const float lower_bound = CalculateLowerBound(min_value, bin_width);
  return std::ceil((max_value - lower_bound) / bin_width);
}

TEST(CalibrationParametersTest, CalculateBinWidthSmallerThanOne) {
  float bin_width = CalculateBinWidth(/*min_value=*/0.0, /*max_value=*/25.0,
                                      /*num_bins=*/256);
  EXPECT_FLOAT_EQ(bin_width, 0.125);
  int32_t actual_num_bins =

#include "tensorflow/core/framework/types.h"
#include "tsl/platform/errors.h"

namespace tensorflow {
namespace {

using ::stablehlo::quantization::CalculateBinIndexSafe;
using ::stablehlo::quantization::CalculateBinWidth;
using ::stablehlo::quantization::CalculateLowerBound;
using ::stablehlo::quantization::CalibrationOptions;
using CPUDevice = ::Eigen::ThreadPoolDevice;
using CalibrationMethod =

namespace tensorflow {
namespace calibrator {
namespace {

using ::stablehlo::quantization::CalculateBinIndex;
using ::stablehlo::quantization::CalculateBinWidth;
using ::stablehlo::quantization::CalculateLowerBound;

// Gets the histogram frequencies for the given range.
float GetRangeFrequencies(absl::Span<const int64_t> histogram,

// Calculates the bin width from the range and expected number of bins. The
// bin width is formalized to the form of 2^n. As a consequence, the actual
// number of bins might be smaller than the given `num_bins`.
inline float CalculateBinWidth(const float min_value, const float max_value,
                               const int32_t num_bins) {
  const float raw_bin_width = (max_value - min_value) / num_bins;
  return std::pow(2, std::ceil(std::log2(raw_bin_width)));