#include "llvm/ADT/STLExtras.h"
using namespace llvm;
+/// 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
+/// creating a new one.
+Value *SCEVExpander::ReuseOrCreateCast(Value *V, const Type *Ty,
+ Instruction::CastOps Op,
+ BasicBlock::iterator IP) {
+ // Check to see if there is already a cast!
+ for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
+ UI != E; ++UI) {
+ User *U = *UI;
+ if (U->getType() == Ty)
+ 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) {
+ // Create a new cast, and leave the old cast in place in case
+ // it is being used as an insert point. Clear its operand
+ // so that it doesn't hold anything live.
+ Instruction *NewCI = CastInst::Create(Op, V, Ty, "", IP);
+ NewCI->takeName(CI);
+ CI->replaceAllUsesWith(NewCI);
+ CI->setOperand(0, UndefValue::get(V->getType()));
+ rememberInstruction(NewCI);
+ return NewCI;
+ }
+ rememberInstruction(CI);
+ return CI;
+ }
+ }
+
+ // Create a new cast.
+ Instruction *I = CastInst::Create(Op, V, Ty, V->getName(), IP);
+ rememberInstruction(I);
+ return I;
+}
+
/// InsertNoopCastOfTo - Insert a cast of V to the specified type,
/// which must be possible with a noop cast, doing what we can to share
/// the casts.
return CE->getOperand(0);
}
+ // Fold a cast of a constant.
if (Constant *C = dyn_cast<Constant>(V))
return ConstantExpr::getCast(Op, C, Ty);
+ // Cast the argument at the beginning of the entry block, after
+ // any bitcasts of other arguments.
if (Argument *A = dyn_cast<Argument>(V)) {
- // Check to see if there is already a cast!
- for (Value::use_iterator UI = A->use_begin(), E = A->use_end();
- UI != E; ++UI)
- if ((*UI)->getType() == Ty)
- if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI)))
- if (CI->getOpcode() == Op) {
- // If the cast isn't the first instruction of the function, move it.
- if (BasicBlock::iterator(CI) !=
- A->getParent()->getEntryBlock().begin()) {
- // Recreate the cast at the beginning of the entry block.
- // The old cast is left in place in case it is being used
- // as an insert point.
- Instruction *NewCI =
- CastInst::Create(Op, V, Ty, "",
- A->getParent()->getEntryBlock().begin());
- NewCI->takeName(CI);
- CI->replaceAllUsesWith(NewCI);
- return NewCI;
- }
- return CI;
- }
-
- Instruction *I = CastInst::Create(Op, V, Ty, V->getName(),
- A->getParent()->getEntryBlock().begin());
- rememberInstruction(I);
- return I;
+ BasicBlock::iterator IP = A->getParent()->getEntryBlock().begin();
+ while ((isa<BitCastInst>(IP) &&
+ isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) &&
+ cast<BitCastInst>(IP)->getOperand(0) != A) ||
+ isa<DbgInfoIntrinsic>(IP))
+ ++IP;
+ return ReuseOrCreateCast(A, Ty, Op, IP);
}
+ // Cast the instruction immediately after the instruction.
Instruction *I = cast<Instruction>(V);
-
- // Check to see if there is already a cast. If there is, use it.
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
- UI != E; ++UI) {
- if ((*UI)->getType() == Ty)
- if (CastInst *CI = dyn_cast<CastInst>(cast<Instruction>(*UI)))
- if (CI->getOpcode() == Op) {
- BasicBlock::iterator It = I; ++It;
- if (isa<InvokeInst>(I))
- It = cast<InvokeInst>(I)->getNormalDest()->begin();
- while (isa<PHINode>(It)) ++It;
- if (It != BasicBlock::iterator(CI)) {
- // Recreate the cast after the user.
- // The old cast is left in place in case it is being used
- // as an insert point.
- Instruction *NewCI = CastInst::Create(Op, V, Ty, "", It);
- NewCI->takeName(CI);
- CI->replaceAllUsesWith(NewCI);
- rememberInstruction(NewCI);
- return NewCI;
- }
- rememberInstruction(CI);
- return CI;
- }
- }
BasicBlock::iterator IP = I; ++IP;
if (InvokeInst *II = dyn_cast<InvokeInst>(I))
IP = II->getNormalDest()->begin();
- while (isa<PHINode>(IP)) ++IP;
- Instruction *CI = CastInst::Create(Op, V, Ty, V->getName(), IP);
- rememberInstruction(CI);
- return CI;
+ while (isa<PHINode>(IP) || isa<DbgInfoIntrinsic>(IP)) ++IP;
+ return ReuseOrCreateCast(I, Ty, Op, IP);
}
/// InsertBinop - Insert the specified binary operator, doing a small amount
// x/x == 1.
if (S == Factor) {
- S = SE.getIntegerSCEV(1, S->getType());
+ S = SE.getConstant(S->getType(), 1);
return true;
}
// Mul's operands. If so, we can just remove it.
for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) {
const SCEV *SOp = M->getOperand(i);
- const SCEV *Remainder = SE.getIntegerSCEV(0, SOp->getType());
+ const SCEV *Remainder = SE.getConstant(SOp->getType(), 0);
if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) &&
Remainder->isZero()) {
SmallVector<const SCEV *, 4> NewMulOps(M->op_begin(), M->op_end());
// In an AddRec, check if both start and step are divisible.
if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) {
const SCEV *Step = A->getStepRecurrence(SE);
- const SCEV *StepRem = SE.getIntegerSCEV(0, Step->getType());
+ const SCEV *StepRem = SE.getConstant(Step->getType(), 0);
if (!FactorOutConstant(Step, StepRem, Factor, SE, TD))
return false;
if (!StepRem->isZero())
SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end());
// Let ScalarEvolution sort and simplify the non-addrecs list.
const SCEV *Sum = NoAddRecs.empty() ?
- SE.getIntegerSCEV(0, Ty) :
+ SE.getConstant(Ty, 0) :
SE.getAddExpr(NoAddRecs);
// If it returned an add, use the operands. Otherwise it simplified
// the sum into a single value, so just use that.
Ops.clear();
if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum))
- Ops.insert(Ops.end(), Add->op_begin(), Add->op_end());
+ Ops.append(Add->op_begin(), Add->op_end());
else if (!Sum->isZero())
Ops.push_back(Sum);
// Then append the addrecs.
- Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end());
+ Ops.append(AddRecs.begin(), AddRecs.end());
}
/// SplitAddRecs - Flatten a list of add operands, moving addrec start values
while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) {
const SCEV *Start = A->getStart();
if (Start->isZero()) break;
- const SCEV *Zero = SE.getIntegerSCEV(0, Ty);
+ const SCEV *Zero = SE.getConstant(Ty, 0);
AddRecs.push_back(SE.getAddRecExpr(Zero,
A->getStepRecurrence(SE),
A->getLoop()));
if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) {
Ops[i] = Zero;
- Ops.insert(Ops.end(), Add->op_begin(), Add->op_end());
+ Ops.append(Add->op_begin(), Add->op_end());
e += Add->getNumOperands();
} else {
Ops[i] = Start;
}
if (!AddRecs.empty()) {
// Add the addrecs onto the end of the list.
- Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end());
+ Ops.append(AddRecs.begin(), AddRecs.end());
// Resort the operand list, moving any constants to the front.
SimplifyAddOperands(Ops, Ty, SE);
}
SmallVector<const SCEV *, 8> NewOps;
for (unsigned i = 0, e = Ops.size(); i != e; ++i) {
const SCEV *Op = Ops[i];
- const SCEV *Remainder = SE.getIntegerSCEV(0, Ty);
+ const SCEV *Remainder = SE.getConstant(Ty, 0);
if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) {
// Op now has ElSize factored out.
ScaledOps.push_back(Op);
llvm_unreachable("Unexpected SCEV type!");
}
+namespace {
+
/// LoopCompare - Compare loops by PickMostRelevantLoop.
class LoopCompare {
DominatorTree &DT;
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;
}
};
+}
+
Value *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) {
const Type *Ty = SE.getEffectiveSCEVType(S->getType());
// 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.
- // Try to form a getelementptr.
+ // Try to form a getelementptr. If the running sum is instructions,
+ // use a SCEVUnknown to avoid re-analyzing them.
SmallVector<const SCEV *, 4> NewOps;
- NewOps.push_back(SE.getUnknown(Sum));
+ NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) :
+ SE.getSCEV(Sum));
for (++I; I != E && I->first == CurLoop; ++I)
NewOps.push_back(I->second);
Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op));
while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) {
Base = A->getStart();
Rest = SE.getAddExpr(Rest,
- SE.getAddRecExpr(SE.getIntegerSCEV(0, A->getType()),
+ SE.getAddRecExpr(SE.getConstant(A->getType(), 0),
A->getStepRecurrence(SE),
A->getLoop()));
}
// Determine a normalized form of this expression, which is the expression
// before any post-inc adjustment is made.
const SCEVAddRecExpr *Normalized = S;
- if (L == PostIncLoop) {
- const SCEV *Step = S->getStepRecurrence(SE);
- Normalized = cast<SCEVAddRecExpr>(SE.getMinusSCEV(S, Step));
+ if (PostIncLoops.count(L)) {
+ PostIncLoopSet Loops;
+ Loops.insert(L);
+ Normalized =
+ cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0,
+ Loops, SE, *SE.DT));
}
// Strip off any non-loop-dominating component from the addrec start.
const SCEV *PostLoopOffset = 0;
if (!Start->properlyDominates(L->getHeader(), SE.DT)) {
PostLoopOffset = Start;
- Start = SE.getIntegerSCEV(0, Normalized->getType());
+ Start = SE.getConstant(Normalized->getType(), 0);
Normalized =
cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start,
Normalized->getStepRecurrence(SE),
// Strip off any non-loop-dominating component from the addrec step.
const SCEV *Step = Normalized->getStepRecurrence(SE);
const SCEV *PostLoopScale = 0;
- if (!Step->hasComputableLoopEvolution(L) &&
- !Step->dominates(L->getHeader(), SE.DT)) {
+ if (!Step->dominates(L->getHeader(), SE.DT)) {
PostLoopScale = Step;
- Step = SE.getIntegerSCEV(1, Normalized->getType());
+ Step = SE.getConstant(Normalized->getType(), 1);
Normalized =
cast<SCEVAddRecExpr>(SE.getAddRecExpr(Start, Step,
Normalized->getLoop()));
// Accommodate post-inc mode, if necessary.
Value *Result;
- if (L != PostIncLoop)
+ if (!PostIncLoops.count(L))
Result = PN;
else {
// In PostInc mode, use the post-incremented value.
// 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
BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint();
BasicBlock::iterator NewInsertPt =
llvm::next(BasicBlock::iterator(cast<Instruction>(V)));
- while (isa<PHINode>(NewInsertPt)) ++NewInsertPt;
+ while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt))
+ ++NewInsertPt;
V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), 0,
NewInsertPt);
restoreInsertPoint(SaveInsertBB, SaveInsertPt);
// {X,+,F} --> X + {0,+,F}
if (!S->getStart()->isZero()) {
SmallVector<const SCEV *, 4> NewOps(S->op_begin(), S->op_end());
- NewOps[0] = SE.getIntegerSCEV(0, Ty);
+ NewOps[0] = SE.getConstant(Ty, 0);
const SCEV *Rest = SE.getAddRecExpr(NewOps, L);
// Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the
}
// {0,+,1} --> Insert a canonical induction variable into the loop!
- if (S->isAffine() &&
- S->getOperand(1) == SE.getIntegerSCEV(1, Ty)) {
+ if (S->isAffine() && S->getOperand(1)->isOne()) {
// If there's a canonical IV, just use it.
if (CanonicalIV) {
assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) &&
Constant *One = ConstantInt::get(Ty, 1);
for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header);
- HPI != HPE; ++HPI)
- if (L->contains(*HPI)) {
+ HPI != HPE; ++HPI) {
+ BasicBlock *HP = *HPI;
+ 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",
- (*HPI)->getTerminator());
+ HP->getTerminator());
rememberInstruction(Add);
- PN->addIncoming(Add, *HPI);
+ PN->addIncoming(Add, HP);
} else {
- PN->addIncoming(Constant::getNullValue(Ty), *HPI);
+ PN->addIncoming(Constant::getNullValue(Ty), HP);
}
+ }
}
// {0,+,F} --> {0,+,1} * F
return LHS;
}
+Value *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty,
+ Instruction *I) {
+ BasicBlock::iterator IP = I;
+ while (isInsertedInstruction(IP) || isa<DbgInfoIntrinsic>(IP))
+ ++IP;
+ Builder.SetInsertPoint(IP->getParent(), IP);
+ return expandCodeFor(SH, Ty);
+}
+
Value *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty) {
// Expand the code for this SCEV.
Value *V = expand(SH);
L = L->getParentLoop())
if (S->isLoopInvariant(L)) {
if (!L) break;
- if (BasicBlock *Preheader = L->getLoopPreheader()) {
+ if (BasicBlock *Preheader = L->getLoopPreheader())
InsertPt = Preheader->getTerminator();
- BasicBlock::iterator IP = InsertPt;
- // Back past any debug info instructions. Sometimes we inserted
- // something earlier before debug info but after any real instructions.
- // This should behave the same as if debug info was not present.
- while (IP != Preheader->begin()) {
- --IP;
- if (!isa<DbgInfoIntrinsic>(IP))
- break;
- InsertPt = IP;
- }
- }
} else {
// If the SCEV is computable at this level, insert it into the header
// after the PHIs (and after any other instructions that we've inserted
// there) so that it is guaranteed to dominate any user inside the loop.
- if (L && S->hasComputableLoopEvolution(L) && L != PostIncLoop)
+ if (L && S->hasComputableLoopEvolution(L) && !PostIncLoops.count(L))
InsertPt = L->getHeader()->getFirstNonPHI();
- while (isa<DbgInfoIntrinsic>(InsertPt))
- InsertPt = llvm::next(BasicBlock::iterator(InsertPt));
- while (isInsertedInstruction(InsertPt))
+ while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt))
InsertPt = llvm::next(BasicBlock::iterator(InsertPt));
break;
}
Value *V = visit(S);
// Remember the expanded value for this SCEV at this location.
- if (!PostIncLoop)
+ if (PostIncLoops.empty())
InsertedExpressions[std::make_pair(S, InsertPt)] = V;
restoreInsertPoint(SaveInsertBB, SaveInsertPt);
}
void SCEVExpander::rememberInstruction(Value *I) {
- if (!PostIncLoop)
+ if (!PostIncLoops.empty())
+ InsertedPostIncValues.insert(I);
+ else
InsertedValues.insert(I);
// If we just claimed an existing instruction and that instruction had
// subsequently inserted code will be dominated.
if (Builder.GetInsertPoint() == I) {
BasicBlock::iterator It = cast<Instruction>(I);
- do { ++It; } while (isInsertedInstruction(It));
+ do { ++It; } while (isInsertedInstruction(It) ||
+ isa<DbgInfoIntrinsic>(It));
Builder.SetInsertPoint(Builder.GetInsertBlock(), It);
}
}
void SCEVExpander::restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I) {
// If we acquired more instructions since the old insert point was saved,
// advance past them.
- while (isInsertedInstruction(I)) ++I;
+ while (isInsertedInstruction(I) || isa<DbgInfoIntrinsic>(I)) ++I;
Builder.SetInsertPoint(BB, I);
}
/// 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!");
- const SCEV *H = SE.getAddRecExpr(SE.getIntegerSCEV(0, Ty),
- SE.getIntegerSCEV(1, Ty), L);
+
+ // 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;
}
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