mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-07-20 10:30:03 +00:00
97f51a3024
methods * Eliminate AnalysisID: Now it is just a typedef for const PassInfo* * Simplify how AnalysisID's are initialized * Eliminate Analysis/Writer.cpp/.h: incorporate printing functionality into the analyses themselves. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3115 91177308-0d34-0410-b5e6-96231b3b80d8
54 lines
2.0 KiB
C++
54 lines
2.0 KiB
C++
//===- llvm/Analysis/InductionVariable.h - Induction variable ----*- C++ -*--=//
|
|
//
|
|
// This interface is used to identify and classify induction variables that
|
|
// exist in the program. Induction variables must contain a PHI node that
|
|
// exists in a loop header. Because of this, they are identified an managed by
|
|
// this PHI node.
|
|
//
|
|
// Induction variables are classified into a type. Knowing that an induction
|
|
// variable is of a specific type can constrain the values of the start and
|
|
// step. For example, a SimpleLinear induction variable must have a start and
|
|
// step values that are constants.
|
|
//
|
|
// Induction variables can be created with or without loop information. If no
|
|
// loop information is available, induction variables cannot be recognized to be
|
|
// more than SimpleLinear variables.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_ANALYSIS_INDUCTIONVARIABLE_H
|
|
#define LLVM_ANALYSIS_INDUCTIONVARIABLE_H
|
|
|
|
#include <iosfwd>
|
|
class Value;
|
|
class PHINode;
|
|
class Instruction;
|
|
class LoopInfo; class Loop;
|
|
|
|
class InductionVariable {
|
|
public:
|
|
enum iType { // Identify the type of this induction variable
|
|
Cannonical, // Starts at 0, counts by 1
|
|
SimpleLinear, // Simple linear: Constant start, constant step
|
|
Linear, // General linear: loop invariant start, and step
|
|
Unknown, // Unknown type. Start & Step are null
|
|
} InductionType;
|
|
|
|
Value *Start, *Step; // Start and step expressions for this indvar
|
|
PHINode *Phi; // The PHI node that corresponds to this indvar
|
|
public:
|
|
|
|
// Create an induction variable for the specified value. If it is a PHI, and
|
|
// if it's recognizable, classify it and fill in instance variables.
|
|
//
|
|
InductionVariable(PHINode *PN, LoopInfo *LoopInfo = 0);
|
|
|
|
// Classify Induction
|
|
static enum iType Classify(const Value *Start, const Value *Step,
|
|
const Loop *L = 0);
|
|
|
|
void print(std::ostream &OS) const;
|
|
};
|
|
|
|
#endif
|