lib/CodeGen/SelectionDAG/SDNodeOrdering.h

   1 //===-- llvm/CodeGen/SDNodeOrdering.h - SDNode Ordering ---------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file declares the SDNodeOrdering class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_CODEGEN_SDNODEORDERING_H
  15 #define LLVM_CODEGEN_SDNODEORDERING_H
  16
  17 #include "llvm/ADT/DenseMap.h"
  18
  19 namespace llvm {
  20
  21 class SDNode;
  22
  23 /// SDNodeOrdering - Maps a unique (monotonically increasing) value to each
  24 /// SDNode that roughly corresponds to the ordering of the original LLVM
  25 /// instruction. This is used for turning off scheduling, because we'll forgo
  26 /// the normal scheduling algorithms and output the instructions according to
  27 /// this ordering.
  28 class SDNodeOrdering {
  29   DenseMap<const SDNode*, unsigned> OrderMap;
  30
  31   void operator=(const SDNodeOrdering&);   // Do not implement.
  32   SDNodeOrdering(const SDNodeOrdering&);   // Do not implement.
  33 public:
  34   SDNodeOrdering() {}
  35
  36   void add(const SDNode *Node, unsigned O) {
  37     OrderMap[Node] = O;
  38   }
  39   void remove(const SDNode *Node) {
  40     DenseMap<const SDNode*, unsigned>::iterator Itr = OrderMap.find(Node);
  41     if (Itr != OrderMap.end())
  42       OrderMap.erase(Itr);
  43   }
  44   void clear() {
  45     OrderMap.clear();
  46   }
  47   unsigned getOrder(const SDNode *Node) {
  48     return OrderMap[Node];
  49   }
  50 };
  51
  52 } // end llvm namespace
  53
  54 #endif