simdjson/benchmark/json_benchmark/diff_results.h

93 lines
3.3 KiB
C++

#pragma once
#include <vector>
#include <sstream>
#include <limits>
namespace json_benchmark {
enum class diff_flags {
NONE = 0,
IMPRECISE_FLOATS = 1
};
template<typename T, typename U>
static bool diff_results(benchmark::State &state, const T &result, const U &reference, diff_flags flags);
template<typename T, typename U>
struct result_differ {
static bool diff(benchmark::State &state, const T &result, const U &reference, diff_flags flags) {
if (result != reference) {
std::stringstream str;
str << "result incorrect: " << result << " ... reference: " << reference;
state.SkipWithError(str.str().data());
return false;
}
return true;
}
};
template<typename T, typename U>
struct result_differ<std::vector<T>, std::vector<U>> {
static bool diff(benchmark::State &state, const std::vector<T> &result, const std::vector<U> &reference, diff_flags flags) {
auto result_iter = result.begin();
auto reference_iter = reference.begin();
while (result_iter != result.end() && reference_iter != reference.end()) {
if (!diff_results(state, *result_iter, *reference_iter, flags)) { return false; }
result_iter++;
reference_iter++;
}
if (result_iter != result.end()) {
std::stringstream str;
str << "extra results (got " << result.size() << ", expected " << reference.size() << "): first extra element: " << *result_iter;
state.SkipWithError(str.str().data());
return false;
} else if (reference_iter != reference.end()) {
std::stringstream str;
str << "missing results (got " << result.size() << ", expected " << reference.size() << "): first missing element: " << *reference_iter;
state.SkipWithError(str.str().data());
return false;
}
return true;
}
};
template<>
struct result_differ<double, double> {
static bool diff(benchmark::State &state, const double &result, const double &reference, diff_flags flags) {
bool different;
if (int(flags) & int(diff_flags::IMPRECISE_FLOATS)) {
different = f64_ulp_dist(result, reference) > 1;
} else {
different = result != reference;
}
if (different) {
std::stringstream str;
// We print it out using full precision.
constexpr auto precision = std::numeric_limits<double>::max_digits10;
str << std::setprecision(precision);
str << "incorrect double result: " << std::endl;
str << " result: " << std::left << std::setw(precision+2) << result << " (hexfloat " << std::hexfloat << result << ")" << std::defaultfloat << std::endl;
str << "reference: " << std::left << std::setw(precision+2) << reference << " (hexfloat " << std::hexfloat << reference << ")" << std::defaultfloat << std::endl;
state.SkipWithError(str.str().data());
}
return true;
}
static uint64_t f64_ulp_dist(double a, double b) {
uint64_t ua, ub;
std::memcpy(&ua, &a, sizeof(ua));
std::memcpy(&ub, &b, sizeof(ub));
if ((int64_t)(ub ^ ua) >= 0)
return (int64_t)(ua - ub) >= 0 ? (ua - ub) : (ub - ua);
return ua + ub + 0x80000000;
}
};
template<typename T, typename U>
static bool diff_results(benchmark::State &state, const T &result, const U &reference, diff_flags flags) {
return result_differ<T, U>::diff(state, result, reference, flags);
}
} // namespace json_benchmark