lib/Target/PIC16/PIC16ISelDAGToDAG.cpp

   1 //===-- PIC16ISelDAGToDAG.cpp - A dag to dag inst selector for PIC16 ------===//
   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 defines an instruction selector for the PIC16 target.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #define DEBUG_TYPE "pic16-isel"
  15
  16 #include "llvm/Support/ErrorHandling.h"
  17 #include "llvm/Support/raw_ostream.h"
  18 #include "PIC16ISelDAGToDAG.h"
  19 #include "llvm/Support/Debug.h"
  20
  21 using namespace llvm;
  22
  23 /// createPIC16ISelDag - This pass converts a legalized DAG into a
  24 /// PIC16-specific DAG, ready for instruction scheduling.
  25 FunctionPass *llvm::createPIC16ISelDag(PIC16TargetMachine &TM) {
  26   return new PIC16DAGToDAGISel(TM);
  27 }
  28
  29
  30 /// InstructionSelect - This callback is invoked by
  31 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
  32 void PIC16DAGToDAGISel::InstructionSelect() {
  33   DEBUG(BB->dump());
  34   SelectRoot(*CurDAG);
  35   CurDAG->RemoveDeadNodes();
  36 }
  37
  38 /// Select - Select instructions not customized! Used for
  39 /// expanded, promoted and normal instructions.
  40 SDNode* PIC16DAGToDAGISel::Select(SDValue N) {
  41
  42   // Select the default instruction.
  43   SDNode *ResNode = SelectCode(N);
  44
  45   return ResNode;
  46 }
  47
  48
  49 // SelectDirectAddr - Match a direct address for DAG.
  50 // A direct address could be a globaladdress or externalsymbol.
  51 bool PIC16DAGToDAGISel::SelectDirectAddr(SDValue Op, SDValue N,
  52                                       SDValue &Address) {
  53   // Return true if TGA or ES.
  54   if (N.getOpcode() == ISD::TargetGlobalAddress
  55       || N.getOpcode() == ISD::TargetExternalSymbol) {
  56     Address = N;
  57     return true;
  58   }
  59
  60   return false;
  61 }