[llvm-exegesis][NFC] Move random functions from CodeTemplate to SnippetGenerator.

[gchatelet]

Summary

Just moving methods around.

llvm/trunk/tools/llvm-exegesis/lib/CodeTemplate.h

struct CodeTemplate {
   std::string Info;
   // The list of the instructions for this template.
   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);
-
-// Assigns a Random Value to all Variables in IT that are still Invalid.
-// Do not use any of the registers in `ForbiddenRegs`.
-void randomizeUnsetVariables(const llvm::BitVector &ForbiddenRegs,
-                             InstructionTemplate &IT);
-
 } // namespace exegesis
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_CODETEMPLATE_H

llvm/trunk/tools/llvm-exegesis/lib/CodeTemplate.cpp

 }
 
 const llvm::MCOperand &
 InstructionTemplate::getValueFor(const Operand &Op) const {
   assert(Op.VariableIndex >= 0);
   return getValueFor(Instr.Variables[Op.VariableIndex]);
 }
 
-// forward declaration.
-static void randomize(const Instruction &Instr, const Variable &Var,
-                      llvm::MCOperand &AssignedValue,
-                      const llvm::BitVector &ForbiddenRegs);
-
 bool InstructionTemplate::hasImmediateVariables() const {
   return llvm::any_of(Instr.Variables, [this](const Variable &Var) {
     assert(!Var.TiedOperands.empty());
     const unsigned OpIndex = Var.TiedOperands[0];
     const Operand &Op = Instr.Operands[OpIndex];
     assert(Op.Info);
     return Op.Info->OperandType == llvm::MCOI::OPERAND_IMMEDIATE;
   });
 }
 
 llvm::MCInst InstructionTemplate::build() const {
   llvm::MCInst Result;
   Result.setOpcode(Instr.Description->Opcode);
   for (const auto &Op : Instr.Operands)
     if (Op.IsExplicit)
       Result.addOperand(getValueFor(Op));
   return Result;
 }
 
-std::mt19937 &randomGenerator() {
-  static std::random_device RandomDevice;
-  static std::mt19937 RandomGenerator(RandomDevice());
-  return RandomGenerator;
-}
-
-static size_t randomIndex(size_t Size) {
-  assert(Size > 0);
-  std::uniform_int_distribution<> Distribution(0, Size - 1);
-  return Distribution(randomGenerator());
-}
-
-template <typename C>
-static auto randomElement(const C &Container) -> decltype(Container[0]) {
-  return Container[randomIndex(Container.size())];
-}
-
-static void randomize(const Instruction &Instr, const Variable &Var,
-                      llvm::MCOperand &AssignedValue,
-                      const llvm::BitVector &ForbiddenRegs) {
-  assert(!Var.TiedOperands.empty());
-  const Operand &Op = Instr.Operands[Var.TiedOperands.front()];
-  assert(Op.Info != nullptr);
-  const auto &OpInfo = *Op.Info;
-  switch (OpInfo.OperandType) {
-  case llvm::MCOI::OperandType::OPERAND_IMMEDIATE:
-    // FIXME: explore immediate values too.
-    AssignedValue = llvm::MCOperand::createImm(1);
-    break;
-  case llvm::MCOI::OperandType::OPERAND_REGISTER: {
-    assert(Op.Tracker);
-    auto AllowedRegs = Op.Tracker->sourceBits();
-    assert(AllowedRegs.size() == ForbiddenRegs.size());
-    for (auto I : ForbiddenRegs.set_bits())
-      AllowedRegs.reset(I);
-    AssignedValue = llvm::MCOperand::createReg(randomBit(AllowedRegs));
-    break;
-  }
-  default:
-    break;
-  }
-}
-
-static void setRegisterOperandValue(const RegisterOperandAssignment &ROV,
-                                    InstructionTemplate &IB) {
-  assert(ROV.Op);
-  if (ROV.Op->IsExplicit) {
-    auto &AssignedValue = IB.getValueFor(*ROV.Op);
-    if (AssignedValue.isValid()) {
-      assert(AssignedValue.isReg() && AssignedValue.getReg() == ROV.Reg);
-      return;
-    }
-    AssignedValue = llvm::MCOperand::createReg(ROV.Reg);
-  } else {
-    assert(ROV.Op->ImplicitReg != nullptr);
-    assert(ROV.Reg == *ROV.Op->ImplicitReg);
-  }
-}
-
-size_t randomBit(const llvm::BitVector &Vector) {
-  assert(Vector.any());
-  auto Itr = Vector.set_bits_begin();
-  for (size_t I = randomIndex(Vector.count()); I != 0; --I)
-    ++Itr;
-  return *Itr;
-}
-
-void setRandomAliasing(const AliasingConfigurations &AliasingConfigurations,
-                       InstructionTemplate &DefIB, InstructionTemplate &UseIB) {
-  assert(!AliasingConfigurations.empty());
-  assert(!AliasingConfigurations.hasImplicitAliasing());
-  const auto &RandomConf = randomElement(AliasingConfigurations.Configurations);
-  setRegisterOperandValue(randomElement(RandomConf.Defs), DefIB);
-  setRegisterOperandValue(randomElement(RandomConf.Uses), UseIB);
-}
-
-void randomizeUnsetVariables(const llvm::BitVector &ForbiddenRegs,
-                             InstructionTemplate &IT) {
-  for (const Variable &Var : IT.Instr.Variables) {
-    llvm::MCOperand &AssignedValue = IT.getValueFor(Var);
-    if (!AssignedValue.isValid())
-      randomize(IT.Instr, Var, AssignedValue, ForbiddenRegs);
-  }
-}
-
 } // namespace exegesis

llvm/trunk/tools/llvm-exegesis/lib/SnippetGenerator.h

generateUnconstrainedCodeTemplate(const Instruction &Instr,
                                     llvm::StringRef Msg) const;
 
 private:
   // API to be implemented by subclasses.
   virtual llvm::Expected<CodeTemplate>
   generateCodeTemplate(unsigned Opcode) 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 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);
+
+// Assigns a Random Value to all Variables in IT that are still Invalid.
+// Do not use any of the registers in `ForbiddenRegs`.
+void randomizeUnsetVariables(const llvm::BitVector &ForbiddenRegs,
+                             InstructionTemplate &IT);
+
 } // namespace exegesis
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_SNIPPETGENERATOR_H

llvm/trunk/tools/llvm-exegesis/lib/SnippetGenerator.cpp

 SnippetGenerator::generateUnconstrainedCodeTemplate(const Instruction &Instr,
                                                     llvm::StringRef Msg) const {
   CodeTemplate CT;
   CT.Info = llvm::formatv("{0}, repeating an unconstrained assignment", Msg);
   CT.Instructions.emplace_back(Instr);
   return std::move(CT);
 }
 
+std::mt19937 &randomGenerator() {
+  static std::random_device RandomDevice;
+  static std::mt19937 RandomGenerator(RandomDevice());
+  return RandomGenerator;
+}
+
+static size_t randomIndex(size_t Size) {
+  assert(Size > 0);
+  std::uniform_int_distribution<> Distribution(0, Size - 1);
+  return Distribution(randomGenerator());
+}
+
+template <typename C>
+static auto randomElement(const C &Container) -> decltype(Container[0]) {
+  return Container[randomIndex(Container.size())];
+}
+
+static void randomize(const Instruction &Instr, const Variable &Var,
+                      llvm::MCOperand &AssignedValue,
+                      const llvm::BitVector &ForbiddenRegs) {
+  assert(!Var.TiedOperands.empty());
+  const Operand &Op = Instr.Operands[Var.TiedOperands.front()];
+  assert(Op.Info != nullptr);
+  const auto &OpInfo = *Op.Info;
+  switch (OpInfo.OperandType) {
+  case llvm::MCOI::OperandType::OPERAND_IMMEDIATE:
+    // FIXME: explore immediate values too.
+    AssignedValue = llvm::MCOperand::createImm(1);
+    break;
+  case llvm::MCOI::OperandType::OPERAND_REGISTER: {
+    assert(Op.Tracker);
+    auto AllowedRegs = Op.Tracker->sourceBits();
+    assert(AllowedRegs.size() == ForbiddenRegs.size());
+    for (auto I : ForbiddenRegs.set_bits())
+      AllowedRegs.reset(I);
+    AssignedValue = llvm::MCOperand::createReg(randomBit(AllowedRegs));
+    break;
+  }
+  default:
+    break;
+  }
+}
+
+static void setRegisterOperandValue(const RegisterOperandAssignment &ROV,
+                                    InstructionTemplate &IB) {
+  assert(ROV.Op);
+  if (ROV.Op->IsExplicit) {
+    auto &AssignedValue = IB.getValueFor(*ROV.Op);
+    if (AssignedValue.isValid()) {
+      assert(AssignedValue.isReg() && AssignedValue.getReg() == ROV.Reg);
+      return;
+    }
+    AssignedValue = llvm::MCOperand::createReg(ROV.Reg);
+  } else {
+    assert(ROV.Op->ImplicitReg != nullptr);
+    assert(ROV.Reg == *ROV.Op->ImplicitReg);
+  }
+}
+
+size_t randomBit(const llvm::BitVector &Vector) {
+  assert(Vector.any());
+  auto Itr = Vector.set_bits_begin();
+  for (size_t I = randomIndex(Vector.count()); I != 0; --I)
+    ++Itr;
+  return *Itr;
+}
+
+void setRandomAliasing(const AliasingConfigurations &AliasingConfigurations,
+                       InstructionTemplate &DefIB, InstructionTemplate &UseIB) {
+  assert(!AliasingConfigurations.empty());
+  assert(!AliasingConfigurations.hasImplicitAliasing());
+  const auto &RandomConf = randomElement(AliasingConfigurations.Configurations);
+  setRegisterOperandValue(randomElement(RandomConf.Defs), DefIB);
+  setRegisterOperandValue(randomElement(RandomConf.Uses), UseIB);
+}
+
+void randomizeUnsetVariables(const llvm::BitVector &ForbiddenRegs,
+                             InstructionTemplate &IT) {
+  for (const Variable &Var : IT.Instr.Variables) {
+    llvm::MCOperand &AssignedValue = IT.getValueFor(Var);
+    if (!AssignedValue.isValid())
+      randomize(IT.Instr, Var, AssignedValue, ForbiddenRegs);
+  }
+}
+
 } // namespace exegesis