X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FConstantFolding.h;h=24ef180b867b18db52ec6ba1b57f4db9ccb7807b;hb=068758e518f0fe4ab67490f2eec0fd3b376a4d2c;hp=a0a01e5306309d71f1cd44c8f1ab8f15f34e5210;hpb=d0fde30ce850b78371fd1386338350591f9ff494;p=oota-llvm.git diff --git a/lib/VMCore/ConstantFolding.h b/lib/VMCore/ConstantFolding.h index a0a01e53063..24ef180b867 100644 --- a/lib/VMCore/ConstantFolding.h +++ b/lib/VMCore/ConstantFolding.h @@ -1,4 +1,4 @@ -//===-- ConstantHandling.h - Stuff for manipulating constants ---*- C++ -*-===// +//===-- ConstantFolding.h - Internal Constant Folding Interface -*- C++ -*-===// // // The LLVM Compiler Infrastructure // @@ -7,247 +7,33 @@ // //===----------------------------------------------------------------------===// // -// This file contains the declarations of some cool operators that allow you -// to do natural things with constant pool values. +// This file defines the (internal) constant folding interfaces for LLVM. These +// interfaces are used by the ConstantExpr::get* methods to automatically fold +// constants when possible. // -// Unfortunately we can't overload operators on pointer types (like this:) -// -// inline bool operator==(const Constant *V1, const Constant *V2) -// -// so we must make due with references, even though it leads to some butt ugly -// looking code downstream. *sigh* (ex: Constant *Result = *V1 + *v2; ) -// -//===----------------------------------------------------------------------===// -// -// WARNING: These operators may return a null object if I don't know how to -// perform the specified operation on the specified constant types. -// -//===----------------------------------------------------------------------===// -// -// Implementation notes: -// This library is implemented this way for a reason: In most cases, we do -// not want to have to link the constant mucking code into an executable. -// We do, however want to tie some of this into the main type system, as an -// optional component. By using a mutable cache member in the Type class, we -// get exactly the kind of behavior we want. -// -// In the end, we get performance almost exactly the same as having a virtual -// function dispatch, but we don't have to put our virtual functions into the -// "Type" class, and we can implement functionality with templates. Good deal. +// These operators may return a null object if I don't know how to perform the +// specified operation on the specified constant types. // //===----------------------------------------------------------------------===// -#ifndef LLVM_CONSTANTHANDLING_H -#define LLVM_CONSTANTHANDLING_H +#ifndef CONSTANTFOLDING_H +#define CONSTANTFOLDING_H -#include "llvm/Constants.h" -#include "llvm/Type.h" +#include namespace llvm { - -class PointerType; - -//===----------------------------------------------------------------------===// -// Implement == and != directly... -//===----------------------------------------------------------------------===// - -inline ConstantBool *operator==(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstantBool::get(&V1 == &V2); -} - -inline ConstantBool *operator!=(const Constant &V1, const Constant &V2) { - return ConstantBool::get(&V1 != &V2); -} - -//===----------------------------------------------------------------------===// -// Implement all other operators indirectly through TypeRules system -//===----------------------------------------------------------------------===// - -class ConstRules : public Annotation { -protected: - inline ConstRules() : Annotation(AID) {} // Can only be subclassed... -public: - static AnnotationID AID; // AnnotationID for this class - - // Binary Operators... - virtual Constant *add(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *sub(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *mul(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *div(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *rem(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *op_and(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *op_or (const Constant *V1, const Constant *V2) const = 0; - virtual Constant *op_xor(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *shl(const Constant *V1, const Constant *V2) const = 0; - virtual Constant *shr(const Constant *V1, const Constant *V2) const = 0; - - virtual ConstantBool *lessthan(const Constant *V1, - const Constant *V2) const = 0; - - // Casting operators. ick - virtual ConstantBool *castToBool (const Constant *V) const = 0; - virtual ConstantSInt *castToSByte (const Constant *V) const = 0; - virtual ConstantUInt *castToUByte (const Constant *V) const = 0; - virtual ConstantSInt *castToShort (const Constant *V) const = 0; - virtual ConstantUInt *castToUShort(const Constant *V) const = 0; - virtual ConstantSInt *castToInt (const Constant *V) const = 0; - virtual ConstantUInt *castToUInt (const Constant *V) const = 0; - virtual ConstantSInt *castToLong (const Constant *V) const = 0; - virtual ConstantUInt *castToULong (const Constant *V) const = 0; - virtual ConstantFP *castToFloat (const Constant *V) const = 0; - virtual ConstantFP *castToDouble(const Constant *V) const = 0; - virtual Constant *castToPointer(const Constant *V, - const PointerType *Ty) const = 0; - - inline Constant *castTo(const Constant *V, const Type *Ty) const { - switch (Ty->getPrimitiveID()) { - case Type::BoolTyID: return castToBool(V); - case Type::UByteTyID: return castToUByte(V); - case Type::SByteTyID: return castToSByte(V); - case Type::UShortTyID: return castToUShort(V); - case Type::ShortTyID: return castToShort(V); - case Type::UIntTyID: return castToUInt(V); - case Type::IntTyID: return castToInt(V); - case Type::ULongTyID: return castToULong(V); - case Type::LongTyID: return castToLong(V); - case Type::FloatTyID: return castToFloat(V); - case Type::DoubleTyID: return castToDouble(V); - case Type::PointerTyID:return castToPointer(V, (PointerType*)Ty); - default: return 0; - } - } - - // ConstRules::get - A type will cache its own type rules if one is needed... - // we just want to make sure to hit the cache instead of doing it indirectly, - // if possible... - // - static inline ConstRules *get(const Constant &V1, const Constant &V2) { - if (isa(V1) || isa(V2)) - return getConstantExprRules(); - return (ConstRules*)V1.getType()->getOrCreateAnnotation(AID); - } -private: - static ConstRules *getConstantExprRules(); - static Annotation *find(AnnotationID AID, const Annotable *Ty, void *); - - ConstRules(const ConstRules &); // Do not implement - ConstRules &operator=(const ConstRules &); // Do not implement -}; - -// Unary operators... -inline Constant *operator~(const Constant &V) { - assert(V.getType()->isIntegral() && "Cannot invert non-integral constant!"); - return ConstRules::get(V, V)->op_xor(&V, - ConstantInt::getAllOnesValue(V.getType())); -} - -inline Constant *operator-(const Constant &V) { - return ConstRules::get(V, V)->sub(Constant::getNullValue(V.getType()), &V); -} - -// Standard binary operators... -inline Constant *operator+(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->add(&V1, &V2); -} - -inline Constant *operator-(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->sub(&V1, &V2); -} - -inline Constant *operator*(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->mul(&V1, &V2); -} - -inline Constant *operator/(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->div(&V1, &V2); -} - -inline Constant *operator%(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->rem(&V1, &V2); -} - -// Logical Operators... -inline Constant *operator&(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->op_and(&V1, &V2); -} - -inline Constant *operator|(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->op_or(&V1, &V2); -} - -inline Constant *operator^(const Constant &V1, const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->op_xor(&V1, &V2); -} - -// Shift Instructions... -inline Constant *operator<<(const Constant &V1, const Constant &V2) { - assert(V1.getType()->isInteger() && V2.getType() == Type::UByteTy); - return ConstRules::get(V1, V2)->shl(&V1, &V2); -} - -inline Constant *operator>>(const Constant &V1, const Constant &V2) { - assert(V1.getType()->isInteger() && V2.getType() == Type::UByteTy); - return ConstRules::get(V1, V2)->shr(&V1, &V2); -} - -inline ConstantBool *operator<(const Constant &V1, - const Constant &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1, V2)->lessthan(&V1, &V2); -} - - -//===----------------------------------------------------------------------===// -// Implement 'derived' operators based on what we already have... -//===----------------------------------------------------------------------===// - -inline ConstantBool *operator>(const Constant &V1, - const Constant &V2) { - return V2 < V1; -} - -inline ConstantBool *operator>=(const Constant &V1, - const Constant &V2) { - if (ConstantBool *V = (V1 < V2)) - return V->inverted(); // !(V1 < V2) - return 0; -} - -inline ConstantBool *operator<=(const Constant &V1, - const Constant &V2) { - if (ConstantBool *V = (V1 > V2)) - return V->inverted(); // !(V1 > V2) - return 0; -} - - -//===----------------------------------------------------------------------===// -// Implement higher level instruction folding type instructions -//===----------------------------------------------------------------------===// - -// ConstantFoldInstruction - Attempt to constant fold the specified instruction. -// If successful, the constant result is returned, if not, null is returned. -// -Constant *ConstantFoldInstruction(Instruction *I); - -// Constant fold various types of instruction... -Constant *ConstantFoldCastInstruction(const Constant *V, const Type *DestTy); -Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1, - const Constant *V2); -Constant *ConstantFoldShiftInstruction(unsigned Opcode, const Constant *V1, - const Constant *V2); -Constant *ConstantFoldGetElementPtr(const Constant *C, - const std::vector &IdxList); - + class Constant; + struct Type; + + // Constant fold various types of instruction... + Constant *ConstantFoldCastInstruction(const Constant *V, const Type *DestTy); + Constant *ConstantFoldSelectInstruction(const Constant *Cond, + const Constant *V1, + const Constant *V2); + Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1, + const Constant *V2); + Constant *ConstantFoldGetElementPtr(const Constant *C, + const std::vector &IdxList); } // End llvm namespace #endif