TosaSoftmaxOperatorUtils.hpp File Reference

#include <gemmlowp/fixedpoint.h>

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Functions
void	CalculateSoftmaxTableValues (double softmaxBeta, double scale, std::array< std::vector< int16_t >, 4 > &tables)

Function Documentation

CalculateSoftmaxTableValues()

void CalculateSoftmaxTableValues ( double softmaxBeta, double scale, std::array< std::vector< int16_t >, 4 > & tables )

inline

Definition at line 60 of file TosaSoftmaxOperatorUtils.hpp.

{
    ARMNN_THROW_INVALIDARG_MSG_IF_FALSE(softmaxBeta == 1.0f,
                                        "CalculateSoftmaxTableValues: Beta values other than 1.0 are not supported");
 
    int32_t input_beta_multiplier = 0;
    int input_beta_left_shift = 0;
 
    const int kScaledDiffIntegerBits = 5;
    using FixedPointScaledDiff = gemmlowp::FixedPoint<int32_t, kScaledDiffIntegerBits>;
    using gemmlowp::SaturatingRoundingDoublingHighMul;
    using gemmlowp::exp_on_negative_values;
 
    SoftmaxScaling5Bits(softmaxBeta, scale, input_beta_multiplier, input_beta_left_shift);
    int diff_min = -1 * CalculateInputRadius5Bits(input_beta_left_shift);
 
    for (int32_t input_diff = -256; input_diff <= 256; input_diff++)
    {
        int32_t output = 0;
        if (input_diff >= diff_min)
        {
            int32_t input_diff_rescaled =
                SaturatingRoundingDoublingHighMul(input_diff * (1 << input_beta_left_shift), input_beta_multiplier);
            const FixedPointScaledDiff input_diff_fixed_point = FixedPointScaledDiff::FromRaw(input_diff_rescaled);
            output = exp_on_negative_values(input_diff_fixed_point).raw();
        }
 
        // Only copy the 8-bit groups
        int32_t first = (output >> 24) & 0xFF;
        int32_t second = (output >> 16) & 0xFF;
        int32_t third = (output >> 8) & 0xFF;
        int32_t fourth = (output) & 0xFF;
        tables[0].push_back(static_cast<int16_t>(first));
        tables[1].push_back(static_cast<int16_t>(second));
        tables[2].push_back(static_cast<int16_t>(third));
        tables[3].push_back(static_cast<int16_t>(fourth));
    }
}

References ARMNN_THROW_INVALIDARG_MSG_IF_FALSE.

Referenced by ConvertSoftmaxToTosaOperator().