#include "llvm/Analysis/ScalarEvolutionExpander.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/ADT/STLExtras.h"
using namespace llvm;
/// InsertCastOfTo - Insert a cast of V to the specified type, doing what
if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S))
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0)))
if (!C->getValue()->getValue().srem(Factor)) {
- std::vector<SCEVHandle> NewMulOps(M->getOperands());
+ const SmallVectorImpl<SCEVHandle> &MOperands = M->getOperands();
+ SmallVector<SCEVHandle, 4> NewMulOps(MOperands.begin(), MOperands.end());
NewMulOps[0] =
SE.getConstant(C->getValue()->getValue().sdiv(Factor));
S = SE.getMulExpr(NewMulOps);
Value *V) {
const Type *ElTy = PTy->getElementType();
SmallVector<Value *, 4> GepIndices;
- std::vector<SCEVHandle> Ops(op_begin, op_end);
+ SmallVector<SCEVHandle, 8> Ops(op_begin, op_end);
bool AnyNonZeroIndices = false;
// Decend down the pointer's type and attempt to convert the other
for (;;) {
APInt ElSize = APInt(SE.getTypeSizeInBits(Ty),
ElTy->isSized() ? SE.TD->getTypeAllocSize(ElTy) : 0);
- std::vector<SCEVHandle> NewOps;
- std::vector<SCEVHandle> ScaledOps;
+ SmallVector<SCEVHandle, 8> NewOps;
+ SmallVector<SCEVHandle, 8> ScaledOps;
for (unsigned i = 0, e = Ops.size(); i != e; ++i) {
// Split AddRecs up into parts as either of the parts may be usable
// without the other.
if (!AnyNonZeroIndices) {
V = InsertNoopCastOfTo(V,
Type::Int8Ty->getPointerTo(PTy->getAddressSpace()));
- Value *Idx = expand(SE.getAddExpr(Ops));
- Idx = InsertNoopCastOfTo(Idx, Ty);
+ Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty);
// Fold a GEP with constant operands.
if (Constant *CLHS = dyn_cast<Constant>(V))
// comments on expandAddToGEP for details.
if (SE.TD)
if (const PointerType *PTy = dyn_cast<PointerType>(V->getType())) {
- const std::vector<SCEVHandle> &Ops = S->getOperands();
+ const SmallVectorImpl<SCEVHandle> &Ops = S->getOperands();
return expandAddToGEP(&Ops[0], &Ops[Ops.size() - 1],
PTy, Ty, V);
}
// Emit a bunch of add instructions
for (int i = S->getNumOperands()-2; i >= 0; --i) {
- Value *W = expand(S->getOperand(i));
- W = InsertNoopCastOfTo(W, Ty);
+ Value *W = expandCodeFor(S->getOperand(i), Ty);
V = InsertBinop(Instruction::Add, V, W, InsertPt);
}
return V;
FirstOp = 1;
int i = S->getNumOperands()-2;
- Value *V = expand(S->getOperand(i+1));
- V = InsertNoopCastOfTo(V, Ty);
+ Value *V = expandCodeFor(S->getOperand(i+1), Ty);
// Emit a bunch of multiply instructions
for (; i >= FirstOp; --i) {
- Value *W = expand(S->getOperand(i));
- W = InsertNoopCastOfTo(W, Ty);
+ Value *W = expandCodeFor(S->getOperand(i), Ty);
V = InsertBinop(Instruction::Mul, V, W, InsertPt);
}
Value *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) {
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
- Value *LHS = expand(S->getLHS());
- LHS = InsertNoopCastOfTo(LHS, Ty);
+ Value *LHS = expandCodeFor(S->getLHS(), Ty);
if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(S->getRHS())) {
const APInt &RHS = SC->getValue()->getValue();
if (RHS.isPowerOf2())
InsertPt);
}
- Value *RHS = expand(S->getRHS());
- RHS = InsertNoopCastOfTo(RHS, Ty);
+ Value *RHS = expandCodeFor(S->getRHS(), Ty);
return InsertBinop(Instruction::UDiv, LHS, RHS, InsertPt);
}
}
if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) {
Base = A->getOperand(A->getNumOperands()-1);
- std::vector<SCEVHandle> NewAddOps(A->op_begin(), A->op_end());
+ SmallVector<SCEVHandle, 8> NewAddOps(A->op_begin(), A->op_end());
NewAddOps.back() = Rest;
Rest = SE.getAddExpr(NewAddOps);
ExposePointerBase(Base, Rest, SE);
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
const Loop *L = S->getLoop();
+ // First check for an existing canonical IV in a suitable type.
+ PHINode *CanonicalIV = 0;
+ if (PHINode *PN = L->getCanonicalInductionVariable())
+ if (SE.isSCEVable(PN->getType()) &&
+ isa<IntegerType>(SE.getEffectiveSCEVType(PN->getType())) &&
+ SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty))
+ CanonicalIV = PN;
+
+ // Rewrite an AddRec in terms of the canonical induction variable, if
+ // its type is more narrow.
+ if (CanonicalIV &&
+ SE.getTypeSizeInBits(CanonicalIV->getType()) >
+ SE.getTypeSizeInBits(Ty)) {
+ SCEVHandle Start = SE.getAnyExtendExpr(S->getStart(),
+ CanonicalIV->getType());
+ SCEVHandle Step = SE.getAnyExtendExpr(S->getStepRecurrence(SE),
+ CanonicalIV->getType());
+ Value *V = expand(SE.getAddRecExpr(Start, Step, S->getLoop()));
+ BasicBlock::iterator SaveInsertPt = getInsertionPoint();
+ BasicBlock::iterator NewInsertPt =
+ next(BasicBlock::iterator(cast<Instruction>(V)));
+ while (isa<PHINode>(NewInsertPt)) ++NewInsertPt;
+ V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0,
+ NewInsertPt);
+ setInsertionPoint(SaveInsertPt);
+ return V;
+ }
+
// {X,+,F} --> X + {0,+,F}
if (!S->getStart()->isZero()) {
- std::vector<SCEVHandle> NewOps(S->getOperands());
+ const SmallVectorImpl<SCEVHandle> &SOperands = S->getOperands();
+ SmallVector<SCEVHandle, 4> NewOps(SOperands.begin(), SOperands.end());
NewOps[0] = SE.getIntegerSCEV(0, Ty);
SCEVHandle Rest = SE.getAddRecExpr(NewOps, L);
// comments on expandAddToGEP for details.
if (SE.TD) {
SCEVHandle Base = S->getStart();
- SCEVHandle RestArray[1] = Rest;
+ SCEVHandle RestArray[1] = { Rest };
// Dig into the expression to find the pointer base for a GEP.
ExposePointerBase(Base, RestArray[0], SE);
// If we found a pointer, expand the AddRec with a GEP.
// {0,+,1} --> Insert a canonical induction variable into the loop!
if (S->isAffine() &&
S->getOperand(1) == SE.getIntegerSCEV(1, Ty)) {
+ // If there's a canonical IV, just use it.
+ if (CanonicalIV) {
+ assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) &&
+ "IVs with types different from the canonical IV should "
+ "already have been handled!");
+ return CanonicalIV;
+ }
+
// Create and insert the PHI node for the induction variable in the
// specified loop.
BasicBlock *Header = L->getHeader();
return PN;
}
+ // {0,+,F} --> {0,+,1} * F
// Get the canonical induction variable I for this loop.
- Value *I = getOrInsertCanonicalInductionVariable(L, Ty);
+ Value *I = CanonicalIV ?
+ CanonicalIV :
+ getOrInsertCanonicalInductionVariable(L, Ty);
// If this is a simple linear addrec, emit it now as a special case.
if (S->isAffine()) { // {0,+,F} --> i*F
- Value *F = expand(S->getOperand(1));
- F = InsertNoopCastOfTo(F, Ty);
-
- // IF the step is by one, just return the inserted IV.
- if (ConstantInt *CI = dyn_cast<ConstantInt>(F))
- if (CI->getValue() == 1)
- return I;
-
+ Value *F = expandCodeFor(S->getOperand(1), Ty);
+
// If the insert point is directly inside of the loop, emit the multiply at
// the insert point. Otherwise, L is a loop that is a parent of the insert
// point loop. If we can, move the multiply to the outer most loop that it
// into this folder.
SCEVHandle IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV.
- SCEVHandle V = S->evaluateAtIteration(IH, SE);
+ // Promote S up to the canonical IV type, if the cast is foldable.
+ SCEVHandle NewS = S;
+ SCEVHandle Ext = SE.getNoopOrAnyExtend(S, I->getType());
+ if (isa<SCEVAddRecExpr>(Ext))
+ NewS = Ext;
+
+ SCEVHandle V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE);
//cerr << "Evaluated: " << *this << "\n to: " << *V << "\n";
+ // Truncate the result down to the original type, if needed.
+ SCEVHandle T = SE.getTruncateOrNoop(V, Ty);
return expand(V);
}
Value *SCEVExpander::visitTruncateExpr(const SCEVTruncateExpr *S) {
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
- Value *V = expand(S->getOperand());
- V = InsertNoopCastOfTo(V, SE.getEffectiveSCEVType(V->getType()));
+ Value *V = expandCodeFor(S->getOperand(),
+ SE.getEffectiveSCEVType(S->getOperand()->getType()));
Instruction *I = new TruncInst(V, Ty, "tmp.", InsertPt);
InsertedValues.insert(I);
return I;
Value *SCEVExpander::visitZeroExtendExpr(const SCEVZeroExtendExpr *S) {
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
- Value *V = expand(S->getOperand());
- V = InsertNoopCastOfTo(V, SE.getEffectiveSCEVType(V->getType()));
+ Value *V = expandCodeFor(S->getOperand(),
+ SE.getEffectiveSCEVType(S->getOperand()->getType()));
Instruction *I = new ZExtInst(V, Ty, "tmp.", InsertPt);
InsertedValues.insert(I);
return I;
Value *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) {
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
- Value *V = expand(S->getOperand());
- V = InsertNoopCastOfTo(V, SE.getEffectiveSCEVType(V->getType()));
+ Value *V = expandCodeFor(S->getOperand(),
+ SE.getEffectiveSCEVType(S->getOperand()->getType()));
Instruction *I = new SExtInst(V, Ty, "tmp.", InsertPt);
InsertedValues.insert(I);
return I;
Value *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) {
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
- Value *LHS = expand(S->getOperand(0));
- LHS = InsertNoopCastOfTo(LHS, Ty);
+ Value *LHS = expandCodeFor(S->getOperand(0), Ty);
for (unsigned i = 1; i < S->getNumOperands(); ++i) {
- Value *RHS = expand(S->getOperand(i));
- RHS = InsertNoopCastOfTo(RHS, Ty);
+ Value *RHS = expandCodeFor(S->getOperand(i), Ty);
Instruction *ICmp =
new ICmpInst(ICmpInst::ICMP_SGT, LHS, RHS, "tmp", InsertPt);
InsertedValues.insert(ICmp);
Value *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) {
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
- Value *LHS = expand(S->getOperand(0));
- LHS = InsertNoopCastOfTo(LHS, Ty);
+ Value *LHS = expandCodeFor(S->getOperand(0), Ty);
for (unsigned i = 1; i < S->getNumOperands(); ++i) {
- Value *RHS = expand(S->getOperand(i));
- RHS = InsertNoopCastOfTo(RHS, Ty);
+ Value *RHS = expandCodeFor(S->getOperand(i), Ty);
Instruction *ICmp =
new ICmpInst(ICmpInst::ICMP_UGT, LHS, RHS, "tmp", InsertPt);
InsertedValues.insert(ICmp);
InsertedExpressions[S] = V;
return V;
}
+
+/// getOrInsertCanonicalInductionVariable - This method returns the
+/// canonical induction variable of the specified type for the specified
+/// loop (inserting one if there is none). A canonical induction variable
+/// starts at zero and steps by one on each iteration.
+Value *
+SCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L,
+ const Type *Ty) {
+ assert(Ty->isInteger() && "Can only insert integer induction variables!");
+ SCEVHandle H = SE.getAddRecExpr(SE.getIntegerSCEV(0, Ty),
+ SE.getIntegerSCEV(1, Ty), L);
+ return expand(H);
+}
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