[llvm-commits] [llvm] r41150 - /llvm/trunk/lib/Target/Mips/MipsDelaySlotFiller.cpp

[Evan Cheng]

Hi Bruno,

Sparc backend also has a delay slot filler that does exactly the same  
thing. Can you change this into a target independent pass instead  
(then you just need to add a target hook to emit nop)?

Evan

On Aug 17, 2007, at 6:50 PM, Bruno Cardoso Lopes wrote:

> Author: bruno
> Date: Fri Aug 17 20:50:47 2007
> New Revision: 41150
>
> URL: http://llvm.org/viewvc/llvm-project?rev=41150&view=rev
> Log:
> A Pass to insert Nops on intructions with DelaySlot
>
> Added:
>    llvm/trunk/lib/Target/Mips/MipsDelaySlotFiller.cpp
>
> Added: llvm/trunk/lib/Target/Mips/MipsDelaySlotFiller.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MipsDelaySlotFiller.cpp?rev=41150&view=auto
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/lib/Target/Mips/MipsDelaySlotFiller.cpp (added)
> +++ llvm/trunk/lib/Target/Mips/MipsDelaySlotFiller.cpp Fri Aug 17  
> 20:50:47 2007
> @@ -0,0 +1,77 @@
> +//===-- DelaySlotFiller.cpp - Mips delay slot filler  
> ---------------------===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file was developed by Bruno Cardoso Lopes and is  
> distributed under
> +// the University of Illinois Open Source License. See LICENSE.TXT  
> for details.
> +//
> +// 
> = 
> = 
> = 
> ----------------------------------------------------------------------= 
> ==//
> +//
> +// Simple pass to fills delay slots with NOPs.
> +//
> +// 
> = 
> = 
> = 
> ----------------------------------------------------------------------= 
> ==//
> +
> +#define DEBUG_TYPE "delay-slot-filler"
> +
> +#include "Mips.h"
> +#include "MipsTargetMachine.h"
> +#include "llvm/CodeGen/MachineFunctionPass.h"
> +#include "llvm/CodeGen/MachineInstrBuilder.h"
> +#include "llvm/Target/TargetInstrInfo.h"
> +#include "llvm/ADT/Statistic.h"
> +
> +using namespace llvm;
> +
> +STATISTIC(FilledSlots, "Number of delay slots filled");
> +
> +namespace {
> +  struct Filler : public MachineFunctionPass {
> +
> +    TargetMachine &TM;
> +    const TargetInstrInfo *TII;
> +
> +    static char ID;
> +    Filler(TargetMachine &tm)
> +      : MachineFunctionPass((intptr_t)&ID), TM(tm),  
> TII(tm.getInstrInfo()) { }
> +
> +    virtual const char *getPassName() const {
> +      return "Mips Delay Slot Filler";
> +    }
> +
> +    bool runOnMachineBasicBlock(MachineBasicBlock &MBB);
> +    bool runOnMachineFunction(MachineFunction &F) {
> +      bool Changed = false;
> +      for (MachineFunction::iterator FI = F.begin(), FE = F.end();
> +           FI != FE; ++FI)
> +        Changed |= runOnMachineBasicBlock(*FI);
> +      return Changed;
> +    }
> +
> +  };
> +  char Filler::ID = 0;
> +} // end of anonymous namespace
> +
> +/// runOnMachineBasicBlock - Fill in delay slots for the given  
> basic block.
> +/// Currently, we fill delay slots with NOPs. We assume there is  
> only one
> +/// delay slot per delayed instruction.
> +bool Filler::
> +runOnMachineBasicBlock(MachineBasicBlock &MBB)
> +{
> +  bool Changed = false;
> +  for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end();  
> ++I)
> +    if (TII->hasDelaySlot(I->getOpcode())) {
> +      MachineBasicBlock::iterator J = I;
> +      ++J;
> +      BuildMI(MBB, J, TII->get(Mips::NOP));
> +      ++FilledSlots;
> +      Changed = true;
> +    }
> +  return Changed;
> +}
> +
> +/// createMipsDelaySlotFillerPass - Returns a pass that fills in  
> delay
> +/// slots in Mips MachineFunctions
> +FunctionPass *llvm::createMipsDelaySlotFillerPass(MipsTargetMachine  
> &tm) {
> +  return new Filler(tm);
> +}
> +
>
>
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