#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Analysis/VectorUtils.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
static Value *SimplifyXorInst(Value *, Value *, const Query &, unsigned);
static Value *SimplifyTruncInst(Value *, Type *, const Query &, unsigned);
-/// getFalse - For a boolean type, or a vector of boolean type, return false, or
+/// For a boolean type, or a vector of boolean type, return false, or
/// a vector with every element false, as appropriate for the type.
static Constant *getFalse(Type *Ty) {
assert(Ty->getScalarType()->isIntegerTy(1) &&
return Constant::getNullValue(Ty);
}
-/// getTrue - For a boolean type, or a vector of boolean type, return true, or
+/// For a boolean type, or a vector of boolean type, return true, or
/// a vector with every element true, as appropriate for the type.
static Constant *getTrue(Type *Ty) {
assert(Ty->getScalarType()->isIntegerTy(1) &&
CRHS == LHS;
}
-/// ValueDominatesPHI - Does the given value dominate the specified phi node?
+/// Does the given value dominate the specified phi node?
static bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) {
Instruction *I = dyn_cast<Instruction>(V);
if (!I)
return DT->dominates(I, P);
}
- // Otherwise, if the instruction is in the entry block, and is not an invoke,
+ // Otherwise, if the instruction is in the entry block and is not an invoke,
// then it obviously dominates all phi nodes.
if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() &&
!isa<InvokeInst>(I))
return false;
}
-/// ExpandBinOp - Simplify "A op (B op' C)" by distributing op over op', turning
-/// it into "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is
+/// Simplify "A op (B op' C)" by distributing op over op', turning it into
+/// "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is
/// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS.
/// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)".
/// Returns the simplified value, or null if no simplification was performed.
return nullptr;
}
-/// SimplifyAssociativeBinOp - Generic simplifications for associative binary
-/// operations. Returns the simpler value, or null if none was found.
+/// Generic simplifications for associative binary operations.
+/// Returns the simpler value, or null if none was found.
static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS,
const Query &Q, unsigned MaxRecurse) {
Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc;
return nullptr;
}
-/// ThreadBinOpOverSelect - In the case of a binary operation with a select
-/// instruction as an operand, try to simplify the binop by seeing whether
-/// evaluating it on both branches of the select results in the same value.
-/// Returns the common value if so, otherwise returns null.
+/// In the case of a binary operation with a select instruction as an operand,
+/// try to simplify the binop by seeing whether evaluating it on both branches
+/// of the select results in the same value. Returns the common value if so,
+/// otherwise returns null.
static Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS,
const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
return nullptr;
}
-/// ThreadCmpOverSelect - In the case of a comparison with a select instruction,
-/// try to simplify the comparison by seeing whether both branches of the select
-/// result in the same value. Returns the common value if so, otherwise returns
-/// null.
+/// In the case of a comparison with a select instruction, try to simplify the
+/// comparison by seeing whether both branches of the select result in the same
+/// value. Returns the common value if so, otherwise returns null.
static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS,
Value *RHS, const Query &Q,
unsigned MaxRecurse) {
return nullptr;
}
-/// ThreadBinOpOverPHI - In the case of a binary operation with an operand that
-/// is a PHI instruction, try to simplify the binop by seeing whether evaluating
-/// it on the incoming phi values yields the same result for every value. If so
-/// returns the common value, otherwise returns null.
+/// In the case of a binary operation with an operand that is a PHI instruction,
+/// try to simplify the binop by seeing whether evaluating it on the incoming
+/// phi values yields the same result for every value. If so returns the common
+/// value, otherwise returns null.
static Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS,
const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
return CommonValue;
}
-/// ThreadCmpOverPHI - In the case of a comparison with a PHI instruction, try
-/// try to simplify the comparison by seeing whether comparing with all of the
-/// incoming phi values yields the same result every time. If so returns the
-/// common result, otherwise returns null.
+/// In the case of a comparison with a PHI instruction, try to simplify the
+/// comparison by seeing whether comparing with all of the incoming phi values
+/// yields the same result every time. If so returns the common result,
+/// otherwise returns null.
static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS,
const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
return CommonValue;
}
-/// SimplifyAddInst - Given operands for an Add, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an Add, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
const Query &Q, unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
return ConstantExpr::getSub(LHSOffset, RHSOffset);
}
-/// SimplifySubInst - Given operands for a Sub, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for a Sub, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
const Query &Q, unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0))
return X;
}
- // fsub nnan ninf x, x ==> 0.0
- if (FMF.noNaNs() && FMF.noInfs() && Op0 == Op1)
+ // fsub nnan x, x ==> 0.0
+ if (FMF.noNaNs() && Op0 == Op1)
return Constant::getNullValue(Op0->getType());
return nullptr;
return nullptr;
}
-/// SimplifyMulInst - Given operands for a Mul, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for a Mul, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
RecursionLimit);
}
-/// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an SDiv or UDiv, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
const Query &Q, unsigned MaxRecurse) {
if (Constant *C0 = dyn_cast<Constant>(Op0)) {
return nullptr;
}
-/// SimplifySDivInst - Given operands for an SDiv, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an SDiv, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse))
RecursionLimit);
}
-/// SimplifyUDivInst - Given operands for a UDiv, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for a UDiv, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse))
if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero()))
return Op0;
+ if (FMF.noNaNs()) {
+ // X / X -> 1.0 is legal when NaNs are ignored.
+ if (Op0 == Op1)
+ return ConstantFP::get(Op0->getType(), 1.0);
+
+ // -X / X -> -1.0 and
+ // X / -X -> -1.0 are legal when NaNs are ignored.
+ // We can ignore signed zeros because +-0.0/+-0.0 is NaN and ignored.
+ if ((BinaryOperator::isFNeg(Op0, /*IgnoreZeroSign=*/true) &&
+ BinaryOperator::getFNegArgument(Op0) == Op1) ||
+ (BinaryOperator::isFNeg(Op1, /*IgnoreZeroSign=*/true) &&
+ BinaryOperator::getFNegArgument(Op1) == Op0))
+ return ConstantFP::get(Op0->getType(), -1.0);
+ }
+
return nullptr;
}
RecursionLimit);
}
-/// SimplifyRem - Given operands for an SRem or URem, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an SRem or URem, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
const Query &Q, unsigned MaxRecurse) {
if (Constant *C0 = dyn_cast<Constant>(Op0)) {
return nullptr;
}
-/// SimplifySRemInst - Given operands for an SRem, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an SRem, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse))
RecursionLimit);
}
-/// SimplifyURemInst - Given operands for a URem, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for a URem, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse))
RecursionLimit);
}
-/// isUndefShift - Returns true if a shift by \c Amount always yields undef.
+/// Returns true if a shift by \c Amount always yields undef.
static bool isUndefShift(Value *Amount) {
Constant *C = dyn_cast<Constant>(Amount);
if (!C)
return false;
}
-/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an Shl, LShr or AShr, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
const Query &Q, unsigned MaxRecurse) {
if (Constant *C0 = dyn_cast<Constant>(Op0)) {
return nullptr;
}
-/// SimplifyShlInst - Given operands for an Shl, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an Shl, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
const Query &Q, unsigned MaxRecurse) {
if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse))
RecursionLimit);
}
-/// SimplifyLShrInst - Given operands for an LShr, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an LShr, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
const Query &Q, unsigned MaxRecurse) {
if (Value *V = SimplifyRightShift(Instruction::LShr, Op0, Op1, isExact, Q,
RecursionLimit);
}
-/// SimplifyAShrInst - Given operands for an AShr, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an AShr, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
const Query &Q, unsigned MaxRecurse) {
if (Value *V = SimplifyRightShift(Instruction::AShr, Op0, Op1, isExact, Q,
return nullptr;
}
-// Simplify (and (icmp ...) (icmp ...)) to true when we can tell that the range
-// of possible values cannot be satisfied.
+/// Simplify (and (icmp ...) (icmp ...)) to true when we can tell that the range
+/// of possible values cannot be satisfied.
static Value *SimplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
ICmpInst::Predicate Pred0, Pred1;
ConstantInt *CI1, *CI2;
return nullptr;
}
-/// SimplifyAndInst - Given operands for an And, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an And, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
RecursionLimit);
}
-// Simplify (or (icmp ...) (icmp ...)) to true when we can tell that the union
-// contains all possible values.
+/// Simplify (or (icmp ...) (icmp ...)) to true when we can tell that the union
+/// contains all possible values.
static Value *SimplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
ICmpInst::Predicate Pred0, Pred1;
ConstantInt *CI1, *CI2;
return nullptr;
}
-/// SimplifyOrInst - Given operands for an Or, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an Or, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
RecursionLimit);
}
-/// SimplifyXorInst - Given operands for a Xor, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for a Xor, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q,
unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
return CmpInst::makeCmpResultType(Op->getType());
}
-/// ExtractEquivalentCondition - Rummage around inside V looking for something
-/// equivalent to the comparison "LHS Pred RHS". Return such a value if found,
-/// otherwise return null. Helper function for analyzing max/min idioms.
+/// Rummage around inside V looking for something equivalent to the comparison
+/// "LHS Pred RHS". Return such a value if found, otherwise return null.
+/// Helper function for analyzing max/min idioms.
static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred,
Value *LHS, Value *RHS) {
SelectInst *SI = dyn_cast<SelectInst>(V);
// Is the set of underlying objects all noalias calls?
auto IsNAC = [](SmallVectorImpl<Value *> &Objects) {
- return std::all_of(Objects.begin(), Objects.end(),
- [](Value *V){ return isNoAliasCall(V); });
+ return std::all_of(Objects.begin(), Objects.end(), isNoAliasCall);
};
// Is the set of underlying objects all things which must be disjoint from
// that might be resolve lazily to symbols in another dynamically-loaded
// library (and, thus, could be malloc'ed by the implementation).
auto IsAllocDisjoint = [](SmallVectorImpl<Value *> &Objects) {
- return std::all_of(Objects.begin(), Objects.end(),
- [](Value *V){
- if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
- return AI->getParent() && AI->getParent()->getParent() &&
- AI->isStaticAlloca();
- if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
- return (GV->hasLocalLinkage() ||
- GV->hasHiddenVisibility() ||
- GV->hasProtectedVisibility() ||
- GV->hasUnnamedAddr()) &&
- !GV->isThreadLocal();
- if (const Argument *A = dyn_cast<Argument>(V))
- return A->hasByValAttr();
- return false;
- });
+ return std::all_of(Objects.begin(), Objects.end(), [](Value *V) {
+ if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
+ return AI->getParent() && AI->getFunction() && AI->isStaticAlloca();
+ if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
+ return (GV->hasLocalLinkage() || GV->hasHiddenVisibility() ||
+ GV->hasProtectedVisibility() || GV->hasUnnamedAddr()) &&
+ !GV->isThreadLocal();
+ if (const Argument *A = dyn_cast<Argument>(V))
+ return A->hasByValAttr();
+ return false;
+ });
};
if ((IsNAC(LHSUObjs) && IsAllocDisjoint(RHSUObjs)) ||
return nullptr;
}
-/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an ICmpInst, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const Query &Q, unsigned MaxRecurse) {
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
// X >=u 1 -> X
if (match(RHS, m_One()))
return LHS;
+ if (isImpliedCondition(RHS, LHS, Q.DL))
+ return getTrue(ITy);
+ break;
+ case ICmpInst::ICMP_SGE:
+ /// For signed comparison, the values for an i1 are 0 and -1
+ /// respectively. This maps into a truth table of:
+ /// LHS | RHS | LHS >=s RHS | LHS implies RHS
+ /// 0 | 0 | 1 (0 >= 0) | 1
+ /// 0 | 1 | 1 (0 >= -1) | 1
+ /// 1 | 0 | 0 (-1 >= 0) | 0
+ /// 1 | 1 | 1 (-1 >= -1) | 1
+ if (isImpliedCondition(LHS, RHS, Q.DL))
+ return getTrue(ITy);
break;
case ICmpInst::ICMP_SLT:
// X <s 0 -> X
if (match(RHS, m_One()))
return LHS;
break;
+ case ICmpInst::ICMP_ULE:
+ if (isImpliedCondition(LHS, RHS, Q.DL))
+ return getTrue(ITy);
+ break;
}
}
} else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) {
// 'and x, CI2' produces [0, CI2].
Upper = CI2->getValue() + 1;
+ } else if (match(LHS, m_NUWAdd(m_Value(), m_ConstantInt(CI2)))) {
+ // 'add nuw x, CI2' produces [CI2, UINT_MAX].
+ Lower = CI2->getValue();
}
- if (Lower != Upper) {
- ConstantRange LHS_CR = ConstantRange(Lower, Upper);
+
+ ConstantRange LHS_CR = Lower != Upper ? ConstantRange(Lower, Upper)
+ : ConstantRange(Width, true);
+
+ if (auto *I = dyn_cast<Instruction>(LHS))
+ if (auto *Ranges = I->getMetadata(LLVMContext::MD_range))
+ LHS_CR = LHS_CR.intersectWith(getConstantRangeFromMetadata(*Ranges));
+
+ if (!LHS_CR.isFullSet()) {
if (RHS_CR.contains(LHS_CR))
return ConstantInt::getTrue(RHS->getContext());
if (RHS_CR.inverse().contains(LHS_CR))
}
}
+ // If both operands have range metadata, use the metadata
+ // to simplify the comparison.
+ if (isa<Instruction>(RHS) && isa<Instruction>(LHS)) {
+ auto RHS_Instr = dyn_cast<Instruction>(RHS);
+ auto LHS_Instr = dyn_cast<Instruction>(LHS);
+
+ if (RHS_Instr->getMetadata(LLVMContext::MD_range) &&
+ LHS_Instr->getMetadata(LLVMContext::MD_range)) {
+ auto RHS_CR = getConstantRangeFromMetadata(
+ *RHS_Instr->getMetadata(LLVMContext::MD_range));
+ auto LHS_CR = getConstantRangeFromMetadata(
+ *LHS_Instr->getMetadata(LLVMContext::MD_range));
+
+ auto Satisfied_CR = ConstantRange::makeSatisfyingICmpRegion(Pred, RHS_CR);
+ if (Satisfied_CR.contains(LHS_CR))
+ return ConstantInt::getTrue(RHS->getContext());
+
+ auto InversedSatisfied_CR = ConstantRange::makeSatisfyingICmpRegion(
+ CmpInst::getInversePredicate(Pred), RHS_CR);
+ if (InversedSatisfied_CR.contains(LHS_CR))
+ return ConstantInt::getFalse(RHS->getContext());
+ }
+ }
+
// Compare of cast, for example (zext X) != 0 -> X != 0
if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
Instruction *LI = cast<CastInst>(LHS);
}
}
+ // icmp eq|ne X, Y -> false|true if X != Y
+ if ((Pred == ICmpInst::ICMP_EQ || Pred == ICmpInst::ICMP_NE) &&
+ isKnownNonEqual(LHS, RHS, Q.DL, Q.AC, Q.CxtI, Q.DT)) {
+ LLVMContext &Ctx = LHS->getType()->getContext();
+ return Pred == ICmpInst::ICMP_NE ?
+ ConstantInt::getTrue(Ctx) : ConstantInt::getFalse(Ctx);
+ }
+
// Special logic for binary operators.
BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS);
BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
const DataLayout &DL,
const TargetLibraryInfo *TLI,
const DominatorTree *DT, AssumptionCache *AC,
- Instruction *CxtI) {
+ const Instruction *CxtI) {
return ::SimplifyICmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
RecursionLimit);
}
-/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an FCmpInst, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const Query &Q, unsigned MaxRecurse) {
+ FastMathFlags FMF, const Query &Q,
+ unsigned MaxRecurse) {
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
if (Pred == FCmpInst::FCMP_TRUE)
return ConstantInt::get(GetCompareTy(LHS), 1);
+ // UNO/ORD predicates can be trivially folded if NaNs are ignored.
+ if (FMF.noNaNs()) {
+ if (Pred == FCmpInst::FCMP_UNO)
+ return ConstantInt::get(GetCompareTy(LHS), 0);
+ if (Pred == FCmpInst::FCMP_ORD)
+ return ConstantInt::get(GetCompareTy(LHS), 1);
+ }
+
// fcmp pred x, undef and fcmp pred undef, x
// fold to true if unordered, false if ordered
if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS)) {
}
Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const DataLayout &DL,
+ FastMathFlags FMF, const DataLayout &DL,
const TargetLibraryInfo *TLI,
const DominatorTree *DT, AssumptionCache *AC,
const Instruction *CxtI) {
- return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
- RecursionLimit);
+ return ::SimplifyFCmpInst(Predicate, LHS, RHS, FMF,
+ Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
+}
+
+/// See if V simplifies when its operand Op is replaced with RepOp.
+static const Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
+ const Query &Q,
+ unsigned MaxRecurse) {
+ // Trivial replacement.
+ if (V == Op)
+ return RepOp;
+
+ auto *I = dyn_cast<Instruction>(V);
+ if (!I)
+ return nullptr;
+
+ // If this is a binary operator, try to simplify it with the replaced op.
+ if (auto *B = dyn_cast<BinaryOperator>(I)) {
+ // Consider:
+ // %cmp = icmp eq i32 %x, 2147483647
+ // %add = add nsw i32 %x, 1
+ // %sel = select i1 %cmp, i32 -2147483648, i32 %add
+ //
+ // We can't replace %sel with %add unless we strip away the flags.
+ if (isa<OverflowingBinaryOperator>(B))
+ if (B->hasNoSignedWrap() || B->hasNoUnsignedWrap())
+ return nullptr;
+ if (isa<PossiblyExactOperator>(B))
+ if (B->isExact())
+ return nullptr;
+
+ if (MaxRecurse) {
+ if (B->getOperand(0) == Op)
+ return SimplifyBinOp(B->getOpcode(), RepOp, B->getOperand(1), Q,
+ MaxRecurse - 1);
+ if (B->getOperand(1) == Op)
+ return SimplifyBinOp(B->getOpcode(), B->getOperand(0), RepOp, Q,
+ MaxRecurse - 1);
+ }
+ }
+
+ // Same for CmpInsts.
+ if (CmpInst *C = dyn_cast<CmpInst>(I)) {
+ if (MaxRecurse) {
+ if (C->getOperand(0) == Op)
+ return SimplifyCmpInst(C->getPredicate(), RepOp, C->getOperand(1), Q,
+ MaxRecurse - 1);
+ if (C->getOperand(1) == Op)
+ return SimplifyCmpInst(C->getPredicate(), C->getOperand(0), RepOp, Q,
+ MaxRecurse - 1);
+ }
+ }
+
+ // TODO: We could hand off more cases to instsimplify here.
+
+ // If all operands are constant after substituting Op for RepOp then we can
+ // constant fold the instruction.
+ if (Constant *CRepOp = dyn_cast<Constant>(RepOp)) {
+ // Build a list of all constant operands.
+ SmallVector<Constant *, 8> ConstOps;
+ for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+ if (I->getOperand(i) == Op)
+ ConstOps.push_back(CRepOp);
+ else if (Constant *COp = dyn_cast<Constant>(I->getOperand(i)))
+ ConstOps.push_back(COp);
+ else
+ break;
+ }
+
+ // All operands were constants, fold it.
+ if (ConstOps.size() == I->getNumOperands()) {
+ if (CmpInst *C = dyn_cast<CmpInst>(I))
+ return ConstantFoldCompareInstOperands(C->getPredicate(), ConstOps[0],
+ ConstOps[1], Q.DL, Q.TLI);
+
+ if (LoadInst *LI = dyn_cast<LoadInst>(I))
+ if (!LI->isVolatile())
+ return ConstantFoldLoadFromConstPtr(ConstOps[0], Q.DL);
+
+ return ConstantFoldInstOperands(I->getOpcode(), I->getType(), ConstOps,
+ Q.DL, Q.TLI);
+ }
+ }
+
+ return nullptr;
}
-/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
-/// the result. If not, this returns null.
+/// Given operands for a SelectInst, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
Value *FalseVal, const Query &Q,
unsigned MaxRecurse) {
if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
return TrueVal;
- const auto *ICI = dyn_cast<ICmpInst>(CondVal);
- unsigned BitWidth = TrueVal->getType()->getScalarSizeInBits();
- if (ICI && BitWidth) {
+ if (const auto *ICI = dyn_cast<ICmpInst>(CondVal)) {
+ unsigned BitWidth = Q.DL.getTypeSizeInBits(TrueVal->getType());
ICmpInst::Predicate Pred = ICI->getPredicate();
+ Value *CmpLHS = ICI->getOperand(0);
+ Value *CmpRHS = ICI->getOperand(1);
APInt MinSignedValue = APInt::getSignBit(BitWidth);
Value *X;
const APInt *Y;
bool TrueWhenUnset;
bool IsBitTest = false;
if (ICmpInst::isEquality(Pred) &&
- match(ICI->getOperand(0), m_And(m_Value(X), m_APInt(Y))) &&
- match(ICI->getOperand(1), m_Zero())) {
+ match(CmpLHS, m_And(m_Value(X), m_APInt(Y))) &&
+ match(CmpRHS, m_Zero())) {
IsBitTest = true;
TrueWhenUnset = Pred == ICmpInst::ICMP_EQ;
- } else if (Pred == ICmpInst::ICMP_SLT &&
- match(ICI->getOperand(1), m_Zero())) {
- X = ICI->getOperand(0);
+ } else if (Pred == ICmpInst::ICMP_SLT && match(CmpRHS, m_Zero())) {
+ X = CmpLHS;
Y = &MinSignedValue;
IsBitTest = true;
TrueWhenUnset = false;
- } else if (Pred == ICmpInst::ICMP_SGT &&
- match(ICI->getOperand(1), m_AllOnes())) {
- X = ICI->getOperand(0);
+ } else if (Pred == ICmpInst::ICMP_SGT && match(CmpRHS, m_AllOnes())) {
+ X = CmpLHS;
Y = &MinSignedValue;
IsBitTest = true;
TrueWhenUnset = true;
return TrueWhenUnset ? TrueVal : FalseVal;
}
}
+ if (ICI->hasOneUse()) {
+ const APInt *C;
+ if (match(CmpRHS, m_APInt(C))) {
+ // X < MIN ? T : F --> F
+ if (Pred == ICmpInst::ICMP_SLT && C->isMinSignedValue())
+ return FalseVal;
+ // X < MIN ? T : F --> F
+ if (Pred == ICmpInst::ICMP_ULT && C->isMinValue())
+ return FalseVal;
+ // X > MAX ? T : F --> F
+ if (Pred == ICmpInst::ICMP_SGT && C->isMaxSignedValue())
+ return FalseVal;
+ // X > MAX ? T : F --> F
+ if (Pred == ICmpInst::ICMP_UGT && C->isMaxValue())
+ return FalseVal;
+ }
+ }
+
+ // If we have an equality comparison then we know the value in one of the
+ // arms of the select. See if substituting this value into the arm and
+ // simplifying the result yields the same value as the other arm.
+ if (Pred == ICmpInst::ICMP_EQ) {
+ if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
+ TrueVal ||
+ SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
+ TrueVal)
+ return FalseVal;
+ if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
+ FalseVal ||
+ SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
+ FalseVal)
+ return FalseVal;
+ } else if (Pred == ICmpInst::ICMP_NE) {
+ if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
+ FalseVal ||
+ SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
+ FalseVal)
+ return TrueVal;
+ if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
+ TrueVal ||
+ SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
+ TrueVal)
+ return TrueVal;
+ }
}
return nullptr;
Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
}
-/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for an GetElementPtrInst, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops,
const Query &Q, unsigned) {
// The type of the GEP pointer operand.
Ops, Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
}
-/// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
-/// can fold the result. If not, this returns null.
+/// Given operands for an InsertValueInst, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
ArrayRef<unsigned> Idxs, const Query &Q,
unsigned) {
RecursionLimit);
}
-/// SimplifyPHINode - See if we can fold the given phi. If not, returns null.
+/// Given operands for an ExtractValueInst, see if we can fold the result.
+/// If not, this returns null.
+static Value *SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
+ const Query &, unsigned) {
+ if (auto *CAgg = dyn_cast<Constant>(Agg))
+ return ConstantFoldExtractValueInstruction(CAgg, Idxs);
+
+ // extractvalue x, (insertvalue y, elt, n), n -> elt
+ unsigned NumIdxs = Idxs.size();
+ for (auto *IVI = dyn_cast<InsertValueInst>(Agg); IVI != nullptr;
+ IVI = dyn_cast<InsertValueInst>(IVI->getAggregateOperand())) {
+ ArrayRef<unsigned> InsertValueIdxs = IVI->getIndices();
+ unsigned NumInsertValueIdxs = InsertValueIdxs.size();
+ unsigned NumCommonIdxs = std::min(NumInsertValueIdxs, NumIdxs);
+ if (InsertValueIdxs.slice(0, NumCommonIdxs) ==
+ Idxs.slice(0, NumCommonIdxs)) {
+ if (NumIdxs == NumInsertValueIdxs)
+ return IVI->getInsertedValueOperand();
+ break;
+ }
+ }
+
+ return nullptr;
+}
+
+Value *llvm::SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT,
+ AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyExtractValueInst(Agg, Idxs, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+/// Given operands for an ExtractElementInst, see if we can fold the result.
+/// If not, this returns null.
+static Value *SimplifyExtractElementInst(Value *Vec, Value *Idx, const Query &,
+ unsigned) {
+ if (auto *CVec = dyn_cast<Constant>(Vec)) {
+ if (auto *CIdx = dyn_cast<Constant>(Idx))
+ return ConstantFoldExtractElementInstruction(CVec, CIdx);
+
+ // The index is not relevant if our vector is a splat.
+ if (auto *Splat = CVec->getSplatValue())
+ return Splat;
+
+ if (isa<UndefValue>(Vec))
+ return UndefValue::get(Vec->getType()->getVectorElementType());
+ }
+
+ // If extracting a specified index from the vector, see if we can recursively
+ // find a previously computed scalar that was inserted into the vector.
+ if (auto *IdxC = dyn_cast<ConstantInt>(Idx))
+ if (Value *Elt = findScalarElement(Vec, IdxC->getZExtValue()))
+ return Elt;
+
+ return nullptr;
+}
+
+Value *llvm::SimplifyExtractElementInst(
+ Value *Vec, Value *Idx, const DataLayout &DL, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC, const Instruction *CxtI) {
+ return ::SimplifyExtractElementInst(Vec, Idx, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
+}
+
+/// See if we can fold the given phi. If not, returns null.
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.
//=== Helper functions for higher up the class hierarchy.
-/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for a BinaryOperator, see if we can fold the result.
+/// If not, this returns null.
static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
const Query &Q, unsigned MaxRecurse) {
switch (Opcode) {
}
}
-/// SimplifyFPBinOp - Given operands for a BinaryOperator, see if we can
-/// fold the result. If not, this returns null.
+/// Given operands for a BinaryOperator, see if we can fold the result.
+/// If not, this returns null.
/// In contrast to SimplifyBinOp, try to use FastMathFlag when folding the
/// result. In case we don't need FastMathFlags, simply fall to SimplifyBinOp.
static Value *SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
RecursionLimit);
}
-/// SimplifyCmpInst - Given operands for a CmpInst, see if we can
-/// fold the result.
+/// Given operands for a CmpInst, see if we can fold the result.
static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const Query &Q, unsigned MaxRecurse) {
if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
- return SimplifyFCmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
+ return SimplifyFCmpInst(Predicate, LHS, RHS, FastMathFlags(), Q, MaxRecurse);
}
Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
}
template <typename IterTy>
-static Value *SimplifyIntrinsic(Intrinsic::ID IID, IterTy ArgBegin, IterTy ArgEnd,
+static Value *SimplifyIntrinsic(Function *F, IterTy ArgBegin, IterTy ArgEnd,
const Query &Q, unsigned MaxRecurse) {
+ Intrinsic::ID IID = F->getIntrinsicID();
+ unsigned NumOperands = std::distance(ArgBegin, ArgEnd);
+ Type *ReturnType = F->getReturnType();
+
+ // Binary Ops
+ if (NumOperands == 2) {
+ Value *LHS = *ArgBegin;
+ Value *RHS = *(ArgBegin + 1);
+ if (IID == Intrinsic::usub_with_overflow ||
+ IID == Intrinsic::ssub_with_overflow) {
+ // X - X -> { 0, false }
+ if (LHS == RHS)
+ return Constant::getNullValue(ReturnType);
+
+ // X - undef -> undef
+ // undef - X -> undef
+ if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS))
+ return UndefValue::get(ReturnType);
+ }
+
+ if (IID == Intrinsic::uadd_with_overflow ||
+ IID == Intrinsic::sadd_with_overflow) {
+ // X + undef -> undef
+ if (isa<UndefValue>(RHS))
+ return UndefValue::get(ReturnType);
+ }
+
+ if (IID == Intrinsic::umul_with_overflow ||
+ IID == Intrinsic::smul_with_overflow) {
+ // X * 0 -> { 0, false }
+ if (match(RHS, m_Zero()))
+ return Constant::getNullValue(ReturnType);
+
+ // X * undef -> { 0, false }
+ if (match(RHS, m_Undef()))
+ return Constant::getNullValue(ReturnType);
+ }
+ }
+
// Perform idempotent optimizations
if (!IsIdempotent(IID))
return nullptr;
// Unary Ops
- if (std::distance(ArgBegin, ArgEnd) == 1)
+ if (NumOperands == 1)
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*ArgBegin))
if (II->getIntrinsicID() == IID)
return II;
if (!F)
return nullptr;
- if (Intrinsic::ID IID = F->getIntrinsicID())
- if (Value *Ret =
- SimplifyIntrinsic(IID, ArgBegin, ArgEnd, Q, MaxRecurse))
+ if (F->isIntrinsic())
+ if (Value *Ret = SimplifyIntrinsic(F, ArgBegin, ArgEnd, Q, MaxRecurse))
return Ret;
if (!canConstantFoldCallTo(F))
Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
}
-/// SimplifyInstruction - See if we can compute a simplified version of this
-/// instruction. If not, this returns null.
+/// See if we can compute a simplified version of this instruction.
+/// If not, this returns null.
Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout &DL,
const TargetLibraryInfo *TLI,
const DominatorTree *DT, AssumptionCache *AC) {
I->getOperand(1), DL, TLI, DT, AC, I);
break;
case Instruction::FCmp:
- Result =
- SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), I->getOperand(0),
- I->getOperand(1), DL, TLI, DT, AC, I);
+ Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
+ I->getOperand(0), I->getOperand(1),
+ I->getFastMathFlags(), DL, TLI, DT, AC, I);
break;
case Instruction::Select:
Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
IV->getIndices(), DL, TLI, DT, AC, I);
break;
}
+ case Instruction::ExtractValue: {
+ auto *EVI = cast<ExtractValueInst>(I);
+ Result = SimplifyExtractValueInst(EVI->getAggregateOperand(),
+ EVI->getIndices(), DL, TLI, DT, AC, I);
+ break;
+ }
+ case Instruction::ExtractElement: {
+ auto *EEI = cast<ExtractElementInst>(I);
+ Result = SimplifyExtractElementInst(
+ EEI->getVectorOperand(), EEI->getIndexOperand(), DL, TLI, DT, AC, I);
+ break;
+ }
case Instruction::PHI:
Result = SimplifyPHINode(cast<PHINode>(I), Query(DL, TLI, DT, AC, I));
break;
break;
}
+ // In general, it is possible for computeKnownBits to determine all bits in a
+ // value even when the operands are not all constants.
+ if (!Result && I->getType()->isIntegerTy()) {
+ unsigned BitWidth = I->getType()->getScalarSizeInBits();
+ APInt KnownZero(BitWidth, 0);
+ APInt KnownOne(BitWidth, 0);
+ computeKnownBits(I, KnownZero, KnownOne, DL, /*Depth*/0, AC, I, DT);
+ if ((KnownZero | KnownOne).isAllOnesValue())
+ Result = ConstantInt::get(I->getContext(), KnownOne);
+ }
+
/// If called on unreachable code, the above logic may report that the
/// instruction simplified to itself. Make life easier for users by
/// detecting that case here, returning a safe value instead.
projects / oota-llvm.git / blobdiff