/// ReassociateInst - Inspect and reassociate the instruction at the
/// given position, post-incrementing the position.
void Reassociate::ReassociateInst(BasicBlock::iterator &BBI) {
Instruction *BI = BBI++;
if (BI->getOpcode() == Instruction::Shl &&
isa<ConstantInt>(BI->getOperand(1)))
if (Instruction *NI = ConvertShiftToMul(BI, ValueRankMap)) {
MadeChange = true;
BI = NI;
}
// Reject cases where it is pointless to do this.
if (!isa<BinaryOperator>(BI) || BI->getType()->isFloatingPointTy() ||
BI->getType()->isVectorTy())
return; // Floating point ops are not associative.
// Do not reassociate boolean (i1) expressions. We want to preserve the
// original order of evaluation for short-circuited comparisons that
// SimplifyCFG has folded to AND/OR expressions. If the expression
// is not further optimized, it is likely to be transformed back to a
// short-circuited form for code gen, and the source order may have been
// optimized for the most likely conditions.
if (BI->getType()->isIntegerTy(1))
return;
// If this is a subtract instruction which is not already in negate form,
// see if we can convert it to X+-Y.
if (BI->getOpcode() == Instruction::Sub) {
if (ShouldBreakUpSubtract(BI)) {
BI = BreakUpSubtract(BI, ValueRankMap);
// Reset the BBI iterator in case BreakUpSubtract changed the
// instruction it points to.
BBI = BI;
++BBI;
MadeChange = true;
} else if (BinaryOperator::isNeg(BI)) {
// Otherwise, this is a negation. See if the operand is a multiply tree
// and if this is not an inner node of a multiply tree.
if (isReassociableOp(BI->getOperand(1), Instruction::Mul) &&
(!BI->hasOneUse() ||
!isReassociableOp(BI->use_back(), Instruction::Mul))) {
BI = LowerNegateToMultiply(BI, ValueRankMap);
MadeChange = true;
}
}
}
// If this instruction is a commutative binary operator, process it.
if (!BI->isAssociative()) return;
BinaryOperator *I = cast<BinaryOperator>(BI);
// If this is an interior node of a reassociable tree, ignore it until we
// get to the root of the tree, to avoid N^2 analysis.
if (I->hasOneUse() && isReassociableOp(I->use_back(), I->getOpcode()))
return;
// If this is an add tree that is used by a sub instruction, ignore it
// until we process the subtract.
if (I->hasOneUse() && I->getOpcode() == Instruction::Add &&
cast<Instruction>(I->use_back())->getOpcode() == Instruction::Sub)
return;
ReassociateExpression(I);
}
/// HandleFloatingPointIV - If the loop has floating induction variable
/// then insert corresponding integer induction variable if possible.
/// For example,
/// for(double i = 0; i < 10000; ++i)
/// bar(i)
/// is converted into
/// for(int i = 0; i < 10000; ++i)
/// bar((double)i);
///
void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PN) {
unsigned IncomingEdge = L->contains(PN->getIncomingBlock(0));
unsigned BackEdge = IncomingEdge^1;
// Check incoming value.
ConstantFP *InitValueVal =
dyn_cast<ConstantFP>(PN->getIncomingValue(IncomingEdge));
int64_t InitValue;
if (!InitValueVal || !ConvertToSInt(InitValueVal->getValueAPF(), InitValue))
return;
// Check IV increment. Reject this PN if increment operation is not
// an add or increment value can not be represented by an integer.
BinaryOperator *Incr =
dyn_cast<BinaryOperator>(PN->getIncomingValue(BackEdge));
if (Incr == 0 || Incr->getOpcode() != Instruction::FAdd) return;
// If this is not an add of the PHI with a constantfp, or if the constant fp
// is not an integer, bail out.
ConstantFP *IncValueVal = dyn_cast<ConstantFP>(Incr->getOperand(1));
int64_t IncValue;
if (IncValueVal == 0 || Incr->getOperand(0) != PN ||
!ConvertToSInt(IncValueVal->getValueAPF(), IncValue))
return;
// Check Incr uses. One user is PN and the other user is an exit condition
// used by the conditional terminator.
Value::use_iterator IncrUse = Incr->use_begin();
Instruction *U1 = cast<Instruction>(IncrUse++);
if (IncrUse == Incr->use_end()) return;
Instruction *U2 = cast<Instruction>(IncrUse++);
if (IncrUse != Incr->use_end()) return;
// Find exit condition, which is an fcmp. If it doesn't exist, or if it isn't
// only used by a branch, we can't transform it.
FCmpInst *Compare = dyn_cast<FCmpInst>(U1);
if (!Compare)
Compare = dyn_cast<FCmpInst>(U2);
if (Compare == 0 || !Compare->hasOneUse() ||
!isa<BranchInst>(Compare->use_back()))
return;
BranchInst *TheBr = cast<BranchInst>(Compare->use_back());
// We need to verify that the branch actually controls the iteration count
// of the loop. If not, the new IV can overflow and no one will notice.
// The branch block must be in the loop and one of the successors must be out
// of the loop.
assert(TheBr->isConditional() && "Can't use fcmp if not conditional");
if (!L->contains(TheBr->getParent()) ||
(L->contains(TheBr->getSuccessor(0)) &&
L->contains(TheBr->getSuccessor(1))))
return;
// If it isn't a comparison with an integer-as-fp (the exit value), we can't
// transform it.
ConstantFP *ExitValueVal = dyn_cast<ConstantFP>(Compare->getOperand(1));
int64_t ExitValue;
if (ExitValueVal == 0 ||
!ConvertToSInt(ExitValueVal->getValueAPF(), ExitValue))
return;
// Find new predicate for integer comparison.
CmpInst::Predicate NewPred = CmpInst::BAD_ICMP_PREDICATE;
switch (Compare->getPredicate()) {
default: return; // Unknown comparison.
case CmpInst::FCMP_OEQ:
case CmpInst::FCMP_UEQ: NewPred = CmpInst::ICMP_EQ; break;
case CmpInst::FCMP_ONE:
case CmpInst::FCMP_UNE: NewPred = CmpInst::ICMP_NE; break;
case CmpInst::FCMP_OGT:
case CmpInst::FCMP_UGT: NewPred = CmpInst::ICMP_SGT; break;
case CmpInst::FCMP_OGE:
case CmpInst::FCMP_UGE: NewPred = CmpInst::ICMP_SGE; break;
case CmpInst::FCMP_OLT:
case CmpInst::FCMP_ULT: NewPred = CmpInst::ICMP_SLT; break;
case CmpInst::FCMP_OLE:
case CmpInst::FCMP_ULE: NewPred = CmpInst::ICMP_SLE; break;
}
// We convert the floating point induction variable to a signed i32 value if
// we can. This is only safe if the comparison will not overflow in a way
// that won't be trapped by the integer equivalent operations. Check for this
// now.
// TODO: We could use i64 if it is native and the range requires it.
// The start/stride/exit values must all fit in signed i32.
if (!isInt<32>(InitValue) || !isInt<32>(IncValue) || !isInt<32>(ExitValue))
return;
// If not actually striding (add x, 0.0), avoid touching the code.
if (IncValue == 0)
return;
// Positive and negative strides have different safety conditions.
if (IncValue > 0) {
// If we have a positive stride, we require the init to be less than the
// exit value and an equality or less than comparison.
if (InitValue >= ExitValue ||
NewPred == CmpInst::ICMP_SGT || NewPred == CmpInst::ICMP_SGE)
return;
uint32_t Range = uint32_t(ExitValue-InitValue);
if (NewPred == CmpInst::ICMP_SLE) {
// Normalize SLE -> SLT, check for infinite loop.
if (++Range == 0) return; // Range overflows.
}
unsigned Leftover = Range % uint32_t(IncValue);
// If this is an equality comparison, we require that the strided value
// exactly land on the exit value, otherwise the IV condition will wrap
// around and do things the fp IV wouldn't.
if ((NewPred == CmpInst::ICMP_EQ || NewPred == CmpInst::ICMP_NE) &&
Leftover != 0)
return;
// If the stride would wrap around the i32 before exiting, we can't
// transform the IV.
if (Leftover != 0 && int32_t(ExitValue+IncValue) < ExitValue)
return;
} else {
// If we have a negative stride, we require the init to be greater than the
// exit value and an equality or greater than comparison.
if (InitValue >= ExitValue ||
NewPred == CmpInst::ICMP_SLT || NewPred == CmpInst::ICMP_SLE)
return;
uint32_t Range = uint32_t(InitValue-ExitValue);
if (NewPred == CmpInst::ICMP_SGE) {
// Normalize SGE -> SGT, check for infinite loop.
if (++Range == 0) return; // Range overflows.
}
unsigned Leftover = Range % uint32_t(-IncValue);
// If this is an equality comparison, we require that the strided value
// exactly land on the exit value, otherwise the IV condition will wrap
// around and do things the fp IV wouldn't.
if ((NewPred == CmpInst::ICMP_EQ || NewPred == CmpInst::ICMP_NE) &&
Leftover != 0)
return;
// If the stride would wrap around the i32 before exiting, we can't
// transform the IV.
if (Leftover != 0 && int32_t(ExitValue+IncValue) > ExitValue)
return;
}
const IntegerType *Int32Ty = Type::getInt32Ty(PN->getContext());
// Insert new integer induction variable.
PHINode *NewPHI = PHINode::Create(Int32Ty, PN->getName()+".int", PN);
NewPHI->addIncoming(ConstantInt::get(Int32Ty, InitValue),
PN->getIncomingBlock(IncomingEdge));
Value *NewAdd =
BinaryOperator::CreateAdd(NewPHI, ConstantInt::get(Int32Ty, IncValue),
Incr->getName()+".int", Incr);
NewPHI->addIncoming(NewAdd, PN->getIncomingBlock(BackEdge));
ICmpInst *NewCompare = new ICmpInst(TheBr, NewPred, NewAdd,
ConstantInt::get(Int32Ty, ExitValue),
Compare->getName());
// In the following deletions, PN may become dead and may be deleted.
// Use a WeakVH to observe whether this happens.
WeakVH WeakPH = PN;
// Delete the old floating point exit comparison. The branch starts using the
// new comparison.
NewCompare->takeName(Compare);
Compare->replaceAllUsesWith(NewCompare);
RecursivelyDeleteTriviallyDeadInstructions(Compare);
// Delete the old floating point increment.
Incr->replaceAllUsesWith(UndefValue::get(Incr->getType()));
RecursivelyDeleteTriviallyDeadInstructions(Incr);
// If the FP induction variable still has uses, this is because something else
// in the loop uses its value. In order to canonicalize the induction
// variable, we chose to eliminate the IV and rewrite it in terms of an
// int->fp cast.
//
// We give preference to sitofp over uitofp because it is faster on most
// platforms.
if (WeakPH) {
Value *Conv = new SIToFPInst(NewPHI, PN->getType(), "indvar.conv",
PN->getParent()->getFirstNonPHI());
PN->replaceAllUsesWith(Conv);
RecursivelyDeleteTriviallyDeadInstructions(PN);
}
// Add a new IVUsers entry for the newly-created integer PHI.
IU->AddUsersIfInteresting(NewPHI);
}
bool AMDGPUCodeGenPrepare::isSigned(const BinaryOperator &I) const {
return I.getOpcode() == Instruction::AShr ||
I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::SRem;
}
bool isRemainderWhenDevidingByTwo(Expr *expr)
{
BinaryOperator *binaryOperator = dyn_cast_or_null<BinaryOperator>(expr);
return binaryOperator &&
binaryOperator->getOpcode() == BO_Rem && isIntegerLiteral(binaryOperator->getRHS(), 2);
}
void IndVarSimplify::EliminateIVRemainders() {
SmallVector<WeakVH, 16> DeadInsts;
// Look for SRem and URem users.
for (IVUsers::iterator I = IU->begin(), E = IU->end(); I != E; ++I) {
IVStrideUse &UI = *I;
BinaryOperator *Rem = dyn_cast<BinaryOperator>(UI.getUser());
if (!Rem) continue;
bool isSigned = Rem->getOpcode() == Instruction::SRem;
if (!isSigned && Rem->getOpcode() != Instruction::URem)
continue;
// We're only interested in the case where we know something about
// the numerator.
if (UI.getOperandValToReplace() != Rem->getOperand(0))
continue;
// Get the SCEVs for the ICmp operands.
const SCEV *S = SE->getSCEV(Rem->getOperand(0));
const SCEV *X = SE->getSCEV(Rem->getOperand(1));
// Simplify unnecessary loops away.
const Loop *ICmpLoop = LI->getLoopFor(Rem->getParent());
S = SE->getSCEVAtScope(S, ICmpLoop);
X = SE->getSCEVAtScope(X, ICmpLoop);
// i % n --> i if i is in [0,n).
if ((!isSigned || SE->isKnownNonNegative(S)) &&
SE->isKnownPredicate(isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
S, X))
Rem->replaceAllUsesWith(Rem->getOperand(0));
else {
// (i+1) % n --> (i+1)==n?0:(i+1) if i is in [0,n).
const SCEV *LessOne =
SE->getMinusSCEV(S, SE->getConstant(S->getType(), 1));
if ((!isSigned || SE->isKnownNonNegative(LessOne)) &&
SE->isKnownPredicate(isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
LessOne, X)) {
ICmpInst *ICmp = new ICmpInst(Rem, ICmpInst::ICMP_EQ,
Rem->getOperand(0), Rem->getOperand(1),
"tmp");
SelectInst *Sel =
SelectInst::Create(ICmp,
ConstantInt::get(Rem->getType(), 0),
Rem->getOperand(0), "tmp", Rem);
Rem->replaceAllUsesWith(Sel);
} else
continue;
}
// Inform IVUsers about the new users.
if (Instruction *I = dyn_cast<Instruction>(Rem->getOperand(0)))
IU->AddUsersIfInteresting(I);
DEBUG(dbgs() << "INDVARS: Simplified rem: " << *Rem << '\n');
DeadInsts.push_back(Rem);
}
// Now that we're done iterating through lists, clean up any instructions
// which are now dead.
while (!DeadInsts.empty())
if (Instruction *Inst =
dyn_cast_or_null<Instruction>(DeadInsts.pop_back_val()))
RecursivelyDeleteTriviallyDeadInstructions(Inst);
}
Instruction *InstCombiner::visitMul(BinaryOperator &I) {
bool Changed = SimplifyAssociativeOrCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (Value *V = SimplifyVectorOp(I))
return ReplaceInstUsesWith(I, V);
if (Value *V = SimplifyMulInst(Op0, Op1, DL))
return ReplaceInstUsesWith(I, V);
if (Value *V = SimplifyUsingDistributiveLaws(I))
return ReplaceInstUsesWith(I, V);
if (match(Op1, m_AllOnes())) // X * -1 == 0 - X
return BinaryOperator::CreateNeg(Op0, I.getName());
// Also allow combining multiply instructions on vectors.
{
Value *NewOp;
Constant *C1, *C2;
const APInt *IVal;
if (match(&I, m_Mul(m_Shl(m_Value(NewOp), m_Constant(C2)),
m_Constant(C1))) &&
match(C1, m_APInt(IVal)))
// ((X << C1)*C2) == (X * (C2 << C1))
return BinaryOperator::CreateMul(NewOp, ConstantExpr::getShl(C1, C2));
if (match(&I, m_Mul(m_Value(NewOp), m_Constant(C1)))) {
Constant *NewCst = nullptr;
if (match(C1, m_APInt(IVal)) && IVal->isPowerOf2())
// Replace X*(2^C) with X << C, where C is either a scalar or a splat.
NewCst = ConstantInt::get(NewOp->getType(), IVal->logBase2());
else if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(C1))
// Replace X*(2^C) with X << C, where C is a vector of known
// constant powers of 2.
NewCst = getLogBase2Vector(CV);
if (NewCst) {
BinaryOperator *Shl = BinaryOperator::CreateShl(NewOp, NewCst);
if (I.hasNoSignedWrap()) Shl->setHasNoSignedWrap();
if (I.hasNoUnsignedWrap()) Shl->setHasNoUnsignedWrap();
return Shl;
}
}
}
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
// (Y - X) * (-(2**n)) -> (X - Y) * (2**n), for positive nonzero n
// (Y + const) * (-(2**n)) -> (-constY) * (2**n), for positive nonzero n
// The "* (2**n)" thus becomes a potential shifting opportunity.
{
const APInt & Val = CI->getValue();
const APInt &PosVal = Val.abs();
if (Val.isNegative() && PosVal.isPowerOf2()) {
Value *X = nullptr, *Y = nullptr;
if (Op0->hasOneUse()) {
ConstantInt *C1;
Value *Sub = nullptr;
if (match(Op0, m_Sub(m_Value(Y), m_Value(X))))
Sub = Builder->CreateSub(X, Y, "suba");
else if (match(Op0, m_Add(m_Value(Y), m_ConstantInt(C1))))
Sub = Builder->CreateSub(Builder->CreateNeg(C1), Y, "subc");
if (Sub)
return
BinaryOperator::CreateMul(Sub,
ConstantInt::get(Y->getType(), PosVal));
}
}
}
}
// Simplify mul instructions with a constant RHS.
if (isa<Constant>(Op1)) {
// Try to fold constant mul into select arguments.
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
if (Instruction *R = FoldOpIntoSelect(I, SI))
return R;
if (isa<PHINode>(Op0))
if (Instruction *NV = FoldOpIntoPhi(I))
return NV;
// Canonicalize (X+C1)*CI -> X*CI+C1*CI.
{
Value *X;
Constant *C1;
if (match(Op0, m_OneUse(m_Add(m_Value(X), m_Constant(C1))))) {
Value *Mul = Builder->CreateMul(C1, Op1);
// Only go forward with the transform if C1*CI simplifies to a tidier
// constant.
if (!match(Mul, m_Mul(m_Value(), m_Value())))
return BinaryOperator::CreateAdd(Builder->CreateMul(X, Op1), Mul);
}
}
}
if (Value *Op0v = dyn_castNegVal(Op0)) // -X * -Y = X*Y
if (Value *Op1v = dyn_castNegVal(Op1))
return BinaryOperator::CreateMul(Op0v, Op1v);
// (X / Y) * Y = X - (X % Y)
// (X / Y) * -Y = (X % Y) - X
{
Value *Op1C = Op1;
BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0);
if (!BO ||
(BO->getOpcode() != Instruction::UDiv &&
BO->getOpcode() != Instruction::SDiv)) {
Op1C = Op0;
BO = dyn_cast<BinaryOperator>(Op1);
}
Value *Neg = dyn_castNegVal(Op1C);
if (BO && BO->hasOneUse() &&
(BO->getOperand(1) == Op1C || BO->getOperand(1) == Neg) &&
(BO->getOpcode() == Instruction::UDiv ||
BO->getOpcode() == Instruction::SDiv)) {
Value *Op0BO = BO->getOperand(0), *Op1BO = BO->getOperand(1);
// If the division is exact, X % Y is zero, so we end up with X or -X.
if (PossiblyExactOperator *SDiv = dyn_cast<PossiblyExactOperator>(BO))
if (SDiv->isExact()) {
if (Op1BO == Op1C)
return ReplaceInstUsesWith(I, Op0BO);
return BinaryOperator::CreateNeg(Op0BO);
}
Value *Rem;
if (BO->getOpcode() == Instruction::UDiv)
Rem = Builder->CreateURem(Op0BO, Op1BO);
else
Rem = Builder->CreateSRem(Op0BO, Op1BO);
Rem->takeName(BO);
if (Op1BO == Op1C)
return BinaryOperator::CreateSub(Op0BO, Rem);
return BinaryOperator::CreateSub(Rem, Op0BO);
}
}
/// i1 mul -> i1 and.
if (I.getType()->getScalarType()->isIntegerTy(1))
return BinaryOperator::CreateAnd(Op0, Op1);
// X*(1 << Y) --> X << Y
// (1 << Y)*X --> X << Y
{
Value *Y;
if (match(Op0, m_Shl(m_One(), m_Value(Y))))
return BinaryOperator::CreateShl(Op1, Y);
if (match(Op1, m_Shl(m_One(), m_Value(Y))))
return BinaryOperator::CreateShl(Op0, Y);
}
// If one of the operands of the multiply is a cast from a boolean value, then
// we know the bool is either zero or one, so this is a 'masking' multiply.
// X * Y (where Y is 0 or 1) -> X & (0-Y)
if (!I.getType()->isVectorTy()) {
// -2 is "-1 << 1" so it is all bits set except the low one.
APInt Negative2(I.getType()->getPrimitiveSizeInBits(), (uint64_t)-2, true);
Value *BoolCast = nullptr, *OtherOp = nullptr;
if (MaskedValueIsZero(Op0, Negative2))
BoolCast = Op0, OtherOp = Op1;
else if (MaskedValueIsZero(Op1, Negative2))
BoolCast = Op1, OtherOp = Op0;
if (BoolCast) {
Value *V = Builder->CreateSub(Constant::getNullValue(I.getType()),
BoolCast);
return BinaryOperator::CreateAnd(V, OtherOp);
}
}
return Changed ? &I : nullptr;
}
bool AlignmentFromAssumptions::extractAlignmentInfo(CallInst *I,
Value *&AAPtr, const SCEV *&AlignSCEV,
const SCEV *&OffSCEV) {
// An alignment assume must be a statement about the least-significant
// bits of the pointer being zero, possibly with some offset.
ICmpInst *ICI = dyn_cast<ICmpInst>(I->getArgOperand(0));
if (!ICI)
return false;
// This must be an expression of the form: x & m == 0.
if (ICI->getPredicate() != ICmpInst::ICMP_EQ)
return false;
// Swap things around so that the RHS is 0.
Value *CmpLHS = ICI->getOperand(0);
Value *CmpRHS = ICI->getOperand(1);
const SCEV *CmpLHSSCEV = SE->getSCEV(CmpLHS);
const SCEV *CmpRHSSCEV = SE->getSCEV(CmpRHS);
if (CmpLHSSCEV->isZero())
std::swap(CmpLHS, CmpRHS);
else if (!CmpRHSSCEV->isZero())
return false;
BinaryOperator *CmpBO = dyn_cast<BinaryOperator>(CmpLHS);
if (!CmpBO || CmpBO->getOpcode() != Instruction::And)
return false;
// Swap things around so that the right operand of the and is a constant
// (the mask); we cannot deal with variable masks.
Value *AndLHS = CmpBO->getOperand(0);
Value *AndRHS = CmpBO->getOperand(1);
const SCEV *AndLHSSCEV = SE->getSCEV(AndLHS);
const SCEV *AndRHSSCEV = SE->getSCEV(AndRHS);
if (isa<SCEVConstant>(AndLHSSCEV)) {
std::swap(AndLHS, AndRHS);
std::swap(AndLHSSCEV, AndRHSSCEV);
}
const SCEVConstant *MaskSCEV = dyn_cast<SCEVConstant>(AndRHSSCEV);
if (!MaskSCEV)
return false;
// The mask must have some trailing ones (otherwise the condition is
// trivial and tells us nothing about the alignment of the left operand).
unsigned TrailingOnes =
MaskSCEV->getValue()->getValue().countTrailingOnes();
if (!TrailingOnes)
return false;
// Cap the alignment at the maximum with which LLVM can deal (and make sure
// we don't overflow the shift).
uint64_t Alignment;
TrailingOnes = std::min(TrailingOnes,
unsigned(sizeof(unsigned) * CHAR_BIT - 1));
Alignment = std::min(1u << TrailingOnes, +Value::MaximumAlignment);
Type *Int64Ty = Type::getInt64Ty(I->getParent()->getParent()->getContext());
AlignSCEV = SE->getConstant(Int64Ty, Alignment);
// The LHS might be a ptrtoint instruction, or it might be the pointer
// with an offset.
AAPtr = nullptr;
OffSCEV = nullptr;
if (PtrToIntInst *PToI = dyn_cast<PtrToIntInst>(AndLHS)) {
AAPtr = PToI->getPointerOperand();
OffSCEV = SE->getConstant(Int64Ty, 0);
} else if (const SCEVAddExpr* AndLHSAddSCEV =
dyn_cast<SCEVAddExpr>(AndLHSSCEV)) {
// Try to find the ptrtoint; subtract it and the rest is the offset.
for (SCEVAddExpr::op_iterator J = AndLHSAddSCEV->op_begin(),
JE = AndLHSAddSCEV->op_end(); J != JE; ++J)
if (const SCEVUnknown *OpUnk = dyn_cast<SCEVUnknown>(*J))
if (PtrToIntInst *PToI = dyn_cast<PtrToIntInst>(OpUnk->getValue())) {
AAPtr = PToI->getPointerOperand();
OffSCEV = SE->getMinusSCEV(AndLHSAddSCEV, *J);
break;
}
}
if (!AAPtr)
return false;
// Sign extend the offset to 64 bits (so that it is like all of the other
// expressions).
unsigned OffSCEVBits = OffSCEV->getType()->getPrimitiveSizeInBits();
if (OffSCEVBits < 64)
OffSCEV = SE->getSignExtendExpr(OffSCEV, Int64Ty);
else if (OffSCEVBits > 64)
return false;
AAPtr = AAPtr->stripPointerCasts();
return true;
}
/// HandleFloatingPointIV - If the loop has floating induction variable
/// then insert corresponding integer induction variable if possible.
/// For example,
/// for(double i = 0; i < 10000; ++i)
/// bar(i)
/// is converted into
/// for(int i = 0; i < 10000; ++i)
/// bar((double)i);
///
void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PH) {
unsigned IncomingEdge = L->contains(PH->getIncomingBlock(0));
unsigned BackEdge = IncomingEdge^1;
// Check incoming value.
ConstantFP *InitValue = dyn_cast<ConstantFP>(PH->getIncomingValue(IncomingEdge));
if (!InitValue) return;
uint64_t newInitValue =
Type::getInt32Ty(PH->getContext())->getPrimitiveSizeInBits();
if (!convertToInt(InitValue->getValueAPF(), &newInitValue))
return;
// Check IV increment. Reject this PH if increment operation is not
// an add or increment value can not be represented by an integer.
BinaryOperator *Incr =
dyn_cast<BinaryOperator>(PH->getIncomingValue(BackEdge));
if (!Incr) return;
if (Incr->getOpcode() != Instruction::FAdd) return;
ConstantFP *IncrValue = NULL;
unsigned IncrVIndex = 1;
if (Incr->getOperand(1) == PH)
IncrVIndex = 0;
IncrValue = dyn_cast<ConstantFP>(Incr->getOperand(IncrVIndex));
if (!IncrValue) return;
uint64_t newIncrValue =
Type::getInt32Ty(PH->getContext())->getPrimitiveSizeInBits();
if (!convertToInt(IncrValue->getValueAPF(), &newIncrValue))
return;
// Check Incr uses. One user is PH and the other users is exit condition used
// by the conditional terminator.
Value::use_iterator IncrUse = Incr->use_begin();
Instruction *U1 = cast<Instruction>(IncrUse++);
if (IncrUse == Incr->use_end()) return;
Instruction *U2 = cast<Instruction>(IncrUse++);
if (IncrUse != Incr->use_end()) return;
// Find exit condition.
FCmpInst *EC = dyn_cast<FCmpInst>(U1);
if (!EC)
EC = dyn_cast<FCmpInst>(U2);
if (!EC) return;
if (BranchInst *BI = dyn_cast<BranchInst>(EC->getParent()->getTerminator())) {
if (!BI->isConditional()) return;
if (BI->getCondition() != EC) return;
}
// Find exit value. If exit value can not be represented as an integer then
// do not handle this floating point PH.
ConstantFP *EV = NULL;
unsigned EVIndex = 1;
if (EC->getOperand(1) == Incr)
EVIndex = 0;
EV = dyn_cast<ConstantFP>(EC->getOperand(EVIndex));
if (!EV) return;
uint64_t intEV = Type::getInt32Ty(PH->getContext())->getPrimitiveSizeInBits();
if (!convertToInt(EV->getValueAPF(), &intEV))
return;
// Find new predicate for integer comparison.
CmpInst::Predicate NewPred = CmpInst::BAD_ICMP_PREDICATE;
switch (EC->getPredicate()) {
case CmpInst::FCMP_OEQ:
case CmpInst::FCMP_UEQ:
NewPred = CmpInst::ICMP_EQ;
break;
case CmpInst::FCMP_OGT:
case CmpInst::FCMP_UGT:
NewPred = CmpInst::ICMP_UGT;
break;
case CmpInst::FCMP_OGE:
case CmpInst::FCMP_UGE:
NewPred = CmpInst::ICMP_UGE;
break;
case CmpInst::FCMP_OLT:
case CmpInst::FCMP_ULT:
NewPred = CmpInst::ICMP_ULT;
break;
case CmpInst::FCMP_OLE:
case CmpInst::FCMP_ULE:
NewPred = CmpInst::ICMP_ULE;
break;
default:
break;
}
if (NewPred == CmpInst::BAD_ICMP_PREDICATE) return;
// Insert new integer induction variable.
PHINode *NewPHI = PHINode::Create(Type::getInt32Ty(PH->getContext()),
PH->getName()+".int", PH);
NewPHI->addIncoming(ConstantInt::get(Type::getInt32Ty(PH->getContext()),
newInitValue),
PH->getIncomingBlock(IncomingEdge));
Value *NewAdd = BinaryOperator::CreateAdd(NewPHI,
ConstantInt::get(Type::getInt32Ty(PH->getContext()),
newIncrValue),
Incr->getName()+".int", Incr);
NewPHI->addIncoming(NewAdd, PH->getIncomingBlock(BackEdge));
// The back edge is edge 1 of newPHI, whatever it may have been in the
// original PHI.
ConstantInt *NewEV = ConstantInt::get(Type::getInt32Ty(PH->getContext()),
intEV);
Value *LHS = (EVIndex == 1 ? NewPHI->getIncomingValue(1) : NewEV);
Value *RHS = (EVIndex == 1 ? NewEV : NewPHI->getIncomingValue(1));
ICmpInst *NewEC = new ICmpInst(EC->getParent()->getTerminator(),
NewPred, LHS, RHS, EC->getName());
// In the following deletions, PH may become dead and may be deleted.
// Use a WeakVH to observe whether this happens.
WeakVH WeakPH = PH;
// Delete old, floating point, exit comparison instruction.
NewEC->takeName(EC);
EC->replaceAllUsesWith(NewEC);
RecursivelyDeleteTriviallyDeadInstructions(EC);
// Delete old, floating point, increment instruction.
Incr->replaceAllUsesWith(UndefValue::get(Incr->getType()));
RecursivelyDeleteTriviallyDeadInstructions(Incr);
// Replace floating induction variable, if it isn't already deleted.
// Give SIToFPInst preference over UIToFPInst because it is faster on
// platforms that are widely used.
if (WeakPH && !PH->use_empty()) {
if (useSIToFPInst(*InitValue, *EV, newInitValue, intEV)) {
SIToFPInst *Conv = new SIToFPInst(NewPHI, PH->getType(), "indvar.conv",
PH->getParent()->getFirstNonPHI());
PH->replaceAllUsesWith(Conv);
} else {
UIToFPInst *Conv = new UIToFPInst(NewPHI, PH->getType(), "indvar.conv",
PH->getParent()->getFirstNonPHI());
PH->replaceAllUsesWith(Conv);
}
RecursivelyDeleteTriviallyDeadInstructions(PH);
}
// Add a new IVUsers entry for the newly-created integer PHI.
IU->AddUsersIfInteresting(NewPHI);
}
Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator &I) {
bool isLeftShift = I.getOpcode() == Instruction::Shl;
// See if we can propagate this shift into the input, this covers the trivial
// cast of lshr(shl(x,c1),c2) as well as other more complex cases.
if (I.getOpcode() != Instruction::AShr &&
CanEvaluateShifted(Op0, Op1->getZExtValue(), isLeftShift, *this)) {
DEBUG(dbgs() << "ICE: GetShiftedValue propagating shift through expression"
" to eliminate shift:\n IN: " << *Op0 << "\n SH: " << I <<"\n");
return ReplaceInstUsesWith(I,
GetShiftedValue(Op0, Op1->getZExtValue(), isLeftShift, *this));
}
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
uint32_t TypeBits = Op0->getType()->getScalarSizeInBits();
// shl i32 X, 32 = 0 and srl i8 Y, 9 = 0, ... just don't eliminate
// a signed shift.
//
if (Op1->uge(TypeBits)) {
if (I.getOpcode() != Instruction::AShr)
return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType()));
// ashr i32 X, 32 --> ashr i32 X, 31
I.setOperand(1, ConstantInt::get(I.getType(), TypeBits-1));
return &I;
}
// ((X*C1) << C2) == (X * (C1 << C2))
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0))
if (BO->getOpcode() == Instruction::Mul && isLeftShift)
if (Constant *BOOp = dyn_cast<Constant>(BO->getOperand(1)))
return BinaryOperator::CreateMul(BO->getOperand(0),
ConstantExpr::getShl(BOOp, Op1));
// Try to fold constant and into select arguments.
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
if (Instruction *R = FoldOpIntoSelect(I, SI))
return R;
if (isa<PHINode>(Op0))
if (Instruction *NV = FoldOpIntoPhi(I))
return NV;
// Fold shift2(trunc(shift1(x,c1)), c2) -> trunc(shift2(shift1(x,c1),c2))
if (TruncInst *TI = dyn_cast<TruncInst>(Op0)) {
Instruction *TrOp = dyn_cast<Instruction>(TI->getOperand(0));
// If 'shift2' is an ashr, we would have to get the sign bit into a funny
// place. Don't try to do this transformation in this case. Also, we
// require that the input operand is a shift-by-constant so that we have
// confidence that the shifts will get folded together. We could do this
// xform in more cases, but it is unlikely to be profitable.
if (TrOp && I.isLogicalShift() && TrOp->isShift() &&
isa<ConstantInt>(TrOp->getOperand(1))) {
// Okay, we'll do this xform. Make the shift of shift.
Constant *ShAmt = ConstantExpr::getZExt(Op1, TrOp->getType());
// (shift2 (shift1 & 0x00FF), c2)
Value *NSh = Builder->CreateBinOp(I.getOpcode(), TrOp, ShAmt,I.getName());
// For logical shifts, the truncation has the effect of making the high
// part of the register be zeros. Emulate this by inserting an AND to
// clear the top bits as needed. This 'and' will usually be zapped by
// other xforms later if dead.
unsigned SrcSize = TrOp->getType()->getScalarSizeInBits();
unsigned DstSize = TI->getType()->getScalarSizeInBits();
APInt MaskV(APInt::getLowBitsSet(SrcSize, DstSize));
// The mask we constructed says what the trunc would do if occurring
// between the shifts. We want to know the effect *after* the second
// shift. We know that it is a logical shift by a constant, so adjust the
// mask as appropriate.
if (I.getOpcode() == Instruction::Shl)
MaskV <<= Op1->getZExtValue();
else {
assert(I.getOpcode() == Instruction::LShr && "Unknown logical shift");
MaskV = MaskV.lshr(Op1->getZExtValue());
}
// shift1 & 0x00FF
Value *And = Builder->CreateAnd(NSh,
ConstantInt::get(I.getContext(), MaskV),
TI->getName());
// Return the value truncated to the interesting size.
return new TruncInst(And, I.getType());
}
}
if (Op0->hasOneUse()) {
if (BinaryOperator *Op0BO = dyn_cast<BinaryOperator>(Op0)) {
// Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
Value *V1, *V2;
ConstantInt *CC;
switch (Op0BO->getOpcode()) {
default: break;
case Instruction::Add:
case Instruction::And:
case Instruction::Or:
case Instruction::Xor: {
// These operators commute.
// Turn (Y + (X >> C)) << C -> (X + (Y << C)) & (~0 << C)
if (isLeftShift && Op0BO->getOperand(1)->hasOneUse() &&
match(Op0BO->getOperand(1), m_Shr(m_Value(V1),
m_Specific(Op1)))) {
Value *YS = // (Y << C)
Builder->CreateShl(Op0BO->getOperand(0), Op1, Op0BO->getName());
// (X + (Y << C))
Value *X = Builder->CreateBinOp(Op0BO->getOpcode(), YS, V1,
Op0BO->getOperand(1)->getName());
uint32_t Op1Val = Op1->getLimitedValue(TypeBits);
return BinaryOperator::CreateAnd(X, ConstantInt::get(I.getContext(),
APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val)));
}
// Turn (Y + ((X >> C) & CC)) << C -> ((X & (CC << C)) + (Y << C))
Value *Op0BOOp1 = Op0BO->getOperand(1);
if (isLeftShift && Op0BOOp1->hasOneUse() &&
match(Op0BOOp1,
m_And(m_OneUse(m_Shr(m_Value(V1), m_Specific(Op1))),
m_ConstantInt(CC)))) {
Value *YS = // (Y << C)
Builder->CreateShl(Op0BO->getOperand(0), Op1,
Op0BO->getName());
// X & (CC << C)
Value *XM = Builder->CreateAnd(V1, ConstantExpr::getShl(CC, Op1),
V1->getName()+".mask");
return BinaryOperator::Create(Op0BO->getOpcode(), YS, XM);
}
}
// FALL THROUGH.
case Instruction::Sub: {
// Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
if (isLeftShift && Op0BO->getOperand(0)->hasOneUse() &&
match(Op0BO->getOperand(0), m_Shr(m_Value(V1),
m_Specific(Op1)))) {
Value *YS = // (Y << C)
Builder->CreateShl(Op0BO->getOperand(1), Op1, Op0BO->getName());
// (X + (Y << C))
Value *X = Builder->CreateBinOp(Op0BO->getOpcode(), V1, YS,
Op0BO->getOperand(0)->getName());
uint32_t Op1Val = Op1->getLimitedValue(TypeBits);
return BinaryOperator::CreateAnd(X, ConstantInt::get(I.getContext(),
APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val)));
}
// Turn (((X >> C)&CC) + Y) << C -> (X + (Y << C)) & (CC << C)
if (isLeftShift && Op0BO->getOperand(0)->hasOneUse() &&
match(Op0BO->getOperand(0),
m_And(m_OneUse(m_Shr(m_Value(V1), m_Value(V2))),
m_ConstantInt(CC))) && V2 == Op1) {
Value *YS = // (Y << C)
Builder->CreateShl(Op0BO->getOperand(1), Op1, Op0BO->getName());
// X & (CC << C)
Value *XM = Builder->CreateAnd(V1, ConstantExpr::getShl(CC, Op1),
V1->getName()+".mask");
return BinaryOperator::Create(Op0BO->getOpcode(), XM, YS);
}
break;
}
}
// If the operand is an bitwise operator with a constant RHS, and the
// shift is the only use, we can pull it out of the shift.
if (ConstantInt *Op0C = dyn_cast<ConstantInt>(Op0BO->getOperand(1))) {
bool isValid = true; // Valid only for And, Or, Xor
bool highBitSet = false; // Transform if high bit of constant set?
switch (Op0BO->getOpcode()) {
default: isValid = false; break; // Do not perform transform!
case Instruction::Add:
isValid = isLeftShift;
break;
case Instruction::Or:
case Instruction::Xor:
highBitSet = false;
break;
case Instruction::And:
highBitSet = true;
break;
}
// If this is a signed shift right, and the high bit is modified
// by the logical operation, do not perform the transformation.
// The highBitSet boolean indicates the value of the high bit of
// the constant which would cause it to be modified for this
// operation.
//
if (isValid && I.getOpcode() == Instruction::AShr)
isValid = Op0C->getValue()[TypeBits-1] == highBitSet;
if (isValid) {
Constant *NewRHS = ConstantExpr::get(I.getOpcode(), Op0C, Op1);
Value *NewShift =
Builder->CreateBinOp(I.getOpcode(), Op0BO->getOperand(0), Op1);
NewShift->takeName(Op0BO);
return BinaryOperator::Create(Op0BO->getOpcode(), NewShift,
NewRHS);
}
}
}
}
// Find out if this is a shift of a shift by a constant.
BinaryOperator *ShiftOp = dyn_cast<BinaryOperator>(Op0);
if (ShiftOp && !ShiftOp->isShift())
ShiftOp = 0;
if (ShiftOp && isa<ConstantInt>(ShiftOp->getOperand(1))) {
// This is a constant shift of a constant shift. Be careful about hiding
// shl instructions behind bit masks. They are used to represent multiplies
// by a constant, and it is important that simple arithmetic expressions
// are still recognizable by scalar evolution.
//
// The transforms applied to shl are very similar to the transforms applied
// to mul by constant. We can be more aggressive about optimizing right
// shifts.
//
// Combinations of right and left shifts will still be optimized in
// DAGCombine where scalar evolution no longer applies.
ConstantInt *ShiftAmt1C = cast<ConstantInt>(ShiftOp->getOperand(1));
uint32_t ShiftAmt1 = ShiftAmt1C->getLimitedValue(TypeBits);
uint32_t ShiftAmt2 = Op1->getLimitedValue(TypeBits);
assert(ShiftAmt2 != 0 && "Should have been simplified earlier");
if (ShiftAmt1 == 0) return 0; // Will be simplified in the future.
Value *X = ShiftOp->getOperand(0);
IntegerType *Ty = cast<IntegerType>(I.getType());
// Check for (X << c1) << c2 and (X >> c1) >> c2
if (I.getOpcode() == ShiftOp->getOpcode()) {
uint32_t AmtSum = ShiftAmt1+ShiftAmt2; // Fold into one big shift.
// If this is oversized composite shift, then unsigned shifts get 0, ashr
// saturates.
if (AmtSum >= TypeBits) {
if (I.getOpcode() != Instruction::AShr)
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
AmtSum = TypeBits-1; // Saturate to 31 for i32 ashr.
}
return BinaryOperator::Create(I.getOpcode(), X,
ConstantInt::get(Ty, AmtSum));
}
if (ShiftAmt1 == ShiftAmt2) {
// If we have ((X << C) >>u C), turn this into X & (-1 >>u C).
if (I.getOpcode() == Instruction::LShr &&
ShiftOp->getOpcode() == Instruction::Shl) {
APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt1));
return BinaryOperator::CreateAnd(X,
ConstantInt::get(I.getContext(), Mask));
}
} else if (ShiftAmt1 < ShiftAmt2) {
uint32_t ShiftDiff = ShiftAmt2-ShiftAmt1;
// (X >>?,exact C1) << C2 --> X << (C2-C1)
// The inexact version is deferred to DAGCombine so we don't hide shl
// behind a bit mask.
if (I.getOpcode() == Instruction::Shl &&
ShiftOp->getOpcode() != Instruction::Shl &&
ShiftOp->isExact()) {
assert(ShiftOp->getOpcode() == Instruction::LShr ||
ShiftOp->getOpcode() == Instruction::AShr);
ConstantInt *ShiftDiffCst = ConstantInt::get(Ty, ShiftDiff);
BinaryOperator *NewShl = BinaryOperator::Create(Instruction::Shl,
X, ShiftDiffCst);
NewShl->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
NewShl->setHasNoSignedWrap(I.hasNoSignedWrap());
return NewShl;
}
// (X << C1) >>u C2 --> X >>u (C2-C1) & (-1 >> C2)
if (I.getOpcode() == Instruction::LShr &&
ShiftOp->getOpcode() == Instruction::Shl) {
ConstantInt *ShiftDiffCst = ConstantInt::get(Ty, ShiftDiff);
// (X <<nuw C1) >>u C2 --> X >>u (C2-C1)
if (ShiftOp->hasNoUnsignedWrap()) {
BinaryOperator *NewLShr = BinaryOperator::Create(Instruction::LShr,
X, ShiftDiffCst);
NewLShr->setIsExact(I.isExact());
return NewLShr;
}
Value *Shift = Builder->CreateLShr(X, ShiftDiffCst);
APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt2));
return BinaryOperator::CreateAnd(Shift,
ConstantInt::get(I.getContext(),Mask));
}
// We can't handle (X << C1) >>s C2, it shifts arbitrary bits in. However,
// we can handle (X <<nsw C1) >>s C2 since it only shifts in sign bits.
if (I.getOpcode() == Instruction::AShr &&
ShiftOp->getOpcode() == Instruction::Shl) {
if (ShiftOp->hasNoSignedWrap()) {
// (X <<nsw C1) >>s C2 --> X >>s (C2-C1)
ConstantInt *ShiftDiffCst = ConstantInt::get(Ty, ShiftDiff);
BinaryOperator *NewAShr = BinaryOperator::Create(Instruction::AShr,
X, ShiftDiffCst);
NewAShr->setIsExact(I.isExact());
return NewAShr;
}
}
} else {
assert(ShiftAmt2 < ShiftAmt1);
uint32_t ShiftDiff = ShiftAmt1-ShiftAmt2;
// (X >>?exact C1) << C2 --> X >>?exact (C1-C2)
// The inexact version is deferred to DAGCombine so we don't hide shl
// behind a bit mask.
if (I.getOpcode() == Instruction::Shl &&
ShiftOp->getOpcode() != Instruction::Shl &&
ShiftOp->isExact()) {
ConstantInt *ShiftDiffCst = ConstantInt::get(Ty, ShiftDiff);
BinaryOperator *NewShr = BinaryOperator::Create(ShiftOp->getOpcode(),
X, ShiftDiffCst);
NewShr->setIsExact(true);
return NewShr;
}
// (X << C1) >>u C2 --> X << (C1-C2) & (-1 >> C2)
if (I.getOpcode() == Instruction::LShr &&
ShiftOp->getOpcode() == Instruction::Shl) {
ConstantInt *ShiftDiffCst = ConstantInt::get(Ty, ShiftDiff);
if (ShiftOp->hasNoUnsignedWrap()) {
// (X <<nuw C1) >>u C2 --> X <<nuw (C1-C2)
BinaryOperator *NewShl = BinaryOperator::Create(Instruction::Shl,
X, ShiftDiffCst);
NewShl->setHasNoUnsignedWrap(true);
return NewShl;
}
Value *Shift = Builder->CreateShl(X, ShiftDiffCst);
APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt2));
return BinaryOperator::CreateAnd(Shift,
ConstantInt::get(I.getContext(),Mask));
}
// We can't handle (X << C1) >>s C2, it shifts arbitrary bits in. However,
// we can handle (X <<nsw C1) >>s C2 since it only shifts in sign bits.
if (I.getOpcode() == Instruction::AShr &&
ShiftOp->getOpcode() == Instruction::Shl) {
if (ShiftOp->hasNoSignedWrap()) {
// (X <<nsw C1) >>s C2 --> X <<nsw (C1-C2)
ConstantInt *ShiftDiffCst = ConstantInt::get(Ty, ShiftDiff);
BinaryOperator *NewShl = BinaryOperator::Create(Instruction::Shl,
X, ShiftDiffCst);
NewShl->setHasNoSignedWrap(true);
return NewShl;
}
}
}
}
return 0;
}
bool RippleElimination::runOnFunction(Function &F) {
std::vector<Instruction*> **RippleLists;
unsigned ListID = 0;
unsigned NumofLists = 0;
RippleLists = new std::vector<Instruction*>*;
RippleLists[ListID] = new std::vector<Instruction*>;
RippleLists[ListID]->clear();
//errs() << "RippleLists[0] size:" << RippleLists[0]->size() << "\n";
for (Function::iterator BB = F.begin(), BE = F.end(); BB != BE; ++BB) {
BasicBlock *BC = dyn_cast<BasicBlock>(BB); //==> how to get an identifier of a BB?
for (BasicBlock::iterator IB = BB->begin(), IE = BB->end(); IB != IE; ++IB) {
// The dyn_cast<> operator is a "checking cast" operation. It checks to
// see if the operand is of the specified type, and if so, returns a
// pointer to it (this operator does not work with references). If the
// operand is not of the correct type, a null pointer is returned.
Instruction *IT = dyn_cast<Instruction>(IB);
Instruction *BackIT;
ICmpInst * cmpinst = dyn_cast<ICmpInst>(IT);
if(cmpinst!=NULL) { // If not a NULL pointer
errs()<< "!!!! In CMP Oh yeah!!!!"<<"\n";
switch(cmpinst->getPredicate()){
case ICmpInst::ICMP_SLE:
{
errs()<<"QQQQ SLE\n";
}
break;
case ICmpInst::ICMP_SLT:
{
Value *op0 = IT->getOperand(0);
Instruction * op0_inst = dyn_cast<Instruction> (op0);
Value *op0_op1 = op0_inst->getOperand(1);
ConstantInt *op0_op1_const = dyn_cast<ConstantInt>(op0_op1);
APInt b = op0_op1_const->getValue();
ConstantInt *op1 = dyn_cast<ConstantInt>(IT->getOperand(1));
APInt a = op1->getValue();
errs() << "CMP Value0 ::" << b.getLimitedValue() << "\n";
errs() << "CMP Value1 ::" << a.getLimitedValue() << "\n";
int aa = a.getLimitedValue();
int bb = b.getLimitedValue();
// errs()<<a.getBitWidth()<<"\n";
errs()<<"The flag adder should be "<<(int)ceil(log(aa)/log(2))<<" bit adder\n";
errs()<<"QQQQ SLT\n";
}
break;
default:
break;
}
}
// Get Binary Operator Instruction::Add
if(dyn_cast<BinaryOperator>(IT)) { // If not a NULL pointer
BinaryOperator* Inst = dyn_cast<BinaryOperator>(IT);
// errs()<<"Zhuangh put: "<<Inst->getOpcode()<<"\n";
if (Inst->getOpcode() == Instruction::Add) {
Value *Op0 = IT->getOperand(0);
Value *Op1 = IT->getOperand(1);
//errs() << "Add Value0 ::" << *Op0 << "\n";
//errs() << "Add Value1 ::" << *Op1 << "\n";
if(RippleLists[0]->empty()) {
RippleLists[0]->push_back(IT);
}
else {
BackIT = dyn_cast<Instruction>(RippleLists[0]->back());
//errs() << "BackIT :" << *BackIT << "\n";
if(BackIT->getName().equals(Op0->getName()) || BackIT->getName().equals(Op1->getName())) {
RippleLists[0]->push_back(IT);
}
}
}
}
} // End Instruction iterator
if(RippleLists[0]->size() < 2) RippleLists[0]->clear(); // No ripple detected
for(std::vector<Instruction*>::iterator RplIT = RippleLists[0]->begin(); RplIT != RippleLists[0]->end(); ++RplIT){
Instruction *Inst = dyn_cast<Instruction>(*RplIT);
errs() << "Ripple Operations:" << *Inst << "\n";
//errs() << "Name:" << Inst->getName().str() << " ";
//errs() << "Op0:" << Inst->getOperand(0)->getName().str() << " ";
//errs() << "Op1:" << Inst->getOperand(1)->getName().str() << "\n";
//It->eraseFromParent();
}
//errs() << "RippleLists[0] size:" << RippleLists[0]->size() << "\n";
errs() << "\n";
RippleLists[0]->clear();
} // End basic block iterator
return true;
}