X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FAnalysis%2FInstructionSimplify.cpp;h=5c536aa79c480c657aefd31481aa65ef1aecddf9;hp=d5e38e5c112493c53b1fd7ea928b01060059b282;hb=e4a5390406b430729dcf7c5eacb8e4083a656ac0;hpb=3e3de565e9c7258fb97773b3a64fc091355cb2de diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index d5e38e5c112..5c536aa79c4 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -17,38 +17,46 @@ // //===----------------------------------------------------------------------===// -#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/MemoryBuiltins.h" #include "llvm/Analysis/ValueTracking.h" +#include "llvm/IR/ConstantRange.h" #include "llvm/IR/DataLayout.h" +#include "llvm/IR/Dominators.h" +#include "llvm/IR/GetElementPtrTypeIterator.h" #include "llvm/IR/GlobalAlias.h" #include "llvm/IR/Operator.h" -#include "llvm/Support/ConstantRange.h" -#include "llvm/Support/GetElementPtrTypeIterator.h" -#include "llvm/Support/PatternMatch.h" -#include "llvm/Support/ValueHandle.h" +#include "llvm/IR/PatternMatch.h" +#include "llvm/IR/ValueHandle.h" +#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; + AssumptionTracker *AT; + 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, AssumptionTracker *at = nullptr, + const Instruction *cxti = nullptr) + : DL(DL), TLI(tli), DT(dt), AT(at), CxtI(cxti) {} }; +} // end anonymous namespace static Value *SimplifyAndInst(Value *, Value *, const Query &, unsigned); static Value *SimplifyBinOp(unsigned, Value *, Value *, const Query &, @@ -131,7 +139,7 @@ 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 +187,7 @@ 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 +199,7 @@ 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 +244,7 @@ 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 +284,7 @@ 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 +295,7 @@ 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 +356,7 @@ 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 +368,7 @@ 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 +392,7 @@ 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 +406,7 @@ 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 +418,7 @@ 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 +438,7 @@ 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 @@ -513,24 +449,24 @@ 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; + Value *CommonValue = nullptr; for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { Value *Incoming = PI->getIncomingValue(i); // If the incoming value is the phi node itself, it can safely be skipped. @@ -541,7 +477,7 @@ 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 +492,7 @@ 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)) { @@ -568,10 +504,10 @@ 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; + Value *CommonValue = nullptr; for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { Value *Incoming = PI->getIncomingValue(i); // If the incoming value is the phi node itself, it can safely be skipped. @@ -580,7 +516,7 @@ static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, 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; } @@ -595,7 +531,7 @@ 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 +549,7 @@ 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 +569,6 @@ 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 @@ -647,14 +578,15 @@ 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), - RecursionLimit); + const DataLayout *DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, + Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } /// \brief Compute the base pointer and cumulative constant offsets for V. @@ -667,17 +599,18 @@ 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) { - assert(V->getType()->isPointerTy()); +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) + if (!DL) 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 +618,8 @@ 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) { @@ -697,24 +631,28 @@ static Constant *stripAndComputeConstantOffsets(const DataLayout *TD, } else { break; } - assert(V->getType()->isPointerTy() && "Unexpected operand type!"); - } while (Visited.insert(V)); + assert(V->getType()->getScalarType()->isPointerTy() && + "Unexpected operand type!"); + } while (Visited.insert(V).second); - Type *IntPtrTy = TD->getIntPtrType(V->getContext()); - return ConstantInt::get(IntPtrTy, Offset); + Constant *OffsetIntPtr = ConstantInt::get(IntPtrTy, Offset); + if (V->getType()->isVectorTy()) + return ConstantVector::getSplat(V->getType()->getVectorNumElements(), + OffsetIntPtr); + return OffsetIntPtr; } /// \brief Compute the constant difference between two pointer values. /// If the difference is not a constant, returns zero. -static Constant *computePointerDifference(const DataLayout *TD, +static Constant *computePointerDifference(const DataLayout *DL, Value *LHS, Value *RHS) { - 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 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 @@ -731,7 +669,7 @@ 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 @@ -747,16 +685,13 @@ 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)) @@ -825,14 +760,9 @@ 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)) @@ -847,14 +777,15 @@ 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), - RecursionLimit); + const DataLayout *DL, const TargetLibraryInfo *TLI, + const DominatorTree *DT, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, + Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } /// Given operands for an FAdd, see if we can fold the result. If not, this @@ -865,7 +796,7 @@ 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. @@ -884,7 +815,7 @@ 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)))) @@ -896,7 +827,7 @@ 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 @@ -907,7 +838,7 @@ 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); } } @@ -933,7 +864,7 @@ static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (FMF.noNaNs() && FMF.noInfs() && Op0 == Op1) return Constant::getNullValue(Op0->getType()); - return 0; + return nullptr; } /// Given the operands for an FMul, see if we can fold the result @@ -945,7 +876,7 @@ 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. @@ -960,7 +891,7 @@ 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 @@ -971,7 +902,7 @@ 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. @@ -991,7 +922,7 @@ 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; @@ -1025,33 +956,42 @@ 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyFAddInst(Op0, Op1, FMF, Query (DL, TLI, DT, AT, 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyFSubInst(Op0, Op1, FMF, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF, - const DataLayout *TD, + const DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFMulInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyFMulInst(Op0, Op1, FMF, Query (DL, TLI, DT, AT, 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyMulInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } /// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can @@ -1061,7 +1001,7 @@ 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); } } @@ -1092,7 +1032,7 @@ 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); @@ -1111,6 +1051,16 @@ 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)) @@ -1123,7 +1073,7 @@ 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 @@ -1133,13 +1083,16 @@ 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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifySDivInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } /// SimplifyUDivInst - Given operands for a UDiv, see if we can @@ -1149,13 +1102,16 @@ 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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyUDivInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q, @@ -1168,13 +1124,16 @@ static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q, if (match(Op1, m_Undef())) return Op1; - return 0; + return nullptr; } -Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const DataLayout *TD, +Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyFDivInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } /// SimplifyRem - Given operands for an SRem or URem, see if we can @@ -1184,7 +1143,7 @@ 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); } } @@ -1216,6 +1175,13 @@ 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)) @@ -1228,7 +1194,7 @@ 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 @@ -1238,13 +1204,16 @@ 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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifySRemInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } /// SimplifyURemInst - Given operands for a URem, see if we can @@ -1254,13 +1223,16 @@ 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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyURemInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &, @@ -1273,13 +1245,43 @@ static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &, if (match(Op1, m_Undef())) return Op1; - return 0; + return nullptr; } -Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const DataLayout *TD, +Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); + const DominatorTree *DT, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyFRemInst(Op0, Op1, Query (DL, TLI, DT, AT, 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 @@ -1289,7 +1291,7 @@ 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); } } @@ -1301,15 +1303,9 @@ 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. @@ -1323,7 +1319,33 @@ 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()); + + // 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.AT, Q.CxtI, + Q.DT); + if (Op0KnownOne[0]) + return Op0; + } + + return nullptr; } /// SimplifyShlInst - Given operands for an Shl, see if we can @@ -1341,13 +1363,14 @@ static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } @@ -1355,8 +1378,9 @@ 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; + if (Value *V = SimplifyRightShift(Instruction::LShr, Op0, Op1, isExact, Q, + MaxRecurse)) + return V; // undef >>l X -> 0 if (match(Op0, m_Undef())) @@ -1364,18 +1388,19 @@ static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, // (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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyLShrInst(Op0, Op1, isExact, Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } @@ -1383,7 +1408,8 @@ 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; // all ones >>a X -> all ones @@ -1396,21 +1422,115 @@ static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, // (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.AT, 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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyAShrInst(Op0, Op1, isExact, Query (DL, TLI, DT, AT, 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; + } + + 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, @@ -1419,7 +1539,7 @@ 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. @@ -1448,7 +1568,7 @@ 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; @@ -1461,12 +1581,21 @@ 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, /*OrZero*/true, 0, Q.AT, Q.CxtI, Q.DT)) return Op0; - if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/true)) + if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/true, 0, Q.AT, 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)) @@ -1482,11 +1611,6 @@ 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)) @@ -1501,13 +1625,67 @@ 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyAndInst(Op0, Op1, Query (DL, TLI, DT, AT, 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 @@ -1518,7 +1696,7 @@ 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. @@ -1547,7 +1725,7 @@ 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; @@ -1567,6 +1745,15 @@ 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)) @@ -1577,11 +1764,6 @@ 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)) @@ -1589,19 +1771,57 @@ 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.AT, Q.CxtI, Q.DT)) + return A; + if (V2 == B && MaskedValueIsZero(V1, C2->getValue(), Q.DL, + 0, Q.AT, 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.AT, Q.CxtI, Q.DT)) + return B; + if (V2 == A && MaskedValueIsZero(V1, C1->getValue(), Q.DL, + 0, Q.AT, 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyOrInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } /// SimplifyXorInst - Given operands for a Xor, see if we can @@ -1612,7 +1832,7 @@ 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. @@ -1641,11 +1861,6 @@ 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 @@ -1655,13 +1870,15 @@ 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyXorInst(Op0, Op1, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } static Type *GetCompareTy(Value *Op) { @@ -1675,26 +1892,65 @@ 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; } -static Constant *computePointerICmp(const DataLayout *TD, +// A significant optimization not implemented here is assuming that alloca +// addresses are not equal to incoming argument values. They don't *alias*, +// as we say, but that doesn't mean they aren't equal, so we take a +// conservative approach. +// +// This is inspired in part by C++11 5.10p1: +// "Two pointers of the same type compare equal if and only if they are both +// null, both point to the same function, or both represent the same +// address." +// +// This is pretty permissive. +// +// It's also partly due to C11 6.5.9p6: +// "Two pointers compare equal if and only if both are null pointers, both are +// pointers to the same object (including a pointer to an object and a +// subobject at its beginning) or function, both are pointers to one past the +// last element of the same array object, or one is a pointer to one past the +// end of one array object and the other is a pointer to the start of a +// different array object that happens to immediately follow the first array +// object in the address space.) +// +// C11's version is more restrictive, however there's no reason why an argument +// couldn't be a one-past-the-end value for a stack object in the caller and be +// equal to the beginning of a stack object in the callee. +// +// 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 *DL, + const TargetLibraryInfo *TLI, 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, TLI) && isa(RHS) && + (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE)) + return ConstantInt::get(GetCompareTy(LHS), + !CmpInst::isTrueWhenEqual(Pred)); + // 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: @@ -1713,15 +1969,138 @@ static Constant *computePointerICmp(const DataLayout *TD, break; } - Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS); - Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS); + // Strip off any constant offsets so that we can reason about them. + // It's tempting to use getUnderlyingObject or even just stripInBoundsOffsets + // here and compare base addresses like AliasAnalysis does, however there are + // 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(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. + if (LHS == RHS) + return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset); + + // Various optimizations for (in)equality comparisons. + if (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE) { + // Different non-empty allocations that exist at the same time have + // different addresses (if the program can tell). Global variables always + // exist, so they always exist during the lifetime of each other and all + // allocas. Two different allocas usually have different addresses... + // + // However, if there's an @llvm.stackrestore dynamically in between two + // allocas, they may have the same address. It's tempting to reduce the + // scope of the problem by only looking at *static* allocas here. That would + // cover the majority of allocas while significantly reducing the likelihood + // of having an @llvm.stackrestore pop up in the middle. However, it's not + // actually impossible for an @llvm.stackrestore to pop up in the middle of + // an entry block. Also, if we have a block that's not attached to a + // function, we can't tell if it's "static" under the current definition. + // Theoretically, this problem could be fixed by creating a new kind of + // instruction kind specifically for static allocas. Such a new instruction + // could be required to be at the top of the entry block, thus preventing it + // from being subject to a @llvm.stackrestore. Instcombine could even + // convert regular allocas into these special allocas. It'd be nifty. + // However, until then, this problem remains open. + // + // So, we'll assume that two non-empty allocas have different addresses + // for now. + // + // With all that, if the offsets are within the bounds of their allocations + // (and not one-past-the-end! so we can't use inbounds!), and their + // allocations aren't the same, the pointers are not equal. + // + // Note that it's not necessary to check for LHS being a global variable + // address, due to canonicalization and constant folding. + if (isa(LHS) && + (isa(RHS) || isa(RHS))) { + ConstantInt *LHSOffsetCI = dyn_cast(LHSOffset); + ConstantInt *RHSOffsetCI = dyn_cast(RHSOffset); + uint64_t LHSSize, RHSSize; + if (LHSOffsetCI && RHSOffsetCI && + getObjectSize(LHS, LHSSize, DL, TLI) && + getObjectSize(RHS, RHSSize, DL, TLI)) { + const APInt &LHSOffsetValue = LHSOffsetCI->getValue(); + const APInt &RHSOffsetValue = RHSOffsetCI->getValue(); + if (!LHSOffsetValue.isNegative() && + !RHSOffsetValue.isNegative() && + LHSOffsetValue.ult(LHSSize) && + RHSOffsetValue.ult(RHSSize)) { + return ConstantInt::get(GetCompareTy(LHS), + !CmpInst::isTrueWhenEqual(Pred)); + } + } - // 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; + // Repeat the above check but this time without depending on DataLayout + // or being able to compute a precise size. + if (!cast(LHS->getType())->isEmptyTy() && + !cast(RHS->getType())->isEmptyTy() && + LHSOffset->isNullValue() && + RHSOffset->isNullValue()) + return ConstantInt::get(GetCompareTy(LHS), + !CmpInst::isTrueWhenEqual(Pred)); + } - return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset); + // 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(), + [](Value *V){ return isNoAliasCall(V); }); + }; + + // 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 nullptr; } /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can @@ -1733,7 +2112,7 @@ 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); @@ -1786,62 +2165,6 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, } } - // icmp , - Different identified objects have - // different addresses (unless null), and what's more the address of an - // identified local is never equal to another argument (again, barring null). - // Note that generalizing to the case where LHS is a global variable address - // or null is pointless, since if both LHS and RHS are constants then we - // already constant folded the compare, and if only one of them is then we - // moved it to RHS already. - Value *LHSPtr = LHS->stripPointerCasts(); - Value *RHSPtr = RHS->stripPointerCasts(); - if (LHSPtr == RHSPtr) - return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred)); - - // Be more aggressive about stripping pointer adjustments when checking a - // comparison of an alloca address to another object. We can rip off all - // inbounds GEP operations, even if they are variable. - LHSPtr = LHSPtr->stripInBoundsOffsets(); - if (llvm::isIdentifiedObject(LHSPtr)) { - RHSPtr = RHSPtr->stripInBoundsOffsets(); - if (llvm::isKnownNonNull(LHSPtr) || llvm::isKnownNonNull(RHSPtr)) { - // If both sides are different identified objects, they aren't equal - // unless they're null. - if (LHSPtr != RHSPtr && llvm::isIdentifiedObject(RHSPtr) && - Pred == CmpInst::ICMP_EQ) - return ConstantInt::get(ITy, false); - - // A local identified object (alloca or noalias call) can't equal any - // incoming argument, unless they're both null or they belong to - // different functions. The latter happens during inlining. - if (Instruction *LHSInst = dyn_cast(LHSPtr)) - if (Argument *RHSArg = dyn_cast(RHSPtr)) - if (LHSInst->getParent()->getParent() == RHSArg->getParent() && - Pred == CmpInst::ICMP_EQ) - return ConstantInt::get(ITy, false); - } - - // Assume that the constant null is on the right. - if (llvm::isKnownNonNull(LHSPtr) && isa(RHSPtr)) { - if (Pred == CmpInst::ICMP_EQ) - return ConstantInt::get(ITy, false); - else if (Pred == CmpInst::ICMP_NE) - return ConstantInt::get(ITy, true); - } - } else if (Argument *LHSArg = dyn_cast(LHSPtr)) { - RHSPtr = RHSPtr->stripInBoundsOffsets(); - // An alloca can't be equal to an argument unless they come from separate - // functions via inlining. - if (AllocaInst *RHSInst = dyn_cast(RHSPtr)) { - if (LHSArg->getParent() == RHSInst->getParent()->getParent()) { - if (Pred == CmpInst::ICMP_EQ) - return ConstantInt::get(ITy, false); - else if (Pred == CmpInst::ICMP_NE) - return ConstantInt::get(ITy, true); - } - } - } - // If we are comparing with zero then try hard since this is a common case. if (match(RHS, m_Zero())) { bool LHSKnownNonNegative, LHSKnownNegative; @@ -1853,40 +2176,46 @@ 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.AT, 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.AT, 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.AT, 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.AT, Q.CxtI, Q.DT); if (LHSKnownNegative) return getTrue(ITy); - if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD)) + if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.DL, + 0, Q.AT, 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.AT, 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.AT, Q.CxtI, Q.DT); if (LHSKnownNegative) return getFalse(ITy); - if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD)) + if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.DL, + 0, Q.AT, Q.CxtI, Q.DT)) return getTrue(ITy); break; } @@ -1903,7 +2232,7 @@ 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; @@ -1922,20 +2251,63 @@ 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); @@ -1944,6 +2316,19 @@ 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(); @@ -1969,8 +2354,8 @@ 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 && Q.DL && 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, @@ -2124,7 +2509,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 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) { @@ -2182,6 +2567,63 @@ 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) { @@ -2189,7 +2631,8 @@ 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.AT, Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2199,7 +2642,8 @@ 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.AT, Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2209,6 +2653,8 @@ 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) { @@ -2216,7 +2662,8 @@ 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.AT, Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2226,7 +2673,8 @@ 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.AT, Q.CxtI, Q.DT); if (!KnownNonNegative) break; // fall-through @@ -2246,6 +2694,41 @@ 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()) { @@ -2469,7 +2952,7 @@ 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, Pred, LHS, RHS)) + if (Constant *C = computePointerICmp(Q.DL, Q.TLI, Pred, LHS, RHS)) return C; if (GetElementPtrInst *GLHS = dyn_cast(LHS)) { @@ -2493,6 +2976,23 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, } } + // 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.AT, + 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)) @@ -2505,14 +3005,16 @@ 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, + AssumptionTracker *AT, + Instruction *CxtI) { + return ::SimplifyICmpInst(Predicate, LHS, RHS, Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } @@ -2525,7 +3027,7 @@ static Value *SimplifyFCmpInst(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); @@ -2602,14 +3104,16 @@ 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, + const DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT), + const DominatorTree *DT, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } @@ -2620,8 +3124,12 @@ 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) @@ -2637,62 +3145,140 @@ 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)) { + Value *X; + const APInt *Y; + if (ICI->isEquality() && + match(ICI->getOperand(0), m_And(m_Value(X), m_APInt(Y))) && + match(ICI->getOperand(1), m_Zero())) { + ICmpInst::Predicate Pred = ICI->getPredicate(); + 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 Pred == ICmpInst::ICMP_EQ ? 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 Pred == ICmpInst::ICMP_EQ ? 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 Pred == ICmpInst::ICMP_EQ ? 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 Pred == ICmpInst::ICMP_EQ ? TrueVal : FalseVal; + } + } + } + + 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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifySelectInst(Cond, TrueVal, FalseVal, + Query (DL, TLI, DT, AT, 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) { // 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; + PointerType *PtrTy = cast(Ops[0]->getType()->getScalarType()); + unsigned AS = PtrTy->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(PtrTy, 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 = PtrTy->getElementType(); + if (Q.DL && 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)); } -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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyGEPInst(Ops, Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we @@ -2721,15 +3307,18 @@ 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 DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query (TD, TLI, DT), + const DominatorTree *DT, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyInsertValueInst(Agg, Val, Idxs, + Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } @@ -2737,7 +3326,7 @@ Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val, static Value *SimplifyPHINode(PHINode *PN, const Query &Q) { // If all of the PHI's incoming values are the same then replace the PHI node // with the common value. - Value *CommonValue = 0; + Value *CommonValue = nullptr; bool HasUndefInput = false; for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { Value *Incoming = PN->getIncomingValue(i); @@ -2749,7 +3338,7 @@ 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; } @@ -2762,22 +3351,25 @@ 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, + AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyTruncInst(Op, Ty, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } //=== Helper functions for higher up the class hierarchy. @@ -2822,7 +3414,7 @@ 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); } @@ -2843,14 +3435,16 @@ static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse)) return V; - return 0; + return nullptr; } } 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyBinOp(Opcode, LHS, RHS, Query (DL, TLI, DT, AT, CxtI), + RecursionLimit); } /// SimplifyCmpInst - Given operands for a CmpInst, see if we can @@ -2863,12 +3457,45 @@ static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, } 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyCmpInst(Predicate, LHS, RHS, Query (DL, TLI, DT, AT, CxtI), RecursionLimit); } +static bool IsIdempotent(Intrinsic::ID ID) { + switch (ID) { + default: return false; + + // Unary idempotent: f(f(x)) = f(x) + case Intrinsic::fabs: + case Intrinsic::floor: + case Intrinsic::ceil: + 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, + const Query &Q, unsigned MaxRecurse) { + // Perform idempotent optimizations + if (!IsIdempotent(IID)) + return nullptr; + + // Unary Ops + if (std::distance(ArgBegin, ArgEnd) == 1) + if (IntrinsicInst *II = dyn_cast(*ArgBegin)) + if (II->getIntrinsicID() == IID) + return II; + + return nullptr; +} + template static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd, const Query &Q, unsigned MaxRecurse) { @@ -2883,17 +3510,22 @@ 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)) + 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); } @@ -2901,136 +3533,152 @@ 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, + User::op_iterator ArgEnd, const DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(TD, TLI, DT), + const DominatorTree *DT, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(DL, TLI, DT, AT, 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, AssumptionTracker *AT, + const Instruction *CxtI) { + return ::SimplifyCall(V, Args.begin(), Args.end(), + Query(DL, TLI, DT, AT, 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, + AssumptionTracker *AT) { 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, AT, I); break; case Instruction::Add: Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1), cast(I)->hasNoSignedWrap(), cast(I)->hasNoUnsignedWrap(), - TD, TLI, DT); + DL, TLI, DT, AT, I); break; case Instruction::FSub: Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1), - I->getFastMathFlags(), TD, TLI, DT); + I->getFastMathFlags(), DL, TLI, DT, AT, I); break; case Instruction::Sub: Result = SimplifySubInst(I->getOperand(0), I->getOperand(1), cast(I)->hasNoSignedWrap(), cast(I)->hasNoUnsignedWrap(), - TD, TLI, DT); + DL, TLI, DT, AT, I); break; case Instruction::FMul: Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1), - I->getFastMathFlags(), TD, TLI, DT); + I->getFastMathFlags(), DL, TLI, DT, AT, 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, AT, 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, AT, 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, AT, I); break; case Instruction::FDiv: - Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), + DL, TLI, DT, AT, 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, AT, 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, AT, I); break; case Instruction::FRem: - Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); + Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), + DL, TLI, DT, AT, I); break; case Instruction::Shl: Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1), cast(I)->hasNoSignedWrap(), cast(I)->hasNoUnsignedWrap(), - TD, TLI, DT); + DL, TLI, DT, AT, I); break; case Instruction::LShr: Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1), cast(I)->isExact(), - TD, TLI, DT); + DL, TLI, DT, AT, I); break; case Instruction::AShr: Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1), cast(I)->isExact(), - TD, TLI, DT); + DL, TLI, DT, AT, 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, AT, 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, + AT, 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, AT, I); break; case Instruction::ICmp: Result = SimplifyICmpInst(cast(I)->getPredicate(), - I->getOperand(0), I->getOperand(1), TD, TLI, DT); + I->getOperand(0), I->getOperand(1), + DL, TLI, DT, AT, 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), + DL, TLI, DT, AT, 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, AT, 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, AT, 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, AT, I); break; } case Instruction::PHI: - Result = SimplifyPHINode(cast(I), Query (TD, TLI, DT)); + Result = SimplifyPHINode(cast(I), Query (DL, TLI, DT, AT, I)); break; case Instruction::Call: { CallSite CS(cast(I)); Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(), - TD, TLI, DT); + DL, TLI, DT, AT, 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, + AT, I); break; } @@ -3052,19 +3700,19 @@ 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 DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { + const DominatorTree *DT, + AssumptionTracker *AT) { bool Simplified = false; SmallSetVector Worklist; // 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); @@ -3082,7 +3730,7 @@ 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, AT); if (!SimpleV) continue; @@ -3091,9 +3739,8 @@ 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); @@ -3107,17 +3754,19 @@ static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV, } bool llvm::recursivelySimplifyInstruction(Instruction *I, - const DataLayout *TD, + const DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { - return replaceAndRecursivelySimplifyImpl(I, 0, TD, TLI, DT); + const DominatorTree *DT, + AssumptionTracker *AT) { + return replaceAndRecursivelySimplifyImpl(I, nullptr, DL, TLI, DT, AT); } bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV, - const DataLayout *TD, + const DataLayout *DL, const TargetLibraryInfo *TLI, - const DominatorTree *DT) { + const DominatorTree *DT, + AssumptionTracker *AT) { 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, DL, TLI, DT, AT); }