1 files changed, 50 insertions, 5 deletions
diff --git a/llvm/tools/llvm-exegesis/lib/CodeTemplate.h b/llvm/tools/llvm-exegesis/lib/CodeTemplate.h
index 80f70bc8b52..b11ef16ab1e 100644
--- a/llvm/tools/llvm-exegesis/lib/CodeTemplate.h
+++ b/llvm/tools/llvm-exegesis/lib/CodeTemplate.h
@@ -8,10 +8,8 @@
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// A CodeTemplate is a set of InstructionBuilders that may not be fully
-/// specified (i.e. some variables are not yet set). This allows the
-/// BenchmarkRunner to instantiate it many times with specific values to study
-/// their impact on instruction's performance.
+/// A set of structures and functions to craft instructions for the
+/// SnippetGenerator.
 ///
 //===----------------------------------------------------------------------===//
 
@@ -22,6 +20,39 @@
 
 namespace exegesis {
 
+// A template for an Instruction holding values for each of its Variables.
+struct InstructionTemplate {
+  InstructionTemplate(const Instruction &Instr);
+
+  InstructionTemplate(const InstructionTemplate &);            // default
+  InstructionTemplate &operator=(const InstructionTemplate &); // default
+  InstructionTemplate(InstructionTemplate &&);                 // default
+  InstructionTemplate &operator=(InstructionTemplate &&);      // default
+
+  unsigned getOpcode() const;
+  llvm::MCOperand &getValueFor(const Variable &Var);
+  const llvm::MCOperand &getValueFor(const Variable &Var) const;
+  llvm::MCOperand &getValueFor(const Operand &Op);
+  const llvm::MCOperand &getValueFor(const Operand &Op) const;
+  bool hasImmediateVariables() const;
+
+  // Assigns a Random Value to all Variables that are still Invalid.
+  // Do not use any of the registers in `ForbiddenRegs`.
+  void randomizeUnsetVariables(const llvm::BitVector &ForbiddenRegs);
+
+  // Builds an llvm::MCInst from this InstructionTemplate setting its operands
+  // to the corresponding variable values. Precondition: All VariableValues must
+  // be set.
+  llvm::MCInst build() const;
+
+  Instruction Instr;
+  llvm::SmallVector<llvm::MCOperand, 4> VariableValues;
+};
+
+// A CodeTemplate is a set of InstructionTemplates that may not be fully
+// specified (i.e. some variables are not yet set). This allows the
+// BenchmarkRunner to instantiate it many times with specific values to study
+// their impact on instruction's performance.
 struct CodeTemplate {
   CodeTemplate() = default;
 
@@ -33,12 +64,26 @@ struct CodeTemplate {
   // Some information about how this template has been created.
   std::string Info;
   // The list of the instructions for this template.
-  std::vector<InstructionBuilder> Instructions;
+  std::vector<InstructionTemplate> Instructions;
   // If the template uses the provided scratch memory, the register in which
   // the pointer to this memory is passed in to the function.
   unsigned ScratchSpacePointerInReg = 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 bit among the bits set in Vector and returns its index.
+// Precondition: Vector must have at least one bit set.
+size_t randomBit(const llvm::BitVector &Vector);
+
+// 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);
+
 } // namespace exegesis
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_CODETEMPLATE_H