llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.h

   1 //===- AMDGPUMCInstLower.h - Lower MachineInstr to MCInst ------*- C++ -*--===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 /// \file
  10 /// Header of lower AMDGPU MachineInstrs to their corresponding MCInst.
  11 //
  12 //===----------------------------------------------------------------------===//
  13 //
  14
  15 #ifndef LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H
  16 #define LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H
  17
  18 #include "AMDGPUTargetMachine.h"
  19 #include "llvm/IR/Constants.h"
  20 #include "llvm/Support/Casting.h"
  21
  22 namespace llvm {
  23 class AsmPrinter;
  24 class MCContext;
  25 } // namespace llvm
  26
  27 using namespace llvm;
  28
  29 class AMDGPUMCInstLower {
  30   MCContext &Ctx;
  31   const TargetSubtargetInfo &ST;
  32   const AsmPrinter &AP;
  33
  34 public:
  35   AMDGPUMCInstLower(MCContext &ctx, const TargetSubtargetInfo &ST,
  36                     const AsmPrinter &AP);
  37
  38   bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const;
  39
  40   /// Lower a MachineInstr to an MCInst
  41   void lower(const MachineInstr *MI, MCInst &OutMI) const;
  42 };
  43
  44 namespace {
  45 static inline const MCExpr *lowerAddrSpaceCast(const TargetMachine &TM,
  46                                                const Constant *CV,
  47                                                MCContext &OutContext) {
  48   // TargetMachine does not support llvm-style cast. Use C++-style cast.
  49   // This is safe since TM is always of type AMDGPUTargetMachine or its
  50   // derived class.
  51   auto &AT = static_cast<const AMDGPUTargetMachine &>(TM);
  52   auto *CE = dyn_cast<ConstantExpr>(CV);
  53
  54   // Lower null pointers in private and local address space.
  55   // Clang generates addrspacecast for null pointers in private and local
  56   // address space, which needs to be lowered.
  57   if (CE && CE->getOpcode() == Instruction::AddrSpaceCast) {
  58     auto Op = CE->getOperand(0);
  59     auto SrcAddr = Op->getType()->getPointerAddressSpace();
  60     if (Op->isNullValue() && AT.getNullPointerValue(SrcAddr) == 0) {
  61       auto DstAddr = CE->getType()->getPointerAddressSpace();
  62       return MCConstantExpr::create(AT.getNullPointerValue(DstAddr),
  63                                     OutContext);
  64     }
  65   }
  66   return nullptr;
  67 }
  68 } // namespace
  69 #endif // LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H