Update prebuilt Clang to r416183b from Android.

https://android.googlesource.com/platform/prebuilts/clang/host/
linux-x86/+/06a71ddac05c22edb2d10b590e1769b3f8619bef

clang 12.0.5 (based on r416183b) from build 7284624.

Change-Id: I277a316abcf47307562d8b748b84870f31a72866
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/linux-x64/clang/include/llvm/Analysis/Utils/TFUtils.h b/linux-x64/clang/include/llvm/Analysis/Utils/TFUtils.h
new file mode 100644
index 0000000..ea6bc2c
--- /dev/null
+++ b/linux-x64/clang/include/llvm/Analysis/Utils/TFUtils.h
@@ -0,0 +1,266 @@
+//===- TFUtils.h - utilities for tensorflow C API ---------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+#ifndef LLVM_ANALYSIS_UTILS_TFUTILS_H
+#define LLVM_ANALYSIS_UTILS_TFUTILS_H
+
+#include "llvm/Config/llvm-config.h"
+
+#ifdef LLVM_HAVE_TF_API
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/Support/JSON.h"
+
+#include <memory>
+#include <vector>
+
+namespace llvm {
+
+/// Load a SavedModel, find the given inputs and outputs, and setup storage
+/// for input tensors. The user is responsible for correctly dimensioning the
+/// input tensors and setting their values before calling evaluate().
+/// To initialize:
+/// - construct the object
+/// - initialize the input tensors using initInput. Indices must correspond to
+///   indices in the InputNames used at construction.
+/// To use:
+/// - set input values by using getInput to get each input tensor, and then
+///   setting internal scalars, for all dimensions (tensors are row-major:
+///   https://github.com/tensorflow/tensorflow/blob/r1.5/tensorflow/c/c_api.h#L205)
+/// - call evaluate. The input tensors' values are not consumed after this, and
+///   may still be read.
+/// - use the outputs in the output vector
+class TFModelEvaluatorImpl;
+class EvaluationResultImpl;
+
+/// TensorSpec encapsulates the specification of a tensor: its dimensions, or
+/// "shape" (row-major), its type (see TensorSpec::getDataType specializations
+/// for supported types), its name and port (see "TensorFlow: Large-Scale
+/// Machine Learning on Heterogeneous Distributed Systems", section 4.2, para 2:
+/// https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/45166.pdf)
+///
+/// TensorSpec is used to set up a TFModelEvaluator by describing the expected
+/// inputs and outputs.
+class TensorSpec final {
+public:
+  template <typename T>
+  static TensorSpec createSpec(const std::string &Name,
+                               const std::vector<int64_t> &Shape,
+                               int Port = 0) {
+    return TensorSpec(Name, Port, getDataType<T>(), Shape);
+  }
+
+  const std::string &name() const { return Name; }
+  int port() const { return Port; }
+  int typeIndex() const { return TypeIndex; }
+  const std::vector<int64_t> &shape() const { return Shape; }
+
+  bool operator==(const TensorSpec &Other) const {
+    return Name == Other.Name && Port == Other.Port &&
+           TypeIndex == Other.TypeIndex && Shape == Other.Shape;
+  }
+
+  bool operator!=(const TensorSpec &Other) const { return !(*this == Other); }
+
+  /// Get the number of elements in a tensor with this shape.
+  size_t getElementCount() const { return ElementCount; }
+  /// Get the size, in bytes, of one element.
+  size_t getElementByteSize() const;
+
+  template <typename T> bool isElementType() const {
+    return getDataType<T>() == TypeIndex;
+  }
+
+private:
+  TensorSpec(const std::string &Name, int Port, int TypeIndex,
+             const std::vector<int64_t> &Shape);
+
+  template <typename T> static int getDataType() {
+    llvm_unreachable("Undefined tensor type");
+  }
+
+  std::string Name;
+  int Port = 0;
+  int TypeIndex = 0;
+  std::vector<int64_t> Shape;
+  size_t ElementCount = 0;
+};
+
+/// Construct a TensorSpec from a JSON dictionary of the form:
+/// { "name": <string>,
+///   "port": <int>,
+///   "type": <string. Use LLVM's types, e.g. float, double, int64_t>,
+///   "shape": <array of ints> }
+/// For the "type" field, see the C++ primitive types used in
+/// TFUTILS_SUPPORTED_TYPES.
+Optional<TensorSpec> getTensorSpecFromJSON(LLVMContext &Ctx,
+                                           const json::Value &Value);
+
+struct LoggedFeatureSpec {
+  TensorSpec Spec;
+  Optional<std::string> LoggingName;
+};
+
+/// Load the output specs. If SpecFileOverride is not empty, that path is used.
+/// Otherwise, the file is assumed to be called 'output_spec.json' and be found
+/// under ModelPath (the model directory).
+/// The first output tensor name must match ExpectedDecisionName.
+/// In case of error, the return is None and the error is logged.
+Optional<std::vector<LoggedFeatureSpec>>
+loadOutputSpecs(LLVMContext &Ctx, StringRef ExpectedDecisionName,
+                StringRef ModelPath, StringRef SpecFileOverride = StringRef());
+
+/// Logging utility - given an ordered specification of features, and assuming
+/// a scalar reward, allow logging feature values and rewards, and then print
+/// as tf.train.SequenceExample text protobuf.
+/// The assumption is that, for an event to be logged (i.e. a set of feature
+/// values and a reward), the user calls the log* API for each feature exactly
+/// once, providing the index matching the position in the feature spec list
+/// provided at construction:
+/// event 0:
+///   logTensorValue(0, ...)
+///   logTensorValue(1, ...)
+///   ...
+///   logReward(...)
+/// event 1:
+///   logTensorValue(0, ...)
+///   logTensorValue(1, ...)
+///   ...
+///   logReward(...)
+///
+/// At the end, call print to generate the protobuf.
+class Logger final {
+public:
+  /// Construct a Logger. If IncludeReward is false, then logReward shouldn't
+  /// be called, and the reward feature won't be printed out.
+  Logger(const std::vector<LoggedFeatureSpec> &FeatureSpecs,
+         const TensorSpec &RewardSpec, bool IncludeReward)
+      : FeatureSpecs(FeatureSpecs), RewardSpec(RewardSpec),
+        RawLogData(FeatureSpecs.size() + IncludeReward),
+        IncludeReward(IncludeReward) {}
+
+  template <typename T> void logReward(T Value) {
+    assert(IncludeReward);
+    logTensorValue(RawLogData.size() - 1, &Value);
+  }
+
+  template <typename T> void logFinalReward(T Value) {
+    assert(RawLogData.back().empty());
+    logReward(Value);
+  }
+
+  template <typename T>
+  void logTensorValue(size_t FeatureID, const T *Value, size_t Size = 1) {
+    const char *Start = reinterpret_cast<const char *>(Value);
+    const char *End = Start + sizeof(T) * Size;
+    RawLogData[FeatureID].insert(RawLogData[FeatureID].end(), Start, End);
+  }
+
+  void print(raw_ostream &OS);
+
+private:
+  std::vector<LoggedFeatureSpec> FeatureSpecs;
+  TensorSpec RewardSpec;
+  /// RawData has one entry per feature, plus one more for the reward.
+  /// Each feature's values are then stored in a vector, in succession.
+  /// This means the ith event is stored at [*][i]
+  std::vector<std::vector<char>> RawLogData;
+  const bool IncludeReward;
+};
+
+class TFModelEvaluator final {
+public:
+  /// The result of a model evaluation. Handles the lifetime of the output
+  /// tensors, which means that their values need to be used before
+  /// the EvaluationResult's dtor is called.
+  class EvaluationResult {
+  public:
+    EvaluationResult(const EvaluationResult &) = delete;
+    EvaluationResult &operator=(const EvaluationResult &Other) = delete;
+
+    EvaluationResult(EvaluationResult &&Other);
+    EvaluationResult &operator=(EvaluationResult &&Other);
+
+    ~EvaluationResult();
+
+    /// Get a (const) pointer to the first element of the tensor at Index.
+    template <typename T> T *getTensorValue(size_t Index) {
+      return static_cast<T *>(getUntypedTensorValue(Index));
+    }
+
+    template <typename T> const T *getTensorValue(size_t Index) const {
+      return static_cast<T *>(getUntypedTensorValue(Index));
+    }
+
+    /// Get a (const) pointer to the untyped data of the tensor.
+    void *getUntypedTensorValue(size_t Index);
+    const void *getUntypedTensorValue(size_t Index) const;
+
+  private:
+    friend class TFModelEvaluator;
+    EvaluationResult(std::unique_ptr<EvaluationResultImpl> Impl);
+    std::unique_ptr<EvaluationResultImpl> Impl;
+  };
+
+  TFModelEvaluator(StringRef SavedModelPath,
+                   const std::vector<TensorSpec> &InputSpecs,
+                   const std::vector<TensorSpec> &OutputSpecs,
+                   const char *Tags = "serve");
+  TFModelEvaluator(StringRef SavedModelPath,
+                   const std::vector<TensorSpec> &InputSpecs,
+                   function_ref<TensorSpec(size_t)> GetOutputSpecs,
+                   size_t OutputSpecsSize, const char *Tags = "serve");
+
+  ~TFModelEvaluator();
+  TFModelEvaluator(const TFModelEvaluator &) = delete;
+  TFModelEvaluator(TFModelEvaluator &&) = delete;
+
+  /// Evaluate the model, assuming it is valid. Returns None if the evaluation
+  /// fails or the model is invalid, or an EvaluationResult otherwise. The
+  /// inputs are assumed to have been already provided via getInput(). When
+  /// returning None, it also invalidates this object.
+  Optional<EvaluationResult> evaluate();
+
+  /// Provides access to the input vector.
+  template <typename T> T *getInput(size_t Index) {
+    return static_cast<T *>(getUntypedInput(Index));
+  }
+
+  /// Returns true if the tensorflow model was loaded successfully, false
+  /// otherwise.
+  bool isValid() const { return !!Impl; }
+
+private:
+  void *getUntypedInput(size_t Index);
+  std::unique_ptr<TFModelEvaluatorImpl> Impl;
+};
+
+/// List of supported types, as a pair:
+/// - C++ type
+/// - enum name (implementation-specific)
+#define TFUTILS_SUPPORTED_TYPES(M)                                             \
+  M(float, TF_FLOAT)                                                           \
+  M(double, TF_DOUBLE)                                                         \
+  M(int8_t, TF_INT8)                                                           \
+  M(uint8_t, TF_UINT8)                                                         \
+  M(int16_t, TF_INT16)                                                         \
+  M(uint16_t, TF_UINT16)                                                       \
+  M(int32_t, TF_INT32)                                                         \
+  M(uint32_t, TF_UINT32)                                                       \
+  M(int64_t, TF_INT64)                                                         \
+  M(uint64_t, TF_UINT64)
+
+#define TFUTILS_GETDATATYPE_DEF(T, E)                                          \
+  template <> int TensorSpec::getDataType<T>();
+
+TFUTILS_SUPPORTED_TYPES(TFUTILS_GETDATATYPE_DEF)
+
+#undef TFUTILS_GETDATATYPE_DEF
+} // namespace llvm
+
+#endif // LLVM_HAVE_TF_API
+#endif // LLVM_ANALYSIS_UTILS_TFUTILS_H