#include "llvm/ADT/STLExtras.h"
using namespace llvm;
-/// ReuseOrCreateCast - Arange for there to be a cast of V to Ty at IP,
+/// ReuseOrCreateCast - Arrange for there to be a cast of V to Ty at IP,
/// reusing an existing cast if a suitable one exists, moving an existing
/// cast if a suitable one exists but isn't in the right place, or
-/// or creating a new one.
+/// creating a new one.
Value *SCEVExpander::ReuseOrCreateCast(Value *V, const Type *Ty,
Instruction::CastOps Op,
BasicBlock::iterator IP) {
UI != E; ++UI) {
User *U = *UI;
if (U->getType() == Ty)
- if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(U)))
+ if (CastInst *CI = dyn_cast<CastInst>(U))
if (CI->getOpcode() == Op) {
// If the cast isn't where we want it, fix it.
if (BasicBlock::iterator(CI) != IP) {
bool operator()(std::pair<const Loop *, const SCEV *> LHS,
std::pair<const Loop *, const SCEV *> RHS) const {
+ // Keep pointer operands sorted at the end.
+ if (LHS.second->getType()->isPointerTy() !=
+ RHS.second->getType()->isPointerTy())
+ return LHS.second->getType()->isPointerTy();
+
// Compare loops with PickMostRelevantLoop.
if (LHS.first != RHS.first)
return PickMostRelevantLoop(LHS.first, RHS.first, DT) != LHS.first;
// The running sum expression is a pointer. Try to form a getelementptr
// at this level with that as the base.
SmallVector<const SCEV *, 4> NewOps;
- for (; I != E && I->first == CurLoop; ++I)
- NewOps.push_back(I->second);
+ for (; I != E && I->first == CurLoop; ++I) {
+ // If the operand is SCEVUnknown and not instructions, peek through
+ // it, to enable more of it to be folded into the GEP.
+ const SCEV *X = I->second;
+ if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(X))
+ if (!isa<Instruction>(U->getValue()))
+ X = SE.getSCEV(U->getValue());
+ NewOps.push_back(X);
+ }
Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum);
} else if (const PointerType *PTy = dyn_cast<PointerType>(Op->getType())) {
// The running sum is an integer, and there's a pointer at this level.
// First check for an existing canonical IV in a suitable type.
PHINode *CanonicalIV = 0;
if (PHINode *PN = L->getCanonicalInductionVariable())
- if (SE.isSCEVable(PN->getType()) &&
- SE.getEffectiveSCEVType(PN->getType())->isIntegerTy() &&
- SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty))
+ if (SE.getTypeSizeInBits(PN->getType()) >= SE.getTypeSizeInBits(Ty))
CanonicalIV = PN;
// Rewrite an AddRec in terms of the canonical induction variable, if
SE.getUnknown(expand(Rest))));
}
- // {0,+,1} --> Insert a canonical induction variable into the loop!
- if (S->isAffine() && S->getOperand(1)->isOne()) {
- // 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;
- }
-
+ // If we don't yet have a canonical IV, create one.
+ if (!CanonicalIV) {
// Create and insert the PHI node for the induction variable in the
// specified loop.
BasicBlock *Header = L->getHeader();
- PHINode *PN = PHINode::Create(Ty, "indvar", Header->begin());
- rememberInstruction(PN);
+ CanonicalIV = PHINode::Create(Ty, "indvar", Header->begin());
+ rememberInstruction(CanonicalIV);
Constant *One = ConstantInt::get(Ty, 1);
for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header);
if (L->contains(HP)) {
// Insert a unit add instruction right before the terminator
// corresponding to the back-edge.
- Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next",
- HP->getTerminator());
+ Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One,
+ "indvar.next",
+ HP->getTerminator());
rememberInstruction(Add);
- PN->addIncoming(Add, HP);
+ CanonicalIV->addIncoming(Add, HP);
} else {
- PN->addIncoming(Constant::getNullValue(Ty), HP);
+ CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP);
}
}
}
+ // {0,+,1} --> Insert a canonical induction variable into the loop!
+ if (S->isAffine() && S->getOperand(1)->isOne()) {
+ assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) &&
+ "IVs with types different from the canonical IV should "
+ "already have been handled!");
+ return CanonicalIV;
+ }
+
// {0,+,F} --> {0,+,1} * F
- // Get the canonical induction variable I for this loop.
- 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
return
expand(SE.getTruncateOrNoop(
- SE.getMulExpr(SE.getUnknown(I),
+ SE.getMulExpr(SE.getUnknown(CanonicalIV),
SE.getNoopOrAnyExtend(S->getOperand(1),
- I->getType())),
+ CanonicalIV->getType())),
Ty));
// If this is a chain of recurrences, turn it into a closed form, using the
// folders, then expandCodeFor the closed form. This allows the folders to
// simplify the expression without having to build a bunch of special code
// into this folder.
- const SCEV *IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV.
+ const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV.
// Promote S up to the canonical IV type, if the cast is foldable.
const SCEV *NewS = S;
- const SCEV *Ext = SE.getNoopOrAnyExtend(S, I->getType());
+ const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType());
if (isa<SCEVAddRecExpr>(Ext))
NewS = Ext;
/// 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 *
+PHINode *
SCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L,
const Type *Ty) {
assert(Ty->isIntegerTy() && "Can only insert integer induction variables!");
+
+ // Build a SCEV for {0,+,1}<L>.
const SCEV *H = SE.getAddRecExpr(SE.getConstant(Ty, 0),
SE.getConstant(Ty, 1), L);
+
+ // Emit code for it.
BasicBlock *SaveInsertBB = Builder.GetInsertBlock();
BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint();
- Value *V = expandCodeFor(H, 0, L->getHeader()->begin());
+ PHINode *V = cast<PHINode>(expandCodeFor(H, 0, L->getHeader()->begin()));
if (SaveInsertBB)
restoreInsertPoint(SaveInsertBB, SaveInsertPt);
+
return V;
}