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//===-- CodeTemplate.cpp ----------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "CodeTemplate.h"
namespace exegesis {
CodeTemplate::CodeTemplate(CodeTemplate &&) = default;
CodeTemplate &CodeTemplate::operator=(CodeTemplate &&) = default;
InstructionTemplate::InstructionTemplate(const Instruction &Instr)
: Instr(Instr), VariableValues(Instr.Variables.size()) {}
InstructionTemplate::InstructionTemplate(InstructionTemplate &&) = default;
InstructionTemplate &InstructionTemplate::
operator=(InstructionTemplate &&) = default;
InstructionTemplate::InstructionTemplate(const InstructionTemplate &) = default;
InstructionTemplate &InstructionTemplate::
operator=(const InstructionTemplate &) = default;
unsigned InstructionTemplate::getOpcode() const {
return Instr.Description->getOpcode();
}
llvm::MCOperand &InstructionTemplate::getValueFor(const Variable &Var) {
return VariableValues[Var.Index];
}
const llvm::MCOperand &
InstructionTemplate::getValueFor(const Variable &Var) const {
return VariableValues[Var.Index];
}
llvm::MCOperand &InstructionTemplate::getValueFor(const Operand &Op) {
assert(Op.VariableIndex >= 0);
return getValueFor(Instr.Variables[Op.VariableIndex]);
}
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;
});
}
void InstructionTemplate::randomizeUnsetVariables(
const llvm::BitVector &ForbiddenRegs) {
for (const Variable &Var : Instr.Variables) {
llvm::MCOperand &AssignedValue = getValueFor(Var);
if (!AssignedValue.isValid())
randomize(Instr, Var, AssignedValue, ForbiddenRegs);
}
}
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);
}
} // namespace exegesis
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