llvm-project/llvm/lib/CodeGen/SelectionDAG/SDNodeOrdering.h

57 lines
1.6 KiB
C++

//===-- llvm/CodeGen/SDNodeOrdering.h - SDNode Ordering ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the SDNodeOrdering class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SDNODEORDERING_H
#define LLVM_CODEGEN_SDNODEORDERING_H
#include "llvm/ADT/DenseMap.h"
namespace llvm {
class SDNode;
/// SDNodeOrdering - Maps a unique (monotonically increasing) value to each
/// SDNode that roughly corresponds to the ordering of the original LLVM
/// instruction. This is used for turning off scheduling, because we'll forgo
/// the normal scheduling algorithms and output the instructions according to
/// this ordering.
class SDNodeOrdering {
DenseMap<const SDNode*, unsigned> OrderMap;
void operator=(const SDNodeOrdering&) LLVM_DELETED_FUNCTION;
SDNodeOrdering(const SDNodeOrdering&) LLVM_DELETED_FUNCTION;
public:
SDNodeOrdering() {}
void add(const SDNode *Node, unsigned NewOrder) {
unsigned &OldOrder = OrderMap[Node];
if (OldOrder == 0 || (OldOrder > 0 && NewOrder < OldOrder))
OldOrder = NewOrder;
}
void remove(const SDNode *Node) {
DenseMap<const SDNode*, unsigned>::iterator Itr = OrderMap.find(Node);
if (Itr != OrderMap.end())
OrderMap.erase(Itr);
}
void clear() {
OrderMap.clear();
}
unsigned getOrder(const SDNode *Node) {
return OrderMap[Node];
}
};
} // end llvm namespace
#endif