X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FInstructionSimplify.cpp;h=459fc92bce1a856a2d621b6aedc24c76c18c2d1a;hb=93710f07f02b3961556d2344e1baab1f53e4b45e;hp=eaeacec65b746663709115431334fab941788560;hpb=19d764fb05662ff6b423cf6dc97d300276e4b586;p=oota-llvm.git diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index eaeacec65b7..459fc92bce1 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -17,7 +17,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "instsimplify" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/ADT/SetVector.h" #include "llvm/ADT/Statistic.h" @@ -35,10 +34,11 @@ 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"); struct Query { @@ -131,7 +131,7 @@ 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 +179,7 @@ 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 +191,7 @@ 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 +236,7 @@ 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 +276,7 @@ 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 +287,7 @@ 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 +348,7 @@ 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 +360,7 @@ 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 +384,7 @@ 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 +398,7 @@ 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 +410,7 @@ 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 +430,7 @@ 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 +441,24 @@ 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 +469,7 @@ 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 +484,7 @@ 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 +496,10 @@ 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 +508,7 @@ 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; } @@ -613,7 +541,7 @@ 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 +561,6 @@ 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 @@ -647,7 +570,7 @@ 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, @@ -720,7 +643,7 @@ static Constant *computePointerDifference(const DataLayout *DL, // 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 @@ -753,16 +676,21 @@ 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; + // X - (0 - Y) -> X if the second sub is NUW. + // If Y != 0, 0 - Y is a poison value. + // If Y == 0, 0 - Y simplifies to 0. + if (BinaryOperator::isNeg(Op1)) { + if (const auto *BO = dyn_cast(Op1)) { + assert(BO->getOpcode() == Instruction::Sub && + "Expected a subtraction operator!"); + if (BO->hasNoUnsignedWrap()) + 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)) @@ -834,11 +762,6 @@ static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 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)) @@ -853,7 +776,7 @@ 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, @@ -890,7 +813,7 @@ 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)))) @@ -902,7 +825,7 @@ 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 @@ -939,7 +862,7 @@ 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 @@ -966,7 +889,7 @@ 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 @@ -997,7 +920,7 @@ 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; @@ -1031,7 +954,7 @@ 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, @@ -1098,7 +1021,7 @@ 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); @@ -1129,7 +1052,7 @@ 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 @@ -1139,7 +1062,7 @@ 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 *DL, @@ -1155,7 +1078,7 @@ 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 *DL, @@ -1174,7 +1097,7 @@ 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 *DL, @@ -1234,7 +1157,7 @@ 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 @@ -1244,7 +1167,7 @@ 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 *DL, @@ -1260,7 +1183,7 @@ 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 *DL, @@ -1279,7 +1202,7 @@ 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 *DL, @@ -1350,7 +1273,7 @@ static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1, if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse)) return V; - return 0; + return nullptr; } /// SimplifyShlInst - Given operands for an Shl, see if we can @@ -1368,7 +1291,7 @@ 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, @@ -1399,7 +1322,7 @@ static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, cast(Op0)->hasNoUnsignedWrap()) return X; - return 0; + return nullptr; } Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, @@ -1435,7 +1358,12 @@ static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, cast(Op0)->hasNoSignedWrap()) return X; - return 0; + // Arithmetic shifting an all-sign-bit value is a no-op. + unsigned NumSignBits = ComputeNumSignBits(Op0, Q.DL); + if (NumSignBits == Op0->getType()->getScalarSizeInBits()) + return Op0; + + return nullptr; } Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, @@ -1483,7 +1411,7 @@ 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; @@ -1517,11 +1445,6 @@ 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)) @@ -1536,7 +1459,7 @@ 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 *DL, @@ -1582,7 +1505,7 @@ 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; @@ -1612,11 +1535,6 @@ 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)) @@ -1624,13 +1542,45 @@ 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())) + return A; + if (V2 == B && MaskedValueIsZero(V1, C2->getValue())) + 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())) + return B; + if (V2 == A && MaskedValueIsZero(V1, C1->getValue())) + 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 *DL, @@ -1676,11 +1626,6 @@ 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 @@ -1690,7 +1635,7 @@ 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 *DL, @@ -1710,17 +1655,17 @@ static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred, Value *LHS, Value *RHS) { SelectInst *SI = dyn_cast(V); if (!SI) - return 0; + return nullptr; CmpInst *Cmp = dyn_cast(SI->getCondition()); if (!Cmp) - return 0; + return nullptr; Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1); if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS) return Cmp; if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) && LHS == CmpRHS && RHS == CmpLHS) return Cmp; - return 0; + return nullptr; } // A significant optimization not implemented here is assuming that alloca @@ -1768,7 +1713,7 @@ static Constant *computePointerICmp(const DataLayout *DL, // 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: @@ -1874,7 +1819,7 @@ static Constant *computePointerICmp(const DataLayout *DL, } // Otherwise, fail. - return 0; + return nullptr; } /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can @@ -2000,7 +1945,7 @@ 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; @@ -2019,20 +1964,47 @@ 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_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); @@ -2041,6 +2013,19 @@ 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(); @@ -2216,12 +2201,31 @@ 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); + APInt RHSKnownZero(BitWidth, 0); + APInt RHSKnownOne(BitWidth, 0); + computeKnownBits(RHS, RHSKnownZero, RHSKnownOne); + if (((LHSKnownOne & RHSKnownZero) != 0) || + ((LHSKnownZero & RHSKnownOne) != 0)) + return (Pred == ICmpInst::ICMP_EQ) + ? ConstantInt::getFalse(CI->getContext()) + : ConstantInt::getTrue(CI->getContext()); + } + } + // Special logic for binary operators. BinaryOperator *LBO = dyn_cast(LHS); BinaryOperator *RBO = dyn_cast(RHS); if (MaxRecurse && (LBO || RBO)) { // Analyze the case when either LHS or RHS is an add instruction. - Value *A = 0, *B = 0, *C = 0, *D = 0; + Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr; // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null). bool NoLHSWrapProblem = false, NoRHSWrapProblem = false; if (LBO && LBO->getOpcode() == Instruction::Add) { @@ -2279,6 +2283,28 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, } } + // 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; @@ -2605,7 +2631,7 @@ 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, @@ -2702,7 +2728,7 @@ 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, @@ -2741,7 +2767,7 @@ static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal, if (isa(FalseVal)) // select C, X, undef -> X return TrueVal; - return 0; + return nullptr; } Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal, @@ -2786,7 +2812,7 @@ static Value *SimplifyGEPInst(ArrayRef Ops, const Query &Q, unsigned) { // 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)); } @@ -2823,7 +2849,7 @@ static Value *SimplifyInsertValueInst(Value *Agg, Value *Val, return Agg; } - return 0; + return nullptr; } Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val, @@ -2839,7 +2865,7 @@ 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); @@ -2851,7 +2877,7 @@ 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; } @@ -2864,7 +2890,7 @@ 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; } @@ -2873,7 +2899,7 @@ static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) { if (Constant *C = dyn_cast(Op)) return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.DL, Q.TLI); - return 0; + return nullptr; } Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *DL, @@ -2945,7 +2971,7 @@ static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse)) return V; - return 0; + return nullptr; } } @@ -2992,7 +3018,7 @@ static Value *SimplifyIntrinsic(Intrinsic::ID IID, IterTy ArgBegin, IterTy ArgEn const Query &Q, unsigned MaxRecurse) { // Perform idempotent optimizations if (!IsIdempotent(IID)) - return 0; + return nullptr; // Unary Ops if (std::distance(ArgBegin, ArgEnd) == 1) @@ -3000,7 +3026,7 @@ static Value *SimplifyIntrinsic(Intrinsic::ID IID, IterTy ArgBegin, IterTy ArgEn if (II->getIntrinsicID() == IID) return II; - return 0; + return nullptr; } template @@ -3017,7 +3043,7 @@ 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 = @@ -3025,14 +3051,14 @@ static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd, 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); } @@ -3200,10 +3226,9 @@ static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV, // 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); @@ -3230,9 +3255,8 @@ 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); @@ -3249,7 +3273,7 @@ bool llvm::recursivelySimplifyInstruction(Instruction *I, const DataLayout *DL, const TargetLibraryInfo *TLI, const DominatorTree *DT) { - return replaceAndRecursivelySimplifyImpl(I, 0, DL, TLI, DT); + return replaceAndRecursivelySimplifyImpl(I, nullptr, DL, TLI, DT); } bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,