1 //===- JITTargetMachineBuilder.h - Build TargetMachines for JIT -*- 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 // A utitily for building TargetMachines for JITs.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_EXECUTIONENGINE_ORC_JITTARGETMACHINEBUILDER_H
14 #define LLVM_EXECUTIONENGINE_ORC_JITTARGETMACHINEBUILDER_H
15 
16 #include "llvm/ADT/Optional.h"
17 #include "llvm/ADT/Triple.h"
18 #include "llvm/MC/SubtargetFeature.h"
19 #include "llvm/Support/CodeGen.h"
20 #include "llvm/Support/Error.h"
21 #include "llvm/Target/TargetMachine.h"
22 #include "llvm/Target/TargetOptions.h"
23 #include <memory>
24 #include <string>
25 #include <vector>
26 
27 namespace llvm {
28 namespace orc {
29 
30 /// A utility class for building TargetMachines for JITs.
31 class JITTargetMachineBuilder {
32 public:
33   /// Create a JITTargetMachineBuilder based on the given triple.
34   ///
35   /// Note: TargetOptions is default-constructed, then EmulatedTLS and
36   /// ExplicitEmulatedTLS are set to true. If EmulatedTLS is not
37   /// required, these values should be reset before calling
38   /// createTargetMachine.
39   JITTargetMachineBuilder(Triple TT);
40 
41   /// Create a JITTargetMachineBuilder for the host system.
42   ///
43   /// Note: TargetOptions is default-constructed, then EmulatedTLS and
44   /// ExplicitEmulatedTLS are set to true. If EmulatedTLS is not
45   /// required, these values should be reset before calling
46   /// createTargetMachine.
47   static Expected<JITTargetMachineBuilder> detectHost();
48 
49   /// Create a TargetMachine.
50   ///
51   /// This operation will fail if the requested target is not registered,
52   /// in which case see llvm/Support/TargetSelect.h. To JIT IR the Target and
53   /// the target's AsmPrinter must both be registered. To JIT assembly
54   /// (including inline and module level assembly) the target's AsmParser must
55   /// also be registered.
56   Expected<std::unique_ptr<TargetMachine>> createTargetMachine();
57 
58   /// Get the default DataLayout for the target.
59   ///
60   /// Note: This is reasonably expensive, as it creates a temporary
61   /// TargetMachine instance under the hood. It is only suitable for use during
62   /// JIT setup.
63   Expected<DataLayout> getDefaultDataLayoutForTarget() {
64     auto TM = createTargetMachine();
65     if (!TM)
66       return TM.takeError();
67     return (*TM)->createDataLayout();
68   }
69 
70   /// Set the CPU string.
71   JITTargetMachineBuilder &setCPU(std::string CPU) {
72     this->CPU = std::move(CPU);
73     return *this;
74   }
75 
76   /// Set the relocation model.
77   JITTargetMachineBuilder &setRelocationModel(Optional<Reloc::Model> RM) {
78     this->RM = std::move(RM);
79     return *this;
80   }
81 
82   /// Set the code model.
83   JITTargetMachineBuilder &setCodeModel(Optional<CodeModel::Model> CM) {
84     this->CM = std::move(CM);
85     return *this;
86   }
87 
88   /// Set the LLVM CodeGen optimization level.
89   JITTargetMachineBuilder &setCodeGenOptLevel(CodeGenOpt::Level OptLevel) {
90     this->OptLevel = OptLevel;
91     return *this;
92   }
93 
94   /// Add subtarget features.
95   JITTargetMachineBuilder &
96   addFeatures(const std::vector<std::string> &FeatureVec);
97 
98   /// Access subtarget features.
99   SubtargetFeatures &getFeatures() { return Features; }
100 
101   /// Access subtarget features.
102   const SubtargetFeatures &getFeatures() const { return Features; }
103 
104   /// Access TargetOptions.
105   TargetOptions &getOptions() { return Options; }
106 
107   /// Access TargetOptions.
108   const TargetOptions &getOptions() const { return Options; }
109 
110   /// Access Triple.
111   Triple &getTargetTriple() { return TT; }
112 
113   /// Access Triple.
114   const Triple &getTargetTriple() const { return TT; }
115 
116 private:
117   Triple TT;
118   std::string CPU;
119   SubtargetFeatures Features;
120   TargetOptions Options;
121   Optional<Reloc::Model> RM;
122   Optional<CodeModel::Model> CM;
123   CodeGenOpt::Level OptLevel = CodeGenOpt::None;
124 };
125 
126 } // end namespace orc
127 } // end namespace llvm
128 
129 #endif // LLVM_EXECUTIONENGINE_ORC_JITTARGETMACHINEBUILDER_H
130