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 ≈
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 void lowerT16D16Helper(const MachineInstr *MI, MCInst &OutMI) const;
44 };
45
46 namespace {
lowerAddrSpaceCast(const TargetMachine & TM,const Constant * CV,MCContext & OutContext)47 static inline const MCExpr *lowerAddrSpaceCast(const TargetMachine &TM,
48 const Constant *CV,
49 MCContext &OutContext) {
50 // TargetMachine does not support llvm-style cast. Use C++-style cast.
51 // This is safe since TM is always of type AMDGPUTargetMachine or its
52 // derived class.
53 auto &AT = static_cast<const AMDGPUTargetMachine &>(TM);
54 auto *CE = dyn_cast<ConstantExpr>(CV);
55
56 // Lower null pointers in private and local address space.
57 // Clang generates addrspacecast for null pointers in private and local
58 // address space, which needs to be lowered.
59 if (CE && CE->getOpcode() == Instruction::AddrSpaceCast) {
60 auto *Op = CE->getOperand(0);
61 auto SrcAddr = Op->getType()->getPointerAddressSpace();
62 if (Op->isNullValue() && AT.getNullPointerValue(SrcAddr) == 0) {
63 auto DstAddr = CE->getType()->getPointerAddressSpace();
64 return MCConstantExpr::create(AT.getNullPointerValue(DstAddr),
65 OutContext);
66 }
67 }
68 return nullptr;
69 }
70 } // namespace
71 #endif // LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H
72