llvm-6502/lib/Transforms/InstCombine/InstCombineWorklist.h

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//===- InstCombineWorklist.h - Worklist for the InstCombine pass ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef INSTCOMBINE_WORKLIST_H
#define INSTCOMBINE_WORKLIST_H
#define DEBUG_TYPE "instcombine"
#include "llvm/Instruction.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Compiler.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
/// InstCombineWorklist - This is the worklist management logic for
/// InstCombine.
class VISIBILITY_HIDDEN InstCombineWorklist {
SmallVector<Instruction*, 256> Worklist;
DenseMap<Instruction*, unsigned> WorklistMap;
void operator=(const InstCombineWorklist&RHS); // DO NOT IMPLEMENT
InstCombineWorklist(const InstCombineWorklist&); // DO NOT IMPLEMENT
public:
InstCombineWorklist() {}
bool isEmpty() const { return Worklist.empty(); }
/// Add - Add the specified instruction to the worklist if it isn't already
/// in it.
void Add(Instruction *I) {
if (WorklistMap.insert(std::make_pair(I, Worklist.size())).second) {
DEBUG(errs() << "IC: ADD: " << *I << '\n');
Worklist.push_back(I);
}
}
void AddValue(Value *V) {
if (Instruction *I = dyn_cast<Instruction>(V))
Add(I);
}
/// AddInitialGroup - Add the specified batch of stuff in reverse order.
/// which should only be done when the worklist is empty and when the group
/// has no duplicates.
void AddInitialGroup(Instruction *const *List, unsigned NumEntries) {
assert(Worklist.empty() && "Worklist must be empty to add initial group");
Worklist.reserve(NumEntries+16);
DEBUG(errs() << "IC: ADDING: " << NumEntries << " instrs to worklist\n");
for (; NumEntries; --NumEntries) {
Instruction *I = List[NumEntries-1];
WorklistMap.insert(std::make_pair(I, Worklist.size()));
Worklist.push_back(I);
}
}
// Remove - remove I from the worklist if it exists.
void Remove(Instruction *I) {
DenseMap<Instruction*, unsigned>::iterator It = WorklistMap.find(I);
if (It == WorklistMap.end()) return; // Not in worklist.
// Don't bother moving everything down, just null out the slot.
Worklist[It->second] = 0;
WorklistMap.erase(It);
}
Instruction *RemoveOne() {
Instruction *I = Worklist.back();
Worklist.pop_back();
WorklistMap.erase(I);
return I;
}
/// AddUsersToWorkList - When an instruction is simplified, add all users of
/// the instruction to the work lists because they might get more simplified
/// now.
///
void AddUsersToWorkList(Instruction &I) {
for (Value::use_iterator UI = I.use_begin(), UE = I.use_end();
UI != UE; ++UI)
Add(cast<Instruction>(*UI));
}
/// Zap - check that the worklist is empty and nuke the backing store for
/// the map if it is large.
void Zap() {
assert(WorklistMap.empty() && "Worklist empty, but map not?");
// Do an explicit clear, this shrinks the map if needed.
WorklistMap.clear();
}
};
} // end namespace llvm.
#endif