1 //===- MLModelRunner.h ---- ML model runner 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 
10 #ifndef LLVM_ANALYSIS_MLMODELRUNNER_H
11 #define LLVM_ANALYSIS_MLMODELRUNNER_H
12 
13 #include "llvm/Analysis/TensorSpec.h"
14 #include "llvm/IR/PassManager.h"
15 
16 namespace llvm {
17 class LLVMContext;
18 
19 /// MLModelRunner interface: abstraction of a mechanism for evaluating a
20 /// ML model. More abstractly, evaluating a function that has as tensors as
21 /// arguments, described via TensorSpecs, and returns a tensor. Currently, the
22 /// latter is assumed to be a scalar, in absence of more elaborate scenarios.
23 /// NOTE: feature indices are expected to be consistent all accross
24 /// MLModelRunners (pertaining to the same model), and also Loggers (see
25 /// TFUtils.h)
26 class MLModelRunner {
27 public:
28   // Disallows copy and assign.
29   MLModelRunner(const MLModelRunner &) = delete;
30   MLModelRunner &operator=(const MLModelRunner &) = delete;
31   virtual ~MLModelRunner() = default;
32 
evaluate()33   template <typename T> T evaluate() {
34     return *reinterpret_cast<T *>(evaluateUntyped());
35   }
36 
getTensor(I FeatureID)37   template <typename T, typename I> T *getTensor(I FeatureID) {
38     return reinterpret_cast<T *>(
39         getTensorUntyped(static_cast<size_t>(FeatureID)));
40   }
41 
getTensor(I FeatureID)42   template <typename T, typename I> const T *getTensor(I FeatureID) const {
43     return reinterpret_cast<const T *>(
44         getTensorUntyped(static_cast<size_t>(FeatureID)));
45   }
46 
getTensorUntyped(size_t Index)47   void *getTensorUntyped(size_t Index) { return InputBuffers[Index]; }
getTensorUntyped(size_t Index)48   const void *getTensorUntyped(size_t Index) const {
49     return (const_cast<MLModelRunner *>(this))->getTensorUntyped(Index);
50   }
51 
52   enum class Kind : int { Unknown, Release, Development, NoOp, Interactive };
getKind()53   Kind getKind() const { return Type; }
switchContext(StringRef Name)54   virtual void switchContext(StringRef Name) {}
55 
56 protected:
MLModelRunner(LLVMContext & Ctx,Kind Type,size_t NrInputs)57   MLModelRunner(LLVMContext &Ctx, Kind Type, size_t NrInputs)
58       : Ctx(Ctx), Type(Type), InputBuffers(NrInputs) {
59     assert(Type != Kind::Unknown);
60   }
61   virtual void *evaluateUntyped() = 0;
62 
setUpBufferForTensor(size_t Index,const TensorSpec & Spec,void * Buffer)63   void setUpBufferForTensor(size_t Index, const TensorSpec &Spec,
64                             void *Buffer) {
65     if (!Buffer) {
66       OwnedBuffers.emplace_back(Spec.getTotalTensorBufferSize());
67       Buffer = OwnedBuffers.back().data();
68     }
69     InputBuffers[Index] = Buffer;
70   }
71 
72   LLVMContext &Ctx;
73   const Kind Type;
74 
75 private:
76   std::vector<void *> InputBuffers;
77   std::vector<std::vector<char *>> OwnedBuffers;
78 };
79 } // namespace llvm
80 
81 #endif // LLVM_ANALYSIS_MLMODELRUNNER_H
82