mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-30 02:32:08 +00:00
d0fde30ce8
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9903 91177308-0d34-0410-b5e6-96231b3b80d8
97 lines
3.2 KiB
C++
97 lines
3.2 KiB
C++
//===-- Support/EquivalenceClasses.h ----------------------------*- 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.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Generic implementation of equivalence classes and implementation of
|
|
// union-find algorithms A not-so-fancy implementation: 2 level tree i.e root
|
|
// and one more level Overhead of a union = size of the equivalence class being
|
|
// attached Overhead of a find = 1.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef SUPPORT_EQUIVALENCECLASSES_H
|
|
#define SUPPORT_EQUIVALENCECLASSES_H
|
|
|
|
#include <map>
|
|
#include <vector>
|
|
|
|
namespace llvm {
|
|
|
|
template <class ElemTy>
|
|
class EquivalenceClasses {
|
|
// Maps each element to the element that is the leader of its
|
|
// equivalence class.
|
|
std::map<ElemTy, ElemTy> Elem2ECLeaderMap;
|
|
|
|
// Make Element2 the leader of the union of classes Element1 and Element2
|
|
// Element1 and Element2 are presumed to be leaders of their respective
|
|
// equivalence classes.
|
|
void attach(ElemTy Element1, ElemTy Element2) {
|
|
for (typename std::map<ElemTy, ElemTy>::iterator ElemI =
|
|
Elem2ECLeaderMap.begin(), ElemE = Elem2ECLeaderMap.end();
|
|
ElemI != ElemE; ++ElemI) {
|
|
if (ElemI->second == Element1)
|
|
Elem2ECLeaderMap[ElemI->first] = Element2;
|
|
}
|
|
}
|
|
|
|
public:
|
|
|
|
void addElement (ElemTy NewElement) {
|
|
if (Elem2ECLeaderMap.find(NewElement) == Elem2ECLeaderMap.end())
|
|
Elem2ECLeaderMap[NewElement] = NewElement;
|
|
}
|
|
|
|
ElemTy findClass(ElemTy Element) {
|
|
if (Elem2ECLeaderMap.find(Element) == Elem2ECLeaderMap.end())
|
|
return 0;
|
|
else
|
|
return Elem2ECLeaderMap[Element];
|
|
}
|
|
|
|
/// Attach the set with Element1 to the set with Element2 adding Element1 and
|
|
/// Element2 to the set of equivalence classes if they are not there already.
|
|
/// Implication: Make Element1 the element in the smaller set.
|
|
void unionSetsWith(ElemTy Element1, ElemTy Element2) {
|
|
// If either Element1 or Element2 does not already exist, include it
|
|
if (Elem2ECLeaderMap.find(Element1) == Elem2ECLeaderMap.end())
|
|
Elem2ECLeaderMap[Element1] = Element1;
|
|
if (Elem2ECLeaderMap.find(Element2) == Elem2ECLeaderMap.end())
|
|
Elem2ECLeaderMap[Element2] = Element2;
|
|
|
|
attach(Elem2ECLeaderMap[Element1], Elem2ECLeaderMap[Element2]);
|
|
}
|
|
|
|
// Returns a vector containing all the elements in the equivalent class
|
|
// including Element1
|
|
std::vector<ElemTy> getEqClass(ElemTy Element1) {
|
|
std::vector<ElemTy> EqClass;
|
|
|
|
if (Elem2ECLeaderMap.find(EqClass) == Elem2ECLeaderMap.end())
|
|
return EqClass;
|
|
|
|
ElemTy classLeader = Elem2ECLeaderMap[Element1];
|
|
for (typename std::map<ElemTy, ElemTy>::iterator ElemI =
|
|
Elem2ECLeaderMap.begin(), ElemE = Elem2ECLeaderMap.end();
|
|
ElemI != ElemE; ++ElemI) {
|
|
if (ElemI->second == classLeader)
|
|
EqClass.push_back(ElemI->first);
|
|
}
|
|
|
|
return EqClass;
|
|
}
|
|
|
|
std::map<ElemTy, ElemTy>& getLeaderMap() {
|
|
return Elem2ECLeaderMap ;
|
|
}
|
|
};
|
|
|
|
} // End llvm namespace
|
|
|
|
#endif
|