llvm16 targets

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diff --git a/contrib/libs/llvm16/tools/llvm-exegesis/lib/SnippetGenerator.h b/contrib/libs/llvm16/tools/llvm-exegesis/lib/SnippetGenerator.h
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+//===-- SnippetGenerator.h --------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Defines the abstract SnippetGenerator class for generating code that allows
+/// measuring a certain property of instructions (e.g. latency).
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLVM_EXEGESIS_SNIPPETGENERATOR_H
+#define LLVM_TOOLS_LLVM_EXEGESIS_SNIPPETGENERATOR_H
+
+#include "Assembler.h"
+#include "BenchmarkCode.h"
+#include "CodeTemplate.h"
+#include "LlvmState.h"
+#include "MCInstrDescView.h"
+#include "RegisterAliasing.h"
+#include "llvm/ADT/CombinationGenerator.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/Support/Error.h"
+#include <cstdlib>
+#include <memory>
+#include <vector>
+
+namespace llvm {
+namespace exegesis {
+
+std::vector<CodeTemplate> getSingleton(CodeTemplate &&CT);
+
+// Generates code templates that has a self-dependency.
+Expected<std::vector<CodeTemplate>>
+generateSelfAliasingCodeTemplates(InstructionTemplate Variant,
+                                  const BitVector &ForbiddenRegisters);
+
+// Generates code templates without assignment constraints.
+Expected<std::vector<CodeTemplate>>
+generateUnconstrainedCodeTemplates(const InstructionTemplate &Variant,
+                                   StringRef Msg);
+
+// A class representing failures that happened during Benchmark, they are used
+// to report informations to the user.
+class SnippetGeneratorFailure : public StringError {
+public:
+  SnippetGeneratorFailure(const Twine &S);
+};
+
+// Common code for all benchmark modes.
+class SnippetGenerator {
+public:
+  struct Options {
+    unsigned MaxConfigsPerOpcode = 1;
+  };
+
+  explicit SnippetGenerator(const LLVMState &State, const Options &Opts);
+
+  virtual ~SnippetGenerator();
+
+  // Calls generateCodeTemplate and expands it into one or more BenchmarkCode.
+  Error generateConfigurations(const InstructionTemplate &Variant,
+                               std::vector<BenchmarkCode> &Benchmarks,
+                               const BitVector &ExtraForbiddenRegs) const;
+
+  // Given a snippet, computes which registers the setup code needs to define.
+  std::vector<RegisterValue> computeRegisterInitialValues(
+      const std::vector<InstructionTemplate> &Snippet) const;
+
+protected:
+  const LLVMState &State;
+  const Options Opts;
+
+private:
+  // API to be implemented by subclasses.
+  virtual Expected<std::vector<CodeTemplate>>
+  generateCodeTemplates(InstructionTemplate Variant,
+                        const BitVector &ForbiddenRegisters) const = 0;
+};
+
+// A global Random Number Generator to randomize configurations.
+// FIXME: Move random number generation into an object and make it seedable for
+// unit tests.
+std::mt19937 &randomGenerator();
+
+// Picks a random unsigned integer from 0 to Max (inclusive).
+size_t randomIndex(size_t Max);
+
+// Picks a random bit among the bits set in Vector and returns its index.
+// Precondition: Vector must have at least one bit set.
+size_t randomBit(const BitVector &Vector);
+
+// Picks a first bit that is common to these two vectors.
+std::optional<int> getFirstCommonBit(const BitVector &A, const BitVector &B);
+
+// Picks a random configuration, then selects a random def and a random use from
+// it and finally set the selected values in the provided InstructionInstances.
+void setRandomAliasing(const AliasingConfigurations &AliasingConfigurations,
+                       InstructionTemplate &DefIB, InstructionTemplate &UseIB);
+
+// Assigns a Random Value to all Variables in IT that are still Invalid.
+// Do not use any of the registers in `ForbiddenRegs`.
+Error randomizeUnsetVariables(const LLVMState &State,
+                              const BitVector &ForbiddenRegs,
+                              InstructionTemplate &IT);
+
+} // namespace exegesis
+} // namespace llvm
+
+#endif // LLVM_TOOLS_LLVM_EXEGESIS_SNIPPETGENERATOR_H