//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "instsimplify"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/Operator.h"
-#include "llvm/Support/ConstantRange.h"
-#include "llvm/Support/GetElementPtrTypeIterator.h"
-#include "llvm/Support/PatternMatch.h"
-#include "llvm/Support/ValueHandle.h"
+#include "llvm/IR/PatternMatch.h"
+#include "llvm/IR/ValueHandle.h"
using namespace llvm;
using namespace llvm::PatternMatch;
+#define DEBUG_TYPE "instsimplify"
+
enum { RecursionLimit = 3 };
STATISTIC(NumExpand, "Number of expansions");
Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand;
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
// Check whether the expression has the form "(A op' B) op C".
if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS))
}
}
- return 0;
+ return nullptr;
}
/// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term
Instruction::BinaryOps OpcodeToExtract = (Instruction::BinaryOps)OpcToExtract;
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
if (!Op0 || Op0->getOpcode() != OpcodeToExtract ||
!Op1 || Op1->getOpcode() != OpcodeToExtract)
- return 0;
+ return nullptr;
// The expression has the form "(A op' B) op (C op' D)".
Value *A = Op0->getOperand(0), *B = Op0->getOperand(1);
}
}
- return 0;
+ return nullptr;
}
/// SimplifyAssociativeBinOp - Generic simplifications for associative binary
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
// The remaining transforms require commutativity as well as associativity.
if (!Instruction::isCommutative(Opcode))
- return 0;
+ return nullptr;
// Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely.
if (Op0 && Op0->getOpcode() == Opcode) {
}
}
- return 0;
+ return nullptr;
}
/// ThreadBinOpOverSelect - In the case of a binary operation with a select
const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
SelectInst *SI;
if (isa<SelectInst>(LHS)) {
}
}
- return 0;
+ return nullptr;
}
/// ThreadCmpOverSelect - In the case of a comparison with a select instruction,
unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
// Make sure the select is on the LHS.
if (!isa<SelectInst>(LHS)) {
// It didn't simplify. However if "cmp TV, RHS" is equal to the select
// condition then we can replace it with 'true'. Otherwise give up.
if (!isSameCompare(Cond, Pred, TV, RHS))
- return 0;
+ return nullptr;
TCmp = getTrue(Cond->getType());
}
// It didn't simplify. However if "cmp FV, RHS" is equal to the select
// condition then we can replace it with 'false'. Otherwise give up.
if (!isSameCompare(Cond, Pred, FV, RHS))
- return 0;
+ return nullptr;
FCmp = getFalse(Cond->getType());
}
// The remaining cases only make sense if the select condition has the same
// type as the result of the comparison, so bail out if this is not so.
if (Cond->getType()->isVectorTy() != RHS->getType()->isVectorTy())
- return 0;
+ return nullptr;
// If the false value simplified to false, then the result of the compare
// is equal to "Cond && TCmp". This also catches the case when the false
// value simplified to false and the true value to true, returning "Cond".
Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
/// ThreadBinOpOverPHI - In the case of a binary operation with an operand that
const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
PHINode *PI;
if (isa<PHINode>(LHS)) {
PI = cast<PHINode>(LHS);
// Bail out if RHS and the phi may be mutually interdependent due to a loop.
if (!ValueDominatesPHI(RHS, PI, Q.DT))
- return 0;
+ return nullptr;
} else {
assert(isa<PHINode>(RHS) && "No PHI instruction operand!");
PI = cast<PHINode>(RHS);
// Bail out if LHS and the phi may be mutually interdependent due to a loop.
if (!ValueDominatesPHI(LHS, PI, Q.DT))
- return 0;
+ return nullptr;
}
// Evaluate the BinOp on the incoming phi values.
- Value *CommonValue = 0;
+ Value *CommonValue = nullptr;
for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PI->getIncomingValue(i);
// If the incoming value is the phi node itself, it can safely be skipped.
// If the operation failed to simplify, or simplified to a different value
// to previously, then give up.
if (!V || (CommonValue && V != CommonValue))
- return 0;
+ return nullptr;
CommonValue = V;
}
const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
- return 0;
+ return nullptr;
// Make sure the phi is on the LHS.
if (!isa<PHINode>(LHS)) {
// Bail out if RHS and the phi may be mutually interdependent due to a loop.
if (!ValueDominatesPHI(RHS, PI, Q.DT))
- return 0;
+ return nullptr;
// Evaluate the BinOp on the incoming phi values.
- Value *CommonValue = 0;
+ Value *CommonValue = nullptr;
for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PI->getIncomingValue(i);
// If the incoming value is the phi node itself, it can safely be skipped.
// If the operation failed to simplify, or simplified to a different value
// to previously, then give up.
if (!V || (CommonValue && V != CommonValue))
- return 0;
+ return nullptr;
CommonValue = V;
}
// X + (Y - X) -> Y
// (Y - X) + X -> Y
// Eg: X + -X -> 0
- Value *Y = 0;
+ Value *Y = nullptr;
if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) ||
match(Op0, m_Sub(m_Value(Y), m_Specific(Op1))))
return Y;
// "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
// for threading over phi nodes.
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
// If LHS and RHS are not related via constant offsets to the same base
// value, there is nothing we can do here.
if (LHS != RHS)
- return 0;
+ return nullptr;
// Otherwise, the difference of LHS - RHS can be computed as:
// LHS - RHS
// (X*2) - X -> X
// (X<<1) - X -> X
- Value *X = 0;
+ Value *X = nullptr;
if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) ||
match(Op0, m_Shl(m_Specific(Op1), m_One())))
return Op1;
// (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
// For example, (X + Y) - Y -> X; (Y + X) - Y -> X
- Value *Y = 0, *Z = Op1;
+ Value *Y = nullptr, *Z = Op1;
if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
// See if "V === Y - Z" simplifies.
if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1))
// "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
// for threading over phi nodes.
- return 0;
+ return nullptr;
}
Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
// fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
// where nnan and ninf have to occur at least once somewhere in this
// expression
- Value *SubOp = 0;
+ Value *SubOp = nullptr;
if (match(Op1, m_FSub(m_AnyZero(), m_Specific(Op0))))
SubOp = Op1;
else if (match(Op0, m_FSub(m_AnyZero(), m_Specific(Op1))))
return Constant::getNullValue(Op0->getType());
}
- return 0;
+ return nullptr;
}
/// Given operands for an FSub, see if we can fold the result. If not, this
if (FMF.noNaNs() && FMF.noInfs() && Op0 == Op1)
return Constant::getNullValue(Op0->getType());
- return 0;
+ return nullptr;
}
/// Given the operands for an FMul, see if we can fold the result
if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZero()))
return Op1;
- return 0;
+ return nullptr;
}
/// SimplifyMulInst - Given operands for a Mul, see if we can
return Op0;
// (X / Y) * Y -> X if the division is exact.
- Value *X = 0;
+ Value *X = nullptr;
if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y
match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y)
return X;
MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
return ConstantInt::get(Op0->getType(), 1);
// (X * Y) / Y -> X if the multiplication does not overflow.
- Value *X = 0, *Y = 0;
+ Value *X = nullptr, *Y = nullptr;
if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0);
if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
/// SimplifySDivInst - Given operands for an SDiv, see if we can
if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const DataLayout *DL,
if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const DataLayout *DL,
if (match(Op1, m_Undef()))
return Op1;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const DataLayout *DL,
if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
/// SimplifySRemInst - Given operands for an SRem, see if we can
if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const DataLayout *DL,
if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const DataLayout *DL,
if (match(Op1, m_Undef()))
return Op1;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const DataLayout *DL,
if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
/// SimplifyShlInst - Given operands for an Shl, see if we can
Value *X;
if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1)))))
return X;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap())
return X;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap())
return X;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
return Constant::getNullValue(Op0->getType());
// (A | ?) & A = A
- Value *A = 0, *B = 0;
+ Value *A = nullptr, *B = nullptr;
if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const DataLayout *DL,
return Constant::getAllOnesValue(Op0->getType());
// (A & ?) | A = A
- Value *A = 0, *B = 0;
+ Value *A = nullptr, *B = nullptr;
if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const DataLayout *DL,
// "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
// for threading over phi nodes.
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const DataLayout *DL,
Value *LHS, Value *RHS) {
SelectInst *SI = dyn_cast<SelectInst>(V);
if (!SI)
- return 0;
+ return nullptr;
CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
if (!Cmp)
- return 0;
+ return nullptr;
Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1);
if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS)
return Cmp;
if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) &&
LHS == CmpRHS && RHS == CmpLHS)
return Cmp;
- return 0;
+ return nullptr;
}
// A significant optimization not implemented here is assuming that alloca
// We can only fold certain predicates on pointer comparisons.
switch (Pred) {
default:
- return 0;
+ return nullptr;
// Equality comaprisons are easy to fold.
case CmpInst::ICMP_EQ:
}
// Otherwise, fail.
- return 0;
+ return nullptr;
}
/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
if (MaxRecurse && (LBO || RBO)) {
// Analyze the case when either LHS or RHS is an add instruction.
- Value *A = 0, *B = 0, *C = 0, *D = 0;
+ Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr;
// LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
if (LBO && LBO->getOpcode() == Instruction::Add) {
if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
return TrueVal;
- return 0;
+ return nullptr;
}
Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
// Check to see if this is constant foldable.
for (unsigned i = 0, e = Ops.size(); i != e; ++i)
if (!isa<Constant>(Ops[i]))
- return 0;
+ return nullptr;
return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), Ops.slice(1));
}
return Agg;
}
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val,
static Value *SimplifyPHINode(PHINode *PN, const Query &Q) {
// If all of the PHI's incoming values are the same then replace the PHI node
// with the common value.
- Value *CommonValue = 0;
+ Value *CommonValue = nullptr;
bool HasUndefInput = false;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PN->getIncomingValue(i);
continue;
}
if (CommonValue && Incoming != CommonValue)
- return 0; // Not the same, bail out.
+ return nullptr; // Not the same, bail out.
CommonValue = Incoming;
}
// instruction, we cannot return X as the result of the PHI node unless it
// dominates the PHI block.
if (HasUndefInput)
- return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : 0;
+ return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : nullptr;
return CommonValue;
}
if (Constant *C = dyn_cast<Constant>(Op))
return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.DL, Q.TLI);
- return 0;
+ return nullptr;
}
Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *DL,
if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
return V;
- return 0;
+ return nullptr;
}
}
const Query &Q, unsigned MaxRecurse) {
// Perform idempotent optimizations
if (!IsIdempotent(IID))
- return 0;
+ return nullptr;
// Unary Ops
if (std::distance(ArgBegin, ArgEnd) == 1)
if (II->getIntrinsicID() == IID)
return II;
- return 0;
+ return nullptr;
}
template <typename IterTy>
Function *F = dyn_cast<Function>(V);
if (!F)
- return 0;
+ return nullptr;
if (unsigned IID = F->getIntrinsicID())
if (Value *Ret =
return Ret;
if (!canConstantFoldCallTo(F))
- return 0;
+ return nullptr;
SmallVector<Constant *, 4> ConstantArgs;
ConstantArgs.reserve(ArgEnd - ArgBegin);
for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) {
Constant *C = dyn_cast<Constant>(*I);
if (!C)
- return 0;
+ return nullptr;
ConstantArgs.push_back(C);
}
// If we have an explicit value to collapse to, do that round of the
// simplification loop by hand initially.
if (SimpleV) {
- for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
- ++UI)
- if (*UI != I)
- Worklist.insert(cast<Instruction>(*UI));
+ for (User *U : I->users())
+ if (U != I)
+ Worklist.insert(cast<Instruction>(U));
// Replace the instruction with its simplified value.
I->replaceAllUsesWith(SimpleV);
// Stash away all the uses of the old instruction so we can check them for
// recursive simplifications after a RAUW. This is cheaper than checking all
// uses of To on the recursive step in most cases.
- for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
- ++UI)
- Worklist.insert(cast<Instruction>(*UI));
+ for (User *U : I->users())
+ Worklist.insert(cast<Instruction>(U));
// Replace the instruction with its simplified value.
I->replaceAllUsesWith(SimpleV);
const DataLayout *DL,
const TargetLibraryInfo *TLI,
const DominatorTree *DT) {
- return replaceAndRecursivelySimplifyImpl(I, 0, DL, TLI, DT);
+ return replaceAndRecursivelySimplifyImpl(I, nullptr, DL, TLI, DT);
}
bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,