blob: 55515938eca6b5450c6a1a6f342bbe93927f50b8 [file] [log] [blame]
//
// This confidential and proprietary software may be used only as
// authorised by a licensing agreement from ARM Limited
// (C) COPYRIGHT 2020-2024 ARM Limited
// ALL RIGHTS RESERVED
// The entire notice above must be reproduced on all authorised
// copies and copies may only be made to the extent permitted
// by a licensing agreement from ARM Limited.
int16_t tanh_reference(int16_t x) { // input x range is -256 to +256 inclusive
fp64_t v = static_cast<fp64_t>(x) / static_cast<fp64_t>(32);
v = exp(-2.0*v);
v = (1.0-v)/(1.0+v);
return round_to_nearest_int(32768.0 * v);
}
generate_lookup_table(&tanh_table, &tanh_reference);