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Current Path: /usr/src/contrib/llvm-project/llvm/lib/Target/NVPTX

usr / src / contrib / llvm-project / llvm / lib / Target / NVPTX /

📁 ..
📁 MCTargetDesc
📄 ManagedStringPool.h(1.41 KB)
📄 NVPTX.h(3.22 KB)
📄 NVPTX.td(4.99 KB)
📄 NVPTXAllocaHoisting.cpp(2.12 KB)
📄 NVPTXAllocaHoisting.h(755 B)
📄 NVPTXAsmPrinter.cpp(71.02 KB)
📄 NVPTXAsmPrinter.h(11.23 KB)
📄 NVPTXAssignValidGlobalNames.cpp(2.74 KB)
📄 NVPTXFrameLowering.cpp(3.41 KB)
📄 NVPTXFrameLowering.h(1.34 KB)
📄 NVPTXGenericToNVVM.cpp(11.59 KB)
📄 NVPTXISelDAGToDAG.cpp(134.03 KB)
📄 NVPTXISelDAGToDAG.h(3.54 KB)
📄 NVPTXISelLowering.cpp(198.59 KB)
📄 NVPTXISelLowering.h(15.65 KB)
📄 NVPTXImageOptimizer.cpp(5.64 KB)
📄 NVPTXInstrFormats.td(1.72 KB)
📄 NVPTXInstrInfo.cpp(7.88 KB)
📄 NVPTXInstrInfo.h(2.87 KB)
📄 NVPTXInstrInfo.td(133.35 KB)
📄 NVPTXIntrinsics.td(329.76 KB)
📄 NVPTXLowerAggrCopies.cpp(4.85 KB)
📄 NVPTXLowerAggrCopies.h(744 B)
📄 NVPTXLowerAlloca.cpp(4.27 KB)
📄 NVPTXLowerArgs.cpp(9.16 KB)
📄 NVPTXMCExpr.cpp(2.04 KB)
📄 NVPTXMCExpr.h(3.92 KB)
📄 NVPTXMachineFunctionInfo.h(1.71 KB)
📄 NVPTXPeephole.cpp(4.92 KB)
📄 NVPTXPrologEpilogPass.cpp(8.91 KB)
📄 NVPTXProxyRegErasure.cpp(3.81 KB)
📄 NVPTXRegisterInfo.cpp(4.41 KB)
📄 NVPTXRegisterInfo.h(2.04 KB)
📄 NVPTXRegisterInfo.td(3.12 KB)
📄 NVPTXReplaceImageHandles.cpp(6.27 KB)
📄 NVPTXSubtarget.cpp(2.15 KB)
📄 NVPTXSubtarget.h(3.02 KB)
📄 NVPTXTargetMachine.cpp(14.25 KB)
📄 NVPTXTargetMachine.h(3.33 KB)
📄 NVPTXTargetObjectFile.h(1.53 KB)
📄 NVPTXTargetTransformInfo.cpp(6.18 KB)
📄 NVPTXTargetTransformInfo.h(4.7 KB)
📄 NVPTXUtilities.cpp(9.37 KB)
📄 NVPTXUtilities.h(2.03 KB)
📄 NVVMIntrRange.cpp(4.88 KB)
📄 NVVMReflect.cpp(6.8 KB)
📁 TargetInfo
📄 cl_common_defines.h(3.94 KB)

Editing: NVPTXPeephole.cpp

//===-- NVPTXPeephole.cpp - NVPTX Peephole Optimiztions -------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// In NVPTX, NVPTXFrameLowering will emit following instruction at the beginning
// of a MachineFunction.
//
//   mov %SPL, %depot
//   cvta.local %SP, %SPL
//
// Because Frame Index is a generic address and alloca can only return generic
// pointer, without this pass the instructions producing alloca'ed address will
// be based on %SP. NVPTXLowerAlloca tends to help replace store and load on
// this address with their .local versions, but this may introduce a lot of
// cvta.to.local instructions. Performance can be improved if we avoid casting
// address back and forth and directly calculate local address based on %SPL.
// This peephole pass optimizes these cases, for example
//
// It will transform the following pattern
//    %0 = LEA_ADDRi64 %VRFrame, 4
//    %1 = cvta_to_local_yes_64 %0
//
// into
//    %1 = LEA_ADDRi64 %VRFrameLocal, 4
//
// %VRFrameLocal is the virtual register name of %SPL
//
//===----------------------------------------------------------------------===//

#include "NVPTX.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"

using namespace llvm;

#define DEBUG_TYPE "nvptx-peephole"

namespace llvm {
void initializeNVPTXPeepholePass(PassRegistry &);
}

namespace {
struct NVPTXPeephole : public MachineFunctionPass {
 public:
  static char ID;
  NVPTXPeephole() : MachineFunctionPass(ID) {
    initializeNVPTXPeepholePass(*PassRegistry::getPassRegistry());
  }

bool runOnMachineFunction(MachineFunction &MF) override;

StringRef getPassName() const override {
    return "NVPTX optimize redundant cvta.to.local instruction";
  }

void getAnalysisUsage(AnalysisUsage &AU) const override {
    MachineFunctionPass::getAnalysisUsage(AU);
  }
};
}

char NVPTXPeephole::ID = 0;

INITIALIZE_PASS(NVPTXPeephole, "nvptx-peephole", "NVPTX Peephole", false, false)

static bool isCVTAToLocalCombinationCandidate(MachineInstr &Root) {
  auto &MBB = *Root.getParent();
  auto &MF = *MBB.getParent();
  // Check current instruction is cvta.to.local
  if (Root.getOpcode() != NVPTX::cvta_to_local_yes_64 &&
      Root.getOpcode() != NVPTX::cvta_to_local_yes)
    return false;

auto &Op = Root.getOperand(1);
  const auto &MRI = MF.getRegInfo();
  MachineInstr *GenericAddrDef = nullptr;
  if (Op.isReg() && Register::isVirtualRegister(Op.getReg())) {
    GenericAddrDef = MRI.getUniqueVRegDef(Op.getReg());
  }

// Check the register operand is uniquely defined by LEA_ADDRi instruction
  if (!GenericAddrDef || GenericAddrDef->getParent() != &MBB ||
      (GenericAddrDef->getOpcode() != NVPTX::LEA_ADDRi64 &&
       GenericAddrDef->getOpcode() != NVPTX::LEA_ADDRi)) {
    return false;
  }

// Check the LEA_ADDRi operand is Frame index
  auto &BaseAddrOp = GenericAddrDef->getOperand(1);
  if (BaseAddrOp.isReg() && BaseAddrOp.getReg() == NVPTX::VRFrame) {
    return true;
  }

return false;
}

static void CombineCVTAToLocal(MachineInstr &Root) {
  auto &MBB = *Root.getParent();
  auto &MF = *MBB.getParent();
  const auto &MRI = MF.getRegInfo();
  const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
  auto &Prev = *MRI.getUniqueVRegDef(Root.getOperand(1).getReg());

MachineInstrBuilder MIB =
      BuildMI(MF, Root.getDebugLoc(), TII->get(Prev.getOpcode()),
              Root.getOperand(0).getReg())
          .addReg(NVPTX::VRFrameLocal)
          .add(Prev.getOperand(2));

MBB.insert((MachineBasicBlock::iterator)&Root, MIB);

// Check if MRI has only one non dbg use, which is Root
  if (MRI.hasOneNonDBGUse(Prev.getOperand(0).getReg())) {
    Prev.eraseFromParentAndMarkDBGValuesForRemoval();
  }
  Root.eraseFromParentAndMarkDBGValuesForRemoval();
}

bool NVPTXPeephole::runOnMachineFunction(MachineFunction &MF) {
  if (skipFunction(MF.getFunction()))
    return false;

bool Changed = false;
  // Loop over all of the basic blocks.
  for (auto &MBB : MF) {
    // Traverse the basic block.
    auto BlockIter = MBB.begin();

while (BlockIter != MBB.end()) {
      auto &MI = *BlockIter++;
      if (isCVTAToLocalCombinationCandidate(MI)) {
        CombineCVTAToLocal(MI);
        Changed = true;
      }
    }  // Instruction
  }    // Basic Block

// Remove unnecessary %VRFrame = cvta.local %VRFrameLocal
  const auto &MRI = MF.getRegInfo();
  if (MRI.use_empty(NVPTX::VRFrame)) {
    if (auto MI = MRI.getUniqueVRegDef(NVPTX::VRFrame)) {
      MI->eraseFromParentAndMarkDBGValuesForRemoval();
    }
  }

return Changed;
}

MachineFunctionPass *llvm::createNVPTXPeephole() { return new NVPTXPeephole(); }

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Editing: NVPTXPeephole.cpp

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