constexpr char kOldBridgeNoMlirSuccess[] = "kOldBridgeNoMlirSuccess";
// There were no MLIR ops so the old bridge was called but it failed.
constexpr char kOldBridgeNoMlirFailure[] = "kOldBridgeNoMlirFailure";

namespace {

// Time the execution of kernels (in CPU cycles). Meant to be used as RAII.
struct CompilationTimer {
  uint64 start_cycles = profile_utils::CpuUtils::GetCurrentClockCycle();