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1// SPDX-License-Identifier: MIT2/*3 * Copyright 2023 Advanced Micro Devices, Inc.4 *5 * Permission is hereby granted, free of charge, to any person obtaining a6 * copy of this software and associated documentation files (the "Software"),7 * to deal in the Software without restriction, including without limitation8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,9 * and/or sell copies of the Software, and to permit persons to whom the10 * Software is furnished to do so, subject to the following conditions:11 *12 * The above copyright notice and this permission notice shall be included in13 * all copies or substantial portions of the Software.14 *15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR21 * OTHER DEALINGS IN THE SOFTWARE.22 *23 * Authors: AMD24 *25 */26#include "dm_services.h"27#include "custom_float.h"28 29static bool build_custom_float(struct fixed31_32 value,30 const struct custom_float_format *format,31 bool *negative,32 uint32_t *mantissa,33 uint32_t *exponenta)34{35 uint32_t exp_offset = (1 << (format->exponenta_bits - 1)) - 1;36 37 const struct fixed31_32 mantissa_constant_plus_max_fraction =38 dc_fixpt_from_fraction((1LL << (format->mantissa_bits + 1)) - 1,39 1LL << format->mantissa_bits);40 41 struct fixed31_32 mantiss;42 43 if (dc_fixpt_eq(value, dc_fixpt_zero)) {44 *negative = false;45 *mantissa = 0;46 *exponenta = 0;47 return true;48 }49 50 if (dc_fixpt_lt(value, dc_fixpt_zero)) {51 *negative = format->sign;52 value = dc_fixpt_neg(value);53 } else {54 *negative = false;55 }56 57 if (dc_fixpt_lt(value, dc_fixpt_one)) {58 uint32_t i = 1;59 60 do {61 value = dc_fixpt_shl(value, 1);62 ++i;63 } while (dc_fixpt_lt(value, dc_fixpt_one));64 65 --i;66 67 if (exp_offset <= i) {68 *mantissa = 0;69 *exponenta = 0;70 return true;71 }72 73 *exponenta = exp_offset - i;74 } else if (dc_fixpt_le(mantissa_constant_plus_max_fraction, value)) {75 uint32_t i = 1;76 77 do {78 value = dc_fixpt_shr(value, 1);79 ++i;80 } while (dc_fixpt_lt(mantissa_constant_plus_max_fraction, value));81 82 *exponenta = exp_offset + i - 1;83 } else {84 *exponenta = exp_offset;85 }86 87 mantiss = dc_fixpt_sub(value, dc_fixpt_one);88 89 if (dc_fixpt_lt(mantiss, dc_fixpt_zero) ||90 dc_fixpt_lt(dc_fixpt_one, mantiss))91 mantiss = dc_fixpt_zero;92 else93 mantiss = dc_fixpt_shl(mantiss, format->mantissa_bits);94 95 *mantissa = dc_fixpt_floor(mantiss);96 97 return true;98}99 100static bool setup_custom_float(const struct custom_float_format *format,101 bool negative,102 uint32_t mantissa,103 uint32_t exponenta,104 uint32_t *result)105{106 uint32_t i = 0;107 uint32_t j = 0;108 uint32_t value = 0;109 110 /* verification code:111 * once calculation is ok we can remove it112 */113 114 const uint32_t mantissa_mask =115 (1 << (format->mantissa_bits + 1)) - 1;116 117 const uint32_t exponenta_mask =118 (1 << (format->exponenta_bits + 1)) - 1;119 120 if (mantissa & ~mantissa_mask) {121 BREAK_TO_DEBUGGER();122 mantissa = mantissa_mask;123 }124 125 if (exponenta & ~exponenta_mask) {126 BREAK_TO_DEBUGGER();127 exponenta = exponenta_mask;128 }129 130 /* end of verification code */131 132 while (i < format->mantissa_bits) {133 uint32_t mask = 1 << i;134 135 if (mantissa & mask)136 value |= mask;137 138 ++i;139 }140 141 while (j < format->exponenta_bits) {142 uint32_t mask = 1 << j;143 144 if (exponenta & mask)145 value |= mask << i;146 147 ++j;148 }149 150 if (negative && format->sign)151 value |= 1 << (i + j);152 153 *result = value;154 155 return true;156}157 158bool convert_to_custom_float_format(struct fixed31_32 value,159 const struct custom_float_format *format,160 uint32_t *result)161{162 uint32_t mantissa;163 uint32_t exponenta;164 bool negative;165 166 return build_custom_float(value, format, &negative, &mantissa, &exponenta) &&167 setup_custom_float(format,168 negative,169 mantissa,170 exponenta,171 result);172}173 174