utils/TableGen/PseudoLoweringEmitter.h

   1 //===- PseudoLoweringEmitter.h - PseudoLowering Generator -------*- 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 #ifndef PSEUDOLOWERINGEMITTER_H
  11 #define PSEUDOLOWERINGEMITTER_H
  12
  13 #include "CodeGenInstruction.h"
  14 #include "CodeGenTarget.h"
  15 #include "TableGenBackend.h"
  16 #include "llvm/ADT/IndexedMap.h"
  17 #include "llvm/ADT/SmallVector.h"
  18
  19 namespace llvm {
  20
  21 class PseudoLoweringEmitter : public TableGenBackend {
  22   struct OpData {
  23     enum MapKind { Operand, Imm, Reg };
  24     MapKind Kind;
  25     union {
  26       unsigned Operand;   // Operand number mapped to.
  27       uint64_t Imm;       // Integer immedate value.
  28       Record *Reg;        // Physical register.
  29     } Data;
  30   };
  31   struct PseudoExpansion {
  32     CodeGenInstruction Source;  // The source pseudo instruction definition.
  33     CodeGenInstruction Dest;    // The destination instruction to lower to.
  34     IndexedMap<OpData> OperandMap;
  35
  36     PseudoExpansion(CodeGenInstruction &s, CodeGenInstruction &d,
  37                     IndexedMap<OpData> &m) :
  38       Source(s), Dest(d), OperandMap(m) {}
  39   };
  40
  41   RecordKeeper &Records;
  42
  43   // It's overkill to have an instance of the full CodeGenTarget object,
  44   // but it loads everything on demand, not in the constructor, so it's
  45   // lightweight in performance, so it works out OK.
  46   CodeGenTarget Target;
  47
  48   SmallVector<PseudoExpansion, 64> Expansions;
  49
  50   unsigned addDagOperandMapping(Record *Rec, DagInit *Dag,
  51                                 CodeGenInstruction &Insn,
  52                                 IndexedMap<OpData> &OperandMap,
  53                                 unsigned BaseIdx);
  54   void evaluateExpansion(Record *Pseudo);
  55   void emitLoweringEmitter(raw_ostream &o);
  56 public:
  57   PseudoLoweringEmitter(RecordKeeper &R) : Records(R), Target(R) {}
  58
  59   /// run - Output the pseudo-lowerings.
  60   void run(raw_ostream &o);
  61 };
  62
  63 } // end llvm namespace
  64
  65 #endif