rom/timer/timer_macros.h

   1 /*
   2  * These are often used by timer.device itself, and inlining
   3  * them saves us from function call overhead.
   4  */
   5
   6 /* Add, then normalize */
   7 #define ADDTIME(dest, src)                      \
   8     (dest)->tv_micro += (src)->tv_micro;        \
   9     (dest)->tv_secs  += (src)->tv_secs;         \
  10     while((dest)->tv_micro > 999999)            \
  11     {                                           \
  12         (dest)->tv_secs++;                      \
  13         (dest)->tv_micro -= 1000000;            \
  14     }
  15
  16 /*
  17  * Subtraction algorithm:
  18  * 1. Normalize values
  19  * 2. Check if wrap around will happen, when subtracting src->tv_micro
  20  *    from dest->tv_micro. If yes, then normalize, by adding 1 sec to
  21  *    micros and subtracting 1 sec from secs. Note: this check must be
  22  *    before subtracting src timeval from dest timeval!
  23  */
  24 #define SUBTIME(dest, src)                      \
  25     while ((src)->tv_micro > 999999)            \
  26     {                                           \
  27         (src)->tv_secs++;                       \
  28         (src)->tv_micro -= 1000000;             \
  29     }                                           \
  30     while ((dest)->tv_micro > 999999)           \
  31     {                                           \
  32         (dest)->tv_secs++;                      \
  33         (dest)->tv_micro -= 1000000;            \
  34     }                                           \
  35     if ((dest)->tv_micro < (src)->tv_micro)     \
  36     {                                           \
  37         (dest)->tv_micro += 1000000;            \
  38         (dest)->tv_secs--;                      \
  39     }                                           \
  40     (dest)->tv_micro -= (src)->tv_micro;        \
  41     (dest)->tv_secs  -= (src)->tv_secs;
  42
  43 static inline LONG CMPTIME(struct timeval *dest, struct timeval *src)
  44 {
  45     LONG diff;
  46
  47     if (dest->tv_secs == src->tv_secs)
  48         diff = src->tv_micro - dest->tv_micro;
  49     else
  50         diff = src->tv_secs - dest->tv_secs;
  51
  52     if (diff < 0)
  53         return -1;
  54     else if (diff > 0)
  55         return 1;
  56     else
  57         return 0;
  58 }
  59
  60 /*
  61  * Add 'diff' EClock ticks to timeval in 'time'.
  62  * Fraction of second value is stored in in 'frac'.
  63  * This macro relies on (CPU-specific) tick2usec() implementation
  64  */
  65 #define INCTIME(time, frac, diff)               \
  66     (frac) += diff;                             \
  67     if ((frac) >= TimerBase->tb_eclock_rate)    \
  68     {                                           \
  69         (frac) -= TimerBase->tb_eclock_rate;    \
  70         (time).tv_secs++;                       \
  71     }                                           \
  72     (time).tv_micro = tick2usec(frac);