path: root/include/llvm/Support/PatternMatch.h

//===-- llvm/Support/PatternMatch.h - Match on the LLVM IR ------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides a simple and efficient mechanism for performing general
// tree-based pattern matches on the LLVM IR.  The power of these routines is
// that it allows you to write concise patterns that are expressive and easy to
// understand.  The other major advantage of this is that it allows you to
// trivially capture/bind elements in the pattern to variables.  For example,
// you can do something like this:
//
//  Value *Exp = ...
//  Value *X, *Y;  ConstantInt *C1, *C2;      // (X & C1) | (Y & C2)
//  if (match(Exp, m_Or(m_And(m_Value(X), m_ConstantInt(C1)),
//                      m_And(m_Value(Y), m_ConstantInt(C2))))) {
//    ... Pattern is matched and variables are bound ...
//  }
//
// This is primarily useful to things like the instruction combiner, but can
// also be useful for static analysis tools or code generators.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_PATTERNMATCH_H
#define LLVM_SUPPORT_PATTERNMATCH_H

#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Operator.h"
#include "llvm/Support/CallSite.h"

namespace llvm {
namespace PatternMatch {

template<typename Val, typename Pattern>
bool match(Val *V, const Pattern &P) {
  return const_cast<Pattern&>(P).match(V);
}


template<typename SubPattern_t>
struct OneUse_match {
  SubPattern_t SubPattern;

  OneUse_match(const SubPattern_t &SP) : SubPattern(SP) {}

  template<typename OpTy>
  bool match(OpTy *V) {
    return V->hasOneUse() && SubPattern.match(V);
  }
};

template<typename T>
inline OneUse_match<T> m_OneUse(const T &SubPattern) { return SubPattern; }


template<typename Class>
struct class_match {
  template<typename ITy>
  bool match(ITy *V) { return isa<Class>(V); }
};

/// m_Value() - Match an arbitrary value and ignore it.
inline class_match<Value> m_Value() { return class_match<Value>(); }
/// m_ConstantInt() - Match an arbitrary ConstantInt and ignore it.
inline class_match<ConstantInt> m_ConstantInt() {
  return class_match<ConstantInt>();
}
/// m_Undef() - Match an arbitrary undef constant.
inline class_match<UndefValue> m_Undef() { return class_match<UndefValue>(); }

inline class_match<Constant> m_Constant() { return class_match<Constant>(); }

/// Matching combinators
template<typename LTy, typename RTy>
struct match_combine_or {
  LTy L;
  RTy R;

  match_combine_or(const LTy &Left, const RTy &Right) : L(Left), R(Right) { }

  template<typename ITy>
  bool match(ITy *V) {
    if (L.match(V))
      return true;
    if (R.match(V))
      return true;
    return false;
  }
};

template<typename LTy, typename RTy>
struct match_combine_and {
  LTy L;
  RTy R;

  match_combine_and(const LTy &Left, const RTy &Right) : L(Left), R(Right) { }

  template<typename ITy>
  bool match(ITy *V) {
    if (L.match(V))
      if (R.match(V))
        return true;
    return false;
  }
};

/// Combine two pattern matchers matching L || R
template<typename LTy, typename RTy>
inline match_combine_or<LTy, RTy> m_CombineOr(const LTy &L, const RTy &R) {
  return match_combine_or<LTy, RTy>(L, R);
}

/// Combine two pattern matchers matching L && R
template<typename LTy, typename RTy>
inline match_combine_and<LTy, RTy> m_CombineAnd(const LTy &L, const RTy &R) {
  return