diff options
Diffstat (limited to 'lib/Transforms/IPO/MergeFunctions.cpp')
| -rw-r--r-- | lib/Transforms/IPO/MergeFunctions.cpp | 734 |
1 files changed, 609 insertions, 125 deletions
diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp index 8555d2c85a..c3a2b1205c 100644 --- a/lib/Transforms/IPO/MergeFunctions.cpp +++ b/lib/Transforms/IPO/MergeFunctions.cpp @@ -43,7 +43,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "mergefunc" #include "llvm/Transforms/IPO.h" #include "llvm/ADT/DenseSet.h" #include "llvm/ADT/FoldingSet.h" @@ -67,6 +66,8 @@ #include <vector> using namespace llvm; +#define DEBUG_TYPE "mergefunc" + STATISTIC(NumFunctionsMerged, "Number of functions merged"); STATISTIC(NumThunksWritten, "Number of thunks generated"); STATISTIC(NumAliasesWritten, "Number of aliases generated"); @@ -120,12 +121,12 @@ public: void release() { assert(Func && "Attempted to release function twice, or release empty/tombstone!"); - Func = NULL; + Func = nullptr; } private: explicit ComparableFunction(unsigned Hash) - : Func(NULL), Hash(Hash), DL(NULL) {} + : Func(nullptr), Hash(Hash), DL(nullptr) {} AssertingVH<Function> Func; unsigned Hash; @@ -175,19 +176,181 @@ private: /// Test whether two basic blocks have equivalent behaviour. bool compare(const BasicBlock *BB1, const BasicBlock *BB2); + /// Constants comparison. + /// Its analog to lexicographical comparison between hypothetical numbers + /// of next format: + /// <bitcastability-trait><raw-bit-contents> + /// + /// 1. Bitcastability. + /// Check whether L's type could be losslessly bitcasted to R's type. + /// On this stage method, in case when lossless bitcast is not possible + /// method returns -1 or 1, thus also defining which type is greater in + /// context of bitcastability. + /// Stage 0: If types are equal in terms of cmpTypes, then we can go straight + /// to the contents comparison. + /// If types differ, remember types comparison result and check + /// whether we still can bitcast types. + /// Stage 1: Types that satisfies isFirstClassType conditions are always + /// greater then others. + /// Stage 2: Vector is greater then non-vector. + /// If both types are vectors, then vector with greater bitwidth is + /// greater. + /// If both types are vectors with the same bitwidth, then types + /// are bitcastable, and we can skip other stages, and go to contents + /// comparison. + /// Stage 3: Pointer types are greater than non-pointers. If both types are + /// pointers of the same address space - go to contents comparison. + /// Different address spaces: pointer with greater address space is + /// greater. + /// Stage 4: Types are neither vectors, nor pointers. And they differ. + /// We don't know how to bitcast them. So, we better don't do it, + /// and return types comparison result (so it determines the + /// relationship among constants we don't know how to bitcast). + /// + /// Just for clearance, let's see how the set of constants could look + /// on single dimension axis: + /// + /// [NFCT], [FCT, "others"], [FCT, pointers], [FCT, vectors] + /// Where: NFCT - Not a FirstClassType + /// FCT - FirstClassTyp: + /// + /// 2. Compare raw contents. + /// It ignores types on this stage and only compares bits from L and R. + /// Returns 0, if L and R has equivalent contents. + /// -1 or 1 if values are different. + /// Pretty trivial: + /// 2.1. If contents are numbers, compare numbers. + /// Ints with greater bitwidth are greater. Ints with same bitwidths + /// compared by their contents. + /// 2.2. "And so on". Just to avoid discrepancies with comments + /// perhaps it would be better to read the implementation itself. + /// 3. And again about overall picture. Let's look back at how the ordered set + /// of constants will look like: + /// [NFCT], [FCT, "others"], [FCT, pointers], [FCT, vectors] + /// + /// Now look, what could be inside [FCT, "others"], for example: + /// [FCT, "others"] = + /// [ + /// [double 0.1], [double 1.23], + /// [i32 1], [i32 2], + /// { double 1.0 }, ; StructTyID, NumElements = 1 + /// { i32 1 }, ; StructTyID, NumElements = 1 + /// { double 1, i32 1 }, ; StructTyID, NumElements = 2 + /// { i32 1, double 1 } ; StructTyID, NumElements = 2 + /// ] + /// + /// Let's explain the order. Float numbers will be less than integers, just + /// because of cmpType terms: FloatTyID < IntegerTyID. + /// Floats (with same fltSemantics) are sorted according to their value. + /// Then you can see integers, and they are, like a floats, + /// could be easy sorted among each others. + /// The structures. Structures are grouped at the tail, again because of their + /// TypeID: StructTyID > IntegerTyID > FloatTyID. + /// Structures with greater number of elements are greater. Structures with + /// greater elements going first are greater. + /// The same logic with vectors, arrays and other possible complex types. + /// + /// Bitcastable constants. + /// Let's assume, that some constant, belongs to some group of + /// "so-called-equal" values with different types, and at the same time + /// belongs to another group of constants with equal types + /// and "really" equal values. + /// + /// Now, prove that this is impossible: + /// + /// If constant A with type TyA is bitcastable to B with type TyB, then: + /// 1. All constants with equal types to TyA, are bitcastable to B. Since + /// those should be vectors (if TyA is vector), pointers + /// (if TyA is pointer), or else (if TyA equal to TyB), those types should + /// be equal to TyB. + /// 2. All constants with non-equal, but bitcastable types to TyA, are + /// bitcastable to B. + /// Once again, just because we allow it to vectors and pointers only. + /// This statement could be expanded as below: + /// 2.1. All vectors with equal bitwidth to vector A, has equal bitwidth to + /// vector B, and thus bitcastable to B as well. + /// 2.2. All pointers of the same address space, no matter what they point to, + /// bitcastable. So if C is pointer, it could be bitcasted to A and to B. + /// So any constant equal or bitcastable to A is equal or bitcastable to B. + /// QED. + /// + /// In another words, for pointers and vectors, we ignore top-level type and + /// look at their particular properties (bit-width for vectors, and + /// address space for pointers). + /// If these properties are equal - compare their contents. + int cmpConstants(const Constant *L, const Constant *R); + /// Assign or look up previously assigned numbers for the two values, and /// return whether the numbers are equal. Numbers are assigned in the order /// visited. - bool enumerate(const Value *V1, const Value *V2); + /// Comparison order: + /// Stage 0: Value that is function itself is always greater then others. + /// If left and right values are references to their functions, then + /// they are equal. + /// Stage 1: Constants are greater than non-constants. + /// If both left and right are constants, then the result of + /// cmpConstants is used as cmpValues result. + /// Stage 2: InlineAsm instances are greater than others. If both left and + /// right are InlineAsm instances, InlineAsm* pointers casted to + /// integers and compared as numbers. + /// Stage 3: For all other cases we compare order we meet these values in + /// their functions. If right value was met first during scanning, + /// then left value is greater. + /// In another words, we compare serial numbers, for more details + /// see comments for sn_mapL and sn_mapR. + int cmpValues(const Value *L, const Value *R); + + bool enumerate(const Value *V1, const Value *V2) { + return cmpValues(V1, V2) == 0; + } /// Compare two Instructions for equivalence, similar to /// Instruction::isSameOperationAs but with modifications to the type /// comparison. + /// Stages are listed in "most significant stage first" order: + /// On each stage below, we do comparison between some left and right + /// operation parts. If parts are non-equal, we assign parts comparison + /// result to the operation comparison result and exit from method. + /// Otherwise we proceed to the next stage. + /// Stages: + /// 1. Operations opcodes. Compared as numbers. + /// 2. Number of operands. + /// 3. Operation types. Compared with cmpType method. + /// 4. Compare operation subclass optional data as stream of bytes: + /// just convert it to integers and call cmpNumbers. + /// 5. Compare in operation operand types with cmpType in + /// most significant operand first order. + /// 6. Last stage. Check operations for some specific attributes. + /// For example, for Load it would be: + /// 6.1.Load: volatile (as boolean flag) + /// 6.2.Load: alignment (as integer numbers) + /// 6.3.Load: synch-scope (as integer numbers) + /// On this stage its better to see the code, since its not more than 10-15 + /// strings for particular instruction, and could change sometimes. + int cmpOperation(const Instruction *L, const Instruction *R) const; + bool isEquivalentOperation(const Instruction *I1, - const Instruction *I2) const; + const Instruction *I2) const { + return cmpOperation(I1, I2) == 0; + } /// Compare two GEPs for equivalent pointer arithmetic. - bool isEquivalentGEP(const GEPOperator *GEP1, const GEPOperator *GEP2); + /// Parts to be compared for each comparison stage, + /// most significant stage first: + /// 1. Address space. As numbers. + /// 2. Constant offset, (if "DataLayout *DL" field is not NULL, + /// using GEPOperator::accumulateConstantOffset method). + /// 3. Pointer operand type (using cmpType method). + /// 4. Number of operands. + /// 5. Compare operands, using cmpValues method. + int cmpGEP(const GEPOperator *GEPL, const GEPOperator *GEPR); + int cmpGEP(const GetElementPtrInst *GEPL, const GetElementPtrInst *GEPR) { + return cmpGEP(cast<GEPOperator>(GEPL), cast<GEPOperator>(GEPR)); + } + + bool isEquivalentGEP(const GEPOperator *GEP1, const GEPOperator *GEP2) { + return cmpGEP(GEP1, GEP2) == 0; + } bool isEquivalentGEP(const GetElementPtrInst *GEP1, const GetElementPtrInst *GEP2) { return isEquivalentGEP(cast<GEPOperator>(GEP1), cast<GEPOperator>(GEP2)); @@ -241,13 +404,50 @@ private: int cmpNumbers(uint64_t L, uint64_t R) const; + int cmpAPInt(const APInt &L, const APInt &R) const; + int cmpAPFloat(const APFloat &L, const APFloat &R) const; + int cmpStrings(StringRef L, StringRef R) const; + int cmpAttrs(const AttributeSet L, const AttributeSet R) const; + // The two functions undergoing comparison. const Function *F1, *F2; const DataLayout *DL; - DenseMap<const Value *, const Value *> id_map; - DenseSet<const Value *> seen_values; + /// Assign serial numbers to values from left function, and values from + /// right function. + /// Explanation: + /// Being comparing functions we need to compare values we meet at left and + /// right sides. + /// Its easy to sort things out for external values. It just should be + /// the same value at left and right. + /// But for local values (those were introduced inside function body) + /// we have to ensure they were introduced at exactly the same place, + /// and plays the same role. + /// Let's assign serial number to each value when we meet it first time. + /// Values that were met at same place will be with same serial numbers. + /// In this case it would be good to explain few points about values assigned + /// to BBs and other ways of implementation (see below). + /// + /// 1. Safety of BB reordering. + /// It's safe to change the order of BasicBlocks in function. + /// Relationship with other functions and serial numbering will not be + /// changed in this case. + /// As follows from FunctionComparator::compare(), we do CFG walk: we start + /// from the entry, and then take each terminator. So it doesn't matter how in + /// fact BBs are ordered in function. And since cmpValues are called during + /// this walk, the numbering depends only on how BBs located inside the CFG. + /// So the answer is - yes. We will get the same numbering. + /// + /// 2. Impossibility to use dominance properties of values. + /// If we compare two instruction operands: first is usage of local + /// variable AL from function FL, and second is usage of local variable AR + /// from FR, we could compare their origins and check whether they are + /// defined at the same place. + /// But, we are still not able to compare operands of PHI nodes, since those + /// could be operands from further BBs we didn't scan yet. + /// So it's impossible to use dominance properties in general. + DenseMap<const Value*, int> sn_mapL, sn_mapR; }; } @@ -258,6 +458,206 @@ int FunctionComparator::cmpNumbers(uint64_t L, uint64_t R) const { return 0; } +int FunctionComparator::cmpAPInt(const APInt &L, const APInt &R) const { + if (int Res = cmpNumbers(L.getBitWidth(), R.getBitWidth())) + return Res; + if (L.ugt(R)) return 1; + if (R.ugt(L)) return -1; + return 0; +} + +int FunctionComparator::cmpAPFloat(const APFloat &L, const APFloat &R) const { + if (int Res = cmpNumbers((uint64_t)&L.getSemantics(), + (uint64_t)&R.getSemantics())) + return Res; + return cmpAPInt(L.bitcastToAPInt(), R.bitcastToAPInt()); +} + +int FunctionComparator::cmpStrings(StringRef L, StringRef R) const { + // Prevent heavy comparison, compare sizes first. + if (int Res = cmpNumbers(L.size(), R.size())) + return Res; + + // Compare strings lexicographically only when it is necessary: only when + // strings are equal in size. + return L.compare(R); +} + +int FunctionComparator::cmpAttrs(const AttributeSet L, + const AttributeSet R) const { + if (int Res = cmpNumbers(L.getNumSlots(), R.getNumSlots())) + return Res; + + for (unsigned i = 0, e = L.getNumSlots(); i != e; ++i) { + AttributeSet::iterator LI = L.begin(i), LE = L.end(i), RI = R.begin(i), + RE = R.end(i); + for (; LI != LE && RI != RE; ++LI, ++RI) { + Attribute LA = *LI; + Attribute RA = *RI; + if (LA < RA) + return -1; + if (RA < LA) + return 1; + } + if (LI != LE) + return 1; + if (RI != RE) + return -1; + } + return 0; +} + +/// Constants comparison: +/// 1. Check whether type of L constant could be losslessly bitcasted to R +/// type. +/// 2. Compare constant contents. +/// For more details see declaration comments. +int FunctionComparator::cmpConstants(const Constant *L, const Constant *R) { + + Type *TyL = L->getType(); + Type *TyR = R->getType(); + + // Check whether types are bitcastable. This part is just re-factored + // Type::canLosslesslyBitCastTo method, but instead of returning true/false, + // we also pack into result which type is "less" for us. + int TypesRes = cmpType(TyL, TyR); + if (TypesRes != 0) { + // Types are different, but check whether we can bitcast them. + if (!TyL->isFirstClassType()) { + if (TyR->isFirstClassType()) + return -1; + // Neither TyL nor TyR are values of first class type. Return the result + // of comparing the types + return TypesRes; + } + if (!TyR->isFirstClassType()) { + if (TyL->isFirstClassType()) + return 1; + return TypesRes; + } + + // Vector -> Vector conversions are always lossless if the two vector types + // have the same size, otherwise not. + unsigned TyLWidth = 0; + unsigned TyRWidth = 0; + + if (const VectorType *VecTyL = dyn_cast<VectorType>(TyL)) + TyLWidth = VecTyL->getBitWidth(); + if (const VectorType *VecTyR = dyn_cast<VectorType>(TyR)) + TyRWidth = VecTyR->getBitWidth(); + + if (TyLWidth != TyRWidth) + return cmpNumbers(TyLWidth, TyRWidth); + + // Zero bit-width means neither TyL nor TyR are vectors. + if (!TyLWidth) { + PointerType *PTyL = dyn_cast<PointerType>(TyL); + PointerType *PTyR = dyn_cast<PointerType>(TyR); + if (PTyL && PTyR) { + unsigned AddrSpaceL = PTyL->getAddressSpace(); + unsigned AddrSpaceR = PTyR->getAddressSpace(); + if (int Res = cmpNumbers(AddrSpaceL, AddrSpaceR)) + return Res; + } + if (PTyL) + return 1; + if (PTyR) + return -1; + + // TyL and TyR aren't vectors, nor pointers. We don't know how to + // bitcast them. + return TypesRes; + } + } + + // OK, types are bitcastable, now check constant contents. + + if (L->isNullValue() && R->isNullValue()) + return TypesRes; + if (L->isNullValue() && !R->isNullValue()) + return 1; + if (!L->isNullValue() && R->isNullValue()) + return -1; + + if (int Res = cmpNumbers(L->getValueID(), R->getValueID())) + return Res; + + switch (L->getValueID()) { + case Value::UndefValueVal: return TypesRes; + case Value::ConstantIntVal: { + const APInt &LInt = cast<ConstantInt>(L)->getValue(); + const APInt &RInt = cast<ConstantInt>(R)->getValue(); + return cmpAPInt(LInt, RInt); + } + case Value::ConstantFPVal: { + const APFloat &LAPF = cast<ConstantFP>(L)->getValueAPF(); + const APFloat &RAPF = cast<ConstantFP>(R)->getValueAPF(); + return cmpAPFloat(LAPF, RAPF); + } + case Value::ConstantArrayVal: { + const ConstantArray *LA = cast<ConstantArray>(L); + const ConstantArray *RA = cast<ConstantArray>(R); + uint64_t NumElementsL = cast<ArrayType>(TyL)->getNumElements(); + uint64_t NumElementsR = cast<ArrayType>(TyR)->getNumElements(); + if (int Res = cmpNumbers(NumElementsL, NumElementsR)) + return Res; + for (uint64_t i = 0; i < NumElementsL; ++i) { + if (int Res = cmpConstants(cast<Constant>(LA->getOperand(i)), + cast<Constant>(RA->getOperand(i)))) + return Res; + } + return 0; + } + case Value::ConstantStructVal: { + const ConstantStruct *LS = cast<ConstantStruct>(L); + const ConstantStruct *RS = cast<ConstantStruct>(R); + unsigned NumElementsL = cast<StructType>(TyL)->getNumElements(); + unsigned NumElementsR = cast<StructType>(TyR)->getNumElements(); + if (int Res = cmpNumbers(NumElementsL, NumElementsR)) + return Res; + for (unsigned i = 0; i != NumElementsL; ++i) { + if (int Res = cmpConstants(cast<Constant>(LS->getOperand(i)), + cast<Constant>(RS->getOperand(i)))) + return Res; + } + return 0; + } + case Value::ConstantVectorVal: { + const ConstantVector *LV = cast<ConstantVector>(L); + const ConstantVector *RV = cast<ConstantVector>(R); + unsigned NumElementsL = cast<VectorType>(TyL)->getNumElements(); + unsigned NumElementsR = cast<VectorType>(TyR)->getNumElements(); + if (int Res = cmpNumbers(NumElementsL, NumElementsR)) + return Res; + for (uint64_t i = 0; i < NumElementsL; ++i) { + if (int Res = cmpConstants(cast<Constant>(LV->getOperand(i)), + cast<Constant>(RV->getOperand(i)))) + return Res; + } + return 0; + } + case Value::ConstantExprVal: { + const ConstantExpr *LE = cast<ConstantExpr>(L); + const ConstantExpr *RE = cast<ConstantExpr>(R); + unsigned NumOperandsL = LE->getNumOperands(); + unsigned NumOperandsR = RE->getNumOperands(); + if (int Res = cmpNumbers(NumOperandsL, NumOperandsR)) + return Res; + for (unsigned i = 0; i < NumOperandsL; ++i) { + if (int Res = cmpConstants(cast<Constant>(LE->getOperand(i)), + cast<Constant>(RE->getOperand(i)))) + return Res; + } + return 0; + } + case Value::FunctionVal: + case Value::GlobalVariableVal: + case Value::GlobalAliasVal: + default: // Unknown constant, cast L and R pointers to numbers and compare. + return cmpNumbers((uint64_t)L, (uint64_t)R); + } +} + /// cmpType - compares two types, /// defines total ordering among the types set. /// See method declaration comments for more details. @@ -350,143 +750,209 @@ int FunctionComparator::cmpType(Type *TyL, Type *TyR) const { // Determine whether the two operations are the same except that pointer-to-A // and pointer-to-B are equivalent. This should be kept in sync with // Instruction::isSameOperationAs. -bool FunctionComparator::isEquivalentOperation(const Instruction *I1, - const Instruction *I2) const { +// Read method declaration comments for more details. +int FunctionComparator::cmpOperation(const Instruction *L, + const Instruction *R) const { // Differences from Instruction::isSameOperationAs: // * replace type comparison with calls to isEquivalentType. // * we test for I->hasSameSubclassOptionalData (nuw/nsw/tail) at the top // * because of the above, we don't test for the tail bit on calls later on - if (I1->getOpcode() != I2->getOpcode() || - I1->getNumOperands() != I2->getNumOperands() || - !isEquivalentType(I1->getType(), I2->getType()) || - !I1->hasSameSubclassOptionalData(I2)) - return false; + if (int Res = cmpNumbers(L->getOpcode(), R->getOpcode())) + return Res; + + if (int Res = cmpNumbers(L->getNumOperands(), R->getNumOperands())) + return Res; + + if (int Res = cmpType(L->getType(), R->getType())) + return Res; + + if (int Res = cmpNumbers(L->getRawSubclassOptionalData(), + R->getRawSubclassOptionalData())) + return Res; // We have two instructions of identical opcode and #operands. Check to see // if all operands are the same type - for (unsigned i = 0, e = I1->getNumOperands(); i != e; ++i) - if (!isEquivalentType(I1->getOperand(i)->getType(), - I2->getOperand(i)->getType())) - return false; + for (unsigned i = 0, e = L->getNumOperands(); i != e; ++i) { + if (int Res = + cmpType(L->getOperand(i)->getType(), R->getOperand(i)->getType())) + return Res; + } // Check special state that is a part of some instructions. - if (const LoadInst *LI = dyn_cast<LoadInst>(I1)) - return LI->isVolatile() == cast<LoadInst>(I2)->isVolatile() && - LI->getAlignment() == cast<LoadInst>(I2)->getAlignment() && - LI->getOrdering() == cast<LoadInst>(I2)->getOrdering() && - LI->getSynchScope() == cast<LoadInst>(I2)->getSynchScope(); - if (const StoreInst *SI = dyn_cast<StoreInst>(I1)) - return SI->isVolatile() == cast<StoreInst>(I2)->isVolatile() && - SI->getAlignment() == cast<StoreInst>(I2)->getAlignment() && - SI->getOrdering() == cast<StoreInst>(I2)->getOrdering() && - SI->getSynchScope() == cast<StoreInst>(I2)->getSynchScope(); - if (const CmpInst *CI = dyn_cast<CmpInst>(I1)) - return CI->getPredicate() == cast<CmpInst>(I2)->getPredicate(); - if (const CallInst *CI = dyn_cast<CallInst>(I1)) - return CI->getCallingConv() == cast<CallInst>(I2)->getCallingConv() && - CI->getAttributes() == cast<CallInst>(I2)->getAttributes(); - if (const InvokeInst *CI = dyn_cast<InvokeInst>(I1)) - return CI->getCallingConv() == cast<InvokeInst>(I2)->getCallingConv() && - CI->getAttributes() == cast<InvokeInst>(I2)->getAttributes(); - if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(I1)) - return IVI->getIndices() == cast<InsertValueInst>(I2)->getIndices(); - if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I1)) - return EVI->getIndices() == cast<ExtractValueInst>(I2)->getIndices(); - if (const FenceInst *FI = dyn_cast<FenceInst>(I1)) - return FI->getOrdering() == cast<FenceInst>(I2)->getOrdering() && - FI->getSynchScope() == cast<FenceInst>(I2)->getSynchScope(); - if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(I1)) - return CXI->isVolatile() == cast<AtomicCmpXchgInst>(I2)->isVolatile() && - CXI->getSuccessOrdering() == - cast<AtomicCmpXchgInst>(I2)->getSuccessOrdering() && - CXI->getFailureOrdering() == - cast<AtomicCmpXchgInst>(I2)->getFailureOrdering() && - CXI->getSynchScope() == cast<AtomicCmpXchgInst>(I2)->getSynchScope(); - if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I1)) - return RMWI->getOperation() == cast<AtomicRMWInst>(I2)->getOperation() && - RMWI->isVolatile() == cast<AtomicRMWInst>(I2)->isVolatile() && - RMWI->getOrdering() == cast<AtomicRMWInst>(I2)->getOrdering() && - RMWI->getSynchScope() == cast<AtomicRMWInst>(I2)->getSynchScope(); + if (const LoadInst *LI = dyn_cast<LoadInst>(L)) { + if (int Res = cmpNumbers(LI->isVolatile(), cast<LoadInst>(R)->isVolatile())) + return Res; + if (int Res = + cmpNumbers(LI->getAlignment(), cast<LoadInst>(R)->getAlignment())) + return Res; + if (int Res = + cmpNumbers(LI->getOrdering(), cast<LoadInst>(R)->getOrdering())) + return Res; + return cmpNumbers(LI->getSynchScope(), cast<LoadInst>(R)->getSynchScope()); + } + if (const StoreInst *SI = dyn_cast<StoreInst>(L)) { + if (int Res = + cmpNumbers(SI->isVolatile(), cast<StoreInst>(R)->isVolatile())) + return Res; + if (int Res = + cmpNumbers(SI->getAlignment(), cast<StoreInst>(R)->getAlignment())) + return Res; + if (int Res = + cmpNumbers(SI->getOrdering(), cast<StoreInst>(R)->getOrdering())) + return Res; + return cmpNumbers(SI->getSynchScope(), cast<StoreInst>(R)->getSynchScope()); + } + if (const CmpInst *CI = dyn_cast<CmpInst>(L)) + return cmpNumbers(CI->getPredicate(), cast<CmpInst>(R)->getPredicate()); + if (const CallInst *CI = dyn_cast<CallInst>(L)) { + if (int Res = cmpNumbers(CI->getCallingConv(), + cast<CallInst>(R)->getCallingConv())) + return Res; + return cmpAttrs(CI->getAttributes(), cast<CallInst>(R)->getAttributes()); + } + if (const InvokeInst *CI = dyn_cast<InvokeInst>(L)) { + if (int Res = cmpNumbers(CI->getCallingConv(), + cast<InvokeInst>(R)->getCallingConv())) + return Res; + return cmpAttrs(CI->getAttributes(), cast<InvokeInst>(R)->getAttributes()); + } + if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(L)) { + ArrayRef<unsigned> LIndices = IVI->getIndices(); + ArrayRef<unsigned> RIndices = cast<InsertValueInst>(R)->getIndices(); + if (int Res = cmpNumbers(LIndices.size(), RIndices.size())) + return Res; + for (size_t i = 0, e = LIndices.size(); i != e; ++i) { + if (int Res = cmpNumbers(LIndices[i], RIndices[i])) + return Res; + } + } + if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(L)) { + ArrayRef<unsigned> LIndices = EVI->getIndices(); + ArrayRef<unsigned> RIndices = cast<ExtractValueInst>(R)->getIndices(); + if (int Res = cmpNumbers(LIndices.size(), RIndices.size())) + return Res; + for (size_t i = 0, e = LIndices.size(); i != e; ++i) { + if (int Res = cmpNumbers(LIndices[i], RIndices[i])) + return Res; + } + } + if (const FenceInst *FI = dyn_cast<FenceInst>(L)) { + if (int Res = + cmpNumbers(FI->getOrdering(), cast<FenceInst>(R)->getOrdering())) + return Res; + return cmpNumbers(FI->getSynchScope(), cast<FenceInst>(R)->getSynchScope()); + } - return true; + if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(L)) { + if (int Res = cmpNumbers(CXI->isVolatile(), + cast<AtomicCmpXchgInst>(R)->isVolatile())) + return Res; + if (int Res = cmpNumbers(CXI->getSuccessOrdering(), + cast<AtomicCmpXchgInst>(R)->getSuccessOrdering())) + return Res; + if (int Res = cmpNumbers(CXI->getFailureOrdering(), + cast<AtomicCmpXchgInst>(R)->getFailureOrdering())) + return Res; + return cmpNumbers(CXI->getSynchScope(), + cast<AtomicCmpXchgInst>(R)->getSynchScope()); + } + if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(L)) { + if (int Res = cmpNumbers(RMWI->getOperation(), + cast<AtomicRMWInst>(R)->getOperation())) + return Res; + if (int Res = cmpNumbers(RMWI->isVolatile(), + cast<AtomicRMWInst>(R)->isVolatile())) + return Res; + if (int Res = cmpNumbers(RMWI->getOrdering(), + cast<AtomicRMWInst>(R)->getOrdering())) + return Res; + return cmpNumbers(RMWI->getSynchScope(), + cast<AtomicRMWInst>(R)->getSynchScope()); + } + return 0; } // Determine whether two GEP operations perform the same underlying arithmetic. -bool FunctionComparator::isEquivalentGEP(const GEPOperator *GEP1, - const GEPOperator *GEP2) { - unsigned AS = GEP1->getPointerAddressSpace(); - if (AS != GEP2->getPointerAddressSpace()) - return false; +// Read method declaration comments for more details. +int FunctionComparator::cmpGEP(const GEPOperator *GEPL, + const GEPOperator *GEPR) { + + unsigned int ASL = GEPL->getPointerAddressSpace(); + unsigned int ASR = GEPR->getPointerAddressSpace(); + if (int Res = cmpNumbers(ASL, ASR)) + return Res; + + // When we have target data, we can reduce the GEP down to the value in bytes + // added to the address. if (DL) { - // When we have target data, we can reduce the GEP down to the value in bytes - // added to the address. - unsigned BitWidth = DL ? DL->getPointerSizeInBits(AS) : 1; - APInt Offset1(BitWidth, 0), Offset2(BitWidth, 0); - if (GEP1->accumulateConstantOffset(*DL, Offset1) && - GEP2->accumulateConstantOffset(*DL, Offset2)) { - return Offset1 == Offset2; - } + unsigned BitWidth = DL->getPointerSizeInBits(ASL); + APInt OffsetL(BitWidth, 0), OffsetR(BitWidth, 0); + if (GEPL->accumulateConstantOffset(*DL, OffsetL) && + GEPR->accumulateConstantOffset(*DL, OffsetR)) + return cmpAPInt(OffsetL, OffsetR); } - if (GEP1->getPointerOperand()->getType() != - GEP2->getPointerOperand()->getType()) - return false; + if (int Res = cmpNumbers((uint64_t)GEPL->getPointerOperand()->getType(), + (uint64_t)GEPR->getPointerOperand()->getType())) + return Res; - if (GEP1->getNumOperands() != GEP2->getNumOperands()) - return false; + if (int Res = cmpNumbers(GEPL->getNumOperands(), GEPR->getNumOperands())) + return Res; - for (unsigned i = 0, e = GEP1->getNumOperands(); i != e; ++i) { - if (!enumerate(GEP1->getOperand(i), GEP2->getOperand(i))) - return false; + for (unsigned i = 0, e = GEPL->getNumOperands(); i != e; ++i) { + if (int Res = cmpValues(GEPL->getOperand(i), GEPR->getOperand(i))) + return Res; } - return true; + return 0; } -// Compare two values used by the two functions under pair-wise comparison. If -// this is the first time the values are seen, they're added to the mapping so -// that we will detect mismatches on next use. -bool FunctionComparator::enumerate(const Value *V1, const Value *V2) { - // Check for function @f1 referring to itself and function @f2 referring to - // itself, or referring to each other, or both referring to either of them. - // They're all equivalent if the two functions are otherwise equivalent. - if (V1 == F1 && V2 == F2) - return true; - if (V1 == F2 && V2 == F1) - return true; +/// Compare two values used by the two functions under pair-wise comparison. If +/// this is the first time the values are seen, they're added to the mapping so +/// that we will detect mismatches on next use. +/// See comments in declaration for more details. +int FunctionComparator::cmpValues(const Value *L, const Value *R) { + // Catch self-reference case. + if (L == F1) { + if (R == F2) + return 0; + return -1; + } + if (R == F2) { + if (L == F1) + return 0; + return 1; + } - if (const Constant *C1 = dyn_cast<Constant>(V1)) { - if (V1 == V2) return true; - const Constant *C2 = dyn_cast<Constant>(V2); - if (!C2) return false; - // TODO: constant expressions with GEP or references to F1 or F2. - if (C1->isNullValue() && C2->isNullValue() && - isEquivalentType(C1->getType(), C2->getType())) - return true; - // Try bitcasting C2 to C1's type. If the bitcast is legal and returns C1 - // then they must have equal bit patterns. - return C1->getType()->canLosslesslyBitCastTo(C2->getType()) && - C1 == ConstantExpr::getBitCast(const_cast<Constant*>(C2), C1->getType()); - } - - if (isa<InlineAsm>(V1) || isa<InlineAsm>(V2)) - return V1 == V2; - - // Check that V1 maps to V2. If we find a value that V1 maps to then we simply - // check whether it's equal to V2. When there is no mapping then we need to - // ensure that V2 isn't already equivalent to something else. For this - // purpose, we track the V2 values in a set. - - const Value *&map_elem = id_map[V1]; - if (map_elem) - return map_elem == V2; - if (!seen_values.insert(V2).second) - return false; - map_elem = V2; - return true; -} + const Constant *ConstL = dyn_cast<Constant>(L); + const Constant *ConstR = dyn_cast<Constant>(R); + if (ConstL && ConstR) { + if (L == R) + return 0; + return cmpConstants(ConstL, ConstR); + } + + if (ConstL) + return 1; + if (ConstR) + return -1; + + const InlineAsm *InlineAsmL = dyn_cast<InlineAsm>(L); + const InlineAsm *InlineAsmR = dyn_cast<InlineAsm>(R); + + if (InlineAsmL && InlineAsmR) + return cmpNumbers((uint64_t)L, (uint64_t)R); + if (InlineAsmL) + return 1; + if (InlineAsmR) + return -1; + + auto LeftSN = sn_mapL.insert(std::make_pair(L, sn_mapL.size())), + RightSN = sn_mapR.insert(std::make_pair(R, sn_mapR.size())); + return cmpNumbers(LeftSN.first->second, RightSN.first->second); +} // Test whether two basic blocks have equivalent behaviour. bool FunctionComparator::compare(const BasicBlock *BB1, const BasicBlock *BB2) { BasicBlock::const_iterator F1I = BB1->begin(), F1E = BB1->end(); @@ -535,6 +1001,9 @@ bool FunctionComparator::compare() { // We need to recheck everything, but check the things that weren't included // in the hash first. + sn_mapL.clear(); + sn_mapR.clear(); + if (F1->getAttributes() != F2->getAttributes()) return false; @@ -683,7 +1152,7 @@ ModulePass *llvm::createMergeFunctionsPass() { bool MergeFunctions::runOnModule(Module &M) { bool Changed = false; DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>(); - DL = DLP ? &DLP->getDataLayout() : 0; + DL = DLP ? &DLP->getDataLayout() : nullptr; for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) { if (!I->isDeclaration() && !I->hasAvailableExternallyLinkage()) @@ -783,8 +1252,23 @@ void MergeFunctions::writeThunkOrAlias(Function *F, Function *G) { // Helper for writeThunk, // Selects proper bitcast operation, // but a bit simpler then CastInst::getCastOpcode. -static Value* createCast(IRBuilder<false> &Builder, Value *V, Type *DestTy) { +static Value *createCast(IRBuilder<false> &Builder, Value *V, Type *DestTy) { Type *SrcTy = V->getType(); + if (SrcTy->isStructTy()) { + assert(DestTy->isStructTy()); + assert(SrcTy->getStructNumElements() == DestTy->getStructNumElements()); + Value *Result = UndefValue::get(DestTy); + for (unsigned int I = 0, E = SrcTy->getStructNumElements(); I < E; ++I) { + Value *Element = createCast( + Builder, Builder.CreateExtractValue(V, ArrayRef<unsigned int>(I)), + DestTy->getStructElementType(I)); + + Result = + Builder.CreateInsertValue(Result, Element, ArrayRef<unsigned int>(I)); + } + return Result; + } + assert(!DestTy->isStructTy()); if (SrcTy->isIntegerTy() && DestTy->isPointerTy()) return Builder.CreateIntToPtr(V, DestTy); else if (SrcTy->isPointerTy() && DestTy->isIntegerTy()) @@ -843,9 +1327,9 @@ void MergeFunctions::writeThunk(Function *F, Function *G) { // Replace G with an alias to F and delete G. void MergeFunctions::writeAlias(Function *F, Function *G) { - Constant *BitcastF = ConstantExpr::getBitCast(F, G->getType()); - GlobalAlias *GA = new GlobalAlias(G->getType(), G->getLinkage(), "", - BitcastF, G->getParent()); + PointerType *PTy = G->getType(); + auto *GA = GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(), + G->getLinkage(), "", F); F->setAlignment(std::max(F->getAlignment(), G->getAlignment())); GA->takeName(G); GA->setVisibility(G->getVisibility()); |