Switch from bintime_add() et al. to bintimeadd(9).

Basically just make all the bintime routines look and behave more like
the timeradd(3) macros.

Switch to three-argument forms for structure math, introduce and use
bintimecmp(9), and rename the structure conversion routines to resemble
e.g. TIMEVAL_TO_TIMESPEC(3).

Document all of this in a new bintimeadd.9 page.

Code input from mpi@, manpage input from schwarze@.

code ok mpi@, docs ok schwarze@, docs probably still ok jmc@

3 files changed, 55 insertions, 62 deletions

diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c
index 4717adc908e..16cf6cdc605 100644
--- a/sys/kern/kern_tc.c
+++ b/sys/kern/kern_tc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_tc.c,v 1.47 2019/05/22 19:59:37 cheloha Exp $ */
+/*	$OpenBSD: kern_tc.c,v 1.48 2019/06/03 01:27:30 cheloha Exp $ */
 
 /*
  * Copyright (c) 2000 Poul-Henning Kamp <phk@FreeBSD.org>
@@ -163,7 +163,7 @@ microboottime(struct timeval *tvp)
 	struct bintime bt;
 	
 	binboottime(&bt);
-	bintime2timeval(&bt, tvp);
+	BINTIME_TO_TIMEVAL(&bt, tvp);
 }
 
 void
@@ -177,7 +177,7 @@ binuptime(struct bintime *bt)
 		gen = th->th_generation;
 		membar_consumer();
 		*bt = th->th_offset;
-		bintime_addx(bt, th->th_scale * tc_delta(th));
+		bintimeaddfrac(bt, th->th_scale * tc_delta(th), bt);
 		membar_consumer();
 	} while (gen == 0 || gen != th->th_generation);
 }
@@ -188,7 +188,7 @@ nanouptime(struct timespec *tsp)
 	struct bintime bt;
 
 	binuptime(&bt);
-	bintime2timespec(&bt, tsp);
+	BINTIME_TO_TIMESPEC(&bt, tsp);
 }
 
 void
@@ -197,7 +197,7 @@ microuptime(struct timeval *tvp)
 	struct bintime bt;
 
 	binuptime(&bt);
-	bintime2timeval(&bt, tvp);
+	BINTIME_TO_TIMEVAL(&bt, tvp);
 }
 
 void
@@ -211,8 +211,8 @@ bintime(struct bintime *bt)
 		gen = th->th_generation;
 		membar_consumer();
 		*bt = th->th_offset;
-		bintime_addx(bt, th->th_scale * tc_delta(th));
-		bintime_add(bt, &th->th_boottime);
+		bintimeaddfrac(bt, th->th_scale * tc_delta(th), bt);
+		bintimeadd(bt, &th->th_boottime, bt);
 		membar_consumer();
 	} while (gen == 0 || gen != th->th_generation);
 }
@@ -223,7 +223,7 @@ nanotime(struct timespec *tsp)
 	struct bintime bt;
 
 	bintime(&bt);
-	bintime2timespec(&bt, tsp);
+	BINTIME_TO_TIMESPEC(&bt, tsp);
 }
 
 void
@@ -232,7 +232,7 @@ microtime(struct timeval *tvp)
 	struct bintime bt;
 
 	bintime(&bt);
-	bintime2timeval(&bt, tvp);
+	BINTIME_TO_TIMEVAL(&bt, tvp);
 }
 
 void
@@ -245,7 +245,7 @@ getnanouptime(struct timespec *tsp)
 		th = timehands;
 		gen = th->th_generation;
 		membar_consumer();
-		bintime2timespec(&th->th_offset, tsp);
+		BINTIME_TO_TIMESPEC(&th->th_offset, tsp);
 		membar_consumer();
 	} while (gen == 0 || gen != th->th_generation);
 }
@@ -260,7 +260,7 @@ getmicrouptime(struct timeval *tvp)
 		th = timehands;
 		gen = th->th_generation;
 		membar_consumer();
-		bintime2timeval(&th->th_offset, tvp);
+		BINTIME_TO_TIMEVAL(&th->th_offset, tvp);
 		membar_consumer();
 	} while (gen == 0 || gen != th->th_generation);
 }
@@ -361,9 +361,9 @@ tc_setrealtimeclock(const struct timespec *ts)
 	rw_enter_write(&tc_lock);
 	mtx_enter(&windup_mtx);
 	binuptime(&bt2);
-	timespec2bintime(ts, &bt);
-	bintime_sub(&bt, &bt2);
-	bintime_add(&bt2, &timehands->th_boottime);
+	TIMESPEC_TO_BINTIME(ts, &bt);
+	bintimesub(&bt, &bt2, &bt);
+	bintimeadd(&bt2, &timehands->th_boottime, &bt2);
 
 	/* XXX fiddle all the little crinkly bits around the fiords... */
 	tc_windup(&bt, NULL, &zero);
@@ -373,7 +373,7 @@ tc_setrealtimeclock(const struct timespec *ts)
 	enqueue_randomness(ts->tv_sec);
 
 	if (timestepwarnings) {
-		bintime2timespec(&bt2, &ts2);
+		BINTIME_TO_TIMESPEC(&bt2, &ts2);
 		log(LOG_INFO, "Time stepped from %lld.%09ld to %lld.%09ld\n",
 		    (long long)ts2.tv_sec, ts2.tv_nsec,
 		    (long long)ts->tv_sec, ts->tv_nsec);
@@ -408,15 +408,13 @@ tc_setclock(const struct timespec *ts)
 	enqueue_randomness(ts->tv_sec);
 
 	mtx_enter(&windup_mtx);
-	timespec2bintime(ts, &bt);
-	bintime_sub(&bt, &timehands->th_boottime);
+	TIMESPEC_TO_BINTIME(ts, &bt);
+	bintimesub(&bt, &timehands->th_boottime, &bt);
 
 	/*
 	 * Don't rewind the offset.
 	 */
-	if (bt.sec < timehands->th_offset.sec ||
-	    (bt.sec == timehands->th_offset.sec &&
-	    bt.frac < timehands->th_offset.frac))
+	if (bintimecmp(&bt, &timehands->th_offset, <))
 		rewind = 1;
 
 	bt2 = timehands->th_offset;
@@ -426,7 +424,7 @@ tc_setclock(const struct timespec *ts)
 	mtx_leave(&windup_mtx);
 
 	if (rewind) {
-		bintime2timespec(&bt, &earlier);
+		BINTIME_TO_TIMESPEC(&bt, &earlier);
 		printf("%s: cannot rewind uptime to %lld.%09ld\n",
 		    __func__, (long long)earlier.tv_sec, earlier.tv_nsec);
 		return;
@@ -434,8 +432,8 @@ tc_setclock(const struct timespec *ts)
 
 #ifndef SMALL_KERNEL
 	/* convert the bintime to ticks */
-	bintime_sub(&bt, &bt2);
-	bintime_add(&naptime, &bt);
+	bintimesub(&bt, &bt2, &bt);
+	bintimeadd(&naptime, &bt, &naptime);
 	adj_ticks = (uint64_t)hz * bt.sec +
 	    (((uint64_t)1000000 * (uint32_t)(bt.frac >> 32)) >> 32) / tick;
 	if (adj_ticks > 0) {
@@ -499,7 +497,7 @@ tc_windup(struct bintime *new_boottime, struct bintime *new_offset,
 		ncount = 0;
 	th->th_offset_count += delta;
 	th->th_offset_count &= th->th_counter->tc_counter_mask;
-	bintime_addx(&th->th_offset, th->th_scale * delta);
+	bintimeaddfrac(&th->th_offset, th->th_scale * delta, &th->th_offset);
 
 #ifdef notyet
 	/*
@@ -533,7 +531,7 @@ tc_windup(struct bintime *new_boottime, struct bintime *new_offset,
 	 * case we missed a leap second.
 	 */
 	bt = th->th_offset;
-	bintime_add(&bt, &th->th_boottime);
+	bintimeadd(&bt, &th->th_boottime, &bt);
 	i = bt.sec - tho->th_microtime.tv_sec;
 	if (i > LARGE_STEP)
 		i = 2;
@@ -542,8 +540,8 @@ tc_windup(struct bintime *new_boottime, struct bintime *new_offset,
 
 	/* Update the UTC timestamps used by the get*() functions. */
 	/* XXX shouldn't do this here.  Should force non-`get' versions. */
-	bintime2timeval(&bt, &th->th_microtime);
-	bintime2timespec(&bt, &th->th_nanotime);
+	BINTIME_TO_TIMEVAL(&bt, &th->th_microtime);
+	BINTIME_TO_TIMESPEC(&bt, &th->th_nanotime);
 
 	/* Now is a good time to change timecounters. */
 	if (th->th_counter != active_tc) {
diff --git a/sys/kern/kern_time.c b/sys/kern/kern_time.c
index ca109f81434..b9030067cfb 100644
--- a/sys/kern/kern_time.c
+++ b/sys/kern/kern_time.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_time.c,v 1.118 2019/06/01 14:11:17 mpi Exp $	*/
+/*	$OpenBSD: kern_time.c,v 1.119 2019/06/03 01:27:30 cheloha Exp $	*/
 /*	$NetBSD: kern_time.c,v 1.20 1996/02/18 11:57:06 fvdl Exp $	*/
 
 /*
@@ -116,8 +116,8 @@ clock_gettime(struct proc *p, clockid_t clock_id, struct timespec *tp)
 		break;
 	case CLOCK_UPTIME:
 		binuptime(&bt);
-		bintime_sub(&bt, &naptime);
-		bintime2timespec(&bt, tp);
+		bintimesub(&bt, &naptime, &bt);
+		BINTIME_TO_TIMESPEC(&bt, tp);
 		break;
 	case CLOCK_MONOTONIC:
 	case CLOCK_BOOTTIME:
diff --git a/sys/sys/time.h b/sys/sys/time.h
index b4e0d20c688..8d4beeec964 100644
--- a/sys/sys/time.h
+++ b/sys/sys/time.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: time.h,v 1.40 2019/01/19 01:53:44 cheloha Exp $	*/
+/*	$OpenBSD: time.h,v 1.41 2019/06/03 01:27:30 cheloha Exp $	*/
 /*	$NetBSD: time.h,v 1.18 1996/04/23 10:29:33 mycroft Exp $	*/
 
 /*
@@ -172,39 +172,38 @@ struct bintime {
 	uint64_t frac;
 };
 
+#define bintimecmp(btp, ctp, cmp)					\
+	((btp)->sec == (ctp)->sec ?					\
+	    (btp)->frac cmp (ctp)->frac :				\
+	    (btp)->sec cmp (ctp)->sec)
+
 static __inline void
-bintime_addx(struct bintime *bt, uint64_t x)
+bintimeaddfrac(const struct bintime *bt, uint64_t x, struct bintime *ct)
 {
-	uint64_t u;
-
-	u = bt->frac;
-	bt->frac += x;
-	if (u > bt->frac)
-		bt->sec++;
+	ct->sec = bt->sec;
+	if (bt->frac > bt->frac + x)
+		ct->sec++;
+	ct->frac = bt->frac + x;
 }
 
 static __inline void
-bintime_add(struct bintime *bt, const struct bintime *bt2)
+bintimeadd(const struct bintime *bt, const struct bintime *ct,
+    struct bintime *dt)
 {
-	uint64_t u;
-
-	u = bt->frac;
-	bt->frac += bt2->frac;
-	if (u > bt->frac)
-		bt->sec++;
-	bt->sec += bt2->sec;
+	dt->sec = bt->sec + ct->sec;
+	if (bt->frac > bt->frac + ct->frac)
+		dt->sec++;
+	dt->frac = bt->frac + ct->frac;
 }
 
 static __inline void
-bintime_sub(struct bintime *bt, const struct bintime *bt2)
+bintimesub(const struct bintime *bt, const struct bintime *ct,
+    struct bintime *dt)
 {
-	uint64_t u;
-
-	u = bt->frac;
-	bt->frac -= bt2->frac;
-	if (u < bt->frac)
-		bt->sec--;
-	bt->sec -= bt2->sec;
+	dt->sec = bt->sec - ct->sec;
+	if (bt->frac < bt->frac - ct->frac)
+		dt->sec--;
+	dt->frac = bt->frac - ct->frac;
 }
 
 /*-
@@ -222,34 +221,30 @@ bintime_sub(struct bintime *bt, const struct bintime *bt2)
  */
 
 static __inline void
-bintime2timespec(const struct bintime *bt, struct timespec *ts)
+BINTIME_TO_TIMESPEC(const struct bintime *bt, struct timespec *ts)
 {
-
 	ts->tv_sec = bt->sec;
 	ts->tv_nsec = (long)(((uint64_t)1000000000 * (uint32_t)(bt->frac >> 32)) >> 32);
 }
 
 static __inline void
-timespec2bintime(const struct timespec *ts, struct bintime *bt)
+TIMESPEC_TO_BINTIME(const struct timespec *ts, struct bintime *bt)
 {
-
 	bt->sec = ts->tv_sec;
 	/* 18446744073 = int(2^64 / 1000000000) */
 	bt->frac = (uint64_t)ts->tv_nsec * (uint64_t)18446744073ULL; 
 }
 
 static __inline void
-bintime2timeval(const struct bintime *bt, struct timeval *tv)
+BINTIME_TO_TIMEVAL(const struct bintime *bt, struct timeval *tv)
 {
-
 	tv->tv_sec = bt->sec;
 	tv->tv_usec = (long)(((uint64_t)1000000 * (uint32_t)(bt->frac >> 32)) >> 32);
 }
 
 static __inline void
-timeval2bintime(const struct timeval *tv, struct bintime *bt)
+TIMEVAL_TO_BINTIME(const struct timeval *tv, struct bintime *bt)
 {
-
 	bt->sec = (time_t)tv->tv_sec;
 	/* 18446744073709 = int(2^64 / 1000000) */
 	bt->frac = (uint64_t)tv->tv_usec * (uint64_t)18446744073709ULL;