Commit 5f493178 authored by Willy Tarreau's avatar Willy Tarreau Committed by Paul E. McKenney
Browse files

tools/nolibc/stdlib: add utoh() and u64toh() 



This adds a pair of functions to emit hex values.

Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent b1c21e7d

tools/include/nolibc/stdlib.h

+80 −0
Original line number Diff line number Diff line
@@ -52,6 +52,46 @@ int atoi(const char *s) 
	return atol(s);

}



/* Converts the unsigned long integer <in> to its hex representation into

 * buffer <buffer>, which must be long enough to store the number and the

 * trailing zero (17 bytes for "ffffffffffffffff" or 9 for "ffffffff"). The

 * buffer is filled from the first byte, and the number of characters emitted

 * (not counting the trailing zero) is returned. The function is constructed

 * in a way to optimize the code size and avoid any divide that could add a

 * dependency on large external functions.

 */

static __attribute__((unused))

int utoh_r(unsigned long in, char *buffer)

{

	signed char pos = (~0UL > 0xfffffffful) ? 60 : 28;

	int digits = 0;

	int dig;



	do {

		dig = in >> pos;

		in -= (uint64_t)dig << pos;

		pos -= 4;

		if (dig || digits || pos < 0) {

			if (dig > 9)

				dig += 'a' - '0' - 10;

			buffer[digits++] = '0' + dig;

		}

	} while (pos >= 0);



	buffer[digits] = 0;

	return digits;

}



/* converts unsigned long <in> to an hex string using the static itoa_buffer

 * and returns the pointer to that string.

 */

static inline __attribute__((unused))

char *utoh(unsigned long in)

{

	utoh_r(in, itoa_buffer);

	return itoa_buffer;

}



/* Converts the unsigned long integer <in> to its string representation into

 * buffer <buffer>, which must be long enough to store the number and the

 * trailing zero (21 bytes for 18446744073709551615 in 64-bit, 11 for
@@ -144,6 +184,46 @@ char *utoa(unsigned long in) 
	return itoa_buffer;

}



/* Converts the unsigned 64-bit integer <in> to its hex representation into

 * buffer <buffer>, which must be long enough to store the number and the

 * trailing zero (17 bytes for "ffffffffffffffff"). The buffer is filled from

 * the first byte, and the number of characters emitted (not counting the

 * trailing zero) is returned. The function is constructed in a way to optimize

 * the code size and avoid any divide that could add a dependency on large

 * external functions.

 */

static __attribute__((unused))

int u64toh_r(uint64_t in, char *buffer)

{

	signed char pos = 60;

	int digits = 0;

	int dig;



	do {

		dig = in >> pos;

		in -= (uint64_t)dig << pos;

		pos -= 4;

		if (dig || digits || pos < 0) {

			if (dig > 9)

				dig += 'a' - '0' - 10;

			buffer[digits++] = '0' + dig;

		}

	} while (pos >= 0);



	buffer[digits] = 0;

	return digits;

}



/* converts uint64_t <in> to an hex string using the static itoa_buffer and

 * returns the pointer to that string.

 */

static inline __attribute__((unused))

char *u64toh(uint64_t in)

{

	u64toh_r(in, itoa_buffer);

	return itoa_buffer;

}



/* Converts the unsigned 64-bit integer <in> to its string representation into

 * buffer <buffer>, which must be long enough to store the number and the

 * trailing zero (21 bytes for 18446744073709551615). The buffer is filled from