llvm-6502/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp

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//===-- PIC16ISelDAGToDAG.cpp - A dag to dag inst selector for PIC16 ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines an instruction selector for the PIC16 target.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "pic16-isel"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "PIC16ISelDAGToDAG.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
/// createPIC16ISelDag - This pass converts a legalized DAG into a
/// PIC16-specific DAG, ready for instruction scheduling.
FunctionPass *llvm::createPIC16ISelDag(PIC16TargetMachine &TM) {
return new PIC16DAGToDAGISel(TM);
}
/// InstructionSelect - This callback is invoked by
/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
void PIC16DAGToDAGISel::InstructionSelect() {
SelectRoot(*CurDAG);
CurDAG->RemoveDeadNodes();
}
/// Select - Select instructions not customized! Used for
/// expanded, promoted and normal instructions.
SDNode* PIC16DAGToDAGISel::Select(SDNode *N) {
// Select the default instruction.
SDNode *ResNode = SelectCode(N);
return ResNode;
}
// SelectDirectAddr - Match a direct address for DAG.
// A direct address could be a globaladdress or externalsymbol.
bool PIC16DAGToDAGISel::SelectDirectAddr(SDNode *Op, SDValue N,
SDValue &Address) {
// Return true if TGA or ES.
if (N.getOpcode() == ISD::TargetGlobalAddress
|| N.getOpcode() == ISD::TargetExternalSymbol) {
Address = N;
return true;
}
return false;
}