand(1);
-
- Builder.SetInsertPoint(LoadCmpBlocks[BlockIndex]);
- Type *LoadSizeType = Type::getInt8Ty(CI->getContext());
- // Cast source to LoadSizeType*.
- if (Source1->getType() != LoadSizeType)
- Source1 = Builder.CreateBitCast(Source1, LoadSizeType->getPointerTo());
- if (Source2->getType() != LoadSizeType)
- Source2 = Builder.CreateBitCast(Source2, LoadSizeType->getPointerTo());
-
- // Get the base address using the GEPIndex.
- if (GEPIndex != 0) {
- Source1 = Builder.CreateGEP(LoadSizeType, Source1,
- ConstantInt::get(LoadSizeType, GEPIndex));
- Source2 = Builder.CreateGEP(LoadSizeType, Source2,
- ConstantInt::get(LoadSizeType, GEPIndex));
- }
-
- Value *LoadSrc1 = Builder.CreateLoad(LoadSizeType, Source1);
- Value *LoadSrc2 = Builder.CreateLoad(LoadSizeType, Source2);
-
- LoadSrc1 = Builder.CreateZExt(LoadSrc1, Type::getInt32Ty(CI->getContext()));
- LoadSrc2 = Builder.CreateZExt(LoadSrc2, Type::getInt32Ty(CI->getContext()));
- Value *Diff = Builder.CreateSub(LoadSrc1, LoadSrc2);
-
- PhiRes->addIncoming(Diff, LoadCmpBlocks[BlockIndex]);
-
- if (BlockIndex < (LoadCmpBlocks.size() - 1)) {
- // Early exit branch if difference found to EndBlock. Otherwise, continue to
- // next LoadCmpBlock,
- Value *Cmp = Builder.CreateICmp(ICmpInst::ICMP_NE, Diff,
- ConstantInt::get(Diff->getType(), 0));
- BranchInst *CmpBr =
- BranchInst::Create(EndBlock, LoadCmpBlocks[BlockIndex + 1], Cmp);
- Builder.Insert(CmpBr);
- } else {
- // The last block has an unconditional branch to EndBlock.
- BranchInst *CmpBr = BranchInst::Create(EndBlock);
- Builder.Insert(CmpBr);
- }
-}
-
-/// Generate an equality comparison for one or more pairs of loaded values.
-/// This is used in the case where the memcmp() call is compared equal or not
-/// equal to zero.
-Value *MemCmpExpansion::getCompareLoadPairs(unsigned BlockIndex,
- unsigned &LoadIndex) {
- assert(LoadIndex < getNumLoads() &&
- "getCompareLoadPairs() called with no remaining loads");
- std::vector<Value *> XorList, OrList;
- Value *Diff;
-
- const unsigned NumLoads =
- std::min(getNumLoads() - LoadIndex, NumLoadsPerBlock);
-
- // For a single-block expansion, start inserting before the memcmp call.
- if (LoadCmpBlocks.empty())
- Builder.SetInsertPoint(CI);
- else
- Builder.SetInsertPoint(LoadCmpBlocks[BlockIndex]);
-
- Value *Cmp = nullptr;
- // If we have multiple loads per block, we need to generate a composite
- // comparison using xor+or. The type for the combinations is the largest load
- // type.
- IntegerType *const MaxLoadType =
- NumLoads == 1 ? nullptr
- : IntegerType::get(CI->getContext(), MaxLoadSize * 8);
- for (unsigned i = 0; i < NumLoads; ++i, ++LoadIndex) {
- const LoadEntry &CurLoadEntry = LoadSequence[LoadIndex];
-
- IntegerType *LoadSizeType =
- IntegerType::get(CI->getContext(), CurLoadEntry.LoadSize * 8);
-
- Value *Source1 = CI->getArgOperand(0);
- Value *Source2 = CI->getArgOperand(1);
-
- // Cast source to LoadSizeType*.
- if (Source1->getType() != LoadSizeType)
- Source1 = Builder.CreateBitCast(Source1, LoadSizeType->getPointerTo());
- if (Source2->getType() != LoadSizeType)
- Source2 = Builder.CreateBitCast(Source2, LoadSizeType->getPointerTo());
-
- // Get the base address using a GEP.
- if (CurLoadEntry.Offset != 0) {
- Source1 = Builder.CreateGEP(
- LoadSizeType, Source1,
- ConstantInt::get(LoadSizeType, CurLoadEntry.getGEPIndex()));
- Source2 = Builder.CreateGEP(
- LoadSizeType, Source2,
- ConstantInt::get(LoadSizeType, CurLoadEntry.getGEPIndex()));
- }
-
- // Get a constant or load a value for each source address.
- Value *LoadSrc1 = nullptr;
- if (auto *Source1C = dyn_cast<Constant>(Source1))
- LoadSrc1 = ConstantFoldLoadFromConstPtr(Source1C, LoadSizeType, DL);
- if (!LoadSrc1)
- LoadSrc1 = Builder.CreateLoad(LoadSizeType, Source1);
-
- Value *LoadSrc2 = nullptr;
- if (auto *Source2C = dyn_cast<Constant>(Source2))
- LoadSrc2 = ConstantFoldLoadFromConstPtr(Source2C, LoadSizeType, DL);
- if (!LoadSrc2)
- LoadSrc2 = Builder.CreateLoad(LoadSizeType, Source2);
-
- if (NumLoads != 1) {
- if (LoadSizeType != MaxLoadType) {
- LoadSrc1 = Builder.CreateZExt(LoadSrc1, MaxLoadType);
- LoadSrc2 = Builder.CreateZExt(LoadSrc2, MaxLoadType);
- }
- // If we have multiple loads per block, we need to generate a composite
- // comparison using xor+or.
- Diff = Builder.CreateXor(LoadSrc1, LoadSrc2);
- Diff = Builder.CreateZExt(Diff, MaxLoadType);
- XorList.push_back(Diff);
- } else {
- // If there's only one load per block, we just compare the loaded values.
- Cmp = Builder.CreateICmpNE(LoadSrc1, LoadSrc2);
- }
- }
-
- auto pairWiseOr = [&](std::vector<Value *> &InList) -> std::vector<Value *> {
- std::vector<Value *> OutList;
- for (unsigned i = 0; i < InList.size() - 1; i = i + 2) {
- Value *Or = Builder.CreateOr(InList[i], InList[i + 1]);
- OutList.push_back(Or);
- }
- if (InList.size() % 2 != 0)
- OutList.push_back(InList.back());
- return OutList;
- };
-
- if (!Cmp) {
- // Pairwise OR the XOR results.
- OrList = pairWiseOr(XorList);
-
- // Pairwise OR the OR results until one result left.
- while (OrList.size() != 1) {
- OrList = pairWiseOr(OrList);
- }
- Cmp = Builder.CreateICmpNE(OrList[0], ConstantInt::get(Diff->getType(), 0));
- }
-
- return Cmp;
-}
-
-void MemCmpExpansion::emitLoadCompareBlockMultipleLoads(unsigned BlockIndex,
- unsigned &LoadIndex) {
- Value *Cmp = getCompareLoadPairs(BlockIndex, LoadIndex);
-
- BasicBlock *NextBB = (BlockIndex == (LoadCmpBlocks.size() - 1))
- ? EndBlock
- : LoadCmpBlocks[BlockIndex + 1];
- // Early exit branch if difference found to ResultBlock. Otherwise,
- // continue to next LoadCmpBlock or EndBlock.
- BranchInst *CmpBr = BranchInst::Create(ResBlock.BB, NextBB, Cmp);
- Builder.Insert(CmpBr);
-
- // Add a phi edge for the last LoadCmpBlock to Endblock with a value of 0
- // since early exit to ResultBlock was not taken (no difference was found in
- // any of the bytes).
- if (BlockIndex == LoadCmpBlocks.size() - 1) {
- Value *Zero = ConstantInt::get(Type::getInt32Ty(CI->getContext()), 0);
- PhiRes->addIncoming(Zero, LoadCmpBlocks[BlockIndex]);
- }
-}
-
-// This function creates the IR intructions for loading and comparing using the
-// given LoadSize. It loads the number of bytes specified by LoadSize from each
-// source of the memcmp parameters. It then does a subtract to see if there was
-// a difference in the loaded values. If a difference is found, it branches
-// with an early exit to the ResultBlock for calculating which source was
-// larger. Otherwise, it falls through to the either the next LoadCmpBlock or
-// the EndBlock if this is the last LoadCmpBlock. Loading 1 byte is handled with
-// a special case through emitLoadCompareByteBlock. The special handling can
-// simply subtract the loaded values and add it to the result phi node.
-void MemCmpExpansion::emitLoadCompareBlock(unsigned BlockIndex) {
- // There is one load per block in this case, BlockIndex == LoadIndex.
- const LoadEntry &CurLoadEntry = LoadSequence[BlockIndex];
-
- if (CurLoadEntry.LoadSize == 1) {
- MemCmpExpansion::emitLoadCompareByteBlock(BlockIndex,
- CurLoadEntry.getGEPIndex());
- return;
- }
-
- Type *LoadSizeType =
- IntegerType::get(CI->getContext(), CurLoadEntry.LoadSize * 8);
- Type *MaxLoadType = IntegerType::get(CI->getContext(), MaxLoadSize * 8);
- assert(CurLoadEntry.LoadSize <= MaxLoadSize && "Unexpected load type");
-
- Value *Source1 = CI->getArgOperand(0);
- Value *Source2 = CI->getArgOperand(1);
-
- Builder.SetInsertPoint(LoadCmpBlocks[BlockIndex]);
- // Cast source to LoadSizeType*.
- if (Source1->getType() != LoadSizeType)
- Source1 = Builder.CreateBitCast(Source1, LoadSizeType->getPointerTo());
- if (Source2->getType() != LoadSizeType)
- Source2 = Builder.CreateBitCast(Source2, LoadSizeType->getPointerTo());
-
- // Get the base address using a GEP.
- if (CurLoadEntry.Offset != 0) {
- Source1 = Builder.CreateGEP(
- LoadSizeType, Source1,
- ConstantInt::get(LoadSizeType, CurLoadEntry.getGEPIndex()));
- Source2 = Builder.CreateGEP(
- LoadSizeType, Source2,
- ConstantInt::get(LoadSizeType, CurLoadEntry.getGEPIndex()));
- }
-
- // Load LoadSizeType from the base address.
- Value *LoadSrc1 = Builder.CreateLoad(LoadSizeType, Source1);
- Value *LoadSrc2 = Builder.CreateLoad(LoadSizeType, Source2);
-
- if (DL.isLittleEndian()) {
- Function *Bswap = Intrinsic::getDeclaration(CI->getModule(),
- Intrinsic::bswap, LoadSizeType);
- LoadSrc1 = Builder.CreateCall(Bswap, LoadSrc1);
- LoadSrc2 = Builder.CreateCall(Bswap, LoadSrc2);
- }
-
- if (LoadSizeType != MaxLoadType) {
- LoadSrc1 = Builder.CreateZExt(LoadSrc1, MaxLoadType);
- LoadSrc2 = Builder.CreateZExt(LoadSrc2, MaxLoadType);
- }
-
- // Add the loaded values to the phi nodes for calculating memcmp result only
- // if result is not used in a zero equality.
- if (!IsUsedForZeroCmp) {
- ResBlock.PhiSrc1->addIncoming(LoadSrc1, LoadCmpBlocks[BlockIndex]);
- ResBlock.PhiSrc2->addIncoming(LoadSrc2, LoadCmpBlocks[BlockIndex]);
- }
-
- Value *Cmp = Builder.CreateICmp(ICmpInst::ICMP_EQ, LoadSrc1, LoadSrc2);
- BasicBlock *NextBB = (BlockIndex == (LoadCmpBlocks.size() - 1))
- ? EndBlock
- : LoadCmpBlocks[BlockIndex + 1];
- // Early exit branch if difference found to ResultBlock. Otherwise, continue
- // to next LoadCmpBlock or EndBlock.
- BranchInst *CmpBr = BranchInst::Create(NextBB, ResBlock.BB, Cmp);
- Builder.Insert(CmpBr);
-
- // Add a phi edge for the last LoadCmpBlock to Endblock with a value of 0
- // since early exit to ResultBlock was not taken (no difference was found in
- // any of the bytes).
- if (BlockIndex == LoadCmpBlocks.size() - 1) {
- Value *Zero = ConstantInt::get(Type::getInt32Ty(CI->getContext()), 0);
- PhiRes->addIncoming(Zero, LoadCmpBlocks[BlockIndex]);
- }
-}
-
-// This function populates the ResultBlock with a sequence to calculate the
-// memcmp result. It compares the two loaded source values and returns -1 if
-// src1 < src2 and 1 if src1 > src2.
-void MemCmpExpansion::emitMemCmpResultBlock() {
- // Special case: if memcmp result is used in a zero equality, result does not
- // need to be calculated and can simply return 1.
- if (IsUsedForZeroCmp) {
- BasicBlock::iterator InsertPt = ResBlock.BB->getFirstInsertionPt();
- Builder.SetInsertPoint(ResBlock.BB, InsertPt);
- Value *Res = ConstantInt::get(Type::getInt32Ty(CI->getContext()), 1);
- PhiRes->addIncoming(Res, ResBlock.BB);
- BranchInst *NewBr = BranchInst::Create(EndBlock);
- Builder.Insert(NewBr);
- return;
- }
- BasicBlock::iterator InsertPt = ResBlock.BB->getFirstInsertionPt();
- Builder.SetInsertPoint(ResBlock.BB, InsertPt);
-
- Value *Cmp = Builder.CreateICmp(ICmpInst::ICMP_ULT, ResBlock.PhiSrc1,
- ResBlock.PhiSrc2);
-
- Value *Res =
- Builder.CreateSelect(Cmp, ConstantInt::get(Builder.getInt32Ty(), -1),
- ConstantInt::get(Builder.getInt32Ty(), 1));
-
- BranchInst *NewBr = BranchInst::Create(EndBlock);
- Builder.Insert(NewBr);
- PhiRes->addIncoming(Res, ResBlock.BB);
-}
-
-void MemCmpExpansion::setupResultBlockPHINodes() {
- Type *MaxLoadType = IntegerType::get(CI->getContext(), MaxLoadSize * 8);
- Builder.SetInsertPoint(ResBlock.BB);
- // Note: this assumes one load per block.
- ResBlock.PhiSrc1 =
- Builder.CreatePHI(MaxLoadType, NumLoadsNonOneByte, "phi.src1");
- ResBlock.PhiSrc2 =
- Builder.CreatePHI(MaxLoadType, NumLoadsNonOneByte, "phi.src2");
-}
-
-void MemCmpExpansion::setupEndBlockPHINodes() {
- Builder.SetInsertPoint(&EndBlock->front());
- PhiRes = Builder.CreatePHI(Type::getInt32Ty(CI->getContext()), 2, "phi.res");
-}
-
-Value *MemCmpExpansion::getMemCmpExpansionZeroCase() {
- unsigned LoadIndex = 0;
- // This loop populates each of the LoadCmpBlocks with the IR sequence to
- // handle multiple loads per block.
- for (unsigned I = 0; I < getNumBlocks(); ++I) {
- emitLoadCompareBlockMultipleLoads(I, LoadIndex);
- }
-
- emitMemCmpResultBlock();
- return PhiRes;
-}
-
-/// A memcmp expansion that compares equality with 0 and only has one block of
-/// load and compare can bypass the compare, branch, and phi IR that is required
-/// in the general case.
-Value *MemCmpExpansion::getMemCmpEqZeroOneBlock() {
- unsigned LoadIndex = 0;
- Value *Cmp = getCompareLoadPairs(0, LoadIndex);
- assert(LoadIndex == getNumLoads() && "some entries were not consumed");
- return Builder.CreateZExt(Cmp, Type::getInt32Ty(CI->getContext()));
-}
-
-/// A memcmp expansion that only has one block of load and compare can bypass
-/// the compare, branch, and phi IR that is required in the general case.
-Value *MemCmpExpansion::getMemCmpOneBlock() {
- assert(NumLoadsPerBlock == 1 && "Only handles one load pair per block");
-
- Type *LoadSizeType = IntegerType::get(CI->getContext(), Size * 8);
- Value *Source1 = CI->getArgOperand(0);
- Value *Source2 = CI->getArgOperand(1);
-
- // Cast source to LoadSizeType*.
- if (Source1->getType() != LoadSizeType)
- Source1 = Builder.CreateBitCast(Source1, LoadSizeType->getPointerTo());
- if (Source2->getType() != LoadSizeType)
- Source2 = Builder.CreateBitCast(Source2, LoadSizeType->getPointerTo());
-
- // Load LoadSizeType from the base address.
- Value *LoadSrc1 = Builder.CreateLoad(LoadSizeType, Source1);
- Value *LoadSrc2 = Builder.CreateLoad(LoadSizeType, Source2);
-
- if (DL.isLittleEndian() && Size != 1) {
- Function *Bswap = Intrinsic::getDeclaration(CI->getModule(),
- Intrinsic::bswap, LoadSizeType);
- LoadSrc1 = Builder.CreateCall(Bswap, LoadSrc1);
- LoadSrc2 = Builder.CreateCall(Bswap, LoadSrc2);
- }
-
- if (Size < 4) {
- // The i8 and i16 cases don't need compares. We zext the loaded values and
- // subtract them to get the suitable negative, zero, or positive i32 result.
- LoadSrc1 = Builder.CreateZExt(LoadSrc1, Builder.getInt32Ty());
- LoadSrc2 = Builder.CreateZExt(LoadSrc2, Builder.getInt32Ty());
- return Builder.CreateSub(LoadSrc1, LoadSrc2);
- }
-
- // The result of memcmp is negative, zero, or positive, so produce that by
- // subtracting 2 extended compare bits: sub (ugt, ult).
- // If a target prefers to use selects to get -1/0/1, they should be able
- // to transform this later. The inverse transform (going from selects to math)
- // may not be possible in the DAG because the selects got converted into
- // branches before we got there.
- Value *CmpUGT = Builder.CreateICmpUGT(LoadSrc1, LoadSrc2);
- Value *CmpULT = Builder.CreateICmpULT(LoadSrc1, LoadSrc2);
- Value *ZextUGT = Builder.CreateZExt(CmpUGT, Builder.getInt32Ty());
- Value *ZextULT = Builder.CreateZExt(CmpULT, Builder.getInt32Ty());
- return Builder.CreateSub(ZextUGT, ZextULT);
-}
-
-// This function expands the memcmp call into an inline expansion and returns
-// the memcmp result.
-Value *MemCmpExpansion::getMemCmpExpansion() {
- // A memcmp with zero-comparison with only one block of load and compare does
- // not need to set up any extra blocks. This case could be handled in the DAG,
- // but since we have all of the machinery to flexibly expand any memcpy here,
- // we choose to handle this case too to avoid fragmented lowering.
- if ((!IsUsedForZeroCmp && NumLoadsPerBlock != 1) || getNumBlocks() != 1) {
- BasicBlock *StartBlock = CI->getParent();
- EndBlock = StartBlock->splitBasicBlock(CI, "endblock");
- setupEndBlockPHINodes();
- createResultBlock();
-
- // If return value of memcmp is not used in a zero equality, we need to
- // calculate which source was larger. The calculation requires the
- // two loaded source values of each load compare block.
- // These will be saved in the phi nodes created by setupResultBlockPHINodes.
- if (!IsUsedForZeroCmp) setupResultBlockPHINodes();
-
- // Create the number of required load compare basic blocks.
- createLoadCmpBlocks();
-
- // Update the terminator added by splitBasicBlock to branch to the first
- // LoadCmpBlock.
- StartBlock->getTerminator()->setSuccessor(0, LoadCmpBlocks[0]);
- }
-
- Builder.SetCurrentDebugLocation(CI->getDebugLoc());
-
- if (IsUsedForZeroCmp)
- return getNumBlocks() == 1 ? getMemCmpEqZeroOneBlock()
- : getMemCmpExpansionZeroCase();
-
- // TODO: Handle more than one load pair per block in getMemCmpOneBlock().
- if (getNumBlocks() == 1 && NumLoadsPerBlock == 1) return getMemCmpOneBlock();
-
- for (unsigned I = 0; I < getNumBlocks(); ++I) {
- emitLoadCompareBlock(I);
- }
-
- emitMemCmpResultBlock();
- return PhiRes;
-}
-
-// This function checks to see if an expansion of memcmp can be generated.
-// It checks for constant compare size that is less than the max inline size.
-// If an expansion cannot occur, returns false to leave as a library call.
-// Otherwise, the library call is replaced with a new IR instruction sequence.
-/// We want to transform:
-/// %call = call signext i32 @memcmp(i8* %0, i8* %1, i64 15)
-/// To:
-/// loadbb:
-/// %0 = bitcast i32* %buffer2 to i8*
-/// %1 = bitcast i32* %buffer1 to i8*
-/// %2 = bitcast i8* %1 to i64*
-/// %3 = bitcast i8* %0 to i64*
-/// %4 = load i64, i64* %2
-/// %5 = load i64, i64* %3
-/// %6 = call i64 @llvm.bswap.i64(i64 %4)
-/// %7 = call i64 @llvm.bswap.i64(i64 %5)
-/// %8 = sub i64 %6, %7
-/// %9 = icmp ne i64 %8, 0
-/// br i1 %9, label %res_block, label %loadbb1
-/// res_block: ; preds = %loadbb2,
-/// %loadbb1, %loadbb
-/// %phi.src1 = phi i64 [ %6, %loadbb ], [ %22, %loadbb1 ], [ %36, %loadbb2 ]
-/// %phi.src2 = phi i64 [ %7, %loadbb ], [ %23, %loadbb1 ], [ %37, %loadbb2 ]
-/// %10 = icmp ult i64 %phi.src1, %phi.src2
-/// %11 = select i1 %10, i32 -1, i32 1
-/// br label %endblock
-/// loadbb1: ; preds = %loadbb
-/// %12 = bitcast i32* %buffer2 to i8*
-/// %13 = bitcast i32* %buffer1 to i8*
-/// %14 = bitcast i8* %13 to i32*
-/// %15 = bitcast i8* %12 to i32*
-/// %16 = getelementptr i32, i32* %14, i32 2
-/// %17 = getelementptr i32, i32* %15, i32 2
-/// %18 = load i32, i32* %16
-/// %19 = load i32, i32* %17
-/// %20 = call i32 @llvm.bswap.i32(i32 %18)
-/// %21 = call i32 @llvm.bswap.i32(i32 %19)
-/// %22 = zext i32 %20 to i64
-/// %23 = zext i32 %21 to i64
-/// %24 = sub i64 %22, %23
-/// %25 = icmp ne i64 %24, 0
-/// br i1 %25, label %res_block, label %loadbb2
-/// loadbb2: ; preds = %loadbb1
-/// %26 = bitcast i32* %buffer2 to i8*
-/// %27 = bitcast i32* %buffer1 to i8*
-/// %28 = bitcast i8* %27 to i16*
-/// %29 = bitcast i8* %26 to i16*
-/// %30 = getelementptr i16, i16* %28, i16 6
-/// %31 = getelementptr i16, i16* %29, i16 6
-/// %32 = load i16, i16* %30
-/// %33 = load i16, i16* %31
-/// %34 = call i16 @llvm.bswap.i16(i16 %32)
-/// %35 = call i16 @llvm.bswap.i16(i16 %33)
-/// %36 = zext i16 %34 to i64
-/// %37 = zext i16 %35 to i64
-/// %38 = sub i64 %36, %37
-/// %39 = icmp ne i64 %38, 0
-/// br i1 %39, label %res_block, label %loadbb3
-/// loadbb3: ; preds = %loadbb2
-/// %40 = bitcast i32* %buffer2 to i8*
-/// %41 = bitcast i32* %buffer1 to i8*
-/// %42 = getelementptr i8, i8* %41, i8 14
-/// %43 = getelementptr i8, i8* %40, i8 14
-/// %44 = load i8, i8* %42
-/// %45 = load i8, i8* %43
-/// %46 = zext i8 %44 to i32
-/// %47 = zext i8 %45 to i32
-/// %48 = sub i32 %46, %47
-/// br label %endblock
-/// endblock: ; preds = %res_block,
-/// %loadbb3
-/// %phi.res = phi i32 [ %48, %loadbb3 ], [ %11, %res_block ]
-/// ret i32 %phi.res
-static bool expandMemCmp(CallInst *CI, const TargetTransformInfo *TTI,
- const TargetLowering *TLI, const DataLayout *DL) {
- NumMemCmpCalls++;
-
- // Early exit from expansion if -Oz.
- if (CI->getFunction()->optForMinSize())
- return false;
-
- // Early exit from expansion if size is not a constant.
- ConstantInt *SizeCast = dyn_cast<ConstantInt>(CI->getArgOperand(2));
- if (!SizeCast) {
- NumMemCmpNotConstant++;
- return false;
- }
- const uint64_t SizeVal = SizeCast->getZExtValue();
-
- // TTI call to check if target would like to expand memcmp. Also, get the
- // max LoadSize.
- unsigned MaxLoadSize;
- if (!TTI->enableMemCmpExpansion(MaxLoadSize)) return false;
-
- MemCmpExpansion Expansion(CI, SizeVal, MaxLoadSize, MemCmpNumLoadsPerBlock,
- *DL);
-
- // Don't expand if this will require more loads than desired by the target.
- if (Expansion.getNumLoads() >
- TLI->getMaxExpandSizeMemcmp(CI->getFunction()->optForSize())) {
- NumMemCmpGreaterThanMax++;
- return false;
- }
-
- NumMemCmpInlined++;
-
- Value *Res = Expansion.getMemCmpExpansion();
-
- // Replace call with result of expansion and erase call.
- CI->replaceAllUsesWith(Res);
- CI->eraseFromParent();
-
- return true;
-}
-
bool CodeGenPrepare::optimizeCallInst(CallInst *CI, bool &ModifiedDT) {
BasicBlock *BB = CI->getParent();
// if size - offset meets the size threshold.
if (!Arg->getType()->isPointerTy())
continue;
- APInt Offset(DL->getPointerSizeInBits(
+ APInt Offset(DL->getIndexSizeInBits(
cast<PointerType>(Arg->getType())->getAddressSpace()),
0);
Value *Val = Arg->stripAndAccumulateInBoundsConstantOffsets(*DL, Offset);
// If this is a memcpy (or similar) then we may be able to improve the
// alignment
if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(CI)) {
- unsigned Align = getKnownAlignment(MI->getDest(), *DL);
- if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI))
- Align = std::min(Align, getKnownAlignment(MTI->getSource(), *DL));
- if (Align > MI->getAlignment())
- MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), Align));
+ unsigned DestAlign = getKnownAlignment(MI->getDest(), *DL);
+ if (DestAlign > MI->getDestAlignment())
+ MI->setDestAlignment(DestAlign);
+ if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
+ unsigned SrcAlign = getKnownAlignment(MTI->getSource(), *DL);
+ if (SrcAlign > MTI->getSourceAlignment())
+ MTI->setSourceAlignment(SrcAlign);
+ }
}
}
InsertedInsts.insert(ExtVal);
return true;
}
- case Intrinsic::invariant_group_barrier:
+ case Intrinsic::launder_invariant_group:
+ case Intrinsic::strip_invariant_group:
II->replaceAllUsesWith(II->getArgOperand(0));
II->eraseFromParent();
return true;
return true;
}
- LibFunc Func;
- if (TLInfo->getLibFunc(ImmutableCallSite(CI), Func) &&
- Func == LibFunc_memcmp && expandMemCmp(CI, TTI, TLI, DL)) {
- ModifiedDT = true;
- return true;
- }
return false;
}
return static_cast<FieldName>(Result);
}
- // AddrModes with a base reg or gv where the reg/gv is just the original
- // value are trivial.
+ // An AddrMode is trivial if it involves no calculation i.e. it is just a base
+ // with no offset.
bool isTrivial() {
- bool Trivial = (BaseGV && BaseGV == OriginalValue) ||
- (BaseReg && BaseReg == OriginalValue);
- // If the AddrMode is trivial it shouldn't have an offset or be scaled.
- if (Trivial) {
- assert(BaseOffs == 0);
- assert(Scale == 0);
+ // An AddrMode is (BaseGV + BaseReg + BaseOffs + ScaleReg * Scale) so it is
+ // trivial if at most one of these terms is nonzero, except that BaseGV and
+ // BaseReg both being zero actually means a null pointer value, which we
+ // consider to be 'non-zero' here.
+ return !BaseOffs && !Scale && !(BaseGV && BaseReg);
+ }
+
+ Value *GetFieldAsValue(FieldName Field, Type *IntPtrTy) {
+ switch (Field) {
+ default:
+ return nullptr;
+ case BaseRegField:
+ return BaseReg;
+ case BaseGVField:
+ return BaseGV;
+ case ScaledRegField:
+ return ScaledReg;
+ case BaseOffsField:
+ return ConstantInt::get(IntPtrTy, BaseOffs);
+ }
+ }
+
+ void SetCombinedField(FieldName Field, Value *V,
+ const SmallVectorImpl<ExtAddrMode> &AddrModes) {
+ switch (Field) {
+ default:
+ llvm_unreachable("Unhandled fields are expected to be rejected earlier");
+ break;
+ case ExtAddrMode::BaseRegField:
+ BaseReg = V;
+ break;
+ case ExtAddrMode::BaseGVField:
+ // A combined BaseGV is an Instruction, not a GlobalValue, so it goes
+ // in the BaseReg field.
+ assert(BaseReg == nullptr);
+ BaseReg = V;
+ BaseGV = nullptr;
+ break;
+ case ExtAddrMode::ScaledRegField:
+ ScaledReg = V;
+ // If we have a mix of scaled and unscaled addrmodes then we want scale
+ // to be the scale and not zero.
+ if (!Scale)
+ for (const ExtAddrMode &AM : AddrModes)
+ if (AM.Scale) {
+ Scale = AM.Scale;
+ break;
+ }
+ break;
+ case ExtAddrMode::BaseOffsField:
+ // The offset is no longer a constant, so it goes in ScaledReg with a
+ // scale of 1.
+ assert(ScaledReg == nullptr);
+ ScaledReg = V;
+ Scale = 1;
+ BaseOffs = 0;
+ break;
}
- return Trivial;
}
};
namespace {
-/// \brief This class provides transaction based operation on the IR.
+/// This class provides transaction based operation on the IR.
/// Every change made through this class is recorded in the internal state and
/// can be undone (rollback) until commit is called.
class TypePromotionTransaction {
- /// \brief This represents the common interface of the individual transaction.
+ /// This represents the common interface of the individual transaction.
/// Each class implements the logic for doing one specific modification on
/// the IR via the TypePromotionTransaction.
class TypePromotionAction {
Instruction *Inst;
public:
- /// \brief Constructor of the action.
+ /// Constructor of the action.
/// The constructor performs the related action on the IR.
TypePromotionAction(Instruction *Inst) : Inst(Inst) {}
virtual ~TypePromotionAction() = default;
- /// \brief Undo the modification done by this action.
+ /// Undo the modification done by this action.
/// When this method is called, the IR must be in the same state as it was
/// before this action was applied.
/// \pre Undoing the action works if and only if the IR is in the exact same
/// state as it was directly after this action was applied.
virtual void undo() = 0;
- /// \brief Advocate every change made by this action.
+ /// Advocate every change made by this action.
/// When the results on the IR of the action are to be kept, it is important
/// to call this function, otherwise hidden information may be kept forever.
virtual void commit() {
}
};
- /// \brief Utility to remember the position of an instruction.
+ /// Utility to remember the position of an instruction.
class InsertionHandler {
/// Position of an instruction.
/// Either an instruction:
/// - Is the first in a basic block: BB is used.
- /// - Has a previous instructon: PrevInst is used.
+ /// - Has a previous instruction: PrevInst is used.
union {
Instruction *PrevInst;
BasicBlock *BB;
bool HasPrevInstruction;
public:
- /// \brief Record the position of \p Inst.
+ /// Record the position of \p Inst.
InsertionHandler(Instruction *Inst) {
BasicBlock::iterator It = Inst->getIterator();
HasPrevInstruction = (It != (Inst->getParent()->begin()));
Point.BB = Inst->getParent();
}
- /// \brief Insert \p Inst at the recorded position.
+ /// Insert \p Inst at the recorded position.
void insert(Instruction *Inst) {
if (HasPrevInstruction) {
if (Inst->getParent())
}
};
- /// \brief Move an instruction before another.
+ /// Move an instruction before another.
class InstructionMoveBefore : public TypePromotionAction {
/// Original position of the instruction.
InsertionHandler Position;
public:
- /// \brief Move \p Inst before \p Before.
+ /// Move \p Inst before \p Before.
InstructionMoveBefore(Instruction *Inst, Instruction *Before)
: TypePromotionAction(Inst), Position(Inst) {
- DEBUG(dbgs() << "Do: move: " << *Inst << "\nbefore: " << *Before << "\n");
+ LLVM_DEBUG(dbgs() << "Do: move: " << *Inst << "\nbefore: " << *Before
+ << "\n");
Inst->moveBefore(Before);
}
- /// \brief Move the instruction back to its original position.
+ /// Move the instruction back to its original position.
void undo() override {
- DEBUG(dbgs() << "Undo: moveBefore: " << *Inst << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: moveBefore: " << *Inst << "\n");
Position.insert(Inst);
}
};
- /// \brief Set the operand of an instruction with a new value.
+ /// Set the operand of an instruction with a new value.
class OperandSetter : public TypePromotionAction {
/// Original operand of the instruction.
Value *Origin;
unsigned Idx;
public:
- /// \brief Set \p Idx operand of \p Inst with \p NewVal.
+ /// Set \p Idx operand of \p Inst with \p NewVal.
OperandSetter(Instruction *Inst, unsigned Idx, Value *NewVal)
: TypePromotionAction(Inst), Idx(Idx) {
- DEBUG(dbgs() << "Do: setOperand: " << Idx << "\n"
- << "for:" << *Inst << "\n"
- << "with:" << *NewVal << "\n");
+ LLVM_DEBUG(dbgs() << "Do: setOperand: " << Idx << "\n"
+ << "for:" << *Inst << "\n"
+ << "with:" << *NewVal << "\n");
Origin = Inst->getOperand(Idx);
Inst->setOperand(Idx, NewVal);
}
- /// \brief Restore the original value of the instruction.
+ /// Restore the original value of the instruction.
void undo() override {
- DEBUG(dbgs() << "Undo: setOperand:" << Idx << "\n"
- << "for: " << *Inst << "\n"
- << "with: " << *Origin << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: setOperand:" << Idx << "\n"
+ << "for: " << *Inst << "\n"
+ << "with: " << *Origin << "\n");
Inst->setOperand(Idx, Origin);
}
};
- /// \brief Hide the operands of an instruction.
+ /// Hide the operands of an instruction.
/// Do as if this instruction was not using any of its operands.
class OperandsHider : public TypePromotionAction {
/// The list of original operands.
SmallVector<Value *, 4> OriginalValues;
public:
- /// \brief Remove \p Inst from the uses of the operands of \p Inst.
+ /// Remove \p Inst from the uses of the operands of \p Inst.
OperandsHider(Instruction *Inst) : TypePromotionAction(Inst) {
- DEBUG(dbgs() << "Do: OperandsHider: " << *Inst << "\n");
+ LLVM_DEBUG(dbgs() << "Do: OperandsHider: " << *Inst << "\n");
unsigned NumOpnds = Inst->getNumOperands();
OriginalValues.reserve(NumOpnds);
for (unsigned It = 0; It < NumOpnds; ++It) {
}
}
- /// \brief Restore the original list of uses.
+ /// Restore the original list of uses.
void undo() override {
- DEBUG(dbgs() << "Undo: OperandsHider: " << *Inst << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: OperandsHider: " << *Inst << "\n");
for (unsigned It = 0, EndIt = OriginalValues.size(); It != EndIt; ++It)
Inst->setOperand(It, OriginalValues[It]);
}
};
- /// \brief Build a truncate instruction.
+ /// Build a truncate instruction.
class TruncBuilder : public TypePromotionAction {
Value *Val;
public:
- /// \brief Build a truncate instruction of \p Opnd producing a \p Ty
+ /// Build a truncate instruction of \p Opnd producing a \p Ty
/// result.
/// trunc Opnd to Ty.
TruncBuilder(Instruction *Opnd, Type *Ty) : TypePromotionAction(Opnd) {
IRBuilder<> Builder(Opnd);
Val = Builder.CreateTrunc(Opnd, Ty, "promoted");
- DEBUG(dbgs() << "Do: TruncBuilder: " << *Val << "\n");
+ LLVM_DEBUG(dbgs() << "Do: TruncBuilder: " << *Val << "\n");
}
- /// \brief Get the built value.
+ /// Get the built value.
Value *getBuiltValue() { return Val; }
- /// \brief Remove the built instruction.
+ /// Remove the built instruction.
void undo() override {
- DEBUG(dbgs() << "Undo: TruncBuilder: " << *Val << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: TruncBuilder: " << *Val << "\n");
if (Instruction *IVal = dyn_cast<Instruction>(Val))
IVal->eraseFromParent();
}
};
- /// \brief Build a sign extension instruction.
+ /// Build a sign extension instruction.
class SExtBuilder : public TypePromotionAction {
Value *Val;
public:
- /// \brief Build a sign extension instruction of \p Opnd producing a \p Ty
+ /// Build a sign extension instruction of \p Opnd producing a \p Ty
/// result.
/// sext Opnd to Ty.
SExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty)
: TypePromotionAction(InsertPt) {
IRBuilder<> Builder(InsertPt);
Val = Builder.CreateSExt(Opnd, Ty, "promoted");
- DEBUG(dbgs() << "Do: SExtBuilder: " << *Val << "\n");
+ LLVM_DEBUG(dbgs() << "Do: SExtBuilder: " << *Val << "\n");
}
- /// \brief Get the built value.
+ /// Get the built value.
Value *getBuiltValue() { return Val; }
- /// \brief Remove the built instruction.
+ /// Remove the built instruction.
void undo() override {
- DEBUG(dbgs() << "Undo: SExtBuilder: " << *Val << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: SExtBuilder: " << *Val << "\n");
if (Instruction *IVal = dyn_cast<Instruction>(Val))
IVal->eraseFromParent();
}
};
- /// \brief Build a zero extension instruction.
+ /// Build a zero extension instruction.
class ZExtBuilder : public TypePromotionAction {
Value *Val;
public:
- /// \brief Build a zero extension instruction of \p Opnd producing a \p Ty
+ /// Build a zero extension instruction of \p Opnd producing a \p Ty
/// result.
/// zext Opnd to Ty.
ZExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty)
: TypePromotionAction(InsertPt) {
IRBuilder<> Builder(InsertPt);
Val = Builder.CreateZExt(Opnd, Ty, "promoted");
- DEBUG(dbgs() << "Do: ZExtBuilder: " << *Val << "\n");
+ LLVM_DEBUG(dbgs() << "Do: ZExtBuilder: " << *Val << "\n");
}
- /// \brief Get the built value.
+ /// Get the built value.
Value *getBuiltValue() { return Val; }
- /// \brief Remove the built instruction.
+ /// Remove the built instruction.
void undo() override {
- DEBUG(dbgs() << "Undo: ZExtBuilder: " << *Val << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: ZExtBuilder: " << *Val << "\n");
if (Instruction *IVal = dyn_cast<Instruction>(Val))
IVal->eraseFromParent();
}
};
- /// \brief Mutate an instruction to another type.
+ /// Mutate an instruction to another type.
class TypeMutator : public TypePromotionAction {
/// Record the original type.
Type *OrigTy;
public:
- /// \brief Mutate the type of \p Inst into \p NewTy.
+ /// Mutate the type of \p Inst into \p NewTy.
TypeMutator(Instruction *Inst, Type *NewTy)
: TypePromotionAction(Inst), OrigTy(Inst->getType()) {
- DEBUG(dbgs() << "Do: MutateType: " << *Inst << " with " << *NewTy
- << "\n");
+ LLVM_DEBUG(dbgs() << "Do: MutateType: " << *Inst << " with " << *NewTy
+ << "\n");
Inst->mutateType(NewTy);
}
- /// \brief Mutate the instruction back to its original type.
+ /// Mutate the instruction back to its original type.
void undo() override {
- DEBUG(dbgs() << "Undo: MutateType: " << *Inst << " with " << *OrigTy
- << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: MutateType: " << *Inst << " with " << *OrigTy
+ << "\n");
Inst->mutateType(OrigTy);
}
};
- /// \brief Replace the uses of an instruction by another instruction.
+ /// Replace the uses of an instruction by another instruction.
class UsesReplacer : public TypePromotionAction {
/// Helper structure to keep track of the replaced uses.
struct InstructionAndIdx {
using use_iterator = SmallVectorImpl<InstructionAndIdx>::iterator;
public:
- /// \brief Replace all the use of \p Inst by \p New.
+ /// Replace all the use of \p Inst by \p New.
UsesReplacer(Instruction *Inst, Value *New) : TypePromotionAction(Inst) {
- DEBUG(dbgs() << "Do: UsersReplacer: " << *Inst << " with " << *New
- << "\n");
+ LLVM_DEBUG(dbgs() << "Do: UsersReplacer: " << *Inst << " with " << *New
+ << "\n");
// Record the original uses.
for (Use &U : Inst->uses()) {
Instruction *UserI = cast<Instruction>(U.getUser());
Inst->replaceAllUsesWith(New);
}
- /// \brief Reassign the original uses of Inst to Inst.
+ /// Reassign the original uses of Inst to Inst.
void undo() override {
- DEBUG(dbgs() << "Undo: UsersReplacer: " << *Inst << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: UsersReplacer: " << *Inst << "\n");
for (use_iterator UseIt = OriginalUses.begin(),
EndIt = OriginalUses.end();
UseIt != EndIt; ++UseIt) {
}
};
- /// \brief Remove an instruction from the IR.
+ /// Remove an instruction from the IR.
class InstructionRemover : public TypePromotionAction {
/// Original position of the instruction.
InsertionHandler Inserter;
SetOfInstrs &RemovedInsts;
public:
- /// \brief Remove all reference of \p Inst and optinally replace all its
+ /// Remove all reference of \p Inst and optionally replace all its
/// uses with New.
/// \p RemovedInsts Keep track of the instructions removed by this Action.
/// \pre If !Inst->use_empty(), then New != nullptr
RemovedInsts(RemovedInsts) {
if (New)
Replacer = new UsesReplacer(Inst, New);
- DEBUG(dbgs() << "Do: InstructionRemover: " << *Inst << "\n");
+ LLVM_DEBUG(dbgs() << "Do: InstructionRemover: " << *Inst << "\n");
RemovedInsts.insert(Inst);
/// The instructions removed here will be freed after completing
/// optimizeBlock() for all blocks as we need to keep track of the
~InstructionRemover() override { delete Replacer; }
- /// \brief Resurrect the instruction and reassign it to the proper uses if
+ /// Resurrect the instruction and reassign it to the proper uses if
/// new value was provided when build this action.
void undo() override {
- DEBUG(dbgs() << "Undo: InstructionRemover: " << *Inst << "\n");
+ LLVM_DEBUG(dbgs() << "Undo: InstructionRemover: " << *Inst << "\n");
Inserter.insert(Inst);
if (Replacer)
Replacer->undo();
namespace {
-/// \brief A helper class for matching addressing modes.
+/// A helper class for matching addressing modes.
///
/// This encapsulates the logic for matching the target-legal addressing modes.
class AddressingModeMatcher {
/// The ongoing transaction where every action should be registered.
TypePromotionTransaction &TPT;
+ // A GEP which has too large offset to be folded into the addressing mode.
+ std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP;
+
/// This is set to true when we should not do profitability checks.
/// When true, IsProfitableToFoldIntoAddressingMode always returns true.
bool IgnoreProfitability;
- AddressingModeMatcher(SmallVectorImpl<Instruction *> &AMI,
- const TargetLowering &TLI,
- const TargetRegisterInfo &TRI,
- Type *AT, unsigned AS,
- Instruction *MI, ExtAddrMode &AM,
- const SetOfInstrs &InsertedInsts,
- InstrToOrigTy &PromotedInsts,
- TypePromotionTransaction &TPT)
+ AddressingModeMatcher(
+ SmallVectorImpl<Instruction *> &AMI, const TargetLowering &TLI,
+ const TargetRegisterInfo &TRI, Type *AT, unsigned AS, Instruction *MI,
+ ExtAddrMode &AM, const SetOfInstrs &InsertedInsts,
+ InstrToOrigTy &PromotedInsts, TypePromotionTransaction &TPT,
+ std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP)
: AddrModeInsts(AMI), TLI(TLI), TRI(TRI),
DL(MI->getModule()->getDataLayout()), AccessTy(AT), AddrSpace(AS),
MemoryInst(MI), AddrMode(AM), InsertedInsts(InsertedInsts),
- PromotedInsts(PromotedInsts), TPT(TPT) {
+ PromotedInsts(PromotedInsts), TPT(TPT), LargeOffsetGEP(LargeOffsetGEP) {
IgnoreProfitability = false;
}
/// optimizations.
/// \p PromotedInsts maps the instructions to their type before promotion.
/// \p The ongoing transaction where every action should be registered.
- static ExtAddrMode Match(Value *V, Type *AccessTy, unsigned AS,
- Instruction *MemoryInst,
- SmallVectorImpl<Instruction*> &AddrModeInsts,
- const TargetLowering &TLI,
- const TargetRegisterInfo &TRI,
- const SetOfInstrs &InsertedInsts,
- InstrToOrigTy &PromotedInsts,
- TypePromotionTransaction &TPT) {
+ static ExtAddrMode
+ Match(Value *V, Type *AccessTy, unsigned AS, Instruction *MemoryInst,
+ SmallVectorImpl<Instruction *> &AddrModeInsts,
+ const TargetLowering &TLI, const TargetRegisterInfo &TRI,
+ const SetOfInstrs &InsertedInsts, InstrToOrigTy &PromotedInsts,
+ TypePromotionTransaction &TPT,
+ std::pair<AssertingVH<GetElementPtrInst>, int64_t> &LargeOffsetGEP) {
ExtAddrMode Result;
- bool Success = AddressingModeMatcher(AddrModeInsts, TLI, TRI,
- AccessTy, AS,
+ bool Success = AddressingModeMatcher(AddrModeInsts, TLI, TRI, AccessTy, AS,
MemoryInst, Result, InsertedInsts,
- PromotedInsts, TPT).matchAddr(V, 0);
+ PromotedInsts, TPT, LargeOffsetGEP)
+ .matchAddr(V, 0);
(void)Success; assert(Success && "Couldn't select *anything*?");
return Result;
}
private:
bool matchScaledValue(Value *ScaleReg, int64_t Scale, unsigned Depth);
- bool matchAddr(Value *V, unsigned Depth);
- bool matchOperationAddr(User *Operation, unsigned Opcode, unsigned Depth,
+ bool matchAddr(Value *Addr, unsigned Depth);
+ bool matchOperationAddr(User *AddrInst, unsigned Opcode, unsigned Depth,
bool *MovedAway = nullptr);
bool isProfitableToFoldIntoAddressingMode(Instruction *I,
ExtAddrMode &AMBefore,
Value *PromotedOperand) const;
};
-/// \brief A helper class for combining addressing modes.
+/// Keep track of simplification of Phi nodes.
+/// Accept the set of all phi nodes and erase phi node from this set
+/// if it is simplified.
+class SimplificationTracker {
+ DenseMap<Value *, Value *> Storage;
+ const SimplifyQuery &SQ;
+ // Tracks newly created Phi nodes. We use a SetVector to get deterministic
+ // order when iterating over the set in MatchPhiSet.
+ SmallSetVector<PHINode *, 32> AllPhiNodes;
+ // Tracks newly created Select nodes.
+ SmallPtrSet<SelectInst *, 32> AllSelectNodes;
+
+public:
+ SimplificationTracker(const SimplifyQuery &sq)
+ : SQ(sq) {}
+
+ Value *Get(Value *V) {
+ do {
+ auto SV = Storage.find(V);
+ if (SV == Storage.end())
+ return V;
+ V = SV->second;
+ } while (true);
+ }
+
+ Value *Simplify(Value *Val) {
+ SmallVector<Value *, 32> WorkList;
+ SmallPtrSet<Value *, 32> Visited;
+ WorkList.push_back(Val);
+ while (!WorkList.empty()) {
+ auto P = WorkList.pop_back_val();
+ if (!Visited.insert(P).second)
+ continue;
+ if (auto *PI = dyn_cast<Instruction>(P))
+ if (Value *V = SimplifyInstruction(cast<Instruction>(PI), SQ)) {
+ for (auto *U : PI->users())
+ WorkList.push_back(cast<Value>(U));
+ Put(PI, V);
+ PI->replaceAllUsesWith(V);
+ if (auto *PHI = dyn_cast<PHINode>(PI))
+ AllPhiNodes.remove(PHI);
+ if (auto *Select = dyn_cast<SelectInst>(PI))
+ AllSelectNodes.erase(Select);
+ PI->eraseFromParent();
+ }
+ }
+ return Get(Val);
+ }
+
+ void Put(Value *From, Value *To) {
+ Storage.insert({ From, To });
+ }
+
+ void ReplacePhi(PHINode *From, PHINode *To) {
+ Value* OldReplacement = Get(From);
+ while (OldReplacement != From) {
+ From = To;
+ To = dyn_cast<PHINode>(OldReplacement);
+ OldReplacement = Get(From);
+ }
+ assert(Get(To) == To && "Replacement PHI node is already replaced.");
+ Put(From, To);
+ From->replaceAllUsesWith(To);
+ AllPhiNodes.remove(From);
+ From->eraseFromParent();
+ }
+
+ SmallSetVector<PHINode *, 32>& newPhiNodes() { return AllPhiNodes; }
+
+ void insertNewPhi(PHINode *PN) { AllPhiNodes.insert(PN); }
+
+ void insertNewSelect(SelectInst *SI) { AllSelectNodes.insert(SI); }
+
+ unsigned countNewPhiNodes() const { return AllPhiNodes.size(); }
+
+ unsigned countNewSelectNodes() const { return AllSelectNodes.size(); }
+
+ void destroyNewNodes(Type *CommonType) {
+ // For safe erasing, replace the uses with dummy value first.
+ auto Dummy = UndefValue::get(CommonType);
+ for (auto I : AllPhiNodes) {
+ I->replaceAllUsesWith(Dummy);
+ I->eraseFromParent();
+ }
+ AllPhiNodes.clear();
+ for (auto I : AllSelectNodes) {
+ I->replaceAllUsesWith(Dummy);
+ I->eraseFromParent();
+ }
+ AllSelectNodes.clear();
+ }
+};
+
+/// A helper class for combining addressing modes.
class AddressingModeCombiner {
+ typedef std::pair<Value *, BasicBlock *> ValueInBB;
+ typedef DenseMap<ValueInBB, Value *> FoldAddrToValueMapping;
+ typedef std::pair<PHINode *, PHINode *> PHIPair;
+
private:
/// The addressing modes we've collected.
SmallVector<ExtAddrMode, 16> AddrModes;
/// Are the AddrModes that we have all just equal to their original values?
bool AllAddrModesTrivial = true;
+ /// Common Type for all different fields in addressing modes.
+ Type *CommonType;
+
+ /// SimplifyQuery for simplifyInstruction utility.
+ const SimplifyQuery &SQ;
+
+ /// Original Address.
+ ValueInBB Original;
+
public:
- /// \brief Get the combined AddrMode
+ AddressingModeCombiner(const SimplifyQuery &_SQ, ValueInBB OriginalValue)
+ : CommonType(nullptr), SQ(_SQ), Original(OriginalValue) {}
+
+ /// Get the combined AddrMode
const ExtAddrMode &getAddrMode() const {
return AddrModes[0];
}
- /// \brief Add a new AddrMode if it's compatible with the AddrModes we already
+ /// Add a new AddrMode if it's compatible with the AddrModes we already
/// have.
/// \return True iff we succeeded in doing so.
bool addNewAddrMode(ExtAddrMode &NewAddrMode) {
else if (DifferentField != ThisDifferentField)
DifferentField = ExtAddrMode::MultipleFields;
- // If this AddrMode is the same as all the others then everything is fine
- // (which should only happen when there is actually only one AddrMode).
- if (DifferentField == ExtAddrMode::NoField) {
- assert(AddrModes.size() == 1);
- return true;
- }
+ // If NewAddrMode differs in more than one dimension we cannot handle it.
+ bool CanHandle = DifferentField != ExtAddrMode::MultipleFields;
+
+ // If Scale Field is different then we reject.
+ CanHandle = CanHandle && DifferentField != ExtAddrMode::ScaleField;
+
+ // We also must reject the case when base offset is different and
+ // scale reg is not null, we cannot handle this case due to merge of
+ // different offsets will be used as ScaleReg.
+ CanHandle = CanHandle && (DifferentField != ExtAddrMode::BaseOffsField ||
+ !NewAddrMode.ScaledReg);
+
+ // We also must reject the case when GV is different and BaseReg installed
+ // due to we want to use base reg as a merge of GV values.
+ CanHandle = CanHandle && (DifferentField != ExtAddrMode::BaseGVField ||
+ !NewAddrMode.HasBaseReg);
- // If NewAddrMode differs in only one dimension then we can handle it by
- // inserting a phi/select later on.
- if (DifferentField != ExtAddrMode::MultipleFields) {
+ // Even if NewAddMode is the same we still need to collect it due to
+ // original value is different. And later we will need all original values
+ // as anchors during finding the common Phi node.
+ if (CanHandle)
AddrModes.emplace_back(NewAddrMode);
- return true;
- }
+ else
+ AddrModes.clear();
- // We couldn't combine NewAddrMode with the rest, so return failure.
- AddrModes.clear();
- return false;
+ return CanHandle;
}
- /// \brief Combine the addressing modes we've collected into a single
+ /// Combine the addressing modes we've collected into a single
/// addressing mode.
/// \return True iff we successfully combined them or we only had one so
/// didn't need to combine them anyway.
return false;
// A single AddrMode can trivially be combined.
- if (AddrModes.size() == 1)
+ if (AddrModes.size() == 1 || DifferentField == ExtAddrMode::NoField)
return true;
// If the AddrModes we collected are all just equal to the value they are
if (AllAddrModesTrivial)
return false;
- // TODO: Combine multiple AddrModes by inserting a select or phi for the
- // field in which the AddrModes differ.
- return false;
+ if (!addrModeCombiningAllowed())
+ return false;
+
+ // Build a map between <original value, basic block where we saw it> to
+ // value of base register.
+ // Bail out if there is no common type.
+ FoldAddrToValueMapping Map;
+ if (!initializeMap(Map))
+ return false;
+
+ Value *CommonValue = findCommon(Map);
+ if (CommonValue)
+ AddrModes[0].SetCombinedField(DifferentField, CommonValue, AddrModes);
+ return CommonValue != nullptr;
+ }
+
+private:
+ /// Initialize Map with anchor values. For address seen in some BB
+ /// we set the value of different field saw in this address.
+ /// If address is not an instruction than basic block is set to null.
+ /// At the same time we find a common type for different field we will
+ /// use to create new Phi/Select nodes. Keep it in CommonType field.
+ /// Return false if there is no common type found.
+ bool initializeMap(FoldAddrToValueMapping &Map) {
+ // Keep track of keys where the value is null. We will need to replace it
+ // with constant null when we know the common type.
+ SmallVector<ValueInBB, 2> NullValue;
+ Type *IntPtrTy = SQ.DL.getIntPtrType(AddrModes[0].OriginalValue->getType());
+ for (auto &AM : AddrModes) {
+ BasicBlock *BB = nullptr;
+ if (Instruction *I = dyn_cast<Instruction>(AM.OriginalValue))
+ BB = I->getParent();
+
+ Value *DV = AM.GetFieldAsValue(DifferentField, IntPtrTy);
+ if (DV) {
+ auto *Type = DV->getType();
+ if (CommonType && CommonType != Type)
+ return false;
+ CommonType = Type;
+ Map[{ AM.OriginalValue, BB }] = DV;
+ } else {
+ NullValue.push_back({ AM.OriginalValue, BB });
+ }
+ }
+ assert(CommonType && "At least one non-null value must be!");
+ for (auto VIBB : NullValue)
+ Map[VIBB] = Constant::getNullValue(CommonType);
+ return true;
+ }
+
+ /// We have mapping between value A and basic block where value A
+ /// seen to other value B where B was a field in addressing mode represented
+ /// by A. Also we have an original value C representing an address in some
+ /// basic block. Traversing from C through phi and selects we ended up with
+ /// A's in a map. This utility function tries to find a value V which is a
+ /// field in addressing mode C and traversing through phi nodes and selects
+ /// we will end up in corresponded values B in a map.
+ /// The utility will create a new Phi/Selects if needed.
+ // The simple example looks as follows:
+ // BB1:
+ // p1 = b1 + 40
+ // br cond BB2, BB3
+ // BB2:
+ // p2 = b2 + 40
+ // br BB3
+ // BB3:
+ // p = phi [p1, BB1], [p2, BB2]
+ // v = load p
+ // Map is
+ // <p1, BB1> -> b1
+ // <p2, BB2> -> b2
+ // Request is
+ // <p, BB3> -> ?
+ // The function tries to find or build phi [b1, BB1], [b2, BB2] in BB3
+ Value *findCommon(FoldAddrToValueMapping &Map) {
+ // Tracks the simplification of newly created phi nodes. The reason we use
+ // this mapping is because we will add new created Phi nodes in AddrToBase.
+ // Simplification of Phi nodes is recursive, so some Phi node may
+ // be simplified after we added it to AddrToBase.
+ // Using this mapping we can find the current value in AddrToBase.
+ SimplificationTracker ST(SQ);
+
+ // First step, DFS to create PHI nodes for all intermediate blocks.
+ // Also fill traverse order for the second step.
+ SmallVector<ValueInBB, 32> TraverseOrder;
+ InsertPlaceholders(Map, TraverseOrder, ST);
+
+ // Second Step, fill new nodes by merged values and simplify if possible.
+ FillPlaceholders(Map, TraverseOrder, ST);
+
+ if (!AddrSinkNewSelects && ST.countNewSelectNodes() > 0) {
+ ST.destroyNewNodes(CommonType);
+ return nullptr;
+ }
+
+ // Now we'd like to match New Phi nodes to existed ones.
+ unsigned PhiNotMatchedCount = 0;
+ if (!MatchPhiSet(ST, AddrSinkNewPhis, PhiNotMatchedCount)) {
+ ST.destroyNewNodes(CommonType);
+ return nullptr;
+ }
+
+ auto *Result = ST.Get(Map.find(Original)->second);
+ if (Result) {
+ NumMemoryInstsPhiCreated += ST.countNewPhiNodes() + PhiNotMatchedCount;
+ NumMemoryInstsSelectCreated += ST.countNewSelectNodes();
+ }
+ return Result;
+ }
+
+ /// Try to match PHI node to Candidate.
+ /// Matcher tracks the matched Phi nodes.
+ bool MatchPhiNode(PHINode *PHI, PHINode *Candidate,
+ SmallSetVector<PHIPair, 8> &Matcher,
+ SmallSetVector<PHINode *, 32> &PhiNodesToMatch) {
+ SmallVector<PHIPair, 8> WorkList;
+ Matcher.insert({ PHI, Candidate });
+ WorkList.push_back({ PHI, Candidate });
+ SmallSet<PHIPair, 8> Visited;
+ while (!WorkList.empty()) {
+ auto Item = WorkList.pop_back_val();
+ if (!Visited.insert(Item).second)
+ continue;
+ // We iterate over all incoming values to Phi to compare them.
+ // If values are different and both of them Phi and the first one is a
+ // Phi we added (subject to match) and both of them is in the same basic
+ // block then we can match our pair if values match. So we state that
+ // these values match and add it to work list to verify that.
+ for (auto B : Item.first->blocks()) {
+ Value *FirstValue = Item.first->getIncomingValueForBlock(B);
+ Value *SecondValue = Item.second->getIncomingValueForBlock(B);
+ if (FirstValue == SecondValue)
+ continue;
+
+ PHINode *FirstPhi = dyn_cast<PHINode>(FirstValue);
+ PHINode *SecondPhi = dyn_cast<PHINode>(SecondValue);
+
+ // One of them is not Phi or
+ // The first one is not Phi node from the set we'd like to match or
+ // Phi nodes from different basic blocks then
+ // we will not be able to match.
+ if (!FirstPhi || !SecondPhi || !PhiNodesToMatch.count(FirstPhi) ||
+ FirstPhi->getParent() != SecondPhi->getParent())
+ return false;
+
+ // If we already matched them then continue.
+ if (Matcher.count({ FirstPhi, SecondPhi }))
+ continue;
+ // So the values are different and does not match. So we need them to
+ // match.
+ Matcher.insert({ FirstPhi, SecondPhi });
+ // But me must check it.
+ WorkList.push_back({ FirstPhi, SecondPhi });
+ }
+ }
+ return true;
+ }
+
+ /// For the given set of PHI nodes (in the SimplificationTracker) try
+ /// to find their equivalents.
+ /// Returns false if this matching fails and creation of new Phi is disabled.
+ bool MatchPhiSet(SimplificationTracker &ST, bool AllowNewPhiNodes,
+ unsigned &PhiNotMatchedCount) {
+ // Use a SetVector for Matched to make sure we do replacements (ReplacePhi)
+ // in a deterministic order below.
+ SmallSetVector<PHIPair, 8> Matched;
+ SmallPtrSet<PHINode *, 8> WillNotMatch;
+ SmallSetVector<PHINode *, 32> &PhiNodesToMatch = ST.newPhiNodes();
+ while (PhiNodesToMatch.size()) {
+ PHINode *PHI = *PhiNodesToMatch.begin();
+
+ // Add us, if no Phi nodes in the basic block we do not match.
+ WillNotMatch.clear();
+ WillNotMatch.insert(PHI);
+
+ // Traverse all Phis until we found equivalent or fail to do that.
+ bool IsMatched = false;
+ for (auto &P : PHI->getParent()->phis()) {
+ if (&P == PHI)
+ continue;
+ if ((IsMatched = MatchPhiNode(PHI, &P, Matched, PhiNodesToMatch)))
+ break;
+ // If it does not match, collect all Phi nodes from matcher.
+ // if we end up with no match, them all these Phi nodes will not match
+ // later.
+ for (auto M : Matched)
+ WillNotMatch.insert(M.first);
+ Matched.clear();
+ }
+ if (IsMatched) {
+ // Replace all matched values and erase them.
+ for (auto MV : Matched)
+ ST.ReplacePhi(MV.first, MV.second);
+ Matched.clear();
+ continue;
+ }
+ // If we are not allowed to create new nodes then bail out.
+ if (!AllowNewPhiNodes)
+ return false;
+ // Just remove all seen values in matcher. They will not match anything.
+ PhiNotMatchedCount += WillNotMatch.size();
+ for (auto *P : WillNotMatch)
+ PhiNodesToMatch.remove(P);
+ }
+ return true;
+ }
+ /// Fill the placeholder with values from predecessors and simplify it.
+ void FillPlaceholders(FoldAddrToValueMapping &Map,
+ SmallVectorImpl<ValueInBB> &TraverseOrder,
+ SimplificationTracker &ST) {
+ while (!TraverseOrder.empty()) {
+ auto Current = TraverseOrder.pop_back_val();
+ assert(Map.find(Current) != Map.end() && "No node to fill!!!");
+ Value *CurrentValue = Current.first;
+ BasicBlock *CurrentBlock = Current.second;
+ Value *V = Map[Current];
+
+ if (SelectInst *Select = dyn_cast<SelectInst>(V)) {
+ // CurrentValue also must be Select.
+ auto *CurrentSelect = cast<SelectInst>(CurrentValue);
+ auto *TrueValue = CurrentSelect->getTrueValue();
+ ValueInBB TrueItem = { TrueValue, isa<Instruction>(TrueValue)
+ ? CurrentBlock
+ : nullptr };
+ assert(Map.find(TrueItem) != Map.end() && "No True Value!");
+ Select->setTrueValue(ST.Get(Map[TrueItem]));
+ auto *FalseValue = CurrentSelect->getFalseValue();
+ ValueInBB FalseItem = { FalseValue, isa<Instruction>(FalseValue)
+ ? CurrentBlock
+ : nullptr };
+ assert(Map.find(FalseItem) != Map.end() && "No False Value!");
+ Select->setFalseValue(ST.Get(Map[FalseItem]));
+ } else {
+ // Must be a Phi node then.
+ PHINode *PHI = cast<PHINode>(V);
+ // Fill the Phi node with values from predecessors.
+ bool IsDefinedInThisBB =
+ cast<Instruction>(CurrentValue)->getParent() == CurrentBlock;
+ auto *CurrentPhi = dyn_cast<PHINode>(CurrentValue);
+ for (auto B : predecessors(CurrentBlock)) {
+ Value *PV = IsDefinedInThisBB
+ ? CurrentPhi->getIncomingValueForBlock(B)
+ : CurrentValue;
+ ValueInBB item = { PV, isa<Instruction>(PV) ? B : nullptr };
+ assert(Map.find(item) != Map.end() && "No predecessor Value!");
+ PHI->addIncoming(ST.Get(Map[item]), B);
+ }
+ }
+ // Simplify if possible.
+ Map[Current] = ST.Simplify(V);
+ }
+ }
+
+ /// Starting from value recursively iterates over predecessors up to known
+ /// ending values represented in a map. For each traversed block inserts
+ /// a placeholder Phi or Select.
+ /// Reports all new created Phi/Select nodes by adding them to set.
+ /// Also reports and order in what basic blocks have been traversed.
+ void InsertPlaceholders(FoldAddrToValueMapping &Map,
+ SmallVectorImpl<ValueInBB> &TraverseOrder,
+ SimplificationTracker &ST) {
+ SmallVector<ValueInBB, 32> Worklist;
+ assert((isa<PHINode>(Original.first) || isa<SelectInst>(Original.first)) &&
+ "Address must be a Phi or Select node");
+ auto *Dummy = UndefValue::get(CommonType);
+ Worklist.push_back(Original);
+ while (!Worklist.empty()) {
+ auto Current = Worklist.pop_back_val();
+ // If value is not an instruction it is something global, constant,
+ // parameter and we can say that this value is observable in any block.
+ // Set block to null to denote it.
+ // Also please take into account that it is how we build anchors.
+ if (!isa<Instruction>(Current.first))
+ Current.second = nullptr;
+ // if it is already visited or it is an ending value then skip it.
+ if (Map.find(Current) != Map.end())
+ continue;
+ TraverseOrder.push_back(Current);
+
+ Value *CurrentValue = Current.first;
+ BasicBlock *CurrentBlock = Current.second;
+ // CurrentValue must be a Phi node or select. All others must be covered
+ // by anchors.
+ Instruction *CurrentI = cast<Instruction>(CurrentValue);
+ bool IsDefinedInThisBB = CurrentI->getParent() == CurrentBlock;
+
+ unsigned PredCount = pred_size(CurrentBlock);
+ // if Current Value is not defined in this basic block we are interested
+ // in values in predecessors.
+ if (!IsDefinedInThisBB) {
+ assert(PredCount && "Unreachable block?!");
+ PHINode *PHI = PHINode::Create(CommonType, PredCount, "sunk_phi",
+ &CurrentBlock->front());
+ Map[Current] = PHI;
+ ST.insertNewPhi(PHI);
+ // Add all predecessors in work list.
+ for (auto B : predecessors(CurrentBlock))
+ Worklist.push_back({ CurrentValue, B });
+ continue;
+ }
+ // Value is defined in this basic block.
+ if (SelectInst *OrigSelect = dyn_cast<SelectInst>(CurrentI)) {
+ // Is it OK to get metadata from OrigSelect?!
+ // Create a Select placeholder with dummy value.
+ SelectInst *Select =
+ SelectInst::Create(OrigSelect->getCondition(), Dummy, Dummy,
+ OrigSelect->getName(), OrigSelect, OrigSelect);
+ Map[Current] = Select;
+ ST.insertNewSelect(Select);
+ // We are interested in True and False value in this basic block.
+ Worklist.push_back({ OrigSelect->getTrueValue(), CurrentBlock });
+ Worklist.push_back({ OrigSelect->getFalseValue(), CurrentBlock });
+ } else {
+ // It must be a Phi node then.
+ auto *CurrentPhi = cast<PHINode>(CurrentI);
+ // Create new Phi node for merge of bases.
+ assert(PredCount && "Unreachable block?!");
+ PHINode *PHI = PHINode::Create(CommonType, PredCount, "sunk_phi",
+ &CurrentBlock->front());
+ Map[Current] = PHI;
+ ST.insertNewPhi(PHI);
+
+ // Add all predecessors in work list.
+ for (auto B : predecessors(CurrentBlock))
+ Worklist.push_back({ CurrentPhi->getIncomingValueForBlock(B), B });
+ }
+ }
}
-};
+ bool addrModeCombiningAllowed() {
+ if (DisableComplexAddrModes)
+ return false;
+ switch (DifferentField) {
+ default:
+ return false;
+ case ExtAddrMode::BaseRegField:
+ return AddrSinkCombineBaseReg;
+ case ExtAddrMode::BaseGVField:
+ return AddrSinkCombineBaseGV;
+ case ExtAddrMode::BaseOffsField:
+ return AddrSinkCombineBaseOffs;
+ case ExtAddrMode::ScaledRegField:
+ return AddrSinkCombineScaledReg;
+ }
+ }
+};
} // end anonymous namespace
/// Try adding ScaleReg*Scale to the current addressing mode.
// Don't touch identity bitcasts.
if (I->getType() == I->getOperand(0)->getType())
return false;
- return I->getType()->isPointerTy() || I->getType()->isIntegerTy();
+ return I->getType()->isIntOrPtrTy();
case Instruction::PtrToInt:
// PtrToInt is always a noop, as we know that the int type is pointer sized.
return true;
}
}
-/// \brief Check whether or not \p Val is a legal instruction for \p TLI.
+/// Check whether or not \p Val is a legal instruction for \p TLI.
/// \note \p Val is assumed to be the product of some type promotion.
/// Therefore if \p Val has an undefined state in \p TLI, this is assumed
/// to be legal, as the non-promoted value would have had the same state.
namespace {
-/// \brief Hepler class to perform type promotion.
+/// Hepler class to perform type promotion.
class TypePromotionHelper {
- /// \brief Utility function to check whether or not a sign or zero extension
+ /// Utility function to add a promoted instruction \p ExtOpnd to
+ /// \p PromotedInsts and record the type of extension we have seen.
+ static void addPromotedInst(InstrToOrigTy &PromotedInsts,
+ Instruction *ExtOpnd,
+ bool IsSExt) {
+ ExtType ExtTy = IsSExt ? SignExtension : ZeroExtension;
+ InstrToOrigTy::iterator It = PromotedInsts.find(ExtOpnd);
+ if (It != PromotedInsts.end()) {
+ // If the new extension is same as original, the information in
+ // PromotedInsts[ExtOpnd] is still correct.
+ if (It->second.getInt() == ExtTy)
+ return;
+
+ // Now the new extension is different from old extension, we make
+ // the type information invalid by setting extension type to
+ // BothExtension.
+ ExtTy = BothExtension;
+ }
+ PromotedInsts[ExtOpnd] = TypeIsSExt(ExtOpnd->getType(), ExtTy);
+ }
+
+ /// Utility function to query the original type of instruction \p Opnd
+ /// with a matched extension type. If the extension doesn't match, we
+ /// cannot use the information we had on the original type.
+ /// BothExtension doesn't match any extension type.
+ static const Type *getOrigType(const InstrToOrigTy &PromotedInsts,
+ Instruction *Opnd,
+ bool IsSExt) {
+ ExtType ExtTy = IsSExt ? SignExtension : ZeroExtension;
+ InstrToOrigTy::const_iterator It = PromotedInsts.find(Opnd);
+ if (It != PromotedInsts.end() && It->second.getInt() == ExtTy)
+ return It->second.getPointer();
+ return nullptr;
+ }
+
+ /// Utility function to check whether or not a sign or zero extension
/// of \p Inst with \p ConsideredExtType can be moved through \p Inst by
/// either using the operands of \p Inst or promoting \p Inst.
/// The type of the extension is defined by \p IsSExt.
static bool canGetThrough(const Instruction *Inst, Type *ConsideredExtType,
const InstrToOrigTy &PromotedInsts, bool IsSExt);
- /// \brief Utility function to determine if \p OpIdx should be promoted when
+ /// Utility function to determine if \p OpIdx should be promoted when
/// promoting \p Inst.
static bool shouldExtOperand(const Instruction *Inst, int OpIdx) {
return !(isa<SelectInst>(Inst) && OpIdx == 0);
}
- /// \brief Utility function to promote the operand of \p Ext when this
+ /// Utility function to promote the operand of \p Ext when this
/// operand is a promotable trunc or sext or zext.
/// \p PromotedInsts maps the instructions to their type before promotion.
/// \p CreatedInstsCost[out] contains the cost of all instructions
SmallVectorImpl<Instruction *> *Exts,
SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI);
- /// \brief Utility function to promote the operand of \p Ext when this
+ /// Utility function to promote the operand of \p Ext when this
/// operand is promotable and is not a supported trunc or sext.
/// \p PromotedInsts maps the instructions to their type before promotion.
/// \p CreatedInstsCost[out] contains the cost of all the instructions
SmallVectorImpl<Instruction *> *Truncs,
const TargetLowering &TLI);
- /// \brief Given a sign/zero extend instruction \p Ext, return the approriate
+ /// Given a sign/zero extend instruction \p Ext, return the appropriate
/// action to promote the operand of \p Ext instead of using Ext.
/// \return NULL if no promotable action is possible with the current
/// sign extension.
(IsSExt && BinOp->hasNoSignedWrap())))
return true;
+ // ext(and(opnd, cst)) --> and(ext(opnd), ext(cst))
+ if ((Inst->getOpcode() == Instruction::And ||
+ Inst->getOpcode() == Instruction::Or))
+ return true;
+
+ // ext(xor(opnd, cst)) --> xor(ext(opnd), ext(cst))
+ if (Inst->getOpcode() == Instruction::Xor) {
+ const ConstantInt *Cst = dyn_cast<ConstantInt>(Inst->getOperand(1));
+ // Make sure it is not a NOT.
+ if (Cst && !Cst->getValue().isAllOnesValue())
+ return true;
+ }
+
+ // zext(shrl(opnd, cst)) --> shrl(zext(opnd), zext(cst))
+ // It may change a poisoned value into a regular value, like
+ // zext i32 (shrl i8 %val, 12) --> shrl i32 (zext i8 %val), 12
+ // poisoned value regular value
+ // It should be OK since undef covers valid value.
+ if (Inst->getOpcode() == Instruction::LShr && !IsSExt)
+ return true;
+
+ // and(ext(shl(opnd, cst)), cst) --> and(shl(ext(opnd), ext(cst)), cst)
+ // It may change a poisoned value into a regular value, like
+ // zext i32 (shl i8 %val, 12) --> shl i32 (zext i8 %val), 12
+ // poisoned value regular value
+ // It should be OK since undef covers valid value.
+ if (Inst->getOpcode() == Instruction::Shl && Inst->hasOneUse()) {
+ const Instruction *ExtInst =
+ dyn_cast<const Instruction>(*Inst->user_begin());
+ if (ExtInst->hasOneUse()) {
+ const Instruction *AndInst =
+ dyn_cast<const Instruction>(*ExtInst->user_begin());
+ if (AndInst && AndInst->getOpcode() == Instruction::And) {
+ const ConstantInt *Cst = dyn_cast<ConstantInt>(AndInst->getOperand(1));
+ if (Cst &&
+ Cst->getValue().isIntN(Inst->getType()->getIntegerBitWidth()))
+ return true;
+ }
+ }
+ }
+
// Check if we can do the following simplification.
// ext(trunc(opnd)) --> ext(opnd)
if (!isa<TruncInst>(Inst))
// I.e., check that trunc just drops extended bits of the same kind of
// the extension.
// #1 get the type of the operand and check the kind of the extended bits.
- const Type *OpndType;
- InstrToOrigTy::const_iterator It = PromotedInsts.find(Opnd);
- if (It != PromotedInsts.end() && It->second.getInt() == IsSExt)
- OpndType = It->second.getPointer();
+ const Type *OpndType = getOrigType(PromotedInsts, Opnd, IsSExt);
+ if (OpndType)
+ ;
else if ((IsSExt && isa<SExtInst>(Opnd)) || (!IsSExt && isa<ZExtInst>(Opnd)))
OpndType = Opnd->getOperand(0)->getType();
else
// Remember the original type of the instruction before promotion.
// This is useful to know that the high bits are sign extended bits.
- PromotedInsts.insert(std::pair<Instruction *, TypeIsSExt>(
- ExtOpnd, TypeIsSExt(ExtOpnd->getType(), IsSExt)));
+ addPromotedInst(PromotedInsts, ExtOpnd, IsSExt);
// Step #1.
TPT.mutateType(ExtOpnd, Ext->getType());
// Step #2.
// Step #3.
Instruction *ExtForOpnd = Ext;
- DEBUG(dbgs() << "Propagate Ext to operands\n");
+ LLVM_DEBUG(dbgs() << "Propagate Ext to operands\n");
for (int OpIdx = 0, EndOpIdx = ExtOpnd->getNumOperands(); OpIdx != EndOpIdx;
++OpIdx) {
- DEBUG(dbgs() << "Operand:\n" << *(ExtOpnd->getOperand(OpIdx)) << '\n');
+ LLVM_DEBUG(dbgs() << "Operand:\n" << *(ExtOpnd->getOperand(OpIdx)) << '\n');
if (ExtOpnd->getOperand(OpIdx)->getType() == Ext->getType() ||
!shouldExtOperand(ExtOpnd, OpIdx)) {
- DEBUG(dbgs() << "No need to propagate\n");
+ LLVM_DEBUG(dbgs() << "No need to propagate\n");
continue;
}
// Check if we can statically extend the operand.
Value *Opnd = ExtOpnd->getOperand(OpIdx);
if (const ConstantInt *Cst = dyn_cast<ConstantInt>(Opnd)) {
- DEBUG(dbgs() << "Statically extend\n");
+ LLVM_DEBUG(dbgs() << "Statically extend\n");
unsigned BitWidth = Ext->getType()->getIntegerBitWidth();
APInt CstVal = IsSExt ? Cst->getValue().sext(BitWidth)
: Cst->getValue().zext(BitWidth);
}
// UndefValue are typed, so we have to statically sign extend them.
if (isa<UndefValue>(Opnd)) {
- DEBUG(dbgs() << "Statically extend\n");
+ LLVM_DEBUG(dbgs() << "Statically extend\n");
TPT.setOperand(ExtOpnd, OpIdx, UndefValue::get(Ext->getType()));
continue;
}
- // Otherwise we have to explicity sign extend the operand.
+ // Otherwise we have to explicitly sign extend the operand.
// Check if Ext was reused to extend an operand.
if (!ExtForOpnd) {
// If yes, create a new one.
- DEBUG(dbgs() << "More operands to ext\n");
+ LLVM_DEBUG(dbgs() << "More operands to ext\n");
Value *ValForExtOpnd = IsSExt ? TPT.createSExt(Ext, Opnd, Ext->getType())
: TPT.createZExt(Ext, Opnd, Ext->getType());
if (!isa<Instruction>(ValForExtOpnd)) {
ExtForOpnd = nullptr;
}
if (ExtForOpnd == Ext) {
- DEBUG(dbgs() << "Extension is useless now\n");
+ LLVM_DEBUG(dbgs() << "Extension is useless now\n");
TPT.eraseInstruction(Ext);
}
return ExtOpnd;
/// \return True if the promotion is profitable, false otherwise.
bool AddressingModeMatcher::isPromotionProfitable(
unsigned NewCost, unsigned OldCost, Value *PromotedOperand) const {
- DEBUG(dbgs() << "OldCost: " << OldCost << "\tNewCost: " << NewCost << '\n');
+ LLVM_DEBUG(dbgs() << "OldCost: " << OldCost << "\tNewCost: " << NewCost
+ << '\n');
// The cost of the new extensions is greater than the cost of the
// old extension plus what we folded.
// This is not profitable.
case Instruction::BitCast:
// BitCast is always a noop, and we can handle it as long as it is
// int->int or pointer->pointer (we don't want int<->fp or something).
- if ((AddrInst->getOperand(0)->getType()->isPointerTy() ||
- AddrInst->getOperand(0)->getType()->isIntegerTy()) &&
+ if (AddrInst->getOperand(0)->getType()->isIntOrPtrTy() &&
// Don't touch identity bitcasts. These were probably put here by LSR,
// and we don't want to mess around with them. Assume it knows what it
// is doing.
case Instruction::Shl: {
// Can only handle X*C and X << C.
ConstantInt *RHS = dyn_cast<ConstantInt>(AddrInst->getOperand(1));
- if (!RHS)
+ if (!RHS || RHS->getBitWidth() > 64)
return false;
int64_t Scale = RHS->getSExtValue();
if (Opcode == Instruction::Shl)
} else {
uint64_t TypeSize = DL.getTypeAllocSize(GTI.getIndexedType());
if (ConstantInt *CI = dyn_cast<ConstantInt>(AddrInst->getOperand(i))) {
- ConstantOffset += CI->getSExtValue()*TypeSize;
+ ConstantOffset += CI->getSExtValue() * TypeSize;
} else if (TypeSize) { // Scales of zero don't do anything.
// We only allow one variable index at the moment.
if (VariableOperand != -1)
// Check to see if we can fold the base pointer in too.
if (matchAddr(AddrInst->getOperand(0), Depth+1))
return true;
+ } else if (EnableGEPOffsetSplit && isa<GetElementPtrInst>(AddrInst) &&
+ TLI.shouldConsiderGEPOffsetSplit() && Depth == 0 &&
+ ConstantOffset > 0) {
+ // Record GEPs with non-zero offsets as candidates for splitting in the
+ // event that the offset cannot fit into the r+i addressing mode.
+ // Simple and common case that only one GEP is used in calculating the
+ // address for the memory access.
+ Value *Base = AddrInst->getOperand(0);
+ auto *BaseI = dyn_cast<Instruction>(Base);
+ auto *GEP = cast<GetElementPtrInst>(AddrInst);
+ if (isa<Argument>(Base) || isa<GlobalValue>(Base) ||
+ (BaseI && !isa<CastInst>(BaseI) &&
+ !isa<GetElementPtrInst>(BaseI))) {
+ // If the base is an instruction, make sure the GEP is not in the same
+ // basic block as the base. If the base is an argument or global
+ // value, make sure the GEP is not in the entry block. Otherwise,
+ // instruction selection can undo the split. Also make sure the
+ // parent block allows inserting non-PHI instructions before the
+ // terminator.
+ BasicBlock *Parent =
+ BaseI ? BaseI->getParent() : &GEP->getFunction()->getEntryBlock();
+ if (GEP->getParent() != Parent && !Parent->getTerminator()->isEHPad())
+ LargeOffsetGEP = std::make_pair(GEP, ConstantOffset);
+ }
}
AddrMode.BaseOffs -= ConstantOffset;
return false;
PromotedOperand)) {
AddrMode = BackupAddrMode;
AddrModeInsts.resize(OldSize);
- DEBUG(dbgs() << "Sign extension does not pay off: rollback\n");
+ LLVM_DEBUG(dbgs() << "Sign extension does not pay off: rollback\n");
TPT.rollback(LastKnownGood);
return false;
}
// will tell us if the addressing mode for the memory operation will
// *actually* cover the shared instruction.
ExtAddrMode Result;
+ std::pair<AssertingVH<GetElementPtrInst>, int64_t> LargeOffsetGEP(nullptr,
+ 0);
TypePromotionTransaction::ConstRestorationPt LastKnownGood =
TPT.getRestorationPoint();
- AddressingModeMatcher Matcher(MatchedAddrModeInsts, TLI, TRI,
- AddressAccessTy, AS,
- MemoryInst, Result, InsertedInsts,
- PromotedInsts, TPT);
+ AddressingModeMatcher Matcher(
+ MatchedAddrModeInsts, TLI, TRI, AddressAccessTy, AS, MemoryInst, Result,
+ InsertedInsts, PromotedInsts, TPT, LargeOffsetGEP);
Matcher.IgnoreProfitability = true;
bool Success = Matcher.matchAddr(Address, 0);
(void)Success; assert(Success && "Couldn't select *anything*?");
// the graph are compatible.
bool PhiOrSelectSeen = false;
SmallVector<Instruction*, 16> AddrModeInsts;
- AddressingModeCombiner AddrModes;
+ const SimplifyQuery SQ(*DL, TLInfo);
+ AddressingModeCombiner AddrModes(SQ, { Addr, MemoryInst->getParent() });
TypePromotionTransaction TPT(RemovedInsts);
TypePromotionTransaction::ConstRestorationPt LastKnownGood =
TPT.getRestorationPoint();
// the result may differ depending on what other uses our candidate
// addressing instructions might have.
AddrModeInsts.clear();
+ std::pair<AssertingVH<GetElementPtrInst>, int64_t> LargeOffsetGEP(nullptr,
+ 0);
ExtAddrMode NewAddrMode = AddressingModeMatcher::Match(
V, AccessTy, AddrSpace, MemoryInst, AddrModeInsts, *TLI, *TRI,
- InsertedInsts, PromotedInsts, TPT);
- NewAddrMode.OriginalValue = V;
+ InsertedInsts, PromotedInsts, TPT, LargeOffsetGEP);
+ GetElementPtrInst *GEP = LargeOffsetGEP.first;
+ if (GEP && GEP->getParent() != MemoryInst->getParent() &&
+ !NewGEPBases.count(GEP)) {
+ // If splitting the underlying data structure can reduce the offset of a
+ // GEP, collect the GEP. Skip the GEPs that are the new bases of
+ // previously split data structures.
+ LargeOffsetGEPMap[GEP->getPointerOperand()].push_back(LargeOffsetGEP);
+ if (LargeOffsetGEPID.find(GEP) == LargeOffsetGEPID.end())
+ LargeOffsetGEPID[GEP] = LargeOffsetGEPID.size();
+ }
+
+ NewAddrMode.OriginalValue = V;
if (!AddrModes.addNewAddrMode(NewAddrMode))
break;
}
if (!PhiOrSelectSeen && none_of(AddrModeInsts, [&](Value *V) {
return IsNonLocalValue(V, MemoryInst->getParent());
})) {
- DEBUG(dbgs() << "CGP: Found local addrmode: " << AddrMode << "\n");
+ LLVM_DEBUG(dbgs() << "CGP: Found local addrmode: " << AddrMode
+ << "\n");
return false;
}
// Now that we determined the addressing expression we want to use and know
// that we have to sink it into this block. Check to see if we have already
- // done this for some other load/store instr in this block. If so, reuse the
- // computation.
- Value *&SunkAddr = SunkAddrs[Addr];
+ // done this for some other load/store instr in this block. If so, reuse
+ // the computation. Before attempting reuse, check if the address is valid
+ // as it may have been erased.
+
+ WeakTrackingVH SunkAddrVH = SunkAddrs[Addr];
+
+ Value * SunkAddr = SunkAddrVH.pointsToAliveValue() ? SunkAddrVH : nullptr;
if (SunkAddr) {
- DEBUG(dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrMode << " for "
- << *MemoryInst << "\n");
+ LLVM_DEBUG(dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrMode
+ << " for " << *MemoryInst << "\n");
if (SunkAddr->getType() != Addr->getType())
SunkAddr = Builder.CreatePointerCast(SunkAddr, Addr->getType());
} else if (AddrSinkUsingGEPs ||
- (!AddrSinkUsingGEPs.getNumOccurrences() && TM &&
- SubtargetInfo->useAA())) {
+ (!AddrSinkUsingGEPs.getNumOccurrences() && TM && TTI->useAA())) {
// By default, we use the GEP-based method when AA is used later. This
// prevents new inttoptr/ptrtoint pairs from degrading AA capabilities.
- DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for "
- << *MemoryInst << "\n");
+ LLVM_DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode
+ << " for " << *MemoryInst << "\n");
Type *IntPtrTy = DL->getIntPtrType(Addr->getType());
Value *ResultPtr = nullptr, *ResultIndex = nullptr;
DL->isNonIntegralPointerType(AddrMode.BaseGV->getType())))
return false;
- DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for "
- << *MemoryInst << "\n");
+ LLVM_DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode
+ << " for " << *MemoryInst << "\n");
Type *IntPtrTy = DL->getIntPtrType(Addr->getType());
Value *Result = nullptr;
}
MemoryInst->replaceUsesOfWith(Repl, SunkAddr);
+ // Store the newly computed address into the cache. In the case we reused a
+ // value, this should be idempotent.
+ SunkAddrs[Addr] = WeakTrackingVH(SunkAddr);
// If we have no uses, recursively delete the value and all dead instructions
// using it.
return MadeChange;
}
-/// \brief Check if all the uses of \p Val are equivalent (or free) zero or
+/// Check if all the uses of \p Val are equivalent (or free) zero or
/// sign extensions.
static bool hasSameExtUse(Value *Val, const TargetLowering &TLI) {
assert(!Val->use_empty() && "Input must have at least one use");
return true;
}
-/// \brief Try to speculatively promote extensions in \p Exts and continue
+/// Try to speculatively promote extensions in \p Exts and continue
/// promoting through newly promoted operands recursively as far as doing so is
/// profitable. Save extensions profitably moved up, in \p ProfitablyMovedExts.
/// When some promotion happened, \p TPT contains the proper state to revert
}
if (!DT.dominates(Pt, Inst))
// Give up if we need to merge in a common dominator as the
- // expermients show it is not profitable.
+ // experiments show it is not profitable.
continue;
Inst->replaceAllUsesWith(Pt);
RemovedInsts.insert(Inst);
return Changed;
}
+// Spliting large data structures so that the GEPs accessing them can have
+// smaller offsets so that they can be sunk to the same blocks as their users.
+// For example, a large struct starting from %base is splitted into two parts
+// where the second part starts from %new_base.
+//
+// Before:
+// BB0:
+// %base =
+//
+// BB1:
+// %gep0 = gep %base, off0
+// %gep1 = gep %base, off1
+// %gep2 = gep %base, off2
+//
+// BB2:
+// %load1 = load %gep0
+// %load2 = load %gep1
+// %load3 = load %gep2
+//
+// After:
+// BB0:
+// %base =
+// %new_base = gep %base, off0
+//
+// BB1:
+// %new_gep0 = %new_base
+// %new_gep1 = gep %new_base, off1 - off0
+// %new_gep2 = gep %new_base, off2 - off0
+//
+// BB2:
+// %load1 = load i32, i32* %new_gep0
+// %load2 = load i32, i32* %new_gep1
+// %load3 = load i32, i32* %new_gep2
+//
+// %new_gep1 and %new_gep2 can be sunk to BB2 now after the splitting because
+// their offsets are smaller enough to fit into the addressing mode.
+bool CodeGenPrepare::splitLargeGEPOffsets() {
+ bool Changed = false;
+ for (auto &Entry : LargeOffsetGEPMap) {
+ Value *OldBase = Entry.first;
+ SmallVectorImpl<std::pair<AssertingVH<GetElementPtrInst>, int64_t>>
+ &LargeOffsetGEPs = Entry.second;
+ auto compareGEPOffset =
+ [&](const std::pair<GetElementPtrInst *, int64_t> &LHS,
+ const std::pair<GetElementPtrInst *, int64_t> &RHS) {
+ if (LHS.first == RHS.first)
+ return false;
+ if (LHS.second != RHS.second)
+ return LHS.second < RHS.second;
+ return LargeOffsetGEPID[LHS.first] < LargeOffsetGEPID[RHS.first];
+ };
+ // Sorting all the GEPs of the same data structures based on the offsets.
+ llvm::sort(LargeOffsetGEPs.begin(), LargeOffsetGEPs.end(),
+ compareGEPOffset);
+ LargeOffsetGEPs.erase(
+ std::unique(LargeOffsetGEPs.begin(), LargeOffsetGEPs.end()),
+ LargeOffsetGEPs.end());
+ // Skip if all the GEPs have the same offsets.
+ if (LargeOffsetGEPs.front().second == LargeOffsetGEPs.back().second)
+ continue;
+ GetElementPtrInst *BaseGEP = LargeOffsetGEPs.begin()->first;
+ int64_t BaseOffset = LargeOffsetGEPs.begin()->second;
+ Value *NewBaseGEP = nullptr;
+
+ auto LargeOffsetGEP = LargeOffsetGEPs.begin();
+ while (LargeOffsetGEP != LargeOffsetGEPs.end()) {
+ GetElementPtrInst *GEP = LargeOffsetGEP->first;
+ int64_t Offset = LargeOffsetGEP->second;
+ if (Offset != BaseOffset) {
+ TargetLowering::AddrMode AddrMode;
+ AddrMode.BaseOffs = Offset - BaseOffset;
+ // The result type of the GEP might not be the type of the memory
+ // access.
+ if (!TLI->isLegalAddressingMode(*DL, AddrMode,
+ GEP->getResultElementType(),
+ GEP->getAddressSpace())) {
+ // We need to create a new base if the offset to the current base is
+ // too large to fit into the addressing mode. So, a very large struct
+ // may be splitted into several parts.
+ BaseGEP = GEP;
+ BaseOffset = Offset;
+ NewBaseGEP = nullptr;
+ }
+ }
+
+ // Generate a new GEP to replace the current one.
+ IRBuilder<> Builder(GEP);
+ Type *IntPtrTy = DL->getIntPtrType(GEP->getType());
+ Type *I8PtrTy =
+ Builder.getInt8PtrTy(GEP->getType()->getPointerAddressSpace());
+ Type *I8Ty = Builder.getInt8Ty();
+
+ if (!NewBaseGEP) {
+ // Create a new base if we don't have one yet. Find the insertion
+ // pointer for the new base first.
+ BasicBlock::iterator NewBaseInsertPt;
+ BasicBlock *NewBaseInsertBB;
+ if (auto *BaseI = dyn_cast<Instruction>(OldBase)) {
+ // If the base of the struct is an instruction, the new base will be
+ // inserted close to it.
+ NewBaseInsertBB = BaseI->getParent();
+ if (isa<PHINode>(BaseI))
+ NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt();
+ else if (InvokeInst *Invoke = dyn_cast<InvokeInst>(BaseI)) {
+ NewBaseInsertBB =
+ SplitEdge(NewBaseInsertBB, Invoke->getNormalDest());
+ NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt();
+ } else
+ NewBaseInsertPt = std::next(BaseI->getIterator());
+ } else {
+ // If the current base is an argument or global value, the new base
+ // will be inserted to the entry block.
+ NewBaseInsertBB = &BaseGEP->getFunction()->getEntryBlock();
+ NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt();
+ }
+ IRBuilder<> NewBaseBuilder(NewBaseInsertBB, NewBaseInsertPt);
+ // Create a new base.
+ Value *BaseIndex = ConstantInt::get(IntPtrTy, BaseOffset);
+ NewBaseGEP = OldBase;
+ if (NewBaseGEP->getType() != I8PtrTy)
+ NewBaseGEP = NewBaseBuilder.CreatePointerCast(NewBaseGEP, I8PtrTy);
+ NewBaseGEP =
+ NewBaseBuilder.CreateGEP(I8Ty, NewBaseGEP, BaseIndex, "splitgep");
+ NewGEPBases.insert(NewBaseGEP);
+ }
+
+ Value *NewGEP = NewBaseGEP;
+ if (Offset == BaseOffset) {
+ if (GEP->getType() != I8PtrTy)
+ NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType());
+ } else {
+ // Calculate the new offset for the new GEP.
+ Value *Index = ConstantInt::get(IntPtrTy, Offset - BaseOffset);
+ NewGEP = Builder.CreateGEP(I8Ty, NewBaseGEP, Index);
+
+ if (GEP->getType() != I8PtrTy)
+ NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType());
+ }
+ GEP->replaceAllUsesWith(NewGEP);
+ LargeOffsetGEPID.erase(GEP);
+ LargeOffsetGEP = LargeOffsetGEPs.erase(LargeOffsetGEP);
+ GEP->eraseFromParent();
+ Changed = true;
+ }
+ }
+ return Changed;
+}
+
/// Return true, if an ext(load) can be formed from an extension in
/// \p MovedExts.
bool CodeGenPrepare::canFormExtLd(
// x = phi x1', x2'
// y = and x, 0xff
bool CodeGenPrepare::optimizeLoadExt(LoadInst *Load) {
- if (!Load->isSimple() ||
- !(Load->getType()->isIntegerTy() || Load->getType()->isPointerTy()))
+ if (!Load->isSimple() || !Load->getType()->isIntOrPtrTy())
return false;
// Skip loads we've already transformed.
namespace {
-/// \brief Helper class to promote a scalar operation to a vector one.
+/// Helper class to promote a scalar operation to a vector one.
/// This class is used to move downward extractelement transition.
/// E.g.,
/// a = vector_op <2 x i32>
/// Instruction that will be combined with the transition.
Instruction *CombineInst = nullptr;
- /// \brief The instruction that represents the current end of the transition.
+ /// The instruction that represents the current end of the transition.
/// Since we are faking the promotion until we reach the end of the chain
/// of computation, we need a way to get the current end of the transition.
Instruction *getEndOfTransition() const {
return InstsToBePromoted.back();
}
- /// \brief Return the index of the original value in the transition.
+ /// Return the index of the original value in the transition.
/// E.g., for "extractelement <2 x i32> c, i32 1" the original value,
/// c, is at index 0.
unsigned getTransitionOriginalValueIdx() const {
return 0;
}
- /// \brief Return the index of the index in the transition.
+ /// Return the index of the index in the transition.
/// E.g., for "extractelement <2 x i32> c, i32 0" the index
/// is at index 1.
unsigned getTransitionIdx() const {
return 1;
}
- /// \brief Get the type of the transition.
+ /// Get the type of the transition.
/// This is the type of the original value.
/// E.g., for "extractelement <2 x i32> c, i32 1" the type of the
/// transition is <2 x i32>.
return Transition->getOperand(getTransitionOriginalValueIdx())->getType();
}
- /// \brief Promote \p ToBePromoted by moving \p Def downward through.
+ /// Promote \p ToBePromoted by moving \p Def downward through.
/// I.e., we have the following sequence:
/// Def = Transition <ty1> a to <ty2>
/// b = ToBePromoted <ty2> Def, ...
/// Def = Transition <ty1> ToBePromoted to <ty2>
void promoteImpl(Instruction *ToBePromoted);
- /// \brief Check whether or not it is profitable to promote all the
+ /// Check whether or not it is profitable to promote all the
/// instructions enqueued to be promoted.
bool isProfitableToPromote() {
Value *ValIdx = Transition->getOperand(getTransitionOriginalValueIdx());
VectorCost += TTI.getArithmeticInstrCost(Inst->getOpcode(), PromotedType,
Arg0OVK, Arg1OVK);
}
- DEBUG(dbgs() << "Estimated cost of computation to be promoted:\nScalar: "
- << ScalarCost << "\nVector: " << VectorCost << '\n');
+ LLVM_DEBUG(
+ dbgs() << "Estimated cost of computation to be promoted:\nScalar: "
+ << ScalarCost << "\nVector: " << VectorCost << '\n');
return ScalarCost > VectorCost;
}
- /// \brief Generate a constant vector with \p Val with the same
+ /// Generate a constant vector with \p Val with the same
/// number of elements as the transition.
/// \p UseSplat defines whether or not \p Val should be replicated
/// across the whole vector.
return ConstantVector::get(ConstVec);
}
- /// \brief Check if promoting to a vector type an operand at \p OperandIdx
+ /// Check if promoting to a vector type an operand at \p OperandIdx
/// in \p Use can trigger undefined behavior.
static bool canCauseUndefinedBehavior(const Instruction *Use,
unsigned OperandIdx) {
assert(Transition && "Do not know how to promote null");
}
- /// \brief Check if we can promote \p ToBePromoted to \p Type.
+ /// Check if we can promote \p ToBePromoted to \p Type.
bool canPromote(const Instruction *ToBePromoted) const {
// We could support CastInst too.
return isa<BinaryOperator>(ToBePromoted);
}
- /// \brief Check if it is profitable to promote \p ToBePromoted
+ /// Check if it is profitable to promote \p ToBePromoted
/// by moving downward the transition through.
bool shouldPromote(const Instruction *ToBePromoted) const {
// Promote only if all the operands can be statically expanded.
ISDOpcode, TLI.getValueType(DL, getTransitionType(), true));
}
- /// \brief Check whether or not \p Use can be combined
+ /// Check whether or not \p Use can be combined
/// with the transition.
/// I.e., is it possible to do Use(Transition) => AnotherUse?
bool canCombine(const Instruction *Use) { return isa<StoreInst>(Use); }
- /// \brief Record \p ToBePromoted as part of the chain to be promoted.
+ /// Record \p ToBePromoted as part of the chain to be promoted.
void enqueueForPromotion(Instruction *ToBePromoted) {
InstsToBePromoted.push_back(ToBePromoted);
}
- /// \brief Set the instruction that will be combined with the transition.
+ /// Set the instruction that will be combined with the transition.
void recordCombineInstruction(Instruction *ToBeCombined) {
assert(canCombine(ToBeCombined) && "Unsupported instruction to combine");
CombineInst = ToBeCombined;
}
- /// \brief Promote all the instructions enqueued for promotion if it is
+ /// Promote all the instructions enqueued for promotion if it is
/// is profitable.
/// \return True if the promotion happened, false otherwise.
bool promote() {
// => we would need to check that we are moving it at a cheaper place and
// we do not do that for now.
BasicBlock *Parent = Inst->getParent();
- DEBUG(dbgs() << "Found an interesting transition: " << *Inst << '\n');
+ LLVM_DEBUG(dbgs() << "Found an interesting transition: " << *Inst << '\n');
VectorPromoteHelper VPH(*DL, *TLI, *TTI, Inst, CombineCost);
// If the transition has more than one use, assume this is not going to be
// beneficial.
while (Inst->hasOneUse()) {
Instruction *ToBePromoted = cast<Instruction>(*Inst->user_begin());
- DEBUG(dbgs() << "Use: " << *ToBePromoted << '\n');
+ LLVM_DEBUG(dbgs() << "Use: " << *ToBePromoted << '\n');
if (ToBePromoted->getParent() != Parent) {
- DEBUG(dbgs() << "Instruction to promote is in a different block ("
- << ToBePromoted->getParent()->getName()
- << ") than the transition (" << Parent->getName() << ").\n");
+ LLVM_DEBUG(dbgs() << "Instruction to promote is in a different block ("
+ << ToBePromoted->getParent()->getName()
+ << ") than the transition (" << Parent->getName()
+ << ").\n");
return false;
}
if (VPH.canCombine(ToBePromoted)) {
- DEBUG(dbgs() << "Assume " << *Inst << '\n'
- << "will be combined with: " << *ToBePromoted << '\n');
+ LLVM_DEBUG(dbgs() << "Assume " << *Inst << '\n'
+ << "will be combined with: " << *ToBePromoted << '\n');
VPH.recordCombineInstruction(ToBePromoted);
bool Changed = VPH.promote();
NumStoreExtractExposed += Changed;
return Changed;
}
- DEBUG(dbgs() << "Try promoting.\n");
+ LLVM_DEBUG(dbgs() << "Try promoting.\n");
if (!VPH.canPromote(ToBePromoted) || !VPH.shouldPromote(ToBePromoted))
return false;
- DEBUG(dbgs() << "Promoting is possible... Enqueue for promotion!\n");
+ LLVM_DEBUG(dbgs() << "Promoting is possible... Enqueue for promotion!\n");
VPH.enqueueForPromotion(ToBePromoted);
Inst = ToBePromoted;
/// For the instruction sequence of store below, F and I values
/// are bundled together as an i64 value before being stored into memory.
-/// Sometimes it is more efficent to generate separate stores for F and I,
+/// Sometimes it is more efficient to generate separate stores for F and I,
/// which can remove the bitwise instructions or sink them to colder places.
///
/// (store (or (zext (bitcast F to i32) to i64),
if (HBC && HBC->getParent() != SI.getParent())
HValue = Builder.CreateBitCast(HBC->getOperand(0), HBC->getType());
+ bool IsLE = SI.getModule()->getDataLayout().isLittleEndian();
auto CreateSplitStore = [&](Value *V, bool Upper) {
V = Builder.CreateZExtOrBitCast(V, SplitStoreType);
Value *Addr = Builder.CreateBitCast(
SI.getOperand(1),
SplitStoreType->getPointerTo(SI.getPointerAddressSpace()));
- if (Upper)
+ if ((IsLE && Upper) || (!IsLE && !Upper))
Addr = Builder.CreateGEP(
SplitStoreType, Addr,
ConstantInt::get(Type::getInt32Ty(SI.getContext()), 1));
/// The GEP operand must be a pointer, so must its result -> BitCast
Instruction *NC = new BitCastInst(GEPI->getOperand(0), GEPI->getType(),
GEPI->getName(), GEPI);
+ NC->setDebugLoc(GEPI->getDebugLoc());
GEPI->replaceAllUsesWith(NC);
GEPI->eraseFromParent();
++NumGEPsElim;
Instruction *Insn = &*BI++;
DbgValueInst *DVI = dyn_cast<DbgValueInst>(Insn);
// Leave dbg.values that refer to an alloca alone. These
- // instrinsics describe the address of a variable (= the alloca)
+ // intrinsics describe the address of a variable (= the alloca)
// being taken. They should not be moved next to the alloca
// (and to the beginning of the scope), but rather stay close to
// where said address is used.
// after it.
if (isa<PHINode>(VI) && VI->getParent()->getTerminator()->isEHPad())
continue;
- DEBUG(dbgs() << "Moving Debug Value before :\n" << *DVI << ' ' << *VI);
+ LLVM_DEBUG(dbgs() << "Moving Debug Value before :\n"
+ << *DVI << ' ' << *VI);
DVI->removeFromParent();
if (isa<PHINode>(VI))
DVI->insertBefore(&*VI->getParent()->getFirstInsertionPt());
return MadeChange;
}
-/// \brief Scale down both weights to fit into uint32_t.
+/// Scale down both weights to fit into uint32_t.
static void scaleWeights(uint64_t &NewTrue, uint64_t &NewFalse) {
uint64_t NewMax = (NewTrue > NewFalse) ? NewTrue : NewFalse;
uint32_t Scale = (NewMax / std::numeric_limits<uint32_t>::max()) + 1;
NewFalse = NewFalse / Scale;
}
-/// \brief Some targets prefer to split a conditional branch like:
+/// Some targets prefer to split a conditional branch like:
/// \code
/// %0 = icmp ne i32 %a, 0
/// %1 = icmp ne i32 %b, 0
!match(Cond2, m_CombineOr(m_Cmp(), m_BinOp())) )
continue;
- DEBUG(dbgs() << "Before branch condition splitting\n"; BB.dump());
+ LLVM_DEBUG(dbgs() << "Before branch condition splitting\n"; BB.dump());
// Create a new BB.
auto TmpBB =
Br1->setCondition(Cond1);
LogicOp->eraseFromParent();
- // Depending on the conditon we have to either replace the true or the false
- // successor of the original branch instruction.
+ // Depending on the condition we have to either replace the true or the
+ // false successor of the original branch instruction.
if (Opc == Instruction::And)
Br1->setSuccessor(0, TmpBB);
else
std::swap(TBB, FBB);
// Replace the old BB with the new BB.
- for (auto &I : *TBB) {
- PHINode *PN = dyn_cast<PHINode>(&I);
- if (!PN)
- break;
+ for (PHINode &PN : TBB->phis()) {
int i;
- while ((i = PN->getBasicBlockIndex(&BB)) >= 0)
- PN->setIncomingBlock(i, TmpBB);
+ while ((i = PN.getBasicBlockIndex(&BB)) >= 0)
+ PN.setIncomingBlock(i, TmpBB);
}
// Add another incoming edge form the new BB.
- for (auto &I : *FBB) {
- PHINode *PN = dyn_cast<PHINode>(&I);
- if (!PN)
- break;
- auto *Val = PN->getIncomingValueForBlock(&BB);
- PN->addIncoming(Val, TmpBB);
+ for (PHINode &PN : FBB->phis()) {
+ auto *Val = PN.getIncomingValueForBlock(&BB);
+ PN.addIncoming(Val, TmpBB);
}
// Update the branch weights (from SelectionDAGBuilder::
// We have flexibility in setting Prob for BB1 and Prob for NewBB.
// The requirement is that
// TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB)
- // = TrueProb for orignal BB.
- // Assuming the orignal weights are A and B, one choice is to set BB1's
+ // = TrueProb for original BB.
+ // Assuming the original weights are A and B, one choice is to set BB1's
// weights to A and A+2B, and set TmpBB's weights to A and 2B. This choice
// assumes that
// TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB.
// We have flexibility in setting Prob for BB1 and Prob for TmpBB.
// The requirement is that
// FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB)
- // = FalseProb for orignal BB.
- // Assuming the orignal weights are A and B, one choice is to set BB1's
+ // = FalseProb for original BB.
+ // Assuming the original weights are A and B, one choice is to set BB1's
// weights to 2A+B and B, and set TmpBB's weights to 2A and B. This choice
// assumes that
// FalseProb for BB1 == TrueProb for BB1 * FalseProb for TmpBB.
MadeChange = true;
- DEBUG(dbgs() << "After branch condition splitting\n"; BB.dump();
- TmpBB->dump());
+ LLVM_DEBUG(dbgs() << "After branch condition splitting\n"; BB.dump();
+ TmpBB->dump());
}
return MadeChange;
}
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