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Revert rL305578. There is still some buildbot failure to be fixed. 

llvm-svn: 305603
This commit is contained in:
Wei Mi 2017-06-16 23:14:35 +00:00
parent 160a97d2e7
commit c7ba876323
5 changed files with 34 additions and 321 deletions
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30
llvm/include/llvm/Transforms/Scalar/GVN.h
View File

@ -68,21 +68,6 @@ public:
class ValueTable {
DenseMap<Value *, uint32_t> valueNumbering;
DenseMap<Expression, uint32_t> expressionNumbering;
// Expressions is the vector of Expression. ExprIdx is the mapping from
// value number to the index of Expression in Expressions. We use it
// instead of a DenseMap because filling such mapping is faster than
// filling a DenseMap and the compile time is a little better.
uint32_t nextExprNumber;
std::vector<Expression> Expressions;
std::vector<uint32_t> ExprIdx;
// Value number to PHINode mapping. Used for phi-translate in scalarpre.
DenseMap<uint32_t, PHINode *> NumberingPhi;
// Cache for phi-translate in scalarpre.
typedef DenseMap<std::pair<uint32_t, const BasicBlock *>, uint32_t>
PhiTranslateMap;
PhiTranslateMap PhiTranslateTable;
AliasAnalysis *AA;
MemoryDependenceResults *MD;
DominatorTree *DT;
@ -94,10 +79,6 @@ public:
Value *LHS, Value *RHS);
Expression createExtractvalueExpr(ExtractValueInst *EI);
uint32_t lookupOrAddCall(CallInst *C);
uint32_t phiTranslateImpl(const BasicBlock *BB, const BasicBlock *PhiBlock,
uint32_t Num, GVN &Gvn);
std::pair<uint32_t, bool> assignExpNewValueNum(Expression &exp);
bool areAllValsInBB(uint32_t num, const BasicBlock *BB, GVN &Gvn);
public:
ValueTable();
@ -106,11 +87,9 @@ public:
~ValueTable();
uint32_t lookupOrAdd(Value *V);
uint32_t lookup(Value *V, bool Verify = true) const;
uint32_t lookup(Value *V) const;
uint32_t lookupOrAddCmp(unsigned Opcode, CmpInst::Predicate Pred,
Value *LHS, Value *RHS);
uint32_t phiTranslate(const BasicBlock *BB, const BasicBlock *PhiBlock,
uint32_t Num, GVN &Gvn);
bool exists(Value *V) const;
void add(Value *V, uint32_t num);
void clear();
@ -152,10 +131,6 @@ private:
SmallMapVector<llvm::Value *, llvm::Constant *, 4> ReplaceWithConstMap;
SmallVector<Instruction *, 8> InstrsToErase;
// Map the block to reversed postorder traversal number. It is used to
// find back edge easily.
DenseMap<const BasicBlock *, uint32_t> BlockRPONumber;
typedef SmallVector<NonLocalDepResult, 64> LoadDepVect;
typedef SmallVector<gvn::AvailableValueInBlock, 64> AvailValInBlkVect;
typedef SmallVector<BasicBlock *, 64> UnavailBlkVect;
@ -239,7 +214,7 @@ private:
bool performPRE(Function &F);
bool performScalarPRE(Instruction *I);
bool performScalarPREInsertion(Instruction *Instr, BasicBlock *Pred,
BasicBlock *Curr, unsigned int ValNo);
unsigned int ValNo);
Value *findLeader(const BasicBlock *BB, uint32_t num);
void cleanupGlobalSets();
void verifyRemoved(const Instruction *I) const;
@ -251,7 +226,6 @@ private:
bool processFoldableCondBr(BranchInst *BI);
void addDeadBlock(BasicBlock *BB);
void assignValNumForDeadCode();
void assignBlockRPONumber(Function &F);
};
/// Create a legacy GVN pass. This also allows parameterizing whether or not

186
llvm/lib/Transforms/Scalar/GVN.cpp
View File

@ -80,10 +80,9 @@ MaxRecurseDepth("max-recurse-depth", cl::Hidden, cl::init(1000), cl::ZeroOrMore,
struct llvm::GVN::Expression {
uint32_t opcode;
Type *type;
bool commutative;
SmallVector<uint32_t, 4> varargs;
Expression(uint32_t o = ~2U) : opcode(o), commutative(false) {}
Expression(uint32_t o = ~2U) : opcode(o) {}
bool operator==(const Expression &other) const {
if (opcode != other.opcode)
@ -247,7 +246,6 @@ GVN::Expression GVN::ValueTable::createExpr(Instruction *I) {
assert(I->getNumOperands() == 2 && "Unsupported commutative instruction!");
if (e.varargs[0] > e.varargs[1])
std::swap(e.varargs[0], e.varargs[1]);
e.commutative = true;
}
if (CmpInst *C = dyn_cast<CmpInst>(I)) {
@ -258,7 +256,6 @@ GVN::Expression GVN::ValueTable::createExpr(Instruction *I) {
Predicate = CmpInst::getSwappedPredicate(Predicate);
}
e.opcode = (C->getOpcode() << 8) | Predicate;
e.commutative = true;
} else if (InsertValueInst *E = dyn_cast<InsertValueInst>(I)) {
for (InsertValueInst::idx_iterator II = E->idx_begin(), IE = E->idx_end();
II != IE; ++II)
@ -284,7 +281,6 @@ GVN::Expression GVN::ValueTable::createCmpExpr(unsigned Opcode,
Predicate = CmpInst::getSwappedPredicate(Predicate);
}
e.opcode = (Opcode << 8) | Predicate;
e.commutative = true;
return e;
}
@ -352,25 +348,25 @@ GVN::ValueTable::~ValueTable() = default;
/// add - Insert a value into the table with a specified value number.
void GVN::ValueTable::add(Value *V, uint32_t num) {
valueNumbering.insert(std::make_pair(V, num));
if (PHINode *PN = dyn_cast<PHINode>(V))
NumberingPhi[num] = PN;
}
uint32_t GVN::ValueTable::lookupOrAddCall(CallInst *C) {
if (AA->doesNotAccessMemory(C)) {
Expression exp = createExpr(C);
uint32_t e = assignExpNewValueNum(exp).first;
uint32_t &e = expressionNumbering[exp];
if (!e) e = nextValueNumber++;
valueNumbering[C] = e;
return e;
} else if (AA->onlyReadsMemory(C)) {
Expression exp = createExpr(C);
auto ValNum = assignExpNewValueNum(exp);
if (ValNum.second) {
valueNumbering[C] = ValNum.first;
return ValNum.first;
uint32_t &e = expressionNumbering[exp];
if (!e) {
e = nextValueNumber++;
valueNumbering[C] = e;
return e;
}
if (!MD) {
uint32_t e = assignExpNewValueNum(exp).first;
e = nextValueNumber++;
valueNumbering[C] = e;
return e;
}
@ -526,29 +522,23 @@ uint32_t GVN::ValueTable::lookupOrAdd(Value *V) {
case Instruction::ExtractValue:
exp = createExtractvalueExpr(cast<ExtractValueInst>(I));
break;
case Instruction::PHI:
valueNumbering[V] = nextValueNumber;
NumberingPhi[nextValueNumber] = cast<PHINode>(V);
return nextValueNumber++;
default:
valueNumbering[V] = nextValueNumber;
return nextValueNumber++;
}
uint32_t e = assignExpNewValueNum(exp).first;
uint32_t& e = expressionNumbering[exp];
if (!e) e = nextValueNumber++;
valueNumbering[V] = e;
return e;
}
/// Returns the value number of the specified value. Fails if
/// the value has not yet been numbered.
uint32_t GVN::ValueTable::lookup(Value *V, bool Verify) const {
uint32_t GVN::ValueTable::lookup(Value *V) const {
DenseMap<Value*, uint32_t>::const_iterator VI = valueNumbering.find(V);
if (Verify) {
assert(VI != valueNumbering.end() && "Value not numbered?");
return VI->second;
}
return (VI != valueNumbering.end()) ? VI->second : 0;
assert(VI != valueNumbering.end() && "Value not numbered?");
return VI->second;
}
/// Returns the value number of the given comparison,
@ -559,28 +549,21 @@ uint32_t GVN::ValueTable::lookupOrAddCmp(unsigned Opcode,
CmpInst::Predicate Predicate,
Value *LHS, Value *RHS) {
Expression exp = createCmpExpr(Opcode, Predicate, LHS, RHS);
return assignExpNewValueNum(exp).first;
uint32_t& e = expressionNumbering[exp];
if (!e) e = nextValueNumber++;
return e;
}
/// Remove all entries from the ValueTable.
void GVN::ValueTable::clear() {
valueNumbering.clear();
expressionNumbering.clear();
NumberingPhi.clear();
PhiTranslateTable.clear();
nextValueNumber = 1;
Expressions.clear();
ExprIdx.clear();
nextExprNumber = 0;
}
/// Remove a value from the value numbering.
void GVN::ValueTable::erase(Value *V) {
uint32_t Num = valueNumbering.lookup(V);
valueNumbering.erase(V);
// If V is PHINode, V <--> value number is an one-to-one mapping.
if (isa<PHINode>(V))
NumberingPhi.erase(Num);
}
/// verifyRemoved - Verify that the value is removed from all internal data
@ -1468,95 +1451,6 @@ bool GVN::processLoad(LoadInst *L) {
return false;
}
/// Return a pair the first field showing the value number of \p Exp and the
/// second field showing whether it is a value number newly created.
std::pair<uint32_t, bool>
GVN::ValueTable::assignExpNewValueNum(Expression &Exp) {
uint32_t &e = expressionNumbering[Exp];
bool CreateNewValNum = !e;
if (CreateNewValNum) {
Expressions.push_back(Exp);
if (ExprIdx.size() < nextValueNumber + 1)
ExprIdx.resize(nextValueNumber * 2);
e = nextValueNumber;
ExprIdx[nextValueNumber++] = nextExprNumber++;
}
return {e, CreateNewValNum};
}
/// Return whether all the values related with the same \p num are
/// defined in \p BB.
bool GVN::ValueTable::areAllValsInBB(uint32_t Num, const BasicBlock *BB,
GVN &Gvn) {
LeaderTableEntry *Vals = &Gvn.LeaderTable[Num];
while (Vals && Vals->BB == BB)
Vals = Vals->Next;
return !Vals;
}
/// Wrap phiTranslateImpl to provide caching functionality.
uint32_t GVN::ValueTable::phiTranslate(const BasicBlock *Pred,
const BasicBlock *PhiBlock, uint32_t Num,
GVN &Gvn) {
auto FindRes = PhiTranslateTable.find({Num, Pred});
if (FindRes != PhiTranslateTable.end())
return FindRes->second;
uint32_t NewNum = phiTranslateImpl(Pred, PhiBlock, Num, Gvn);
PhiTranslateTable.insert({{Num, Pred}, NewNum});
return NewNum;
}
/// Translate value number \p Num using phis, so that it has the values of
/// the phis in BB.
uint32_t GVN::ValueTable::phiTranslateImpl(const BasicBlock *Pred,
const BasicBlock *PhiBlock,
uint32_t Num, GVN &Gvn) {
if (PHINode *PN = NumberingPhi[Num]) {
for (unsigned i = 0; i != PN->getNumIncomingValues(); ++i) {
if (PN->getParent() == PhiBlock && PN->getIncomingBlock(i) == Pred)
if (uint32_t TransVal = lookup(PN->getIncomingValue(i), false))
return TransVal;
}
return Num;
}
// If there is any value related with Num is defined in a BB other than
// PhiBlock, it cannot depend on a phi in PhiBlock without going through
// a backedge. We can do an early exit in that case to save compile time.
if (!areAllValsInBB(Num, PhiBlock, Gvn))
return Num;
if (ExprIdx[Num] == 0 || Num >= ExprIdx.size())
return Num;
Expression Exp = Expressions[ExprIdx[Num]];
for (unsigned i = 0; i < Exp.varargs.size(); i++) {
// For InsertValue and ExtractValue, some varargs are index numbers
// instead of value numbers. Those index numbers should not be
// translated.
if ((i > 1 && Exp.opcode == Instruction::InsertValue) ||
(i > 0 && Exp.opcode == Instruction::ExtractValue))
continue;
Exp.varargs[i] = phiTranslate(Pred, PhiBlock, Exp.varargs[i], Gvn);
}
if (Exp.commutative) {
assert(Exp.varargs.size() == 2 && "Unsupported commutative expression!");
if (Exp.varargs[0] > Exp.varargs[1]) {
std::swap(Exp.varargs[0], Exp.varargs[1]);
uint32_t Opcode = Exp.opcode >> 8;
if (Opcode == Instruction::ICmp || Opcode == Instruction::FCmp)
Exp.opcode = (Opcode << 8) |
CmpInst::getSwappedPredicate(
static_cast<CmpInst::Predicate>(Exp.opcode & 255));
}
}
if (uint32_t NewNum = expressionNumbering[Exp])
return NewNum;
return Num;
}
// In order to find a leader for a given value number at a
// specific basic block, we first obtain the list of all Values for that number,
// and then scan the list to find one whose block dominates the block in
@ -1601,15 +1495,6 @@ static bool isOnlyReachableViaThisEdge(const BasicBlockEdge &E,
return Pred != nullptr;
}
void GVN::assignBlockRPONumber(Function &F) {
uint32_t NextBlockNumber = 1;
ReversePostOrderTraversal<Function *> RPOT(&F);
for (BasicBlock *BB : RPOT)
BlockRPONumber[BB] = NextBlockNumber++;
}
// Tries to replace instruction with const, using information from
// ReplaceWithConstMap.
bool GVN::replaceOperandsWithConsts(Instruction *Instr) const {
@ -1971,7 +1856,6 @@ bool GVN::runImpl(Function &F, AssumptionCache &RunAC, DominatorTree &RunDT,
// Fabricate val-num for dead-code in order to suppress assertion in
// performPRE().
assignValNumForDeadCode();
assignBlockRPONumber(F);
bool PREChanged = true;
while (PREChanged) {
PREChanged = performPRE(F);
@ -2043,7 +1927,7 @@ bool GVN::processBlock(BasicBlock *BB) {
// Instantiate an expression in a predecessor that lacked it.
bool GVN::performScalarPREInsertion(Instruction *Instr, BasicBlock *Pred,
BasicBlock *Curr, unsigned int ValNo) {
unsigned int ValNo) {
// Because we are going top-down through the block, all value numbers
// will be available in the predecessor by the time we need them. Any
// that weren't originally present will have been instantiated earlier
@ -2061,9 +1945,7 @@ bool GVN::performScalarPREInsertion(Instruction *Instr, BasicBlock *Pred,
success = false;
break;
}
uint32_t TValNo =
VN.phiTranslate(Pred, Curr, VN.lookup(Op), *this);
if (Value *V = findLeader(Pred, TValNo)) {
if (Value *V = findLeader(Pred, VN.lookup(Op))) {
Instr->setOperand(i, V);
} else {
success = false;
@ -2080,12 +1962,10 @@ bool GVN::performScalarPREInsertion(Instruction *Instr, BasicBlock *Pred,
Instr->insertBefore(Pred->getTerminator());
Instr->setName(Instr->getName() + ".pre");
Instr->setDebugLoc(Instr->getDebugLoc());
unsigned Num = VN.lookupOrAdd(Instr);
VN.add(Instr, Num);
VN.add(Instr, ValNo);
// Update the availability map to include the new instruction.
addToLeaderTable(Num, Instr, Pred);
addToLeaderTable(ValNo, Instr, Pred);
return true;
}
@ -2123,27 +2003,18 @@ bool GVN::performScalarPRE(Instruction *CurInst) {
SmallVector<std::pair<Value *, BasicBlock *>, 8> predMap;
for (BasicBlock *P : predecessors(CurrentBlock)) {
// We're not interested in PRE where blocks with predecessors that are
// not reachable.
if (!DT->isReachableFromEntry(P)) {
// We're not interested in PRE where the block is its
// own predecessor, or in blocks with predecessors
// that are not reachable.
if (P == CurrentBlock) {
NumWithout = 2;
break;
}
// It is not safe to do PRE when P->CurrentBlock is a loop backedge, and
// when CurInst has operand defined in CurrentBlock (so it may be defined
// by phi in the loop header).
if (BlockRPONumber[P] >= BlockRPONumber[CurrentBlock] &&
any_of(CurInst->operands(), [&](const Use &U) {
if (auto *Inst = dyn_cast<Instruction>(U.get()))
return Inst->getParent() == CurrentBlock;
return false;
})) {
} else if (!DT->isReachableFromEntry(P)) {
NumWithout = 2;
break;
}
uint32_t TValNo = VN.phiTranslate(P, CurrentBlock, ValNo, *this);
Value *predV = findLeader(P, TValNo);
Value *predV = findLeader(P, ValNo);
if (!predV) {
predMap.push_back(std::make_pair(static_cast<Value *>(nullptr), P));
PREPred = P;
@ -2183,7 +2054,7 @@ bool GVN::performScalarPRE(Instruction *CurInst) {
}
// We need to insert somewhere, so let's give it a shot
PREInstr = CurInst->clone();
if (!performScalarPREInsertion(PREInstr, PREPred, CurrentBlock, ValNo)) {
if (!performScalarPREInsertion(PREInstr, PREPred, ValNo)) {
// If we failed insertion, make sure we remove the instruction.
DEBUG(verifyRemoved(PREInstr));
PREInstr->deleteValue();
@ -2297,7 +2168,6 @@ bool GVN::iterateOnFunction(Function &F) {
void GVN::cleanupGlobalSets() {
VN.clear();
LeaderTable.clear();
BlockRPONumber.clear();
TableAllocator.Reset();
}

131
llvm/test/Transforms/GVN/PRE/phi-translate-2.ll
View File

@ -1,131 +0,0 @@
; RUN: opt < %s -gvn -S | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
@a = common global [100 x i64] zeroinitializer, align 16
@b = common global [100 x i64] zeroinitializer, align 16
@g1 = common global i64 0, align 8
@g2 = common global i64 0, align 8
@g3 = common global i64 0, align 8
declare i64 @goo(...) local_unnamed_addr #1
define void @test1(i64 %a, i64 %b, i64 %c, i64 %d) {
entry:
%mul = mul nsw i64 %b, %a
store i64 %mul, i64* @g1, align 8
%t0 = load i64, i64* @g2, align 8
%cmp = icmp sgt i64 %t0, 3
br i1 %cmp, label %if.then, label %if.end
if.then: ; preds = %entry
%mul2 = mul nsw i64 %d, %c
store i64 %mul2, i64* @g2, align 8
br label %if.end
; Check phi-translate works and mul is removed.
; CHECK-LABEL: @test1(
; CHECK: if.end:
; CHECK: %[[MULPHI:.*]] = phi i64 [ {{.*}}, %if.then ], [ %mul, %entry ]
; CHECK-NOT: = mul
; CHECK: store i64 %[[MULPHI]], i64* @g3, align 8
if.end: ; preds = %if.then, %entry
%b.addr.0 = phi i64 [ %d, %if.then ], [ %b, %entry ]
%a.addr.0 = phi i64 [ %c, %if.then ], [ %a, %entry ]
%mul3 = mul nsw i64 %a.addr.0, %b.addr.0
store i64 %mul3, i64* @g3, align 8
ret void
}
define void @test2(i64 %i) {
entry:
%arrayidx = getelementptr inbounds [100 x i64], [100 x i64]* @a, i64 0, i64 %i
%t0 = load i64, i64* %arrayidx, align 8
%arrayidx1 = getelementptr inbounds [100 x i64], [100 x i64]* @b, i64 0, i64 %i
%t1 = load i64, i64* %arrayidx1, align 8
%mul = mul nsw i64 %t1, %t0
store i64 %mul, i64* @g1, align 8
%cmp = icmp sgt i64 %mul, 3
br i1 %cmp, label %if.then, label %if.end
; Check phi-translate works for the phi generated by loadpre. A new mul will be
; inserted in if.then block.
; CHECK-LABEL: @test2(
; CHECK: if.then:
; CHECK: %[[MUL_THEN:.*]] = mul
; CHECK: br label %if.end
if.then: ; preds = %entry
%call = tail call i64 (...) @goo() #2
store i64 %call, i64* @g2, align 8
br label %if.end
; CHECK: if.end:
; CHECK: %[[MULPHI:.*]] = phi i64 [ %[[MUL_THEN]], %if.then ], [ %mul, %entry ]
; CHECK-NOT: = mul
; CHECK: store i64 %[[MULPHI]], i64* @g3, align 8
if.end: ; preds = %if.then, %entry
%i.addr.0 = phi i64 [ 3, %if.then ], [ %i, %entry ]
%arrayidx3 = getelementptr inbounds [100 x i64], [100 x i64]* @a, i64 0, i64 %i.addr.0
%t2 = load i64, i64* %arrayidx3, align 8
%arrayidx4 = getelementptr inbounds [100 x i64], [100 x i64]* @b, i64 0, i64 %i.addr.0
%t3 = load i64, i64* %arrayidx4, align 8
%mul5 = mul nsw i64 %t3, %t2
store i64 %mul5, i64* @g3, align 8
ret void
}
; Check phi-translate doesn't go through backedge, which may lead to incorrect
; pre transformation.
; CHECK: for.end:
; CHECK-NOT: %{{.*pre-phi}} = phi
; CHECK: ret void
define void @test3(i64 %N, i64* nocapture readonly %a) {
entry:
br label %for.cond
for.cond: ; preds = %for.body, %entry
%i.0 = phi i64 [ 0, %entry ], [ %add, %for.body ]
%add = add nuw nsw i64 %i.0, 1
%arrayidx = getelementptr inbounds i64, i64* %a, i64 %add
%tmp0 = load i64, i64* %arrayidx, align 8
%cmp = icmp slt i64 %i.0, %N
br i1 %cmp, label %for.body, label %for.end
for.body: ; preds = %for.cond
%call = tail call i64 (...) @goo() #2
%add1 = sub nsw i64 0, %call
%tobool = icmp eq i64 %tmp0, %add1
br i1 %tobool, label %for.cond, label %for.end
for.end: ; preds = %for.body, %for.cond
%i.0.lcssa = phi i64 [ %i.0, %for.body ], [ %i.0, %for.cond ]
%arrayidx2 = getelementptr inbounds i64, i64* %a, i64 %i.0.lcssa
%tmp1 = load i64, i64* %arrayidx2, align 8
store i64 %tmp1, i64* @g1, align 8
ret void
}
; It is incorrect to use the value of %andres in last loop iteration
; to do pre.
; CHECK-LABEL: @test4(
; CHECK: for.body:
; CHECK-NOT: %andres.pre-phi = phi i32
; CHECK: br i1 %tobool1
define i32 @test4(i32 %cond, i32 %SectionAttrs.0231.ph, i32 *%AttrFlag) {
for.body.preheader:
%t514 = load volatile i32, i32* %AttrFlag
br label %for.body
for.body:
%t320 = phi i32 [ %t334, %bb343 ], [ %t514, %for.body.preheader ]
%andres = and i32 %t320, %SectionAttrs.0231.ph
%tobool1 = icmp eq i32 %andres, 0
br i1 %tobool1, label %bb343, label %critedge.loopexit
bb343:
%t334 = load volatile i32, i32* %AttrFlag
%tobool2 = icmp eq i32 %cond, 0
br i1 %tobool2, label %critedge.loopexit, label %for.body
critedge.loopexit:
unreachable
}

2
llvm/test/Transforms/GVN/PRE/pre-gep-load.ll
View File

@ -37,7 +37,7 @@ sw.bb2: ; preds = %if.end, %entry
%3 = load double, double* %arrayidx5, align 8
; CHECK: sw.bb2:
; CHECK-NOT: sext
; CHECK: phi double [
; CHECK-NEXT: phi double [
; CHECK-NOT: load
%sub6 = fsub double 3.000000e+00, %3
br label %return

6
llvm/test/Transforms/GVN/PRE/pre-load.ll
View File

@ -72,7 +72,7 @@ block4:
%PRE = load i32, i32* %P3
ret i32 %PRE
; CHECK: block4:
; CHECK: phi i32 [
; CHECK-NEXT: phi i32 [
; CHECK-NOT: load
; CHECK: ret i32
}
@ -104,7 +104,7 @@ block4:
%PRE = load i32, i32* %P3
ret i32 %PRE
; CHECK: block4:
; CHECK: phi i32 [
; CHECK-NEXT: phi i32 [
; CHECK-NOT: load
; CHECK: ret i32
}
@ -263,7 +263,7 @@ block4:
%PRE = load i32, i32* %P3
ret i32 %PRE
; CHECK: block4:
; CHECK: phi i32 [
; CHECK-NEXT: phi i32 [
; CHECK-NOT: load
; CHECK: ret i32
}