diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 198 |
1 files changed, 76 insertions, 122 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index b1206359247..6308788cd61 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -39,30 +39,29 @@ static inline Value *dyn_castNotVal(Value *V) { } /// Similar to getICmpCode but for FCmpInst. This encodes a fcmp predicate into -/// a three bit mask. It also returns whether it is an ordered predicate by -/// reference. -static unsigned getFCmpCode(FCmpInst::Predicate CC, bool &isOrdered) { - isOrdered = false; - switch (CC) { - case FCmpInst::FCMP_ORD: isOrdered = true; return 0; // 000 - case FCmpInst::FCMP_UNO: return 0; // 000 - case FCmpInst::FCMP_OGT: isOrdered = true; return 1; // 001 - case FCmpInst::FCMP_UGT: return 1; // 001 - case FCmpInst::FCMP_OEQ: isOrdered = true; return 2; // 010 - case FCmpInst::FCMP_UEQ: return 2; // 010 - case FCmpInst::FCMP_OGE: isOrdered = true; return 3; // 011 - case FCmpInst::FCMP_UGE: return 3; // 011 - case FCmpInst::FCMP_OLT: isOrdered = true; return 4; // 100 - case FCmpInst::FCMP_ULT: return 4; // 100 - case FCmpInst::FCMP_ONE: isOrdered = true; return 5; // 101 - case FCmpInst::FCMP_UNE: return 5; // 101 - case FCmpInst::FCMP_OLE: isOrdered = true; return 6; // 110 - case FCmpInst::FCMP_ULE: return 6; // 110 - // True -> 7 - default: - // Not expecting FCMP_FALSE and FCMP_TRUE; - llvm_unreachable("Unexpected FCmp predicate!"); - } +/// a four bit mask. +static unsigned getFCmpCode(FCmpInst::Predicate CC) { + assert(FCmpInst::FCMP_FALSE <= CC && CC <= FCmpInst::FCMP_TRUE && + "Unexpected FCmp predicate!"); + // Take advantage of the bit pattern of FCmpInst::Predicate here. + // U L G E + static_assert(FCmpInst::FCMP_FALSE == 0, ""); // 0 0 0 0 + static_assert(FCmpInst::FCMP_OEQ == 1, ""); // 0 0 0 1 + static_assert(FCmpInst::FCMP_OGT == 2, ""); // 0 0 1 0 + static_assert(FCmpInst::FCMP_OGE == 3, ""); // 0 0 1 1 + static_assert(FCmpInst::FCMP_OLT == 4, ""); // 0 1 0 0 + static_assert(FCmpInst::FCMP_OLE == 5, ""); // 0 1 0 1 + static_assert(FCmpInst::FCMP_ONE == 6, ""); // 0 1 1 0 + static_assert(FCmpInst::FCMP_ORD == 7, ""); // 0 1 1 1 + static_assert(FCmpInst::FCMP_UNO == 8, ""); // 1 0 0 0 + static_assert(FCmpInst::FCMP_UEQ == 9, ""); // 1 0 0 1 + static_assert(FCmpInst::FCMP_UGT == 10, ""); // 1 0 1 0 + static_assert(FCmpInst::FCMP_UGE == 11, ""); // 1 0 1 1 + static_assert(FCmpInst::FCMP_ULT == 12, ""); // 1 1 0 0 + static_assert(FCmpInst::FCMP_ULE == 13, ""); // 1 1 0 1 + static_assert(FCmpInst::FCMP_UNE == 14, ""); // 1 1 1 0 + static_assert(FCmpInst::FCMP_TRUE == 15, ""); // 1 1 1 1 + return CC; } /// This is the complement of getICmpCode, which turns an opcode and two @@ -78,26 +77,16 @@ static Value *getNewICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS, } /// This is the complement of getFCmpCode, which turns an opcode and two -/// operands into either a FCmp instruction. isordered is passed in to determine -/// which kind of predicate to use in the new fcmp instruction. -static Value *getFCmpValue(bool isordered, unsigned code, - Value *LHS, Value *RHS, +/// operands into either a FCmp instruction, or a true/false constant. +static Value *getFCmpValue(unsigned Code, Value *LHS, Value *RHS, InstCombiner::BuilderTy *Builder) { - CmpInst::Predicate Pred; - switch (code) { - default: llvm_unreachable("Illegal FCmp code!"); - case 0: Pred = isordered ? FCmpInst::FCMP_ORD : FCmpInst::FCMP_UNO; break; - case 1: Pred = isordered ? FCmpInst::FCMP_OGT : FCmpInst::FCMP_UGT; break; - case 2: Pred = isordered ? FCmpInst::FCMP_OEQ : FCmpInst::FCMP_UEQ; break; - case 3: Pred = isordered ? FCmpInst::FCMP_OGE : FCmpInst::FCMP_UGE; break; - case 4: Pred = isordered ? FCmpInst::FCMP_OLT : FCmpInst::FCMP_ULT; break; - case 5: Pred = isordered ? FCmpInst::FCMP_ONE : FCmpInst::FCMP_UNE; break; - case 6: Pred = isordered ? FCmpInst::FCMP_OLE : FCmpInst::FCMP_ULE; break; - case 7: - if (!isordered) - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1); - Pred = FCmpInst::FCMP_ORD; break; - } + const auto Pred = static_cast<FCmpInst::Predicate>(Code); + assert(FCmpInst::FCMP_FALSE <= Pred && Pred <= FCmpInst::FCMP_TRUE && + "Unexpected FCmp predicate!"); + if (Pred == FCmpInst::FCMP_FALSE) + return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); + if (Pred == FCmpInst::FCMP_TRUE) + return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1); return Builder->CreateFCmp(Pred, LHS, RHS); } @@ -1107,6 +1096,29 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { /// Optimize (fcmp)&(fcmp). NOTE: Unlike the rest of instcombine, this returns /// a Value which should already be inserted into the function. Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { + Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1); + Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1); + FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate(); + + if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) { + // Swap RHS operands to match LHS. + Op1CC = FCmpInst::getSwappedPredicate(Op1CC); + std::swap(Op1LHS, Op1RHS); + } + + // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y). + // Suppose the relation between x and y is R, where R is one of + // U(1000), L(0100), G(0010) or E(0001), and CC0 and CC1 are the bitmasks for + // testing the desired relations. + // + // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this: + // bool(R & CC0) && bool(R & CC1) + // = bool((R & CC0) & (R & CC1)) + // = bool(R & (CC0 & CC1)) <= by re-association, commutation, and idempotency + if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) + return getFCmpValue(getFCmpCode(Op0CC) & getFCmpCode(Op1CC), Op0LHS, Op0RHS, + Builder); + if (LHS->getPredicate() == FCmpInst::FCMP_ORD && RHS->getPredicate() == FCmpInst::FCMP_ORD) { if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType()) @@ -1130,56 +1142,6 @@ Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { return nullptr; } - Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1); - Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1); - FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate(); - - - if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) { - // Swap RHS operands to match LHS. - Op1CC = FCmpInst::getSwappedPredicate(Op1CC); - std::swap(Op1LHS, Op1RHS); - } - - if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) { - // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y). - if (Op0CC == Op1CC) - return Builder->CreateFCmp((FCmpInst::Predicate)Op0CC, Op0LHS, Op0RHS); - if (Op0CC == FCmpInst::FCMP_FALSE || Op1CC == FCmpInst::FCMP_FALSE) - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); - if (Op0CC == FCmpInst::FCMP_TRUE) - return Builder->CreateFCmp(Op1CC, Op0LHS, Op0RHS); - if (Op1CC == FCmpInst::FCMP_TRUE) - return Builder->CreateFCmp(Op0CC, Op0LHS, Op0RHS); - - bool Op0Ordered; - bool Op1Ordered; - unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered); - unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered); - // uno && ord -> false - if (Op0Pred == 0 && Op1Pred == 0 && Op0Ordered != Op1Ordered) - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); - if (Op1Pred == 0) { - std::swap(LHS, RHS); - std::swap(Op0Pred, Op1Pred); - std::swap(Op0Ordered, Op1Ordered); - } - if (Op0Pred == 0) { - // uno && ueq -> uno && (uno || eq) -> uno - // ord && olt -> ord && (ord && lt) -> olt - if (!Op0Ordered && (Op0Ordered == Op1Ordered)) - return Builder->CreateFCmp(Op0CC, Op0LHS, Op0RHS); - if (Op0Ordered && (Op0Ordered == Op1Ordered)) - return Builder->CreateFCmp(Op1CC, Op0LHS, Op0RHS); - - // uno && oeq -> uno && (ord && eq) -> false - if (!Op0Ordered) - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); - // ord && ueq -> ord && (uno || eq) -> oeq - return getFCmpValue(true, Op1Pred, Op0LHS, Op0RHS, Builder); - } - } - return nullptr; } @@ -1996,6 +1958,27 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS, /// Optimize (fcmp)|(fcmp). NOTE: Unlike the rest of instcombine, this returns /// a Value which should already be inserted into the function. Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { + Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1); + Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1); + FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate(); + + if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) { + // Swap RHS operands to match LHS. + Op1CC = FCmpInst::getSwappedPredicate(Op1CC); + std::swap(Op1LHS, Op1RHS); + } + + // Simplify (fcmp cc0 x, y) | (fcmp cc1 x, y). + // This is a similar transformation to the one in FoldAndOfFCmps. + // + // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this: + // bool(R & CC0) || bool(R & CC1) + // = bool((R & CC0) | (R & CC1)) + // = bool(R & (CC0 | CC1)) <= by reversed distribution (contribution? ;) + if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) + return getFCmpValue(getFCmpCode(Op0CC) | getFCmpCode(Op1CC), Op0LHS, Op0RHS, + Builder); + if (LHS->getPredicate() == FCmpInst::FCMP_UNO && RHS->getPredicate() == FCmpInst::FCMP_UNO && LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType()) { @@ -2020,35 +2003,6 @@ Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) { return nullptr; } - Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1); - Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1); - FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate(); - - if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) { - // Swap RHS operands to match LHS. - Op1CC = FCmpInst::getSwappedPredicate(Op1CC); - std::swap(Op1LHS, Op1RHS); - } - if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) { - // Simplify (fcmp cc0 x, y) | (fcmp cc1 x, y). - if (Op0CC == Op1CC) - return Builder->CreateFCmp((FCmpInst::Predicate)Op0CC, Op0LHS, Op0RHS); - if (Op0CC == FCmpInst::FCMP_TRUE || Op1CC == FCmpInst::FCMP_TRUE) - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1); - if (Op0CC == FCmpInst::FCMP_FALSE) - return Builder->CreateFCmp(Op1CC, Op0LHS, Op0RHS); - if (Op1CC == FCmpInst::FCMP_FALSE) - return Builder->CreateFCmp(Op0CC, Op0LHS, Op0RHS); - bool Op0Ordered; - bool Op1Ordered; - unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered); - unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered); - if (Op0Ordered == Op1Ordered) { - // If both are ordered or unordered, return a new fcmp with - // or'ed predicates. - return getFCmpValue(Op0Ordered, Op0Pred|Op1Pred, Op0LHS, Op0RHS, Builder); - } - } return nullptr; } |
