xref: /freebsd/contrib/llvm-project/llvm/lib/Target/SPIRV/SPIRVISelLowering.h (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 //===-- SPIRVISelLowering.h - SPIR-V DAG Lowering Interface -----*- 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 // This file defines the interfaces that SPIR-V uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_SPIRV_SPIRVISELLOWERING_H
15 #define LLVM_LIB_TARGET_SPIRV_SPIRVISELLOWERING_H
16 
17 #include "SPIRVGlobalRegistry.h"
18 #include "llvm/CodeGen/TargetLowering.h"
19 #include <set>
20 
21 namespace llvm {
22 class SPIRVSubtarget;
23 
24 class SPIRVTargetLowering : public TargetLowering {
25   const SPIRVSubtarget &STI;
26 
27   // Record of already processed machine functions
28   mutable std::set<const MachineFunction *> ProcessedMF;
29 
30 public:
31   explicit SPIRVTargetLowering(const TargetMachine &TM,
32                                const SPIRVSubtarget &ST)
33       : TargetLowering(TM), STI(ST) {}
34 
35   // Stop IRTranslator breaking up FMA instrs to preserve types information.
36   bool isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
37                                   EVT) const override {
38     return true;
39   }
40 
41   // prevent creation of jump tables
42   bool areJTsAllowed(const Function *) const override { return false; }
43 
44   // This is to prevent sexts of non-i64 vector indices which are generated
45   // within general IRTranslator hence type generation for it is omitted.
46   MVT getVectorIdxTy(const DataLayout &DL) const override {
47     return MVT::getIntegerVT(32);
48   }
49   unsigned getNumRegistersForCallingConv(LLVMContext &Context,
50                                          CallingConv::ID CC,
51                                          EVT VT) const override;
52   MVT getRegisterTypeForCallingConv(LLVMContext &Context, CallingConv::ID CC,
53                                     EVT VT) const override;
54   bool getTgtMemIntrinsic(IntrinsicInfo &Info, const CallInst &I,
55                           MachineFunction &MF,
56                           unsigned Intrinsic) const override;
57 
58   std::pair<unsigned, const TargetRegisterClass *>
59   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
60                                StringRef Constraint, MVT VT) const override;
61   unsigned
62   getNumRegisters(LLVMContext &Context, EVT VT,
63                   std::optional<MVT> RegisterVT = std::nullopt) const override {
64     return 1;
65   }
66 
67   // Call the default implementation and finalize target lowering by inserting
68   // extra instructions required to preserve validity of SPIR-V code imposed by
69   // the standard.
70   void finalizeLowering(MachineFunction &MF) const override;
71 
72   MVT getPreferredSwitchConditionType(LLVMContext &Context,
73                                       EVT ConditionVT) const override {
74     return ConditionVT.getSimpleVT();
75   }
76 };
77 } // namespace llvm
78 
79 #endif // LLVM_LIB_TARGET_SPIRV_SPIRVISELLOWERING_H
80