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-rw-r--r--lib/Transforms/Scalar/GVN.cpp115
1 files changed, 55 insertions, 60 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 33c387c..6d07ddd 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -15,11 +15,11 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "gvn"
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
@@ -50,6 +50,8 @@
using namespace llvm;
using namespace PatternMatch;
+#define DEBUG_TYPE "gvn"
+
STATISTIC(NumGVNInstr, "Number of instructions deleted");
STATISTIC(NumGVNLoad, "Number of loads deleted");
STATISTIC(NumGVNPRE, "Number of instructions PRE'd");
@@ -213,13 +215,13 @@ Expression ValueTable::create_cmp_expression(unsigned Opcode,
}
Expression ValueTable::create_extractvalue_expression(ExtractValueInst *EI) {
- assert(EI != 0 && "Not an ExtractValueInst?");
+ assert(EI && "Not an ExtractValueInst?");
Expression e;
e.type = EI->getType();
e.opcode = 0;
IntrinsicInst *I = dyn_cast<IntrinsicInst>(EI->getAggregateOperand());
- if (I != 0 && EI->getNumIndices() == 1 && *EI->idx_begin() == 0 ) {
+ if (I != nullptr && EI->getNumIndices() == 1 && *EI->idx_begin() == 0 ) {
// EI might be an extract from one of our recognised intrinsics. If it
// is we'll synthesize a semantically equivalent expression instead on
// an extract value expression.
@@ -327,7 +329,7 @@ uint32_t ValueTable::lookup_or_add_call(CallInst *C) {
const MemoryDependenceAnalysis::NonLocalDepInfo &deps =
MD->getNonLocalCallDependency(CallSite(C));
// FIXME: Move the checking logic to MemDep!
- CallInst* cdep = 0;
+ CallInst* cdep = nullptr;
// Check to see if we have a single dominating call instruction that is
// identical to C.
@@ -338,8 +340,8 @@ uint32_t ValueTable::lookup_or_add_call(CallInst *C) {
// We don't handle non-definitions. If we already have a call, reject
// instruction dependencies.
- if (!I->getResult().isDef() || cdep != 0) {
- cdep = 0;
+ if (!I->getResult().isDef() || cdep != nullptr) {
+ cdep = nullptr;
break;
}
@@ -350,7 +352,7 @@ uint32_t ValueTable::lookup_or_add_call(CallInst *C) {
continue;
}
- cdep = 0;
+ cdep = nullptr;
break;
}
@@ -551,7 +553,7 @@ namespace {
static AvailableValueInBlock getUndef(BasicBlock *BB) {
AvailableValueInBlock Res;
Res.BB = BB;
- Res.Val.setPointer(0);
+ Res.Val.setPointer(nullptr);
Res.Val.setInt(UndefVal);
Res.Offset = 0;
return Res;
@@ -611,7 +613,7 @@ namespace {
public:
static char ID; // Pass identification, replacement for typeid
explicit GVN(bool noloads = false)
- : FunctionPass(ID), NoLoads(noloads), MD(0) {
+ : FunctionPass(ID), NoLoads(noloads), MD(nullptr) {
initializeGVNPass(*PassRegistry::getPassRegistry());
}
@@ -649,7 +651,7 @@ namespace {
/// removeFromLeaderTable - Scan the list of values corresponding to a given
/// value number, and remove the given instruction if encountered.
void removeFromLeaderTable(uint32_t N, Instruction *I, BasicBlock *BB) {
- LeaderTableEntry* Prev = 0;
+ LeaderTableEntry* Prev = nullptr;
LeaderTableEntry* Curr = &LeaderTable[N];
while (Curr->Val != I || Curr->BB != BB) {
@@ -661,8 +663,8 @@ namespace {
Prev->Next = Curr->Next;
} else {
if (!Curr->Next) {
- Curr->Val = 0;
- Curr->BB = 0;
+ Curr->Val = nullptr;
+ Curr->BB = nullptr;
} else {
LeaderTableEntry* Next = Curr->Next;
Curr->Val = Next->Val;
@@ -855,7 +857,7 @@ static Value *CoerceAvailableValueToLoadType(Value *StoredVal,
Instruction *InsertPt,
const DataLayout &DL) {
if (!CanCoerceMustAliasedValueToLoad(StoredVal, LoadedTy, DL))
- return 0;
+ return nullptr;
// If this is already the right type, just return it.
Type *StoredValTy = StoredVal->getType();
@@ -1060,7 +1062,7 @@ static int AnalyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr,
const DataLayout &DL) {
// If the mem operation is a non-constant size, we can't handle it.
ConstantInt *SizeCst = dyn_cast<ConstantInt>(MI->getLength());
- if (SizeCst == 0) return -1;
+ if (!SizeCst) return -1;
uint64_t MemSizeInBits = SizeCst->getZExtValue()*8;
// If this is memset, we just need to see if the offset is valid in the size
@@ -1075,10 +1077,10 @@ static int AnalyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr,
MemTransferInst *MTI = cast<MemTransferInst>(MI);
Constant *Src = dyn_cast<Constant>(MTI->getSource());
- if (Src == 0) return -1;
+ if (!Src) return -1;
GlobalVariable *GV = dyn_cast<GlobalVariable>(GetUnderlyingObject(Src, &DL));
- if (GV == 0 || !GV->isConstant()) return -1;
+ if (!GV || !GV->isConstant()) return -1;
// See if the access is within the bounds of the transfer.
int Offset = AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr,
@@ -1420,8 +1422,7 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps,
// If this is a clobber and L is the first instruction in its block, then
// we have the first instruction in the entry block.
if (DepLI != LI && Address && DL) {
- int Offset = AnalyzeLoadFromClobberingLoad(LI->getType(),
- LI->getPointerOperand(),
+ int Offset = AnalyzeLoadFromClobberingLoad(LI->getType(), Address,
DepLI, *DL);
if (Offset != -1) {
@@ -1469,8 +1470,8 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps,
if (S->getValueOperand()->getType() != LI->getType()) {
// If the stored value is larger or equal to the loaded value, we can
// reuse it.
- if (DL == 0 || !CanCoerceMustAliasedValueToLoad(S->getValueOperand(),
- LI->getType(), *DL)) {
+ if (!DL || !CanCoerceMustAliasedValueToLoad(S->getValueOperand(),
+ LI->getType(), *DL)) {
UnavailableBlocks.push_back(DepBB);
continue;
}
@@ -1486,7 +1487,7 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps,
if (LD->getType() != LI->getType()) {
// If the stored value is larger or equal to the loaded value, we can
// reuse it.
- if (DL == 0 || !CanCoerceMustAliasedValueToLoad(LD, LI->getType(),*DL)){
+ if (!DL || !CanCoerceMustAliasedValueToLoad(LD, LI->getType(),*DL)) {
UnavailableBlocks.push_back(DepBB);
continue;
}
@@ -1539,7 +1540,7 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// Check to see how many predecessors have the loaded value fully
// available.
- DenseMap<BasicBlock*, Value*> PredLoads;
+ MapVector<BasicBlock *, Value *> PredLoads;
DenseMap<BasicBlock*, char> FullyAvailableBlocks;
for (unsigned i = 0, e = ValuesPerBlock.size(); i != e; ++i)
FullyAvailableBlocks[ValuesPerBlock[i].BB] = true;
@@ -1553,7 +1554,6 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
if (IsValueFullyAvailableInBlock(Pred, FullyAvailableBlocks, 0)) {
continue;
}
- PredLoads[Pred] = 0;
if (Pred->getTerminator()->getNumSuccessors() != 1) {
if (isa<IndirectBrInst>(Pred->getTerminator())) {
@@ -1570,11 +1570,14 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
}
CriticalEdgePred.push_back(Pred);
+ } else {
+ // Only add the predecessors that will not be split for now.
+ PredLoads[Pred] = nullptr;
}
}
// Decide whether PRE is profitable for this load.
- unsigned NumUnavailablePreds = PredLoads.size();
+ unsigned NumUnavailablePreds = PredLoads.size() + CriticalEdgePred.size();
assert(NumUnavailablePreds != 0 &&
"Fully available value should already be eliminated!");
@@ -1586,12 +1589,10 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
return false;
// Split critical edges, and update the unavailable predecessors accordingly.
- for (SmallVectorImpl<BasicBlock *>::iterator I = CriticalEdgePred.begin(),
- E = CriticalEdgePred.end(); I != E; I++) {
- BasicBlock *OrigPred = *I;
+ for (BasicBlock *OrigPred : CriticalEdgePred) {
BasicBlock *NewPred = splitCriticalEdges(OrigPred, LoadBB);
- PredLoads.erase(OrigPred);
- PredLoads[NewPred] = 0;
+ assert(!PredLoads.count(OrigPred) && "Split edges shouldn't be in map!");
+ PredLoads[NewPred] = nullptr;
DEBUG(dbgs() << "Split critical edge " << OrigPred->getName() << "->"
<< LoadBB->getName() << '\n');
}
@@ -1599,9 +1600,8 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// Check if the load can safely be moved to all the unavailable predecessors.
bool CanDoPRE = true;
SmallVector<Instruction*, 8> NewInsts;
- for (DenseMap<BasicBlock*, Value*>::iterator I = PredLoads.begin(),
- E = PredLoads.end(); I != E; ++I) {
- BasicBlock *UnavailablePred = I->first;
+ for (auto &PredLoad : PredLoads) {
+ BasicBlock *UnavailablePred = PredLoad.first;
// Do PHI translation to get its value in the predecessor if necessary. The
// returned pointer (if non-null) is guaranteed to dominate UnavailablePred.
@@ -1610,20 +1610,20 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// the load on the pred (?!?), so we can insert code to materialize the
// pointer if it is not available.
PHITransAddr Address(LI->getPointerOperand(), DL);
- Value *LoadPtr = 0;
+ Value *LoadPtr = nullptr;
LoadPtr = Address.PHITranslateWithInsertion(LoadBB, UnavailablePred,
*DT, NewInsts);
// If we couldn't find or insert a computation of this phi translated value,
// we fail PRE.
- if (LoadPtr == 0) {
+ if (!LoadPtr) {
DEBUG(dbgs() << "COULDN'T INSERT PHI TRANSLATED VALUE OF: "
<< *LI->getPointerOperand() << "\n");
CanDoPRE = false;
break;
}
- I->second = LoadPtr;
+ PredLoad.second = LoadPtr;
}
if (!CanDoPRE) {
@@ -1632,8 +1632,8 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
if (MD) MD->removeInstruction(I);
I->eraseFromParent();
}
- // HINT:Don't revert the edge-splitting as following transformation may
- // also need to split these critial edges.
+ // HINT: Don't revert the edge-splitting as following transformation may
+ // also need to split these critical edges.
return !CriticalEdgePred.empty();
}
@@ -1654,10 +1654,9 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
VN.lookup_or_add(NewInsts[i]);
}
- for (DenseMap<BasicBlock*, Value*>::iterator I = PredLoads.begin(),
- E = PredLoads.end(); I != E; ++I) {
- BasicBlock *UnavailablePred = I->first;
- Value *LoadPtr = I->second;
+ for (const auto &PredLoad : PredLoads) {
+ BasicBlock *UnavailablePred = PredLoad.first;
+ Value *LoadPtr = PredLoad.second;
Instruction *NewLoad = new LoadInst(LoadPtr, LI->getName()+".pre", false,
LI->getAlignment(),
@@ -1776,7 +1775,7 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) {
MDNode *ReplMD = Metadata[i].second;
switch(Kind) {
default:
- ReplInst->setMetadata(Kind, NULL); // Remove unknown metadata
+ ReplInst->setMetadata(Kind, nullptr); // Remove unknown metadata
break;
case LLVMContext::MD_dbg:
llvm_unreachable("getAllMetadataOtherThanDebugLoc returned a MD_dbg");
@@ -1832,7 +1831,7 @@ bool GVN::processLoad(LoadInst *L) {
// a common base + constant offset, and if the previous store (or memset)
// completely covers this load. This sort of thing can happen in bitfield
// access code.
- Value *AvailVal = 0;
+ Value *AvailVal = nullptr;
if (StoreInst *DepSI = dyn_cast<StoreInst>(Dep.getInst())) {
int Offset = AnalyzeLoadFromClobberingStore(L->getType(),
L->getPointerOperand(),
@@ -1920,7 +1919,7 @@ bool GVN::processLoad(LoadInst *L) {
if (DL) {
StoredVal = CoerceAvailableValueToLoadType(StoredVal, L->getType(),
L, *DL);
- if (StoredVal == 0)
+ if (!StoredVal)
return false;
DEBUG(dbgs() << "GVN COERCED STORE:\n" << *DepSI << '\n' << *StoredVal
@@ -1949,7 +1948,7 @@ bool GVN::processLoad(LoadInst *L) {
if (DL) {
AvailableVal = CoerceAvailableValueToLoadType(DepLI, L->getType(),
L, *DL);
- if (AvailableVal == 0)
+ if (!AvailableVal)
return false;
DEBUG(dbgs() << "GVN COERCED LOAD:\n" << *DepLI << "\n" << *AvailableVal
@@ -1999,9 +1998,9 @@ bool GVN::processLoad(LoadInst *L) {
// a few comparisons of DFS numbers.
Value *GVN::findLeader(const BasicBlock *BB, uint32_t num) {
LeaderTableEntry Vals = LeaderTable[num];
- if (!Vals.Val) return 0;
+ if (!Vals.Val) return nullptr;
- Value *Val = 0;
+ Value *Val = nullptr;
if (DT->dominates(Vals.BB, BB)) {
Val = Vals.Val;
if (isa<Constant>(Val)) return Val;
@@ -2052,7 +2051,7 @@ static bool isOnlyReachableViaThisEdge(const BasicBlockEdge &E,
const BasicBlock *Src = E.getStart();
assert((!Pred || Pred == Src) && "No edge between these basic blocks!");
(void)Src;
- return Pred != 0;
+ return Pred != nullptr;
}
/// propagateEquality - The given values are known to be equal in every block
@@ -2296,7 +2295,7 @@ bool GVN::processInstruction(Instruction *I) {
// Perform fast-path value-number based elimination of values inherited from
// dominators.
Value *repl = findLeader(I->getParent(), Num);
- if (repl == 0) {
+ if (!repl) {
// Failure, just remember this instance for future use.
addToLeaderTable(Num, I, I->getParent());
return false;
@@ -2319,7 +2318,7 @@ bool GVN::runOnFunction(Function& F) {
MD = &getAnalysis<MemoryDependenceAnalysis>();
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
- DL = DLP ? &DLP->getDataLayout() : 0;
+ DL = DLP ? &DLP->getDataLayout() : nullptr;
TLI = &getAnalysis<TargetLibraryInfo>();
VN.setAliasAnalysis(&getAnalysis<AliasAnalysis>());
VN.setMemDep(MD);
@@ -2421,10 +2420,7 @@ bool GVN::processBlock(BasicBlock *BB) {
bool GVN::performPRE(Function &F) {
bool Changed = false;
SmallVector<std::pair<Value*, BasicBlock*>, 8> predMap;
- for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()),
- DE = df_end(&F.getEntryBlock()); DI != DE; ++DI) {
- BasicBlock *CurrentBlock = *DI;
-
+ for (BasicBlock *CurrentBlock : depth_first(&F.getEntryBlock())) {
// Nothing to PRE in the entry block.
if (CurrentBlock == &F.getEntryBlock()) continue;
@@ -2464,7 +2460,7 @@ bool GVN::performPRE(Function &F) {
// more complicated to get right.
unsigned NumWith = 0;
unsigned NumWithout = 0;
- BasicBlock *PREPred = 0;
+ BasicBlock *PREPred = nullptr;
predMap.clear();
for (pred_iterator PI = pred_begin(CurrentBlock),
@@ -2482,8 +2478,8 @@ bool GVN::performPRE(Function &F) {
}
Value* predV = findLeader(P, ValNo);
- if (predV == 0) {
- predMap.push_back(std::make_pair(static_cast<Value *>(0), P));
+ if (!predV) {
+ predMap.push_back(std::make_pair(static_cast<Value *>(nullptr), P));
PREPred = P;
++NumWithout;
} else if (predV == CurInst) {
@@ -2637,9 +2633,8 @@ bool GVN::iterateOnFunction(Function &F) {
//
std::vector<BasicBlock *> BBVect;
BBVect.reserve(256);
- for (df_iterator<DomTreeNode*> DI = df_begin(DT->getRootNode()),
- DE = df_end(DT->getRootNode()); DI != DE; ++DI)
- BBVect.push_back(DI->getBlock());
+ for (DomTreeNode *x : depth_first(DT->getRootNode()))
+ BBVect.push_back(x->getBlock());
for (std::vector<BasicBlock *>::iterator I = BBVect.begin(), E = BBVect.end();
I != E; I++)
generated by cgit v1.1 at 2024-05-18 03:28:48 +0000