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sys: fmt: add fmt_u64_dec()

pr/spi.typo
Kaspar Schleiser 7 years ago
parent
commit
5923f6b137
  1. 62
      sys/fmt/fmt.c
  2. 24
      sys/include/fmt.h

62
sys/fmt/fmt.c

@ -22,6 +22,7 @@
#include <stdarg.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#ifdef __WITH_AVRLIBC__
#include <stdio.h> /* for fwrite() */
@ -102,6 +103,60 @@ size_t fmt_u64_hex(char *out, uint64_t val)
return fmt_bytes_hex_reverse(out, (uint8_t*) &val, 8);
}
size_t fmt_u64_dec(char *out, uint64_t val)
{
uint32_t d[5];
uint32_t q;
size_t len = 0;
d[0] = val & 0xFFFF;
d[1] = (val>>16) & 0xFFFF;
d[2] = (val>>32) & 0xFFFF;
d[3] = (val>>48) & 0xFFFF;
d[0] = 656 * d[3] + 7296 * d[2] + 5536 * d[1] + d[0];
q = d[0] / 10000;
d[0] = d[0] % 10000;
d[1] = q + 7671 * d[3] + 9496 * d[2] + 6 * d[1];
q = d[1] / 10000;
d[1] = d[1] % 10000;
d[2] = q + 4749 * d[3] + 42 * d[2];
q = d[2] / 10000;
d[2] = d[2] % 10000;
d[3] = q + 281 * d[3];
q = d[3] / 10000;
d[3] = d[3] % 10000;
d[4] = q;
int first = 4;
while (!d[first] && first) {
first--;
}
len = fmt_u32_dec(out, d[first]);
int total_len = len + (first * 4);
if (out) {
out += len;
memset(out, '0', total_len - len);
while(first) {
first--;
if (d[first]) {
size_t tmp = fmt_u32_dec(NULL, d[first]);
fmt_u32_dec(out+(4-tmp), d[first]);
}
out += 4;
}
}
return total_len;
}
size_t fmt_u32_dec(char *out, uint32_t val)
{
size_t len = 1;
@ -248,6 +303,13 @@ void print_u64_hex(uint64_t val)
print_u32_hex(val);
}
void print_u64_dec(uint64_t val)
{
char buf[18];
size_t len = fmt_u64_dec(buf, val);
print(buf, len);
}
void print_str(const char* str)
{
print(str, fmt_strlen(str));

24
sys/include/fmt.h

@ -101,6 +101,21 @@ size_t fmt_u64_hex(char *out, uint64_t val);
*/
size_t fmt_u32_dec(char *out, uint32_t val);
/**
* @brief Convert a uint64 value to decimal string.
*
* If @p out is NULL, will only return the number of bytes that would have
* been written.
*
* @note This adds ~400b of code when used.
*
* @param[out] out Pointer to output buffer, or NULL
* @param[in] val Value to convert
*
* @return nr of digits written to (or needed in) @p out
*/
size_t fmt_u64_dec(char *out, uint64_t val);
/**
* @brief Convert a uint16 value to decimal string.
*
@ -244,6 +259,15 @@ void print_u32_hex(uint32_t val);
*/
void print_u64_hex(uint64_t val);
/**
* @brief Print uint64 value as decimal to stdout
*
* @note This used fmt_u64_dec(), which uses ~400b of code.
*
* @param[in] val Value to print
*/
void print_u64_dec(uint64_t val);
/**
* @brief Print null-terminated string to stdout
*

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