1 //===- JITTargetMachineBuilder.h - Build TargetMachines for JIT -*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // A utitily for building TargetMachines for JITs.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_EXECUTIONENGINE_ORC_JITTARGETMACHINEBUILDER_H
15 #define LLVM_EXECUTIONENGINE_ORC_JITTARGETMACHINEBUILDER_H
16 
17 #include "llvm/ADT/Optional.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/MC/SubtargetFeature.h"
20 #include "llvm/Support/CodeGen.h"
21 #include "llvm/Support/Error.h"
22 #include "llvm/Target/TargetMachine.h"
23 #include "llvm/Target/TargetOptions.h"
24 #include <memory>
25 #include <string>
26 #include <vector>
27 
28 namespace llvm {
29 namespace orc {
30 
31 /// A utility class for building TargetMachines for JITs.
32 class JITTargetMachineBuilder {
33 public:
34   /// Create a JITTargetMachineBuilder based on the given triple.
35   ///
36   /// Note: TargetOptions is default-constructed, then EmulatedTLS and
37   /// ExplicitEmulatedTLS are set to true. If EmulatedTLS is not
38   /// required, these values should be reset before calling
39   /// createTargetMachine.
40   JITTargetMachineBuilder(Triple TT);
41 
42   /// Create a JITTargetMachineBuilder for the host system.
43   ///
44   /// Note: TargetOptions is default-constructed, then EmulatedTLS and
45   /// ExplicitEmulatedTLS are set to true. If EmulatedTLS is not
46   /// required, these values should be reset before calling
47   /// createTargetMachine.
48   static Expected<JITTargetMachineBuilder> detectHost();
49 
50   /// Create a TargetMachine.
51   ///
52   /// This operation will fail if the requested target is not registered,
53   /// in which case see llvm/Support/TargetSelect.h. To JIT IR the Target and
54   /// the target's AsmPrinter must both be registered. To JIT assembly
55   /// (including inline and module level assembly) the target's AsmParser must
56   /// also be registered.
57   Expected<std::unique_ptr<TargetMachine>> createTargetMachine();
58 
59   /// Get the default DataLayout for the target.
60   ///
61   /// Note: This is reasonably expensive, as it creates a temporary
62   /// TargetMachine instance under the hood. It is only suitable for use during
63   /// JIT setup.
getDefaultDataLayoutForTarget()64   Expected<DataLayout> getDefaultDataLayoutForTarget() {
65     auto TM = createTargetMachine();
66     if (!TM)
67       return TM.takeError();
68     return (*TM)->createDataLayout();
69   }
70 
71   /// Set the CPU string.
setCPU(std::string CPU)72   JITTargetMachineBuilder &setCPU(std::string CPU) {
73     this->CPU = std::move(CPU);
74     return *this;
75   }
76 
77   /// Set the relocation model.
setRelocationModel(Optional<Reloc::Model> RM)78   JITTargetMachineBuilder &setRelocationModel(Optional<Reloc::Model> RM) {
79     this->RM = std::move(RM);
80     return *this;
81   }
82 
83   /// Set the code model.
setCodeModel(Optional<CodeModel::Model> CM)84   JITTargetMachineBuilder &setCodeModel(Optional<CodeModel::Model> CM) {
85     this->CM = std::move(CM);
86     return *this;
87   }
88 
89   /// Set the LLVM CodeGen optimization level.
setCodeGenOptLevel(CodeGenOpt::Level OptLevel)90   JITTargetMachineBuilder &setCodeGenOptLevel(CodeGenOpt::Level OptLevel) {
91     this->OptLevel = OptLevel;
92     return *this;
93   }
94 
95   /// Add subtarget features.
96   JITTargetMachineBuilder &
97   addFeatures(const std::vector<std::string> &FeatureVec);
98 
99   /// Access subtarget features.
getFeatures()100   SubtargetFeatures &getFeatures() { return Features; }
101 
102   /// Access subtarget features.
getFeatures()103   const SubtargetFeatures &getFeatures() const { return Features; }
104 
105   /// Access TargetOptions.
getOptions()106   TargetOptions &getOptions() { return Options; }
107 
108   /// Access TargetOptions.
getOptions()109   const TargetOptions &getOptions() const { return Options; }
110 
111   /// Access Triple.
getTargetTriple()112   Triple &getTargetTriple() { return TT; }
113 
114   /// Access Triple.
getTargetTriple()115   const Triple &getTargetTriple() const { return TT; }
116 
117 private:
118   Triple TT;
119   std::string CPU;
120   SubtargetFeatures Features;
121   TargetOptions Options;
122   Optional<Reloc::Model> RM;
123   Optional<CodeModel::Model> CM;
124   CodeGenOpt::Level OptLevel = CodeGenOpt::None;
125 };
126 
127 } // end namespace orc
128 } // end namespace llvm
129 
130 #endif // LLVM_EXECUTIONENGINE_ORC_JITTARGETMACHINEBUILDER_H
131