Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 | /*
* Copyright (c) 2019 Foundries.io
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include "lwm2m_util.h"
#define SHIFT_LEFT(v, o, m) (((v) << (o)) & (m))
#define SHIFT_RIGHT(v, o, m) (((v) >> (o)) & (m))
/* convert from float32 to binary32 */
int lwm2m_f32_to_b32(float32_value_t *f32, u8_t *b32, size_t len)
{
s32_t e = -1, v, f = 0;
int i;
if (len != 4) {
return -EINVAL;
}
/* handle zero value special case */
if (f32->val1 == 0 && f32->val2 == 0) {
memset(b32, 0, len);
return 0;
}
v = f32->val1;
/* sign handled later */
if (v < 0) {
v = -v;
}
/* add whole value to fraction */
while (v > 0) {
f >>= 1;
if (v & 1) {
f |= (1 << 23);
}
v >>= 1;
e++;
}
v = f32->val2;
/* sign handled later */
if (v < 0) {
v = -v;
}
/* add decimal to fraction */
i = e;
while (v > 0 && i < 23) {
v *= 2;
if (!f && e < 0 && v < LWM2M_FLOAT32_DEC_MAX) {
/* handle -e */
e--;
continue;
} else if (v >= LWM2M_FLOAT32_DEC_MAX) {
v -= LWM2M_FLOAT32_DEC_MAX;
f |= 1 << (22 - i);
}
if (v == 0) {
break;
}
i++;
}
/* adjust exponent for bias */
e += 127;
memset(b32, 0, len);
/* sign: bit 31 */
b32[0] = f32->val1 < 0 ? 0x80 : 0;
/* exponent: bits 30-23 */
b32[0] |= e >> 1;
b32[1] = (e & 1) << 7;
/* fraction: bits 22-0 */
/* NOTE: ignore the "hidden" bit 23 in fraction */
b32[1] |= (f >> 16) & 0x7F;
b32[2] = (f >> 8) & 0xFF;
b32[3] = f & 0xFF;
return 0;
}
/* convert from float64 to binary64 */
int lwm2m_f64_to_b64(float64_value_t *f64, u8_t *b64, size_t len)
{
s64_t v, f = 0;
s32_t e = -1;
int i;
if (len != 8) {
return -EINVAL;
}
/* handle zero value special case */
if (f64->val1 == 0LL && f64->val2 == 0LL) {
memset(b64, 0, len);
return 0;
}
v = f64->val1;
/* sign handled later */
if (v < 0) {
v = -v;
}
/* add whole value to fraction */
while (v > 0) {
f >>= 1;
if (v & 1) {
f |= ((s64_t)1 << 52);
}
v >>= 1;
e++;
}
v = f64->val2;
/* sign handled later */
if (v < 0) {
v = -v;
}
/* add decimal to fraction */
i = e;
while (v > 0 && i < 52) {
v *= 2;
if (!f && e < 0 && v < LWM2M_FLOAT64_DEC_MAX) {
/* handle -e */
e--;
continue;
} else if (v >= LWM2M_FLOAT64_DEC_MAX) {
v -= LWM2M_FLOAT64_DEC_MAX;
f |= (s64_t)1 << (51 - i);
}
if (v == 0) {
break;
}
i++;
}
/* adjust exponent for bias */
e += 1023;
memset(b64, 0, len);
/* sign: bit 63 */
b64[0] = f64->val1 < 0 ? 0x80 : 0;
/* exponent: bits 62-52 */
b64[0] |= (e >> 4);
b64[1] = ((e & 0xF) << 4);
/* fraction: bits 51-0 */
/* NOTE: ignore the "hidden" bit 52 in fraction */
b64[1] |= ((f >> 48) & 0xF);
b64[2] = (f >> 40) & 0xFF;
b64[3] = (f >> 32) & 0xFF;
b64[4] = (f >> 24) & 0xFF;
b64[5] = (f >> 16) & 0xFF;
b64[6] = (f >> 8) & 0xFF;
b64[7] = f & 0xFF;
return 0;
}
/* convert from binary32 to float32 */
int lwm2m_b32_to_f32(u8_t *b32, size_t len, float32_value_t *f32)
{
s32_t f, k, i, e;
bool sign = false;
if (len != 4) {
return -EINVAL;
}
f32->val1 = 0;
f32->val2 = 0;
/* calc sign: bit 31 */
sign = SHIFT_RIGHT(b32[0], 7, 0x1);
/* calc exponent: bits 30-23 */
e = SHIFT_LEFT(b32[0], 1, 0xFF);
e += SHIFT_RIGHT(b32[1], 7, 0x1);
/* remove bias */
e -= 127;
/* enable "hidden" fraction bit 23 which is always 1 */
f = ((s32_t)1 << 22);
/* calc fraction: bits 22-0 */
f += ((s32_t)(b32[1] & 0x7F) << 16);
f += ((s32_t)b32[2] << 8);
f += b32[3];
/* handle whole number */
if (e > -1) {
/* precision overflow */
if (e > 23) {
e = 23;
}
f32->val1 = (f >> (23 - e)) * (sign ? -1 : 1);
}
/* calculate the rest of the decimal */
k = LWM2M_FLOAT32_DEC_MAX;
/* account for -e */
while (e < -1) {
k /= 2;
e++;
}
for (i = 22 - e; i >= 0; i--) {
k /= 2;
if (f & (1 << i)) {
f32->val2 += k;
}
}
return 0;
}
/* convert from binary64 to float64 */
int lwm2m_b64_to_f64(u8_t *b64, size_t len, float64_value_t *f64)
{
s64_t f, k;
int i, e;
bool sign = false;
if (len != 8) {
return -EINVAL;
}
f64->val1 = 0LL;
f64->val2 = 0LL;
/* calc sign: bit 63 */
sign = SHIFT_RIGHT(b64[0], 7, 0x1);
/* get exponent: bits 62-52 */
e = SHIFT_LEFT((u16_t)b64[0], 4, 0x7F0);
e += SHIFT_RIGHT(b64[1], 4, 0xF);
/* remove bias */
e -= 1023;
/* enable "hidden" fraction bit 53 which is always 1 */
f = ((s64_t)1 << 52);
/* get fraction: bits 51-0 */
f += ((s64_t)(b64[1] & 0xF) << 48);
f += ((s64_t)b64[2] << 40);
f += ((s64_t)b64[3] << 32);
f += ((s64_t)b64[4] << 24);
f += ((s64_t)b64[5] << 16);
f += ((s64_t)b64[6] << 8);
f += b64[7];
/* handle whole number */
if (e > -1) {
/* precision overflow */
if (e > 52) {
e = 52;
}
f64->val1 = (f >> (52 - e)) * (sign ? -1 : 1);
}
/* calculate the rest of the decimal */
k = LWM2M_FLOAT64_DEC_MAX;
/* account for -e */
while (e < -1) {
k /= 2;
e++;
}
for (i = 51 - e; i >= 0; i--) {
k /= 2;
if (f & ((s64_t)1 << i)) {
f64->val2 += k;
}
}
return 0;
}
|