X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FConstantFold.h;h=24ef180b867b18db52ec6ba1b57f4db9ccb7807b;hb=5527c0b6d1bda2c63212f91837792663469fd764;hp=79dd21c2c67465e5bdebf316da634d9b8d545420;hpb=0908309e3c4b4f423e88d8d8fe8060cb10eaa1c9;p=oota-llvm.git diff --git a/lib/VMCore/ConstantFold.h b/lib/VMCore/ConstantFold.h index 79dd21c2c67..24ef180b867 100644 --- a/lib/VMCore/ConstantFold.h +++ b/lib/VMCore/ConstantFold.h @@ -1,174 +1,39 @@ -//===-- ConstantHandling.h - Stuff for manipulating constants ----*- C++ -*--=// -// -// This file contains the declarations of some cool operators that allow you -// to do natural things with constant pool values. -// -// Unfortunately we can't overload operators on pointer types (like this:) -// -// inline bool operator==(const ConstPoolVal *V1, const ConstPoolVal *V2) -// -// so we must make due with references, even though it leads to some butt ugly -// looking code downstream. *sigh* (ex: ConstPoolVal *Result = *V1 + *v2; ) +//===-- ConstantFolding.h - Internal Constant Folding Interface -*- C++ -*-===// +// +// The LLVM Compiler Infrastructure // +// This file was developed by the LLVM research group and is distributed under +// the University of Illinois Open Source License. See LICENSE.TXT for details. +// //===----------------------------------------------------------------------===// // -// WARNING: These operators return pointers to newly 'new'd objects. You MUST -// make sure to free them if you don't want them hanging around. Also, -// note that these may return a null object if I don't know how to -// perform those operations on the specified constant types. -// -//===----------------------------------------------------------------------===// +// 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. // -// 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. +// These operators may return a null object if I don't know how to perform the +// specified operation on the specified constant types. // -// 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. -// -//===----------------------------------------------------------------------===// - -#ifndef LLVM_OPT_CONSTANTHANDLING_H -#define LLVM_OPT_CONSTANTHANDLING_H - -#include "llvm/ConstPoolVals.h" -#include "llvm/Instruction.h" -#include "llvm/Type.h" - -namespace opt { - -//===----------------------------------------------------------------------===// -// Implement == directly... -//===----------------------------------------------------------------------===// - -inline ConstPoolBool *operator==(const ConstPoolVal &V1, - const ConstPoolVal &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return new ConstPoolBool(V1.equals(&V2)); -} - -//===----------------------------------------------------------------------===// -// Implement all other operators indirectly through TypeRules system -//===----------------------------------------------------------------------===// - -class ConstRules { -protected: - inline ConstRules() {} // Can only be subclassed... -public: - // Unary Operators... - virtual ConstPoolVal *not(const ConstPoolVal *V) const = 0; - - // Binary Operators... - virtual ConstPoolVal *add(const ConstPoolVal *V1, - const ConstPoolVal *V2) const = 0; - virtual ConstPoolVal *sub(const ConstPoolVal *V1, - const ConstPoolVal *V2) const = 0; - - virtual ConstPoolBool *lessthan(const ConstPoolVal *V1, - const ConstPoolVal *V2) const = 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 const ConstRules *get(const ConstPoolVal &V) { - const ConstRules *Result = V.getType()->getConstRules(); - return Result ? Result : find(V.getType()); - } -private : - static const ConstRules *find(const Type *Ty); - - ConstRules(const ConstRules &); // Do not implement - ConstRules &operator=(const ConstRules &); // Do not implement -}; - - -inline ConstPoolVal *operator!(const ConstPoolVal &V) { - return ConstRules::get(V)->not(&V); -} - - - -inline ConstPoolVal *operator+(const ConstPoolVal &V1, const ConstPoolVal &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1)->add(&V1, &V2); -} - -inline ConstPoolVal *operator-(const ConstPoolVal &V1, const ConstPoolVal &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1)->sub(&V1, &V2); -} - -inline ConstPoolBool *operator<(const ConstPoolVal &V1, - const ConstPoolVal &V2) { - assert(V1.getType() == V2.getType() && "Constant types must be identical!"); - return ConstRules::get(V1)->lessthan(&V1, &V2); -} - - -//===----------------------------------------------------------------------===// -// Implement 'derived' operators based on what we already have... -//===----------------------------------------------------------------------===// - -inline ConstPoolBool *operator>(const ConstPoolVal &V1, - const ConstPoolVal &V2) { - return V2 < V1; -} - -inline ConstPoolBool *operator!=(const ConstPoolVal &V1, - const ConstPoolVal &V2) { - ConstPoolBool *Result = V1 == V2; - Result->setValue(!Result->getValue()); // Invert value - return Result; // !(V1 == V2) -} - -inline ConstPoolBool *operator>=(const ConstPoolVal &V1, - const ConstPoolVal &V2) { - ConstPoolBool *Result = V1 < V2; - Result->setValue(!Result->getValue()); // Invert value - return Result; // !(V1 < V2) -} - -inline ConstPoolBool *operator<=(const ConstPoolVal &V1, - const ConstPoolVal &V2) { - ConstPoolBool *Result = V1 > V2; - Result->setValue(!Result->getValue()); // Invert value - return Result; // !(V1 > V2) -} - - -//===----------------------------------------------------------------------===// -// Implement higher level instruction folding type instructions //===----------------------------------------------------------------------===// -inline ConstPoolVal *ConstantFoldUnaryInstruction(unsigned Opcode, - ConstPoolVal *V) { - switch (Opcode) { - case Instruction::Not: return !*V; - } - return 0; -} +#ifndef CONSTANTFOLDING_H +#define CONSTANTFOLDING_H -inline ConstPoolVal *ConstantFoldBinaryInstruction(unsigned Opcode, - ConstPoolVal *V1, - ConstPoolVal *V2) { - switch (Opcode) { - case Instruction::Add: return *V1 + *V2; - case Instruction::Sub: return *V1 - *V2; +#include - case Instruction::SetEQ: return *V1 == *V2; - case Instruction::SetNE: return *V1 != *V2; - case Instruction::SetLE: return *V1 <= *V2; - case Instruction::SetGE: return *V1 >= *V2; - case Instruction::SetLT: return *V1 < *V2; - case Instruction::SetGT: return *V1 > *V2; - } - return 0; -} +namespace llvm { + 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 -} // end namespace opt #endif