llvm dev - Mar 2012 - [LLVMdev] VLIWPacketizerList: failing to schedule terminators

Hi,

I'm trying to use the VLIWPacketizerList to schedule instructions for
the R600 target, and I'm running into this assertion failure:
ScheduleDAGInstrs.cpp:558: Cannot schedule terminators or labels!

I think I might not be using the VLIWPacketizerList class correctly.
I've attached my code to this email.  Can anyone spot what I'm doing
wrong?

Also, I had to add a LiveIntervals * parameter to the constructor of
this class in order to do pre-RA scheduling.


Thanks,
Tom
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#include "AMDGPU.h"
#include "llvm/PassRegistry.h"
#include "llvm/CodeGen/DFAPacketizer.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineLoopInfo.h"

using namespace llvm;

namespace {

class R600Packetizer : public VLIWPacketizerList {

public:

  R600Packetizer(MachineFunction &MF, MachineLoopInfo &MLI,
                 MachineDominatorTree &MDT, LiveIntervals * LIS);

  virtual bool isLegalToPacketizeTogether(SUnit *SUI, SUnit * SUJ);

  virtual bool isLegalToPruneDependencies(SUnit *SUI, SUnit * SUJ);
};

R600Packetizer::R600Packetizer(MachineFunction &MF, MachineLoopInfo
&MLI,
                               MachineDominatorTree &MDT, LiveIntervals *
LIS) :
  VLIWPacketizerList(MF, MLI, MDT, false /* isPostRA */, LIS) { }

bool R600Packetizer::isLegalToPacketizeTogether(SUnit *SUI, SUnit *SUJ)
{
  return true;
}

bool R600Packetizer::isLegalToPruneDependencies(SUnit *SUI, SUnit * SUJ)
{
  return false;
}

class R600PacketizeInstrsPass : public MachineFunctionPass {

public:

  static char ID;
  R600PacketizeInstrsPass(TargetMachine &tm) : MachineFunctionPass(ID) {
    initializeMachineDominatorTreePass(*PassRegistry::getPassRegistry());
    initializeMachineLoopInfoPass(*PassRegistry::getPassRegistry());
  }

  const char *getPassName() const {
    return "R600 Packetize Instructions";
  }
  virtual void getAnalysisUsage(AnalysisUsage &AU) const;
  bool runOnMachineFunction(MachineFunction &MF);
};

char R600PacketizeInstrsPass::ID = 0;

void R600PacketizeInstrsPass::getAnalysisUsage(AnalysisUsage &AU) const
{
  AU.addRequired<LiveIntervals>();
  AU.addRequired<MachineDominatorTree>();
  AU.addRequired<MachineLoopInfo>();
  MachineFunctionPass::getAnalysisUsage(AU);
}

bool R600PacketizeInstrsPass::runOnMachineFunction(MachineFunction &MF)
{
  MF.dump();
  MachineLoopInfo & MLI = getAnalysis<MachineLoopInfo>();
  MachineDominatorTree & MDT = getAnalysis<MachineDominatorTree>();
  LiveIntervals * LIS = &getAnalysis<LiveIntervals>();
  R600Packetizer packetizer(MF, MLI, MDT, LIS);

  for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
                                                  BB != BB_E; ++BB) {
    packetizer.PacketizeMIs(BB, BB->begin(), BB->end());
  }
  MF.dump();
  return false;
}

} // End anonymous namespace

FunctionPass *llvm::createR600PacketizeInstrsPass(TargetMachine &tm)
{
  return new R600PacketizeInstrsPass(tm);
}

Tom, 

  What is in your isSchedulingBoundary? If it contains isLabel you might
need to disable that assert:

assert(!MI->isTerminator() && !MI->isLabel() &&
           "Cannot schedule terminators or labels!");

Sergei Larin

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum.

> -----Original Message-----
> From: Tom Stellard [mailto:thomas.stellard at amd.com]
> Sent: Thursday, March 29, 2012 11:01 AM
> To: Anshuman Dasgupta; Sergei Larin
> Cc: llvmdev at cs.uiuc.edu
> Subject: VLIWPacketizerList: failing to schedule terminators
> 
> Hi,
> 
> I'm trying to use the VLIWPacketizerList to schedule instructions for
> the R600 target, and I'm running into this assertion failure:
> ScheduleDAGInstrs.cpp:558: Cannot schedule terminators or labels!
> 
> I think I might not be using the VLIWPacketizerList class correctly.
> I've attached my code to this email.  Can anyone spot what I'm
doing
> wrong?
> 
> Also, I had to add a LiveIntervals * parameter to the constructor of
> this class in order to do pre-RA scheduling.
> 
> 
> Thanks,
> Tom

On Thu, Mar 29, 2012 at 01:50:58PM -0500, Sergei Larin
wrote:
> Tom, 
> 
>   What is in your isSchedulingBoundary? If it contains isLabel you might
> need to disable that assert:
> 
> assert(!MI->isTerminator() && !MI->isLabel() &&
>            "Cannot schedule terminators or labels!");
> 
> Sergei Larin
> 
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum.
> 
> 
I haven't implemented it, so it's still the default implementation.
Though, the assertion failure is happening before the main packetizer
loop, so  it doesn't look like that function is ever called.

-Tom

> > -----Original Message-----
> > From: Tom Stellard [mailto:thomas.stellard at amd.com]
> > Sent: Thursday, March 29, 2012 11:01 AM
> > To: Anshuman Dasgupta; Sergei Larin
> > Cc: llvmdev at cs.uiuc.edu
> > Subject: VLIWPacketizerList: failing to schedule terminators
> > 
> > Hi,
> > 
> > I'm trying to use the VLIWPacketizerList to schedule instructions
for
> > the R600 target, and I'm running into this assertion failure:
> > ScheduleDAGInstrs.cpp:558: Cannot schedule terminators or labels!
> > 
> > I think I might not be using the VLIWPacketizerList class correctly.
> > I've attached my code to this email.  Can anyone spot what I'm
doing
> > wrong?
> > 
> > Also, I had to add a LiveIntervals * parameter to the constructor of
> > this class in order to do pre-RA scheduling.
> > 
> > 
> > Thanks,
> > Tom
> 
>