X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FAnalysis%2FInstructionSimplify.cpp;h=0bd18c1a35cd447d4cb7c0e78b12955b89c4169f;hp=d66ecca928aa854e66d5f76113d81557e95433cd;hb=b013b28ec87299c64b5a1888dfea7c3883682775;hpb=8c5c6f0e090f91b6555cdd9d2eea238fff3befe6 diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index d66ecca928a..0bd18c1a35c 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -17,42 +17,53 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "instsimplify" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/ADT/SetVector.h" #include "llvm/ADT/Statistic.h" +#include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/ConstantFolding.h" -#include "llvm/Analysis/Dominators.h" -#include "llvm/Analysis/ValueTracking.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" +#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" +#include using namespace llvm; using namespace llvm::PatternMatch; +#define DEBUG_TYPE "instsimplify" + enum { RecursionLimit = 3 }; STATISTIC(NumExpand, "Number of expansions"); -STATISTIC(NumFactor , "Number of factorizations"); STATISTIC(NumReassoc, "Number of reassociations"); +namespace { struct Query { - const DataLayout *TD; + const DataLayout &DL; const TargetLibraryInfo *TLI; const DominatorTree *DT; + AssumptionCache *AC; + const Instruction *CxtI; - Query(const DataLayout *td, const TargetLibraryInfo *tli, - const DominatorTree *dt) : TD(td), TLI(tli), DT(dt) {} + Query(const DataLayout &DL, const TargetLibraryInfo *tli, + const DominatorTree *dt, AssumptionCache *ac = nullptr, + const Instruction *cxti = nullptr) + : DL(DL), TLI(tli), DT(dt), AC(ac), CxtI(cxti) {} }; +} // end anonymous namespace static Value *SimplifyAndInst(Value *, Value *, const Query &, unsigned); static Value *SimplifyBinOp(unsigned, Value *, Value *, const Query &, unsigned); +static Value *SimplifyFPBinOp(unsigned, Value *, Value *, const FastMathFlags &, + const Query &, unsigned); static Value *SimplifyCmpInst(unsigned, Value *, Value *, const Query &, unsigned); static Value *SimplifyOrInst(Value *, Value *, const Query &, unsigned); @@ -112,9 +123,9 @@ static bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) { } // Otherwise, if the instruction is in the entry block, and is not an invoke, - // then it obviously dominates all phi nodes. + // and is not a catchpad, then it obviously dominates all phi nodes. if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() && - !isa(I)) + !isa(I) && !isa(I)) return true; return false; @@ -131,7 +142,7 @@ static Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS, 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(LHS)) @@ -179,79 +190,7 @@ static Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS, } } - return 0; -} - -/// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term -/// using the operation OpCodeToExtract. For example, when Opcode is Add and -/// OpCodeToExtract is Mul then this tries to turn "(A*B)+(A*C)" into "A*(B+C)". -/// Returns the simplified value, or null if no simplification was performed. -static Value *FactorizeBinOp(unsigned Opcode, Value *LHS, Value *RHS, - unsigned OpcToExtract, const Query &Q, - unsigned MaxRecurse) { - 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; - - BinaryOperator *Op0 = dyn_cast(LHS); - BinaryOperator *Op1 = dyn_cast(RHS); - - if (!Op0 || Op0->getOpcode() != OpcodeToExtract || - !Op1 || Op1->getOpcode() != OpcodeToExtract) - return 0; - - // The expression has the form "(A op' B) op (C op' D)". - Value *A = Op0->getOperand(0), *B = Op0->getOperand(1); - Value *C = Op1->getOperand(0), *D = Op1->getOperand(1); - - // Use left distributivity, i.e. "X op' (Y op Z) = (X op' Y) op (X op' Z)". - // Does the instruction have the form "(A op' B) op (A op' D)" or, in the - // commutative case, "(A op' B) op (C op' A)"? - if (A == C || (Instruction::isCommutative(OpcodeToExtract) && A == D)) { - Value *DD = A == C ? D : C; - // Form "A op' (B op DD)" if it simplifies completely. - // Does "B op DD" simplify? - if (Value *V = SimplifyBinOp(Opcode, B, DD, Q, MaxRecurse)) { - // It does! Return "A op' V" if it simplifies or is already available. - // If V equals B then "A op' V" is just the LHS. If V equals DD then - // "A op' V" is just the RHS. - if (V == B || V == DD) { - ++NumFactor; - return V == B ? LHS : RHS; - } - // Otherwise return "A op' V" if it simplifies. - if (Value *W = SimplifyBinOp(OpcodeToExtract, A, V, Q, MaxRecurse)) { - ++NumFactor; - return W; - } - } - } - - // Use right distributivity, i.e. "(X op Y) op' Z = (X op' Z) op (Y op' Z)". - // Does the instruction have the form "(A op' B) op (C op' B)" or, in the - // commutative case, "(A op' B) op (B op' D)"? - if (B == D || (Instruction::isCommutative(OpcodeToExtract) && B == C)) { - Value *CC = B == D ? C : D; - // Form "(A op CC) op' B" if it simplifies completely.. - // Does "A op CC" simplify? - if (Value *V = SimplifyBinOp(Opcode, A, CC, Q, MaxRecurse)) { - // It does! Return "V op' B" if it simplifies or is already available. - // If V equals A then "V op' B" is just the LHS. If V equals CC then - // "V op' B" is just the RHS. - if (V == A || V == CC) { - ++NumFactor; - return V == A ? LHS : RHS; - } - // Otherwise return "V op' B" if it simplifies. - if (Value *W = SimplifyBinOp(OpcodeToExtract, V, B, Q, MaxRecurse)) { - ++NumFactor; - return W; - } - } - } - - return 0; + return nullptr; } /// SimplifyAssociativeBinOp - Generic simplifications for associative binary @@ -263,7 +202,7 @@ static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS, // 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(LHS); BinaryOperator *Op1 = dyn_cast(RHS); @@ -308,7 +247,7 @@ static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *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) { @@ -348,7 +287,7 @@ static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS, } } - return 0; + return nullptr; } /// ThreadBinOpOverSelect - In the case of a binary operation with a select @@ -359,7 +298,7 @@ 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. if (!MaxRecurse--) - return 0; + return nullptr; SelectInst *SI; if (isa(LHS)) { @@ -420,7 +359,7 @@ static Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS, } } - return 0; + return nullptr; } /// ThreadCmpOverSelect - In the case of a comparison with a select instruction, @@ -432,7 +371,7 @@ static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS, 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(LHS)) { @@ -456,7 +395,7 @@ static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *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()); } @@ -470,7 +409,7 @@ static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS, // 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()); } @@ -482,7 +421,7 @@ static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS, // 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". @@ -502,7 +441,7 @@ static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS, Q, MaxRecurse)) return V; - return 0; + return nullptr; } /// ThreadBinOpOverPHI - In the case of a binary operation with an operand that @@ -513,26 +452,25 @@ 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. if (!MaxRecurse--) - return 0; + return nullptr; PHINode *PI; if (isa(LHS)) { PI = cast(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(RHS) && "No PHI instruction operand!"); PI = cast(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; - for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { - Value *Incoming = PI->getIncomingValue(i); + Value *CommonValue = nullptr; + for (Value *Incoming : PI->incoming_values()) { // If the incoming value is the phi node itself, it can safely be skipped. if (Incoming == PI) continue; Value *V = PI == LHS ? @@ -541,7 +479,7 @@ static Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS, // 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; } @@ -556,7 +494,7 @@ 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. if (!MaxRecurse--) - return 0; + return nullptr; // Make sure the phi is on the LHS. if (!isa(LHS)) { @@ -568,19 +506,18 @@ static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS, // 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; - for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { - Value *Incoming = PI->getIncomingValue(i); + Value *CommonValue = nullptr; + for (Value *Incoming : PI->incoming_values()) { // If the incoming value is the phi node itself, it can safely be skipped. if (Incoming == PI) continue; Value *V = SimplifyCmpInst(Pred, Incoming, RHS, Q, MaxRecurse); // 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; } @@ -595,7 +532,7 @@ static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), Ops, - Q.TD, Q.TLI); + Q.DL, Q.TLI); } // Canonicalize the constant to the RHS. @@ -613,7 +550,7 @@ static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, // 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; @@ -633,11 +570,6 @@ static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, MaxRecurse)) return V; - // Mul distributes over Add. Try some generic simplifications based on this. - if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul, - Q, MaxRecurse)) - return V; - // Threading Add over selects and phi nodes is pointless, so don't bother. // Threading over the select in "A + select(cond, B, C)" means evaluating // "A+B" and "A+C" and seeing if they are equal; but they are equal if and @@ -647,13 +579,14 @@ static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, // "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, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT), + const DataLayout &DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } @@ -667,17 +600,12 @@ Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, /// This is very similar to GetPointerBaseWithConstantOffset except it doesn't /// follow non-inbounds geps. This allows it to remain usable for icmp ult/etc. /// folding. -static Constant *stripAndComputeConstantOffsets(const DataLayout *TD, - Value *&V) { +static Constant *stripAndComputeConstantOffsets(const DataLayout &DL, Value *&V, + bool AllowNonInbounds = false) { assert(V->getType()->getScalarType()->isPointerTy()); - // Without DataLayout, just be conservative for now. Theoretically, more could - // be done in this case. - if (!TD) - return ConstantInt::get(IntegerType::get(V->getContext(), 64), 0); - - unsigned IntPtrWidth = TD->getPointerSizeInBits(); - APInt Offset = APInt::getNullValue(IntPtrWidth); + Type *IntPtrTy = DL.getIntPtrType(V->getType())->getScalarType(); + APInt Offset = APInt::getNullValue(IntPtrTy->getIntegerBitWidth()); // Even though we don't look through PHI nodes, we could be called on an // instruction in an unreachable block, which may be on a cycle. @@ -685,7 +613,8 @@ static Constant *stripAndComputeConstantOffsets(const DataLayout *TD, Visited.insert(V); do { if (GEPOperator *GEP = dyn_cast(V)) { - if (!GEP->isInBounds() || !GEP->accumulateConstantOffset(*TD, Offset)) + if ((!AllowNonInbounds && !GEP->isInBounds()) || + !GEP->accumulateConstantOffset(DL, Offset)) break; V = GEP->getPointerOperand(); } else if (Operator::getOpcode(V) == Instruction::BitCast) { @@ -699,9 +628,8 @@ static Constant *stripAndComputeConstantOffsets(const DataLayout *TD, } assert(V->getType()->getScalarType()->isPointerTy() && "Unexpected operand type!"); - } while (Visited.insert(V)); + } while (Visited.insert(V).second); - Type *IntPtrTy = TD->getIntPtrType(V->getContext()); Constant *OffsetIntPtr = ConstantInt::get(IntPtrTy, Offset); if (V->getType()->isVectorTy()) return ConstantVector::getSplat(V->getType()->getVectorNumElements(), @@ -711,15 +639,15 @@ static Constant *stripAndComputeConstantOffsets(const DataLayout *TD, /// \brief Compute the constant difference between two pointer values. /// If the difference is not a constant, returns zero. -static Constant *computePointerDifference(const DataLayout *TD, - Value *LHS, Value *RHS) { - Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS); - Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS); +static Constant *computePointerDifference(const DataLayout &DL, Value *LHS, + Value *RHS) { + Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS); + Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS); // 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 @@ -736,7 +664,7 @@ static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } // X - undef -> undef @@ -752,16 +680,13 @@ static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, if (Op0 == Op1) return Constant::getNullValue(Op0->getType()); - // (X*2) - X -> X - // (X<<1) - X -> X - Value *X = 0; - if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) || - match(Op0, m_Shl(m_Specific(Op1), m_One()))) - return Op1; + // 0 - X -> 0 if the sub is NUW. + if (isNUW && match(Op0, m_Zero())) + return Op0; // (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 *X = nullptr, *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)) @@ -830,14 +755,9 @@ static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...). if (match(Op0, m_PtrToInt(m_Value(X))) && match(Op1, m_PtrToInt(m_Value(Y)))) - if (Constant *Result = computePointerDifference(Q.TD, X, Y)) + if (Constant *Result = computePointerDifference(Q.DL, X, Y)) return ConstantExpr::getIntegerCast(Result, Op0->getType(), true); - // Mul distributes over Sub. Try some generic simplifications based on this. - if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul, - Q, MaxRecurse)) - return V; - // i1 sub -> xor. if (MaxRecurse && Op0->getType()->isIntegerTy(1)) if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1)) @@ -852,13 +772,14 @@ static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, // "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, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT), + const DataLayout &DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } @@ -870,7 +791,7 @@ static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::FAdd, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } // Canonicalize the constant to the RHS. @@ -889,7 +810,7 @@ static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF, // 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)))) @@ -901,7 +822,7 @@ static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF, return Constant::getNullValue(Op0->getType()); } - return 0; + return nullptr; } /// Given operands for an FSub, see if we can fold the result. If not, this @@ -912,7 +833,7 @@ static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::FSub, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } } @@ -934,11 +855,11 @@ static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF, 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 0; + return nullptr; } /// Given the operands for an FMul, see if we can fold the result @@ -950,7 +871,7 @@ static Value *SimplifyFMulInst(Value *Op0, Value *Op1, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::FMul, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } // Canonicalize the constant to the RHS. @@ -965,7 +886,7 @@ static Value *SimplifyFMulInst(Value *Op0, Value *Op1, 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 @@ -976,7 +897,7 @@ static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } // Canonicalize the constant to the RHS. @@ -996,7 +917,7 @@ static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q, 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; @@ -1030,33 +951,42 @@ static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q, MaxRecurse)) return V; - return 0; + return nullptr; } Value *llvm::SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFAddInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit); + const DataLayout &DL, + const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyFAddInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } Value *llvm::SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFSubInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit); + const DataLayout &DL, + const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyFSubInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } -Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1, - FastMathFlags FMF, - const DataLayout *TD, +Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF, + const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFMulInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyFMulInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } -Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const DataLayout *TD, +Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyMulInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyMulInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } /// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can @@ -1066,7 +996,7 @@ static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, if (Constant *C0 = dyn_cast(Op0)) { if (Constant *C1 = dyn_cast(Op1)) { Constant *Ops[] = { C0, C1 }; - return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI); + return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI); } } @@ -1076,6 +1006,10 @@ static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, if (match(Op1, m_Undef())) return Op1; + // X / 0 -> undef, we don't need to preserve faults! + if (match(Op1, m_Zero())) + return UndefValue::get(Op1->getType()); + // undef / X -> 0 if (match(Op0, m_Undef())) return Constant::getNullValue(Op0->getType()); @@ -1097,7 +1031,7 @@ static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, 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(Op0); @@ -1116,6 +1050,16 @@ static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1))))) return Constant::getNullValue(Op0->getType()); + // (X /u C1) /u C2 -> 0 if C1 * C2 overflow + ConstantInt *C1, *C2; + if (!isSigned && match(Op0, m_UDiv(m_Value(X), m_ConstantInt(C1))) && + match(Op1, m_ConstantInt(C2))) { + bool Overflow; + C1->getValue().umul_ov(C2->getValue(), Overflow); + if (Overflow) + return Constant::getNullValue(Op0->getType()); + } + // If the operation is with the result of a select instruction, check whether // operating on either branch of the select always yields the same value. if (isa(Op0) || isa(Op1)) @@ -1128,7 +1072,7 @@ static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, 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 @@ -1138,13 +1082,15 @@ static Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q, 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 *TD, +Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifySDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifySDivInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } /// SimplifyUDivInst - Given operands for a UDiv, see if we can @@ -1154,17 +1100,19 @@ static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q, 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 *TD, +Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyUDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyUDivInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } -static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q, - unsigned) { +static Value *SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF, + const Query &Q, unsigned) { // undef / X -> undef (the undef could be a snan). if (match(Op0, m_Undef())) return Op0; @@ -1173,13 +1121,37 @@ static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q, if (match(Op1, m_Undef())) return Op1; - return 0; + // 0 / X -> 0 + // Requires that NaNs are off (X could be zero) and signed zeroes are + // ignored (X could be positive or negative, so the output sign is unknown). + 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; } -Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const DataLayout *TD, +Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF, + const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyFDivInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } /// SimplifyRem - Given operands for an SRem or URem, see if we can @@ -1189,7 +1161,7 @@ static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, if (Constant *C0 = dyn_cast(Op0)) { if (Constant *C1 = dyn_cast(Op1)) { Constant *Ops[] = { C0, C1 }; - return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI); + return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI); } } @@ -1221,6 +1193,13 @@ static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, if (Op0 == Op1) return Constant::getNullValue(Op0->getType()); + // (X % Y) % Y -> X % Y + if ((Opcode == Instruction::SRem && + match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) || + (Opcode == Instruction::URem && + match(Op0, m_URem(m_Value(), m_Specific(Op1))))) + return Op0; + // If the operation is with the result of a select instruction, check whether // operating on either branch of the select always yields the same value. if (isa(Op0) || isa(Op1)) @@ -1233,7 +1212,7 @@ static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, 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 @@ -1243,13 +1222,15 @@ static Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q, 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 *TD, +Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifySRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifySRemInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } /// SimplifyURemInst - Given operands for a URem, see if we can @@ -1259,17 +1240,19 @@ static Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q, 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 *TD, +Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyURemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyURemInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } -static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &, - unsigned) { +static Value *SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF, + const Query &, unsigned) { // undef % X -> undef (the undef could be a snan). if (match(Op0, m_Undef())) return Op0; @@ -1278,13 +1261,49 @@ static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &, if (match(Op1, m_Undef())) return Op1; - return 0; + // 0 % X -> 0 + // Requires that NaNs are off (X could be zero) and signed zeroes are + // ignored (X could be positive or negative, so the output sign is unknown). + if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero())) + return Op0; + + return nullptr; } -Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const DataLayout *TD, +Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF, + const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyFRemInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); +} + +/// isUndefShift - Returns true if a shift by \c Amount always yields undef. +static bool isUndefShift(Value *Amount) { + Constant *C = dyn_cast(Amount); + if (!C) + return false; + + // X shift by undef -> undef because it may shift by the bitwidth. + if (isa(C)) + return true; + + // Shifting by the bitwidth or more is undefined. + if (ConstantInt *CI = dyn_cast(C)) + if (CI->getValue().getLimitedValue() >= + CI->getType()->getScalarSizeInBits()) + return true; + + // If all lanes of a vector shift are undefined the whole shift is. + if (isa(C) || isa(C)) { + for (unsigned I = 0, E = C->getType()->getVectorNumElements(); I != E; ++I) + if (!isUndefShift(C->getAggregateElement(I))) + return false; + return true; + } + + return false; } /// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can @@ -1294,7 +1313,7 @@ static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1, if (Constant *C0 = dyn_cast(Op0)) { if (Constant *C1 = dyn_cast(Op1)) { Constant *Ops[] = { C0, C1 }; - return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI); + return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI); } } @@ -1306,15 +1325,9 @@ static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1, if (match(Op1, m_Zero())) return Op0; - // X shift by undef -> undef because it may shift by the bitwidth. - if (match(Op1, m_Undef())) - return Op1; - - // Shifting by the bitwidth or more is undefined. - if (ConstantInt *CI = dyn_cast(Op1)) - if (CI->getValue().getLimitedValue() >= - Op0->getType()->getScalarSizeInBits()) - return UndefValue::get(Op0->getType()); + // Fold undefined shifts. + if (isUndefShift(Op1)) + return UndefValue::get(Op0->getType()); // If the operation is with the result of a select instruction, check whether // operating on either branch of the select always yields the same value. @@ -1328,7 +1341,38 @@ static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1, if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse)) return V; - return 0; + return nullptr; +} + +/// \brief Given operands for an Shl, LShr or AShr, see if we can +/// fold the result. If not, this returns null. +static Value *SimplifyRightShift(unsigned Opcode, Value *Op0, Value *Op1, + bool isExact, const Query &Q, + unsigned MaxRecurse) { + if (Value *V = SimplifyShift(Opcode, Op0, Op1, Q, MaxRecurse)) + return V; + + // X >> X -> 0 + if (Op0 == Op1) + return Constant::getNullValue(Op0->getType()); + + // undef >> X -> 0 + // undef >> X -> undef (if it's exact) + if (match(Op0, m_Undef())) + return isExact ? Op0 : Constant::getNullValue(Op0->getType()); + + // The low bit cannot be shifted out of an exact shift if it is set. + if (isExact) { + unsigned BitWidth = Op0->getType()->getScalarSizeInBits(); + APInt Op0KnownZero(BitWidth, 0); + APInt Op0KnownOne(BitWidth, 0); + computeKnownBits(Op0, Op0KnownZero, Op0KnownOne, Q.DL, /*Depth=*/0, Q.AC, + Q.CxtI, Q.DT); + if (Op0KnownOne[0]) + return Op0; + } + + return nullptr; } /// SimplifyShlInst - Given operands for an Shl, see if we can @@ -1339,20 +1383,22 @@ static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, return V; // undef << X -> 0 + // undef << X -> undef if (if it's NSW/NUW) if (match(Op0, m_Undef())) - return Constant::getNullValue(Op0->getType()); + return isNSW || isNUW ? Op0 : Constant::getNullValue(Op0->getType()); // (X >> A) << A -> X 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, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT), + const DataLayout &DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } @@ -1360,31 +1406,24 @@ Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, /// 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 = SimplifyShift(Instruction::LShr, Op0, Op1, Q, MaxRecurse)) - return V; - - // X >> X -> 0 - if (Op0 == Op1) - return Constant::getNullValue(Op0->getType()); - - // undef >>l X -> 0 - if (match(Op0, m_Undef())) - return Constant::getNullValue(Op0->getType()); + if (Value *V = SimplifyRightShift(Instruction::LShr, Op0, Op1, isExact, Q, + MaxRecurse)) + return V; // (X << A) >> A -> X Value *X; - if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) && - cast(Op0)->hasNoUnsignedWrap()) + if (match(Op0, m_NUWShl(m_Value(X), m_Specific(Op1)))) return X; - return 0; + return nullptr; } Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, - const DataLayout *TD, + const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyLShrInst(Op0, Op1, isExact, Query (TD, TLI, DT), + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyLShrInst(Op0, Op1, isExact, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } @@ -1392,38 +1431,129 @@ Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, /// 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 = SimplifyShift(Instruction::AShr, Op0, Op1, Q, MaxRecurse)) + if (Value *V = SimplifyRightShift(Instruction::AShr, Op0, Op1, isExact, Q, + MaxRecurse)) return V; - // X >> X -> 0 - if (Op0 == Op1) - return Constant::getNullValue(Op0->getType()); - // all ones >>a X -> all ones if (match(Op0, m_AllOnes())) return Op0; - // undef >>a X -> all ones - if (match(Op0, m_Undef())) - return Constant::getAllOnesValue(Op0->getType()); - // (X << A) >> A -> X Value *X; - if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) && - cast(Op0)->hasNoSignedWrap()) + if (match(Op0, m_NSWShl(m_Value(X), m_Specific(Op1)))) return X; - return 0; + // Arithmetic shifting an all-sign-bit value is a no-op. + unsigned NumSignBits = ComputeNumSignBits(Op0, Q.DL, 0, Q.AC, Q.CxtI, Q.DT); + if (NumSignBits == Op0->getType()->getScalarSizeInBits()) + return Op0; + + return nullptr; } Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, - const DataLayout *TD, + const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyAShrInst(Op0, Op1, isExact, Query (TD, TLI, DT), + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyAShrInst(Op0, Op1, isExact, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } +static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp, + ICmpInst *UnsignedICmp, bool IsAnd) { + Value *X, *Y; + + ICmpInst::Predicate EqPred; + if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) || + !ICmpInst::isEquality(EqPred)) + return nullptr; + + ICmpInst::Predicate UnsignedPred; + if (match(UnsignedICmp, m_ICmp(UnsignedPred, m_Value(X), m_Specific(Y))) && + ICmpInst::isUnsigned(UnsignedPred)) + ; + else if (match(UnsignedICmp, + m_ICmp(UnsignedPred, m_Value(Y), m_Specific(X))) && + ICmpInst::isUnsigned(UnsignedPred)) + UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred); + else + return nullptr; + + // X < Y && Y != 0 --> X < Y + // X < Y || Y != 0 --> Y != 0 + if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_NE) + return IsAnd ? UnsignedICmp : ZeroICmp; + + // X >= Y || Y != 0 --> true + // X >= Y || Y == 0 --> X >= Y + if (UnsignedPred == ICmpInst::ICMP_UGE && !IsAnd) { + if (EqPred == ICmpInst::ICMP_NE) + return getTrue(UnsignedICmp->getType()); + return UnsignedICmp; + } + + // X < Y && Y == 0 --> false + if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_EQ && + IsAnd) + return getFalse(UnsignedICmp->getType()); + + return nullptr; +} + +// 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; + Value *V; + + if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true)) + return X; + + if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)), + m_ConstantInt(CI2)))) + return nullptr; + + if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Specific(CI1)))) + return nullptr; + + Type *ITy = Op0->getType(); + + auto *AddInst = cast(Op0->getOperand(0)); + bool isNSW = AddInst->hasNoSignedWrap(); + bool isNUW = AddInst->hasNoUnsignedWrap(); + + const APInt &CI1V = CI1->getValue(); + const APInt &CI2V = CI2->getValue(); + const APInt Delta = CI2V - CI1V; + if (CI1V.isStrictlyPositive()) { + if (Delta == 2) { + if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_SGT) + return getFalse(ITy); + if (Pred0 == ICmpInst::ICMP_SLT && Pred1 == ICmpInst::ICMP_SGT && isNSW) + return getFalse(ITy); + } + if (Delta == 1) { + if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_SGT) + return getFalse(ITy); + if (Pred0 == ICmpInst::ICMP_SLE && Pred1 == ICmpInst::ICMP_SGT && isNSW) + return getFalse(ITy); + } + } + if (CI1V.getBoolValue() && isNUW) { + if (Delta == 2) + if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_UGT) + return getFalse(ITy); + if (Delta == 1) + if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGT) + return getFalse(ITy); + } + + return nullptr; +} + /// SimplifyAndInst - 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, @@ -1432,7 +1562,7 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::And, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } // Canonicalize the constant to the RHS. @@ -1461,7 +1591,7 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q, 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; @@ -1474,12 +1604,23 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q, // A & (-A) = A if A is a power of two or zero. if (match(Op0, m_Neg(m_Specific(Op1))) || match(Op1, m_Neg(m_Specific(Op0)))) { - if (isKnownToBeAPowerOfTwo(Op0, /*OrZero*/true)) + if (isKnownToBeAPowerOfTwo(Op0, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI, + Q.DT)) return Op0; - if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/true)) + if (isKnownToBeAPowerOfTwo(Op1, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI, + Q.DT)) return Op1; } + if (auto *ICILHS = dyn_cast(Op0)) { + if (auto *ICIRHS = dyn_cast(Op1)) { + if (Value *V = SimplifyAndOfICmps(ICILHS, ICIRHS)) + return V; + if (Value *V = SimplifyAndOfICmps(ICIRHS, ICILHS)) + return V; + } + } + // Try some generic simplifications for associative operations. if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q, MaxRecurse)) @@ -1495,11 +1636,6 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q, Q, MaxRecurse)) return V; - // Or distributes over And. Try some generic simplifications based on this. - if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or, - Q, MaxRecurse)) - return V; - // If the operation is with the result of a select instruction, check whether // operating on either branch of the select always yields the same value. if (isa(Op0) || isa(Op1)) @@ -1514,13 +1650,67 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q, MaxRecurse)) return V; - return 0; + return nullptr; } -Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const DataLayout *TD, +Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyAndInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyAndInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); +} + +// 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; + Value *V; + + if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false)) + return X; + + if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)), + m_ConstantInt(CI2)))) + return nullptr; + + if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Specific(CI1)))) + return nullptr; + + Type *ITy = Op0->getType(); + + auto *AddInst = cast(Op0->getOperand(0)); + bool isNSW = AddInst->hasNoSignedWrap(); + bool isNUW = AddInst->hasNoUnsignedWrap(); + + const APInt &CI1V = CI1->getValue(); + const APInt &CI2V = CI2->getValue(); + const APInt Delta = CI2V - CI1V; + if (CI1V.isStrictlyPositive()) { + if (Delta == 2) { + if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_SLE) + return getTrue(ITy); + if (Pred0 == ICmpInst::ICMP_SGE && Pred1 == ICmpInst::ICMP_SLE && isNSW) + return getTrue(ITy); + } + if (Delta == 1) { + if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_SLE) + return getTrue(ITy); + if (Pred0 == ICmpInst::ICMP_SGT && Pred1 == ICmpInst::ICMP_SLE && isNSW) + return getTrue(ITy); + } + } + if (CI1V.getBoolValue() && isNUW) { + if (Delta == 2) + if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_ULE) + return getTrue(ITy); + if (Delta == 1) + if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_ULE) + return getTrue(ITy); + } + + return nullptr; } /// SimplifyOrInst - Given operands for an Or, see if we can @@ -1531,7 +1721,7 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } // Canonicalize the constant to the RHS. @@ -1560,7 +1750,7 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q, 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; @@ -1580,6 +1770,15 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q, (A == Op0 || B == Op0)) return Constant::getAllOnesValue(Op0->getType()); + if (auto *ICILHS = dyn_cast(Op0)) { + if (auto *ICIRHS = dyn_cast(Op1)) { + if (Value *V = SimplifyOrOfICmps(ICILHS, ICIRHS)) + return V; + if (Value *V = SimplifyOrOfICmps(ICIRHS, ICILHS)) + return V; + } + } + // Try some generic simplifications for associative operations. if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q, MaxRecurse)) @@ -1590,11 +1789,6 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q, MaxRecurse)) return V; - // And distributes over Or. Try some generic simplifications based on this. - if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And, - Q, MaxRecurse)) - return V; - // If the operation is with the result of a select instruction, check whether // operating on either branch of the select always yields the same value. if (isa(Op0) || isa(Op1)) @@ -1602,19 +1796,57 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q, MaxRecurse)) return V; + // (A & C)|(B & D) + Value *C = nullptr, *D = nullptr; + if (match(Op0, m_And(m_Value(A), m_Value(C))) && + match(Op1, m_And(m_Value(B), m_Value(D)))) { + ConstantInt *C1 = dyn_cast(C); + ConstantInt *C2 = dyn_cast(D); + if (C1 && C2 && (C1->getValue() == ~C2->getValue())) { + // (A & C1)|(B & C2) + // If we have: ((V + N) & C1) | (V & C2) + // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0 + // replace with V+N. + Value *V1, *V2; + if ((C2->getValue() & (C2->getValue() + 1)) == 0 && // C2 == 0+1+ + match(A, m_Add(m_Value(V1), m_Value(V2)))) { + // Add commutes, try both ways. + if (V1 == B && + MaskedValueIsZero(V2, C2->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) + return A; + if (V2 == B && + MaskedValueIsZero(V1, C2->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) + return A; + } + // Or commutes, try both ways. + if ((C1->getValue() & (C1->getValue() + 1)) == 0 && + match(B, m_Add(m_Value(V1), m_Value(V2)))) { + // Add commutes, try both ways. + if (V1 == A && + MaskedValueIsZero(V2, C1->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) + return B; + if (V2 == A && + MaskedValueIsZero(V1, C1->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) + return B; + } + } + } + // If the operation is with the result of a phi instruction, check whether // operating on all incoming values of the phi always yields the same value. if (isa(Op0) || isa(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 *TD, +Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyOrInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyOrInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } /// SimplifyXorInst - Given operands for a Xor, see if we can @@ -1625,7 +1857,7 @@ static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q, if (Constant *CRHS = dyn_cast(Op1)) { Constant *Ops[] = { CLHS, CRHS }; return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(), - Ops, Q.TD, Q.TLI); + Ops, Q.DL, Q.TLI); } // Canonicalize the constant to the RHS. @@ -1654,11 +1886,6 @@ static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q, MaxRecurse)) return V; - // And distributes over Xor. Try some generic simplifications based on this. - if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And, - Q, MaxRecurse)) - return V; - // Threading Xor over selects and phi nodes is pointless, so don't bother. // Threading over the select in "A ^ select(cond, B, C)" means evaluating // "A^B" and "A^C" and seeing if they are equal; but they are equal if and @@ -1668,13 +1895,15 @@ static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q, // "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 *TD, +Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyXorInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyXorInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } static Type *GetCompareTy(Value *Op) { @@ -1688,17 +1917,17 @@ static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred, Value *LHS, Value *RHS) { SelectInst *SI = dyn_cast(V); if (!SI) - return 0; + return nullptr; CmpInst *Cmp = dyn_cast(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 @@ -1729,16 +1958,16 @@ static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred, // If the C and C++ standards are ever made sufficiently restrictive in this // area, it may be possible to update LLVM's semantics accordingly and reinstate // this optimization. -static Constant *computePointerICmp(const DataLayout *TD, +static Constant *computePointerICmp(const DataLayout &DL, const TargetLibraryInfo *TLI, - CmpInst::Predicate Pred, - Value *LHS, Value *RHS) { + CmpInst::Predicate Pred, Value *LHS, + Value *RHS) { // First, skip past any trivial no-ops. LHS = LHS->stripPointerCasts(); RHS = RHS->stripPointerCasts(); // A non-null pointer is not equal to a null pointer. - if (llvm::isKnownNonNull(LHS) && isa(RHS) && + if (llvm::isKnownNonNull(LHS, TLI) && isa(RHS) && (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE)) return ConstantInt::get(GetCompareTy(LHS), !CmpInst::isTrueWhenEqual(Pred)); @@ -1746,7 +1975,7 @@ static Constant *computePointerICmp(const DataLayout *TD, // 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: @@ -1771,8 +2000,8 @@ static Constant *computePointerICmp(const DataLayout *TD, // numerous hazards. AliasAnalysis and its utilities rely on special rules // governing loads and stores which don't apply to icmps. Also, AliasAnalysis // doesn't need to guarantee pointer inequality when it says NoAlias. - Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS); - Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS); + Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS); + Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS); // If LHS and RHS are related via constant offsets to the same base // value, we can replace it with an icmp which just compares the offsets. @@ -1816,8 +2045,8 @@ static Constant *computePointerICmp(const DataLayout *TD, ConstantInt *RHSOffsetCI = dyn_cast(RHSOffset); uint64_t LHSSize, RHSSize; if (LHSOffsetCI && RHSOffsetCI && - getObjectSize(LHS, LHSSize, TD, TLI) && - getObjectSize(RHS, RHSSize, TD, TLI)) { + getObjectSize(LHS, LHSSize, DL, TLI) && + getObjectSize(RHS, RHSSize, DL, TLI)) { const APInt &LHSOffsetValue = LHSOffsetCI->getValue(); const APInt &RHSOffsetValue = RHSOffsetCI->getValue(); if (!LHSOffsetValue.isNegative() && @@ -1838,10 +2067,64 @@ static Constant *computePointerICmp(const DataLayout *TD, return ConstantInt::get(GetCompareTy(LHS), !CmpInst::isTrueWhenEqual(Pred)); } + + // Even if an non-inbounds GEP occurs along the path we can still optimize + // equality comparisons concerning the result. We avoid walking the whole + // chain again by starting where the last calls to + // stripAndComputeConstantOffsets left off and accumulate the offsets. + Constant *LHSNoBound = stripAndComputeConstantOffsets(DL, LHS, true); + Constant *RHSNoBound = stripAndComputeConstantOffsets(DL, RHS, true); + if (LHS == RHS) + return ConstantExpr::getICmp(Pred, + ConstantExpr::getAdd(LHSOffset, LHSNoBound), + ConstantExpr::getAdd(RHSOffset, RHSNoBound)); + + // If one side of the equality comparison must come from a noalias call + // (meaning a system memory allocation function), and the other side must + // come from a pointer that cannot overlap with dynamically-allocated + // memory within the lifetime of the current function (allocas, byval + // arguments, globals), then determine the comparison result here. + SmallVector LHSUObjs, RHSUObjs; + GetUnderlyingObjects(LHS, LHSUObjs, DL); + GetUnderlyingObjects(RHS, RHSUObjs, DL); + + // Is the set of underlying objects all noalias calls? + auto IsNAC = [](SmallVectorImpl &Objects) { + return std::all_of(Objects.begin(), Objects.end(), isNoAliasCall); + }; + + // Is the set of underlying objects all things which must be disjoint from + // noalias calls. For allocas, we consider only static ones (dynamic + // allocas might be transformed into calls to malloc not simultaneously + // live with the compared-to allocation). For globals, we exclude symbols + // that might be resolve lazily to symbols in another dynamically-loaded + // library (and, thus, could be malloc'ed by the implementation). + auto IsAllocDisjoint = [](SmallVectorImpl &Objects) { + return std::all_of(Objects.begin(), Objects.end(), + [](Value *V){ + if (const AllocaInst *AI = dyn_cast(V)) + return AI->getParent() && AI->getParent()->getParent() && + AI->isStaticAlloca(); + if (const GlobalValue *GV = dyn_cast(V)) + return (GV->hasLocalLinkage() || + GV->hasHiddenVisibility() || + GV->hasProtectedVisibility() || + GV->hasUnnamedAddr()) && + !GV->isThreadLocal(); + if (const Argument *A = dyn_cast(V)) + return A->hasByValAttr(); + return false; + }); + }; + + if ((IsNAC(LHSUObjs) && IsAllocDisjoint(RHSUObjs)) || + (IsNAC(RHSUObjs) && IsAllocDisjoint(LHSUObjs))) + return ConstantInt::get(GetCompareTy(LHS), + !CmpInst::isTrueWhenEqual(Pred)); } // Otherwise, fail. - return 0; + return nullptr; } /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can @@ -1853,7 +2136,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, if (Constant *CLHS = dyn_cast(LHS)) { if (Constant *CRHS = dyn_cast(RHS)) - return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI); + return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI); // If we have a constant, make sure it is on the RHS. std::swap(LHS, RHS); @@ -1892,6 +2175,19 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // 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 X @@ -1903,6 +2199,10 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, if (match(RHS, m_One())) return LHS; break; + case ICmpInst::ICMP_ULE: + if (isImpliedCondition(LHS, RHS, Q.DL)) + return getTrue(ITy); + break; } } @@ -1917,40 +2217,46 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, return getTrue(ITy); case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_ULE: - if (isKnownNonZero(LHS, Q.TD)) + if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) return getFalse(ITy); break; case ICmpInst::ICMP_NE: case ICmpInst::ICMP_UGT: - if (isKnownNonZero(LHS, Q.TD)) + if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) return getTrue(ITy); break; case ICmpInst::ICMP_SLT: - ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); + ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (LHSKnownNegative) return getTrue(ITy); if (LHSKnownNonNegative) return getFalse(ITy); break; case ICmpInst::ICMP_SLE: - ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); + ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (LHSKnownNegative) return getTrue(ITy); - if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD)) + if (LHSKnownNonNegative && + isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) return getFalse(ITy); break; case ICmpInst::ICMP_SGE: - ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); + ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (LHSKnownNegative) return getFalse(ITy); if (LHSKnownNonNegative) return getTrue(ITy); break; case ICmpInst::ICMP_SGT: - ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); + ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (LHSKnownNegative) return getFalse(ITy); - if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD)) + if (LHSKnownNonNegative && + isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT)) return getTrue(ITy); break; } @@ -1967,7 +2273,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // Many binary operators with constant RHS have easy to compute constant // range. Use them to check whether the comparison is a tautology. - uint32_t Width = CI->getBitWidth(); + unsigned Width = CI->getBitWidth(); APInt Lower = APInt(Width, 0); APInt Upper = APInt(Width, 0); ConstantInt *CI2; @@ -1986,20 +2292,63 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, APInt NegOne = APInt::getAllOnesValue(Width); if (!CI2->isZero()) Upper = NegOne.udiv(CI2->getValue()) + 1; + } else if (match(LHS, m_SDiv(m_ConstantInt(CI2), m_Value()))) { + if (CI2->isMinSignedValue()) { + // 'sdiv INT_MIN, x' produces [INT_MIN, INT_MIN / -2]. + Lower = CI2->getValue(); + Upper = Lower.lshr(1) + 1; + } else { + // 'sdiv CI2, x' produces [-|CI2|, |CI2|]. + Upper = CI2->getValue().abs() + 1; + Lower = (-Upper) + 1; + } } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) { - // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2]. APInt IntMin = APInt::getSignedMinValue(Width); APInt IntMax = APInt::getSignedMaxValue(Width); - APInt Val = CI2->getValue().abs(); - if (!Val.isMinValue()) { + APInt Val = CI2->getValue(); + if (Val.isAllOnesValue()) { + // 'sdiv x, -1' produces [INT_MIN + 1, INT_MAX] + // where CI2 != -1 and CI2 != 0 and CI2 != 1 + Lower = IntMin + 1; + Upper = IntMax + 1; + } else if (Val.countLeadingZeros() < Width - 1) { + // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2] + // where CI2 != -1 and CI2 != 0 and CI2 != 1 Lower = IntMin.sdiv(Val); - Upper = IntMax.sdiv(Val) + 1; + Upper = IntMax.sdiv(Val); + if (Lower.sgt(Upper)) + std::swap(Lower, Upper); + Upper = Upper + 1; + assert(Upper != Lower && "Upper part of range has wrapped!"); + } + } else if (match(LHS, m_NUWShl(m_ConstantInt(CI2), m_Value()))) { + // 'shl nuw CI2, x' produces [CI2, CI2 << CLZ(CI2)] + Lower = CI2->getValue(); + Upper = Lower.shl(Lower.countLeadingZeros()) + 1; + } else if (match(LHS, m_NSWShl(m_ConstantInt(CI2), m_Value()))) { + if (CI2->isNegative()) { + // 'shl nsw CI2, x' produces [CI2 << CLO(CI2)-1, CI2] + unsigned ShiftAmount = CI2->getValue().countLeadingOnes() - 1; + Lower = CI2->getValue().shl(ShiftAmount); + Upper = CI2->getValue() + 1; + } else { + // 'shl nsw CI2, x' produces [CI2, CI2 << CLZ(CI2)-1] + unsigned ShiftAmount = CI2->getValue().countLeadingZeros() - 1; + Lower = CI2->getValue(); + Upper = CI2->getValue().shl(ShiftAmount) + 1; } } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) { // 'lshr x, CI2' produces [0, UINT_MAX >> CI2]. APInt NegOne = APInt::getAllOnesValue(Width); if (CI2->getValue().ult(Width)) Upper = NegOne.lshr(CI2->getValue()) + 1; + } else if (match(LHS, m_LShr(m_ConstantInt(CI2), m_Value()))) { + // 'lshr CI2, x' produces [CI2 >> (Width-1), CI2]. + unsigned ShiftAmount = Width - 1; + if (!CI2->isZero() && cast(LHS)->isExact()) + ShiftAmount = CI2->getValue().countTrailingZeros(); + Lower = CI2->getValue().lshr(ShiftAmount); + Upper = CI2->getValue() + 1; } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) { // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2]. APInt IntMin = APInt::getSignedMinValue(Width); @@ -2008,15 +2357,38 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, Lower = IntMin.ashr(CI2->getValue()); Upper = IntMax.ashr(CI2->getValue()) + 1; } + } else if (match(LHS, m_AShr(m_ConstantInt(CI2), m_Value()))) { + unsigned ShiftAmount = Width - 1; + if (!CI2->isZero() && cast(LHS)->isExact()) + ShiftAmount = CI2->getValue().countTrailingZeros(); + if (CI2->isNegative()) { + // 'ashr CI2, x' produces [CI2, CI2 >> (Width-1)] + Lower = CI2->getValue(); + Upper = CI2->getValue().ashr(ShiftAmount) + 1; + } else { + // 'ashr CI2, x' produces [CI2 >> (Width-1), CI2] + Lower = CI2->getValue().ashr(ShiftAmount); + Upper = CI2->getValue() + 1; + } } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) { // 'or x, CI2' produces [CI2, UINT_MAX]. Lower = CI2->getValue(); } 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(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)) @@ -2024,6 +2396,30 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, } } + // If both operands have range metadata, use the metadata + // to simplify the comparison. + if (isa(RHS) && isa(LHS)) { + auto RHS_Instr = dyn_cast(RHS); + auto LHS_Instr = dyn_cast(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(LHS) && (isa(RHS) || isa(RHS))) { Instruction *LI = cast(LHS); @@ -2033,8 +2429,8 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input // if the integer type is the same size as the pointer type. - if (MaxRecurse && Q.TD && isa(LI) && - Q.TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) { + if (MaxRecurse && isa(LI) && + Q.DL.getTypeSizeInBits(SrcTy) == DstTy->getPrimitiveSizeInBits()) { if (Constant *RHSC = dyn_cast(RHS)) { // Transfer the cast to the constant. if (Value *V = SimplifyICmpInst(Pred, SrcOp, @@ -2183,12 +2579,20 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, } } + // 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(LHS); BinaryOperator *RBO = dyn_cast(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) { @@ -2246,6 +2650,63 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, } } + // icmp pred (or X, Y), X + if (LBO && match(LBO, m_CombineOr(m_Or(m_Value(), m_Specific(RHS)), + m_Or(m_Specific(RHS), m_Value())))) { + if (Pred == ICmpInst::ICMP_ULT) + return getFalse(ITy); + if (Pred == ICmpInst::ICMP_UGE) + return getTrue(ITy); + } + // icmp pred X, (or X, Y) + if (RBO && match(RBO, m_CombineOr(m_Or(m_Value(), m_Specific(LHS)), + m_Or(m_Specific(LHS), m_Value())))) { + if (Pred == ICmpInst::ICMP_ULE) + return getTrue(ITy); + if (Pred == ICmpInst::ICMP_UGT) + return getFalse(ITy); + } + + // icmp pred (and X, Y), X + if (LBO && match(LBO, m_CombineOr(m_And(m_Value(), m_Specific(RHS)), + m_And(m_Specific(RHS), m_Value())))) { + if (Pred == ICmpInst::ICMP_UGT) + return getFalse(ITy); + if (Pred == ICmpInst::ICMP_ULE) + return getTrue(ITy); + } + // icmp pred X, (and X, Y) + if (RBO && match(RBO, m_CombineOr(m_And(m_Value(), m_Specific(LHS)), + m_And(m_Specific(LHS), m_Value())))) { + if (Pred == ICmpInst::ICMP_UGE) + return getTrue(ITy); + if (Pred == ICmpInst::ICMP_ULT) + return getFalse(ITy); + } + + // 0 - (zext X) pred C + if (!CmpInst::isUnsigned(Pred) && match(LHS, m_Neg(m_ZExt(m_Value())))) { + if (ConstantInt *RHSC = dyn_cast(RHS)) { + if (RHSC->getValue().isStrictlyPositive()) { + if (Pred == ICmpInst::ICMP_SLT) + return ConstantInt::getTrue(RHSC->getContext()); + if (Pred == ICmpInst::ICMP_SGE) + return ConstantInt::getFalse(RHSC->getContext()); + if (Pred == ICmpInst::ICMP_EQ) + return ConstantInt::getFalse(RHSC->getContext()); + if (Pred == ICmpInst::ICMP_NE) + return ConstantInt::getTrue(RHSC->getContext()); + } + if (RHSC->getValue().isNonNegative()) { + if (Pred == ICmpInst::ICMP_SLE) + return ConstantInt::getTrue(RHSC->getContext()); + if (Pred == ICmpInst::ICMP_SGT) + return ConstantInt::getFalse(RHSC->getContext()); + } + } + } + + // icmp pred (urem X, Y), Y if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) { bool KnownNonNegative, KnownNegative; switch (Pred) { @@ -2253,7 +2714,8 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, break; case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_SGE: - ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD); + ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2263,7 +2725,8 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, return getFalse(ITy); case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_SLE: - ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD); + ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2273,6 +2736,8 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, return getTrue(ITy); } } + + // icmp pred X, (urem Y, X) if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) { bool KnownNonNegative, KnownNegative; switch (Pred) { @@ -2280,7 +2745,8 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, break; case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_SGE: - ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD); + ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2290,7 +2756,8 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, return getTrue(ITy); case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_SLE: - ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD); + ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC, + Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2310,6 +2777,41 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, return getTrue(ITy); } + // handle: + // CI2 << X == CI + // CI2 << X != CI + // + // where CI2 is a power of 2 and CI isn't + if (auto *CI = dyn_cast(RHS)) { + const APInt *CI2Val, *CIVal = &CI->getValue(); + if (LBO && match(LBO, m_Shl(m_APInt(CI2Val), m_Value())) && + CI2Val->isPowerOf2()) { + if (!CIVal->isPowerOf2()) { + // CI2 << X can equal zero in some circumstances, + // this simplification is unsafe if CI is zero. + // + // We know it is safe if: + // - The shift is nsw, we can't shift out the one bit. + // - The shift is nuw, we can't shift out the one bit. + // - CI2 is one + // - CI isn't zero + if (LBO->hasNoSignedWrap() || LBO->hasNoUnsignedWrap() || + *CI2Val == 1 || !CI->isZero()) { + if (Pred == ICmpInst::ICMP_EQ) + return ConstantInt::getFalse(RHS->getContext()); + if (Pred == ICmpInst::ICMP_NE) + return ConstantInt::getTrue(RHS->getContext()); + } + } + if (CIVal->isSignBit() && *CI2Val == 1) { + if (Pred == ICmpInst::ICMP_UGT) + return ConstantInt::getFalse(RHS->getContext()); + if (Pred == ICmpInst::ICMP_ULE) + return ConstantInt::getTrue(RHS->getContext()); + } + } + } + if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() && LBO->getOperand(1) == RBO->getOperand(1)) { switch (LBO->getOpcode()) { @@ -2533,7 +3035,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // Simplify comparisons of related pointers using a powerful, recursive // GEP-walk when we have target data available.. if (LHS->getType()->isPointerTy()) - if (Constant *C = computePointerICmp(Q.TD, Q.TLI, Pred, LHS, RHS)) + if (Constant *C = computePointerICmp(Q.DL, Q.TLI, Pred, LHS, RHS)) return C; if (GetElementPtrInst *GLHS = dyn_cast(LHS)) { @@ -2548,15 +3050,34 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // what constant folding can make out of it. Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType()); SmallVector IndicesLHS(GLHS->idx_begin(), GLHS->idx_end()); - Constant *NewLHS = ConstantExpr::getGetElementPtr(Null, IndicesLHS); + Constant *NewLHS = ConstantExpr::getGetElementPtr( + GLHS->getSourceElementType(), Null, IndicesLHS); SmallVector IndicesRHS(GRHS->idx_begin(), GRHS->idx_end()); - Constant *NewRHS = ConstantExpr::getGetElementPtr(Null, IndicesRHS); + Constant *NewRHS = ConstantExpr::getGetElementPtr( + GLHS->getSourceElementType(), Null, IndicesRHS); return ConstantExpr::getICmp(Pred, NewLHS, NewRHS); } } } + // If a bit is known to be zero for A and known to be one for B, + // then A and B cannot be equal. + if (ICmpInst::isEquality(Pred)) { + if (ConstantInt *CI = dyn_cast(RHS)) { + uint32_t BitWidth = CI->getBitWidth(); + APInt LHSKnownZero(BitWidth, 0); + APInt LHSKnownOne(BitWidth, 0); + computeKnownBits(LHS, LHSKnownZero, LHSKnownOne, Q.DL, /*Depth=*/0, Q.AC, + Q.CxtI, Q.DT); + const APInt &RHSVal = CI->getValue(); + if (((LHSKnownZero & RHSVal) != 0) || ((LHSKnownOne & ~RHSVal) != 0)) + return Pred == ICmpInst::ICMP_EQ + ? ConstantInt::getFalse(CI->getContext()) + : ConstantInt::getTrue(CI->getContext()); + } + } + // If the comparison is with the result of a select instruction, check whether // comparing with either branch of the select always yields the same value. if (isa(LHS) || isa(RHS)) @@ -2569,27 +3090,29 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse)) return V; - return 0; + return nullptr; } Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, - const DataLayout *TD, + const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyICmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT), + const DominatorTree *DT, AssumptionCache *AC, + 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. 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 (Constant *CLHS = dyn_cast(LHS)) { if (Constant *CRHS = dyn_cast(RHS)) - return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI); + return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI); // If we have a constant, make sure it is on the RHS. std::swap(LHS, RHS); @@ -2602,8 +3125,21 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, if (Pred == FCmpInst::FCMP_TRUE) return ConstantInt::get(GetCompareTy(LHS), 1); - if (isa(RHS)) // fcmp pred X, undef -> undef - return UndefValue::get(GetCompareTy(LHS)); + // 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(LHS) || isa(RHS)) { + // Choosing NaN for the undef will always make unordered comparison succeed + // and ordered comparison fail. + return ConstantInt::get(GetCompareTy(LHS), CmpInst::isUnordered(Pred)); + } // fcmp x,x -> true/false. Not all compares are foldable. if (LHS == RHS) { @@ -2614,42 +3150,55 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, } // Handle fcmp with constant RHS - if (Constant *RHSC = dyn_cast(RHS)) { + if (ConstantFP *CFP = dyn_cast(RHS)) { // If the constant is a nan, see if we can fold the comparison based on it. - if (ConstantFP *CFP = dyn_cast(RHSC)) { - if (CFP->getValueAPF().isNaN()) { - if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo" + if (CFP->getValueAPF().isNaN()) { + if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo" + return ConstantInt::getFalse(CFP->getContext()); + assert(FCmpInst::isUnordered(Pred) && + "Comparison must be either ordered or unordered!"); + // True if unordered. + return ConstantInt::getTrue(CFP->getContext()); + } + // Check whether the constant is an infinity. + if (CFP->getValueAPF().isInfinity()) { + if (CFP->getValueAPF().isNegative()) { + switch (Pred) { + case FCmpInst::FCMP_OLT: + // No value is ordered and less than negative infinity. return ConstantInt::getFalse(CFP->getContext()); - assert(FCmpInst::isUnordered(Pred) && - "Comparison must be either ordered or unordered!"); - // True if unordered. - return ConstantInt::getTrue(CFP->getContext()); - } - // Check whether the constant is an infinity. - if (CFP->getValueAPF().isInfinity()) { - if (CFP->getValueAPF().isNegative()) { - switch (Pred) { - case FCmpInst::FCMP_OLT: - // No value is ordered and less than negative infinity. - return ConstantInt::getFalse(CFP->getContext()); - case FCmpInst::FCMP_UGE: - // All values are unordered with or at least negative infinity. - return ConstantInt::getTrue(CFP->getContext()); - default: - break; - } - } else { - switch (Pred) { - case FCmpInst::FCMP_OGT: - // No value is ordered and greater than infinity. - return ConstantInt::getFalse(CFP->getContext()); - case FCmpInst::FCMP_ULE: - // All values are unordered with and at most infinity. - return ConstantInt::getTrue(CFP->getContext()); - default: - break; - } + case FCmpInst::FCMP_UGE: + // All values are unordered with or at least negative infinity. + return ConstantInt::getTrue(CFP->getContext()); + default: + break; } + } else { + switch (Pred) { + case FCmpInst::FCMP_OGT: + // No value is ordered and greater than infinity. + return ConstantInt::getFalse(CFP->getContext()); + case FCmpInst::FCMP_ULE: + // All values are unordered with and at most infinity. + return ConstantInt::getTrue(CFP->getContext()); + default: + break; + } + } + } + if (CFP->getValueAPF().isZero()) { + switch (Pred) { + case FCmpInst::FCMP_UGE: + if (CannotBeOrderedLessThanZero(LHS)) + return ConstantInt::getTrue(CFP->getContext()); + break; + case FCmpInst::FCMP_OLT: + // X < 0 + if (CannotBeOrderedLessThanZero(LHS)) + return ConstantInt::getFalse(CFP->getContext()); + break; + default: + break; } } } @@ -2666,15 +3215,100 @@ static Value *SimplifyFCmpInst(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, - const DataLayout *TD, + FastMathFlags FMF, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT), - RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyFCmpInst(Predicate, LHS, RHS, FMF, + Query(DL, TLI, DT, AC, CxtI), RecursionLimit); +} + +/// SimplifyWithOpReplaced - 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(V); + if (!I) + return nullptr; + + // If this is a binary operator, try to simplify it with the replaced op. + if (auto *B = dyn_cast(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(B)) + if (B->hasNoSignedWrap() || B->hasNoUnsignedWrap()) + return nullptr; + if (isa(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(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(RepOp)) { + // Build a list of all constant operands. + SmallVector 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(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(I)) + return ConstantFoldCompareInstOperands(C->getPredicate(), ConstOps[0], + ConstOps[1], Q.DL, Q.TLI); + + if (LoadInst *LI = dyn_cast(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 @@ -2684,8 +3318,12 @@ static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal, unsigned MaxRecurse) { // select true, X, Y -> X // select false, X, Y -> Y - if (ConstantInt *CB = dyn_cast(CondVal)) - return CB->getZExtValue() ? TrueVal : FalseVal; + if (Constant *CB = dyn_cast(CondVal)) { + if (CB->isAllOnesValue()) + return TrueVal; + if (CB->isNullValue()) + return FalseVal; + } // select C, X, X -> X if (TrueVal == FalseVal) @@ -2701,62 +3339,207 @@ static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal, if (isa(FalseVal)) // select C, X, undef -> X return TrueVal; - return 0; + if (const auto *ICI = dyn_cast(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(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(CmpRHS, m_Zero())) { + X = CmpLHS; + Y = &MinSignedValue; + IsBitTest = true; + TrueWhenUnset = false; + } else if (Pred == ICmpInst::ICMP_SGT && match(CmpRHS, m_AllOnes())) { + X = CmpLHS; + Y = &MinSignedValue; + IsBitTest = true; + TrueWhenUnset = true; + } + if (IsBitTest) { + const APInt *C; + // (X & Y) == 0 ? X & ~Y : X --> X + // (X & Y) != 0 ? X & ~Y : X --> X & ~Y + if (FalseVal == X && match(TrueVal, m_And(m_Specific(X), m_APInt(C))) && + *Y == ~*C) + return TrueWhenUnset ? FalseVal : TrueVal; + // (X & Y) == 0 ? X : X & ~Y --> X & ~Y + // (X & Y) != 0 ? X : X & ~Y --> X + if (TrueVal == X && match(FalseVal, m_And(m_Specific(X), m_APInt(C))) && + *Y == ~*C) + return TrueWhenUnset ? FalseVal : TrueVal; + + if (Y->isPowerOf2()) { + // (X & Y) == 0 ? X | Y : X --> X | Y + // (X & Y) != 0 ? X | Y : X --> X + if (FalseVal == X && match(TrueVal, m_Or(m_Specific(X), m_APInt(C))) && + *Y == *C) + return TrueWhenUnset ? TrueVal : FalseVal; + // (X & Y) == 0 ? X : X | Y --> X + // (X & Y) != 0 ? X : X | Y --> X | Y + if (TrueVal == X && match(FalseVal, m_Or(m_Specific(X), m_APInt(C))) && + *Y == *C) + 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; } Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal, - const DataLayout *TD, + const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifySelectInst(Cond, TrueVal, FalseVal, Query (TD, TLI, DT), - RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifySelectInst(Cond, TrueVal, FalseVal, + 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. -static Value *SimplifyGEPInst(ArrayRef Ops, const Query &Q, unsigned) { +static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef Ops, + const Query &Q, unsigned) { // The type of the GEP pointer operand. - PointerType *PtrTy = dyn_cast(Ops[0]->getType()); - // The GEP pointer operand is not a pointer, it's a vector of pointers. - if (!PtrTy) - return 0; + unsigned AS = + cast(Ops[0]->getType()->getScalarType())->getAddressSpace(); // getelementptr P -> P. if (Ops.size() == 1) return Ops[0]; - if (isa(Ops[0])) { - // Compute the (pointer) type returned by the GEP instruction. - Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1)); - Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace()); + // Compute the (pointer) type returned by the GEP instruction. + Type *LastType = GetElementPtrInst::getIndexedType(SrcTy, Ops.slice(1)); + Type *GEPTy = PointerType::get(LastType, AS); + if (VectorType *VT = dyn_cast(Ops[0]->getType())) + GEPTy = VectorType::get(GEPTy, VT->getNumElements()); + + if (isa(Ops[0])) return UndefValue::get(GEPTy); - } if (Ops.size() == 2) { // getelementptr P, 0 -> P. - if (ConstantInt *C = dyn_cast(Ops[1])) - if (C->isZero()) - return Ops[0]; - // getelementptr P, N -> P if P points to a type of zero size. - if (Q.TD) { - Type *Ty = PtrTy->getElementType(); - if (Ty->isSized() && Q.TD->getTypeAllocSize(Ty) == 0) + if (match(Ops[1], m_Zero())) + return Ops[0]; + + Type *Ty = SrcTy; + if (Ty->isSized()) { + Value *P; + uint64_t C; + uint64_t TyAllocSize = Q.DL.getTypeAllocSize(Ty); + // getelementptr P, N -> P if P points to a type of zero size. + if (TyAllocSize == 0) return Ops[0]; + + // The following transforms are only safe if the ptrtoint cast + // doesn't truncate the pointers. + if (Ops[1]->getType()->getScalarSizeInBits() == + Q.DL.getPointerSizeInBits(AS)) { + auto PtrToIntOrZero = [GEPTy](Value *P) -> Value * { + if (match(P, m_Zero())) + return Constant::getNullValue(GEPTy); + Value *Temp; + if (match(P, m_PtrToInt(m_Value(Temp)))) + if (Temp->getType() == GEPTy) + return Temp; + return nullptr; + }; + + // getelementptr V, (sub P, V) -> P if P points to a type of size 1. + if (TyAllocSize == 1 && + match(Ops[1], m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))))) + if (Value *R = PtrToIntOrZero(P)) + return R; + + // getelementptr V, (ashr (sub P, V), C) -> Q + // if P points to a type of size 1 << C. + if (match(Ops[1], + m_AShr(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))), + m_ConstantInt(C))) && + TyAllocSize == 1ULL << C) + if (Value *R = PtrToIntOrZero(P)) + return R; + + // getelementptr V, (sdiv (sub P, V), C) -> Q + // if P points to a type of size C. + if (match(Ops[1], + m_SDiv(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))), + m_SpecificInt(TyAllocSize)))) + if (Value *R = PtrToIntOrZero(P)) + return R; + } } } // Check to see if this is constant foldable. for (unsigned i = 0, e = Ops.size(); i != e; ++i) if (!isa(Ops[i])) - return 0; + return nullptr; - return ConstantExpr::getGetElementPtr(cast(Ops[0]), Ops.slice(1)); + return ConstantExpr::getGetElementPtr(SrcTy, cast(Ops[0]), + Ops.slice(1)); } -Value *llvm::SimplifyGEPInst(ArrayRef Ops, const DataLayout *TD, +Value *llvm::SimplifyGEPInst(ArrayRef Ops, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyGEPInst(Ops, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyGEPInst( + cast(Ops[0]->getType()->getScalarType())->getElementType(), + Ops, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we @@ -2785,26 +3568,91 @@ static Value *SimplifyInsertValueInst(Value *Agg, Value *Val, return Agg; } - return 0; + return nullptr; } -Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val, - ArrayRef Idxs, - const DataLayout *TD, - const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query (TD, TLI, DT), +Value *llvm::SimplifyInsertValueInst( + Value *Agg, Value *Val, ArrayRef Idxs, const DataLayout &DL, + const TargetLibraryInfo *TLI, const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } +/// SimplifyExtractValueInst - Given operands for an ExtractValueInst, see if we +/// can fold the result. If not, this returns null. +static Value *SimplifyExtractValueInst(Value *Agg, ArrayRef Idxs, + const Query &, unsigned) { + if (auto *CAgg = dyn_cast(Agg)) + return ConstantFoldExtractValueInstruction(CAgg, Idxs); + + // extractvalue x, (insertvalue y, elt, n), n -> elt + unsigned NumIdxs = Idxs.size(); + for (auto *IVI = dyn_cast(Agg); IVI != nullptr; + IVI = dyn_cast(IVI->getAggregateOperand())) { + ArrayRef 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 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); +} + +/// SimplifyExtractElementInst - 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(Vec)) { + if (auto *CIdx = dyn_cast(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(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(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); +} + /// SimplifyPHINode - 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. - Value *CommonValue = 0; + Value *CommonValue = nullptr; bool HasUndefInput = false; - for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { - Value *Incoming = PN->getIncomingValue(i); + for (Value *Incoming : PN->incoming_values()) { // If the incoming value is the phi node itself, it can safely be skipped. if (Incoming == PN) continue; if (isa(Incoming)) { @@ -2813,7 +3661,7 @@ static Value *SimplifyPHINode(PHINode *PN, const Query &Q) { continue; } if (CommonValue && Incoming != CommonValue) - return 0; // Not the same, bail out. + return nullptr; // Not the same, bail out. CommonValue = Incoming; } @@ -2826,22 +3674,24 @@ static Value *SimplifyPHINode(PHINode *PN, const Query &Q) { // 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; } static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) { if (Constant *C = dyn_cast(Op)) - return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.TD, Q.TLI); + return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.DL, Q.TLI); - return 0; + return nullptr; } -Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *TD, +Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyTruncInst(Op, Ty, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyTruncInst(Op, Ty, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } //=== Helper functions for higher up the class hierarchy. @@ -2868,10 +3718,12 @@ static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, return SimplifyFMulInst (LHS, RHS, FastMathFlags(), Q, MaxRecurse); case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse); case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse); - case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, Q, MaxRecurse); + case Instruction::FDiv: + return SimplifyFDivInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse); case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse); case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse); - case Instruction::FRem: return SimplifyFRemInst(LHS, RHS, Q, MaxRecurse); + case Instruction::FRem: + return SimplifyFRemInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse); case Instruction::Shl: return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false, Q, MaxRecurse); @@ -2886,7 +3738,7 @@ static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, if (Constant *CLHS = dyn_cast(LHS)) if (Constant *CRHS = dyn_cast(RHS)) { Constant *COps[] = {CLHS, CRHS}; - return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.TD, + return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.DL, Q.TLI); } @@ -2907,14 +3759,44 @@ static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse)) return V; - return 0; + return nullptr; + } +} + +/// SimplifyFPBinOp - 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, + const FastMathFlags &FMF, const Query &Q, + unsigned MaxRecurse) { + switch (Opcode) { + case Instruction::FAdd: + return SimplifyFAddInst(LHS, RHS, FMF, Q, MaxRecurse); + case Instruction::FSub: + return SimplifyFSubInst(LHS, RHS, FMF, Q, MaxRecurse); + case Instruction::FMul: + return SimplifyFMulInst(LHS, RHS, FMF, Q, MaxRecurse); + default: + return SimplifyBinOp(Opcode, LHS, RHS, Q, MaxRecurse); } } Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyBinOp(Opcode, LHS, RHS, Query (TD, TLI, DT), RecursionLimit); + const DataLayout &DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyBinOp(Opcode, LHS, RHS, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); +} + +Value *llvm::SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS, + const FastMathFlags &FMF, const DataLayout &DL, + const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyFPBinOp(Opcode, LHS, RHS, FMF, Query(DL, TLI, DT, AC, CxtI), + RecursionLimit); } /// SimplifyCmpInst - Given operands for a CmpInst, see if we can @@ -2923,13 +3805,14 @@ 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, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT), + const DataLayout &DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyCmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } @@ -2944,24 +3827,64 @@ static bool IsIdempotent(Intrinsic::ID ID) { case Intrinsic::trunc: case Intrinsic::rint: case Intrinsic::nearbyint: + case Intrinsic::round: return true; } } template -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(LHS) || isa(RHS)) + return UndefValue::get(ReturnType); + } + + if (IID == Intrinsic::uadd_with_overflow || + IID == Intrinsic::sadd_with_overflow) { + // X + undef -> undef + if (isa(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 0; + return nullptr; // Unary Ops - if (std::distance(ArgBegin, ArgEnd) == 1) + if (NumOperands == 1) if (IntrinsicInst *II = dyn_cast(*ArgBegin)) if (II->getIntrinsicID() == IID) return II; - return 0; + return nullptr; } template @@ -2978,22 +3901,21 @@ static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd, Function *F = dyn_cast(V); if (!F) - return 0; + return nullptr; - if (unsigned IID = F->getIntrinsicID()) - if (Value *Ret = - SimplifyIntrinsic((Intrinsic::ID) IID, ArgBegin, ArgEnd, Q, MaxRecurse)) + if (F->isIntrinsic()) + if (Value *Ret = SimplifyIntrinsic(F, ArgBegin, ArgEnd, Q, MaxRecurse)) return Ret; if (!canConstantFoldCallTo(F)) - return 0; + return nullptr; SmallVector ConstantArgs; ConstantArgs.reserve(ArgEnd - ArgBegin); for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) { Constant *C = dyn_cast(*I); if (!C) - return 0; + return nullptr; ConstantArgs.push_back(C); } @@ -3001,139 +3923,176 @@ static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd, } Value *llvm::SimplifyCall(Value *V, User::op_iterator ArgBegin, - User::op_iterator ArgEnd, const DataLayout *TD, - const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(TD, TLI, DT), + User::op_iterator ArgEnd, const DataLayout &DL, + const TargetLibraryInfo *TLI, const DominatorTree *DT, + AssumptionCache *AC, const Instruction *CxtI) { + return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } Value *llvm::SimplifyCall(Value *V, ArrayRef Args, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyCall(V, Args.begin(), Args.end(), Query(TD, TLI, DT), - RecursionLimit); + const DataLayout &DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionCache *AC, + const Instruction *CxtI) { + return ::SimplifyCall(V, Args.begin(), Args.end(), + Query(DL, TLI, DT, AC, CxtI), RecursionLimit); } /// SimplifyInstruction - See if we can compute a simplified version of this /// instruction. If not, this returns null. -Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout *TD, +Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout &DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { + const DominatorTree *DT, AssumptionCache *AC) { Value *Result; switch (I->getOpcode()) { default: - Result = ConstantFoldInstruction(I, TD, TLI); + Result = ConstantFoldInstruction(I, DL, TLI); break; case Instruction::FAdd: Result = SimplifyFAddInst(I->getOperand(0), I->getOperand(1), - I->getFastMathFlags(), TD, TLI, DT); + I->getFastMathFlags(), DL, TLI, DT, AC, I); break; case Instruction::Add: Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1), cast(I)->hasNoSignedWrap(), - cast(I)->hasNoUnsignedWrap(), - TD, TLI, DT); + cast(I)->hasNoUnsignedWrap(), DL, + TLI, DT, AC, I); break; case Instruction::FSub: Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1), - I->getFastMathFlags(), TD, TLI, DT); + I->getFastMathFlags(), DL, TLI, DT, AC, I); break; case Instruction::Sub: Result = SimplifySubInst(I->getOperand(0), I->getOperand(1), cast(I)->hasNoSignedWrap(), - cast(I)->hasNoUnsignedWrap(), - TD, TLI, DT); + cast(I)->hasNoUnsignedWrap(), DL, + TLI, DT, AC, I); break; case Instruction::FMul: Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1), - I->getFastMathFlags(), TD, TLI, DT); + I->getFastMathFlags(), DL, TLI, DT, AC, I); break; case Instruction::Mul: - Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = + SimplifyMulInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I); break; case Instruction::SDiv: - Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, + AC, I); break; case Instruction::UDiv: - Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, + AC, I); break; case Instruction::FDiv: - Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), + I->getFastMathFlags(), DL, TLI, DT, AC, I); break; case Instruction::SRem: - Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, + AC, I); break; case Instruction::URem: - Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, + AC, I); break; case Instruction::FRem: - Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), + I->getFastMathFlags(), DL, TLI, DT, AC, I); break; case Instruction::Shl: Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1), cast(I)->hasNoSignedWrap(), - cast(I)->hasNoUnsignedWrap(), - TD, TLI, DT); + cast(I)->hasNoUnsignedWrap(), DL, + TLI, DT, AC, I); break; case Instruction::LShr: Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1), - cast(I)->isExact(), - TD, TLI, DT); + cast(I)->isExact(), DL, TLI, DT, + AC, I); break; case Instruction::AShr: Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1), - cast(I)->isExact(), - TD, TLI, DT); + cast(I)->isExact(), DL, TLI, DT, + AC, I); break; case Instruction::And: - Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = + SimplifyAndInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I); break; case Instruction::Or: - Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = + SimplifyOrInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I); break; case Instruction::Xor: - Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = + SimplifyXorInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I); break; case Instruction::ICmp: - Result = SimplifyICmpInst(cast(I)->getPredicate(), - I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = + SimplifyICmpInst(cast(I)->getPredicate(), I->getOperand(0), + I->getOperand(1), DL, TLI, DT, AC, I); break; case Instruction::FCmp: Result = SimplifyFCmpInst(cast(I)->getPredicate(), - I->getOperand(0), I->getOperand(1), TD, TLI, DT); + 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), - I->getOperand(2), TD, TLI, DT); + I->getOperand(2), DL, TLI, DT, AC, I); break; case Instruction::GetElementPtr: { SmallVector Ops(I->op_begin(), I->op_end()); - Result = SimplifyGEPInst(Ops, TD, TLI, DT); + Result = SimplifyGEPInst(Ops, DL, TLI, DT, AC, I); break; } case Instruction::InsertValue: { InsertValueInst *IV = cast(I); Result = SimplifyInsertValueInst(IV->getAggregateOperand(), IV->getInsertedValueOperand(), - IV->getIndices(), TD, TLI, DT); + IV->getIndices(), DL, TLI, DT, AC, I); + break; + } + case Instruction::ExtractValue: { + auto *EVI = cast(I); + Result = SimplifyExtractValueInst(EVI->getAggregateOperand(), + EVI->getIndices(), DL, TLI, DT, AC, I); + break; + } + case Instruction::ExtractElement: { + auto *EEI = cast(I); + Result = SimplifyExtractElementInst( + EEI->getVectorOperand(), EEI->getIndexOperand(), DL, TLI, DT, AC, I); break; } case Instruction::PHI: - Result = SimplifyPHINode(cast(I), Query (TD, TLI, DT)); + Result = SimplifyPHINode(cast(I), Query(DL, TLI, DT, AC, I)); break; case Instruction::Call: { CallSite CS(cast(I)); - Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(), - TD, TLI, DT); + Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(), DL, + TLI, DT, AC, I); break; } case Instruction::Trunc: - Result = SimplifyTruncInst(I->getOperand(0), I->getType(), TD, TLI, DT); + Result = + SimplifyTruncInst(I->getOperand(0), I->getType(), DL, TLI, DT, AC, I); 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. @@ -3152,19 +4111,19 @@ Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout *TD, /// This routine returns 'true' only when *it* simplifies something. The passed /// in simplified value does not count toward this. static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { + const DominatorTree *DT, + AssumptionCache *AC) { bool Simplified = false; SmallSetVector Worklist; + const DataLayout &DL = I->getModule()->getDataLayout(); // 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(*UI)); + for (User *U : I->users()) + if (U != I) + Worklist.insert(cast(U)); // Replace the instruction with its simplified value. I->replaceAllUsesWith(SimpleV); @@ -3182,7 +4141,7 @@ static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV, I = Worklist[Idx]; // See if this instruction simplifies. - SimpleV = SimplifyInstruction(I, TD, TLI, DT); + SimpleV = SimplifyInstruction(I, DL, TLI, DT, AC); if (!SimpleV) continue; @@ -3191,9 +4150,8 @@ static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *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(*UI)); + for (User *U : I->users()) + Worklist.insert(cast(U)); // Replace the instruction with its simplified value. I->replaceAllUsesWith(SimpleV); @@ -3207,17 +4165,17 @@ static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV, } bool llvm::recursivelySimplifyInstruction(Instruction *I, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return replaceAndRecursivelySimplifyImpl(I, 0, TD, TLI, DT); + const DominatorTree *DT, + AssumptionCache *AC) { + return replaceAndRecursivelySimplifyImpl(I, nullptr, TLI, DT, AC); } bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV, - const DataLayout *TD, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { + const DominatorTree *DT, + AssumptionCache *AC) { assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!"); assert(SimpleV && "Must provide a simplified value."); - return replaceAndRecursivelySimplifyImpl(I, SimpleV, TD, TLI, DT); + return replaceAndRecursivelySimplifyImpl(I, SimpleV, TLI, DT, AC); }