time: Allow gcc to fold constants when possible

 *   handling any 32-bit overflows.

 *   handling any 32-bit overflows.

 *   for the details see __msecs_to_jiffies()

 *   for the details see __msecs_to_jiffies()

 *

 *

 * the HZ range specific helpers _msecs_to_jiffies() are called from

 * msecs_to_jiffies() checks for the passed in value being a constant

 * __msecs_to_jiffies().

 * via __builtin_constant_p() allowing gcc to eliminate most of the

 * code, __msecs_to_jiffies() is called if the value passed does not

 * allow constant folding and the actual conversion must be done at

 * runtime.

 * the HZ range specific helpers _msecs_to_jiffies() are called both

 * directly here and from __msecs_to_jiffies() in the case where

 * constant folding is not possible.

 */

 */

static inline unsigned long msecs_to_jiffies(const unsigned int m)

static inline unsigned long msecs_to_jiffies(const unsigned int m)

{

{

	if (__builtin_constant_p(m)) {

		if ((int)m < 0)

			return MAX_JIFFY_OFFSET;

		return _msecs_to_jiffies(m);

	} else {

		return __msecs_to_jiffies(m);

		return __msecs_to_jiffies(m);

	}

	}

}

extern unsigned long usecs_to_jiffies(const unsigned int u);

extern unsigned long usecs_to_jiffies(const unsigned int u);

extern unsigned long timespec_to_jiffies(const struct timespec *value);

extern unsigned long timespec_to_jiffies(const struct timespec *value);