bool BytecodeLivenessAnalysis::operandIsLiveAtBytecodeOffset(int operand, unsigned bytecodeOffset)
{
if (operandIsAlwaysLive(operand))
return true;
FastBitVector result;
getLivenessInfoAtBytecodeOffset(bytecodeOffset, result);
return operandThatIsNotAlwaysLiveIsLive(result, operand);
}
void run()
{
// Perform modified liveness analysis to determine which locals are live at the merge points.
// This produces the conservative results for the question, "which variables should be saved and resumed?".
runLivenessFixpoint(m_generatorification.graph());
for (YieldData& data : m_generatorification.yields())
data.liveness = getLivenessInfoAtBytecodeOffset(m_generatorification.graph(), data.point + opcodeLength(op_yield));
}
void run(UnlinkedCodeBlock* codeBlock, InstructionStreamWriter& instructions)
{
// Perform modified liveness analysis to determine which locals are live at the merge points.
// This produces the conservative results for the question, "which variables should be saved and resumed?".
runLivenessFixpoint(codeBlock, instructions, m_generatorification.graph());
for (YieldData& data : m_generatorification.yields())
data.liveness = getLivenessInfoAtBytecodeOffset(codeBlock, instructions, m_generatorification.graph(), m_generatorification.instructions().at(data.point).next().offset());
}
void BytecodeLivenessAnalysis::dumpResults()
{
Interpreter* interpreter = m_codeBlock->vm()->interpreter;
Instruction* instructionsBegin = m_codeBlock->instructions().begin();
for (unsigned i = 0; i < m_basicBlocks.size(); i++) {
BytecodeBasicBlock* block = m_basicBlocks[i].get();
dataLogF("\nBytecode basic block %u: %p (offset: %u, length: %u)\n", i, block, block->leaderBytecodeOffset(), block->totalBytecodeLength());
dataLogF("Predecessors: ");
for (unsigned j = 0; j < block->predecessors().size(); j++) {
BytecodeBasicBlock* predecessor = block->predecessors()[j];
dataLogF("%p ", predecessor);
}
dataLogF("\n");
dataLogF("Successors: ");
for (unsigned j = 0; j < block->successors().size(); j++) {
BytecodeBasicBlock* successor = block->successors()[j];
dataLogF("%p ", successor);
}
dataLogF("\n");
if (block->isEntryBlock()) {
dataLogF("Entry block %p\n", block);
continue;
}
if (block->isExitBlock()) {
dataLogF("Exit block: %p\n", block);
continue;
}
for (unsigned bytecodeOffset = block->leaderBytecodeOffset(); bytecodeOffset < block->leaderBytecodeOffset() + block->totalBytecodeLength();) {
const Instruction* currentInstruction = &instructionsBegin[bytecodeOffset];
dataLogF("Live variables: ");
FastBitVector liveBefore = getLivenessInfoAtBytecodeOffset(bytecodeOffset);
for (unsigned j = 0; j < liveBefore.numBits(); j++) {
if (liveBefore.get(j))
dataLogF("%u ", j);
}
dataLogF("\n");
m_codeBlock->dumpBytecode(WTF::dataFile(), m_codeBlock->globalObject()->globalExec(), instructionsBegin, currentInstruction);
OpcodeID opcodeID = interpreter->getOpcodeID(instructionsBegin[bytecodeOffset].u.opcode);
unsigned opcodeLength = opcodeLengths[opcodeID];
bytecodeOffset += opcodeLength;
}
dataLogF("Live variables: ");
FastBitVector liveAfter = block->out();
for (unsigned j = 0; j < liveAfter.numBits(); j++) {
if (liveAfter.get(j))
dataLogF("%u ", j);
}
dataLogF("\n");
}
}
FastBitVector BytecodeLivenessAnalysis::getLivenessInfoAtBytecodeOffset(unsigned bytecodeOffset)
{
FastBitVector out;
getLivenessInfoAtBytecodeOffset(bytecodeOffset, out);
return out;
}
