llvm-6502/include/llvm/Analysis/Expressions.h
Misha Brukman dd298c8c6e Doxygenified and cleand up comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12294 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-11 23:08:20 +00:00

64 lines
2.1 KiB
C++

//===- llvm/Analysis/Expressions.h - Expression Analysis Utils --*- 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.
//
//===----------------------------------------------------------------------===//
//
// This file defines a package of expression analysis utilties:
//
// ClassifyExpr: Analyze an expression to determine the complexity of the
// expression, and which other variables it depends on.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_EXPRESSIONS_H
#define LLVM_ANALYSIS_EXPRESSIONS_H
namespace llvm {
class Type;
class Value;
class ConstantInt;
struct ExprType;
/// ClassifyExpr - Analyze an expression to determine the complexity of the
/// expression, and which other values it depends on.
///
ExprType ClassifyExpr(Value *Expr);
/// ExprType Class - Represent an expression of the form CONST*VAR+CONST
/// or simpler. The expression form that yields the least information about the
/// expression is just the Linear form with no offset.
///
struct ExprType {
enum ExpressionType {
Constant, // Expr is a simple constant, Offset is value
Linear, // Expr is linear expr, Value is Var+Offset
ScaledLinear, // Expr is scaled linear exp, Value is Scale*Var+Offset
} ExprTy;
const ConstantInt *Offset; // Offset of expr, or null if 0
Value *Var; // Var referenced, if Linear or above (null if 0)
const ConstantInt *Scale; // Scale of var if ScaledLinear expr (null if 1)
inline ExprType(const ConstantInt *CPV = 0) {
Offset = CPV; Var = 0; Scale = 0;
ExprTy = Constant;
}
ExprType(Value *Val); // Create a linear or constant expression
ExprType(const ConstantInt *scale, Value *var, const ConstantInt *offset);
/// If this expression has an intrinsic type, return it. If it is zero,
/// return the specified type.
///
const Type *getExprType(const Type *Default) const;
};
} // End llvm namespace
#endif