DelaySlotFiller.cpp revision 9ccaf53ada99c63737547c0235baeb8454b04e80
1//===-- DelaySlotFiller.cpp - SPARC delay slot filler ---------------------===// 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 is a simple local pass that fills delay slots with NOPs. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "delayslotfiller" 15#include "Sparc.h" 16#include "llvm/CodeGen/MachineFunctionPass.h" 17#include "llvm/CodeGen/MachineInstrBuilder.h" 18#include "llvm/Target/TargetMachine.h" 19#include "llvm/Target/TargetInstrInfo.h" 20#include "llvm/ADT/Statistic.h" 21using namespace llvm; 22 23STATISTIC(FilledSlots, "Number of delay slots filled"); 24 25namespace { 26 struct Filler : public MachineFunctionPass { 27 /// Target machine description which we query for reg. names, data 28 /// layout, etc. 29 /// 30 TargetMachine &TM; 31 const TargetInstrInfo *TII; 32 33 static char ID; 34 Filler(TargetMachine &tm) 35 : MachineFunctionPass(ID), TM(tm), TII(tm.getInstrInfo()) { } 36 37 virtual const char *getPassName() const { 38 return "SPARC Delay Slot Filler"; 39 } 40 41 bool runOnMachineBasicBlock(MachineBasicBlock &MBB); 42 bool runOnMachineFunction(MachineFunction &F) { 43 bool Changed = false; 44 for (MachineFunction::iterator FI = F.begin(), FE = F.end(); 45 FI != FE; ++FI) 46 Changed |= runOnMachineBasicBlock(*FI); 47 return Changed; 48 } 49 50 }; 51 char Filler::ID = 0; 52} // end of anonymous namespace 53 54/// createSparcDelaySlotFillerPass - Returns a pass that fills in delay 55/// slots in Sparc MachineFunctions 56/// 57FunctionPass *llvm::createSparcDelaySlotFillerPass(TargetMachine &tm) { 58 return new Filler(tm); 59} 60 61/// runOnMachineBasicBlock - Fill in delay slots for the given basic block. 62/// Currently, we fill delay slots with NOPs. We assume there is only one 63/// delay slot per delayed instruction. 64/// 65bool Filler::runOnMachineBasicBlock(MachineBasicBlock &MBB) { 66 bool Changed = false; 67 for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ++I) 68 if (I->getDesc().hasDelaySlot()) { 69 MachineBasicBlock::iterator J = I; 70 ++J; 71 BuildMI(MBB, J, DebugLoc(), TII->get(SP::NOP)); 72 ++FilledSlots; 73 Changed = true; 74 } 75 return Changed; 76} 77