X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftally%2Ftally.c;h=29f055588015f5e38f02513c6dcce39b4657ff20;hp=a5eedcb951bfafc819701a740bcad64e68f162ac;hb=HEAD;hpb=b10913e2abf41d97a3a7b4a00cc0909986d947d5

diff --git a/ccan/tally/tally.c b/ccan/tally/tally.c
index a5eedcb9..5cc3352a 100644
--- a/ccan/tally/tally.c
+++ b/ccan/tally/tally.c
@@ -25,12 +25,15 @@ struct tally *tally_new(unsigned buckets)
 	struct tally *tally;
 
 	/* There is always 1 bucket. */
-	if (buckets == 0)
+	if (buckets == 0) {
 		buckets = 1;
+	}
 
 	/* Overly cautious check for overflow. */
-	if (sizeof(*tally) * buckets / sizeof(*tally) != buckets)
+	if (sizeof(*tally) * buckets / sizeof(*tally) != buckets) {
 		return NULL;
+	}
+
 	tally = (struct tally *)malloc(
 		sizeof(*tally) + sizeof(tally->counts[0])*(buckets-1));
 	if (tally == NULL) {
@@ -49,27 +52,33 @@ struct tally *tally_new(unsigned buckets)
 static unsigned bucket_of(ssize_t min, unsigned step_bits, ssize_t val)
 {
 	/* Don't over-shift. */
-	if (step_bits == SIZET_BITS)
+	if (step_bits == SIZET_BITS) {
 		return 0;
+	}
 	assert(step_bits < SIZET_BITS);
-	return (size_t)(val - min) >> step_bits;
+	return ((size_t)val - (size_t)min) >> step_bits;
 }
 
 /* Return the min value in bucket b. */
 static ssize_t bucket_min(ssize_t min, unsigned step_bits, unsigned b)
 {
 	/* Don't over-shift. */
-	if (step_bits == SIZET_BITS)
+	if (step_bits == SIZET_BITS) {
 		return min;
+	}
 	assert(step_bits < SIZET_BITS);
-	return min + ((ssize_t)b << step_bits);
+	return min + ((size_t)b << step_bits);
 }
 
 /* Does shifting by this many bits truncate the number? */
 static bool shift_overflows(size_t num, unsigned bits)
 {
-	if (bits == 0)
+	if (bits == 0) {
 		return false;
+	}
+	if (bits >= SIZET_BITS) {
+		return true;
+	}
 
 	return ((num << bits) >> 1) != (num << (bits - 1));
 }
@@ -82,12 +91,13 @@ static void renormalize(struct tally *tally,
 	unsigned int i, old_min;
 
 	/* Uninitialized?  Don't do anything... */
-	if (tally->max < tally->min)
+	if (tally->max < tally->min) {
 		goto update;
+	}
 
 	/* If we don't have sufficient range, increase step bits until
 	 * buckets cover entire range of ssize_t anyway. */
-	range = (new_max - new_min) + 1;
+	range = ((size_t)new_max - (size_t)new_min) + 1;
 	while (!shift_overflows(tally->buckets, tally->step_bits)
 	       && range > ((size_t)tally->buckets << tally->step_bits)) {
 		/* Collapse down. */
@@ -106,11 +116,13 @@ static void renormalize(struct tally *tally,
 	memset(tally->counts, 0, sizeof(tally->counts[0]) * old_min);
 
 	/* If we moved boundaries, adjust buckets to that ratio. */
-	spill = (tally->min - new_min) % (1 << tally->step_bits);
-	for (i = 0; i < tally->buckets-1; i++) {
-		size_t adjust = (tally->counts[i] >> tally->step_bits) * spill;
-		tally->counts[i] -= adjust;
-		tally->counts[i+1] += adjust;
+	if (tally->step_bits < SIZET_BITS) {
+		spill = (tally->min - new_min) % ((size_t)1 << tally->step_bits);
+		for (i = 0; i < tally->buckets-1; i++) {
+			size_t adjust = (tally->counts[i] >> tally->step_bits) * spill;
+			tally->counts[i] -= adjust;
+			tally->counts[i+1] += adjust;
+		}
 	}
 
 update:
@@ -131,15 +143,17 @@ void tally_add(struct tally *tally, ssize_t val)
 		new_max = val;
 		need_renormalize = true;
 	}
-	if (need_renormalize)
+	if (need_renormalize) {
 		renormalize(tally, new_min, new_max);
+	}
 
 	/* 128-bit arithmetic!  If we didn't want exact mean, we could just
 	 * pull it out of counts. */
-	if (val > 0 && tally->total[0] + val < tally->total[0])
+	if (val > 0 && tally->total[0] + val < tally->total[0]) {
 		tally->total[1]++;
-	else if (val < 0 && tally->total[0] + val > tally->total[0])
+	} else if (val < 0 && tally->total[0] + val > tally->total[0]) {
 		tally->total[1]--;
+	}
 	tally->total[0] += val;
 	tally->counts[bucket_of(tally->min, tally->step_bits, val)]++;
 }
@@ -147,8 +161,9 @@ void tally_add(struct tally *tally, ssize_t val)
 size_t tally_num(const struct tally *tally)
 {
 	size_t i, num = 0;
-	for (i = 0; i < tally->buckets; i++)
+	for (i = 0; i < tally->buckets; i++) {
 		num += tally->counts[i];
+	}
 	return num;
 }
 
@@ -173,8 +188,9 @@ static unsigned fls64(uint64_t val)
 #endif
 	uint64_t r = 64;
 
-	if (!val)
+	if (!val) {
 		return 0;
+	}
 	if (!(val & 0xffffffff00000000ull)) {
 		val <<= 32;
 		r -= 32;
@@ -208,46 +224,49 @@ static unsigned fls64(uint64_t val)
 /* This is stolen straight from Hacker's Delight. */
 static uint64_t divlu64(uint64_t u1, uint64_t u0, uint64_t v)
 {
-	const uint64_t b = 4294967296ULL; // Number base (32 bits).
-	uint32_t un[4],		  // Dividend and divisor
-		vn[2];		  // normalized and broken
-				  // up into halfwords.
-	uint32_t q[2];		  // Quotient as halfwords.
-	uint64_t un1, un0,	  // Dividend and divisor
-		vn0;		  // as fullwords.
-	uint64_t qhat;		  // Estimated quotient digit.
-	uint64_t rhat;		  // A remainder.
-	uint64_t p;		  // Product of two digits.
+	const uint64_t b = 4294967296ULL; /* Number base (32 bits). */
+	uint32_t un[4],		  /* Dividend and divisor */
+		vn[2];		  /* normalized and broken */
+				  /* up into halfwords. */
+	uint32_t q[2];		  /* Quotient as halfwords. */
+	uint64_t un1, un0,	  /* Dividend and divisor */
+		vn0;		  /* as fullwords. */
+	uint64_t qhat;		  /* Estimated quotient digit. */
+	uint64_t rhat;		  /* A remainder. */
+	uint64_t p;		  /* Product of two digits. */
 	int64_t s, i, j, t, k;
 
-	if (u1 >= v)		  // If overflow, return the largest
-		return (uint64_t)-1; // possible quotient.
+	if (u1 >= v) {		  /* If overflow, return the largest */
+		return (uint64_t)-1; /* possible quotient. */
+	}
 
-	s = 64 - fls64(v);		  // 0 <= s <= 63.
-	vn0 = v << s;		  // Normalize divisor.
-	vn[1] = vn0 >> 32;	  // Break divisor up into
-	vn[0] = vn0 & 0xFFFFFFFF; // two 32-bit halves.
+	s = 64 - fls64(v);		  /* 0 <= s <= 63. */
+	vn0 = v << s;		  /* Normalize divisor. */
+	vn[1] = vn0 >> 32;	  /* Break divisor up into */
+	vn[0] = vn0 & 0xFFFFFFFF; /* two 32-bit halves. */
 
 	// Shift dividend left.
 	un1 = ((u1 << s) | (u0 >> (64 - s))) & (-s >> 63);
 	un0 = u0 << s;
-	un[3] = un1 >> 32;	  // Break dividend up into
-	un[2] = un1;		  // four 32-bit halfwords
-	un[1] = un0 >> 32;	  // Note: storing into
-	un[0] = un0;		  // halfwords truncates.
+	un[3] = un1 >> 32;	  /* Break dividend up into */
+	un[2] = un1;		  /* four 32-bit halfwords */
+	un[1] = un0 >> 32;	  /* Note: storing into */
+	un[0] = un0;		  /* halfwords truncates. */
 
 	for (j = 1; j >= 0; j--) {
-		// Compute estimate qhat of q[j].
+		/* Compute estimate qhat of q[j]. */
 		qhat = (un[j+2]*b + un[j+1])/vn[1];
 		rhat = (un[j+2]*b + un[j+1]) - qhat*vn[1];
 	again:
 		if (qhat >= b || qhat*vn[0] > b*rhat + un[j]) {
 			qhat = qhat - 1;
 			rhat = rhat + vn[1];
-			if (rhat < b) goto again;
+			if (rhat < b) {
+				goto again;
+			}
 		}
 
-		// Multiply and subtract.
+		/* Multiply and subtract. */
 		k = 0;
 		for (i = 0; i < 2; i++) {
 			p = qhat*vn[i];
@@ -258,9 +277,9 @@ static uint64_t divlu64(uint64_t u1, uint64_t u0, uint64_t v)
 		t = un[j+2] - k;
 		un[j+2] = t;
 
-		q[j] = qhat;		  // Store quotient digit.
-		if (t < 0) {		  // If we subtracted too
-			q[j] = q[j] - 1;  // much, add back.
+		q[j] = qhat;		  /* Store quotient digit. */
+		if (t < 0) {		  /* If we subtracted too */
+			q[j] = q[j] - 1;  /* much, add back. */
 			k = 0;
 			for (i = 0; i < 2; i++) {
 				t = un[i+j] + vn[i] + k;
@@ -269,7 +288,7 @@ static uint64_t divlu64(uint64_t u1, uint64_t u0, uint64_t v)
 			}
 			un[j+2] = un[j+2] + k;
 		}
-	} // End j.
+	} /* End j. */
 
 	return q[1]*b + q[0];
 }
@@ -278,26 +297,28 @@ static int64_t divls64(int64_t u1, uint64_t u0, int64_t v)
 {
 	int64_t q, uneg, vneg, diff, borrow;
 
-	uneg = u1 >> 63;	  // -1 if u < 0.
-	if (uneg) {		  // Compute the absolute
-		u0 = -u0;	  // value of the dividend u.
+	uneg = u1 >> 63;	  /* -1 if u < 0. */
+	if (uneg) {		  /* Compute the absolute */
+		u0 = -u0;	  /* value of the dividend u. */
 		borrow = (u0 != 0);
 		u1 = -u1 - borrow;
 	}
 
-	vneg = v >> 63;		  // -1 if v < 0.
-	v = (v ^ vneg) - vneg;	  // Absolute value of v.
+	vneg = v >> 63;		  /* -1 if v < 0. */
+	v = (v ^ vneg) - vneg;	  /* Absolute value of v. */
 
-	if ((uint64_t)u1 >= (uint64_t)v)
+	if ((uint64_t)u1 >= (uint64_t)v) {
 		goto overflow;
+	}
 
 	q = divlu64(u1, u0, v);
 
-	diff = uneg ^ vneg;	  // Negate q if signs of
-	q = (q ^ diff) - diff;	  // u and v differed.
+	diff = uneg ^ vneg;	  /* Negate q if signs of */
+	q = (q ^ diff) - diff;	  /* u and v differed. */
 
-	if ((diff ^ q) < 0 && q != 0) {	   // If overflow, return the largest
-	overflow:			   // possible neg. quotient.
+	if ((diff ^ q) < 0 && q != 0) {	   /* If overflow, return the
+					      largest */
+	overflow:			   /* possible neg. quotient. */
 		q = 0x8000000000000000ULL;
 	}
 	return q;
@@ -306,8 +327,9 @@ static int64_t divls64(int64_t u1, uint64_t u0, int64_t v)
 ssize_t tally_mean(const struct tally *tally)
 {
 	size_t count = tally_num(tally);
-	if (!count)
+	if (!count) {
 		return 0;
+	}
 
 	if (sizeof(tally->total[0]) == sizeof(uint32_t)) {
 		/* Use standard 64-bit arithmetic. */
@@ -350,10 +372,11 @@ static ssize_t bucket_range(const struct tally *tally, unsigned b, size_t *err)
 	ssize_t min, max;
 
 	min = bucket_min(tally->min, tally->step_bits, b);
-	if (b == tally->buckets - 1)
+	if (b == tally->buckets - 1) {
 		max = tally->max;
-	else
+	} else {
 		max = bucket_min(tally->min, tally->step_bits, b+1) - 1;
+	}
 
 	/* FIXME: Think harder about cumulative error; is this enough?. */
 	*err = (max - min + 1) / 2;
@@ -368,8 +391,9 @@ ssize_t tally_approx_median(const struct tally *tally, size_t *err)
 
 	for (i = 0; i < tally->buckets; i++) {
 		total += tally->counts[i];
-		if (total * 2 >= count)
+		if (total * 2 >= count) {
 			break;
+		}
 	}
 	return bucket_range(tally, i, err);
 }
@@ -403,9 +427,11 @@ static unsigned get_max_bucket(const struct tally *tally)
 {
 	unsigned int i;
 
-	for (i = tally->buckets; i > 0; i--)
-		if (tally->counts[i-1])
+	for (i = tally->buckets; i > 0; i--) {
+		if (tally->counts[i-1]) {
 			break;
+		}
+	}
 	return i;
 }
 
@@ -430,15 +456,17 @@ char *tally_histogram(const struct tally *tally,
 		/* We create a temporary then renormalize so < height. */
 		/* FIXME: Antialias properly! */
 		tmp = tally_new(tally->buckets);
-		if (!tmp)
+		if (!tmp) {
 			return NULL;
+		}
 		tmp->min = tally->min;
 		tmp->max = tally->max;
 		tmp->step_bits = tally->step_bits;
 		memcpy(tmp->counts, tally->counts,
 		       sizeof(tally->counts[0]) * tmp->buckets);
-		while ((max_bucket = get_max_bucket(tmp)) >= height)
+		while ((max_bucket = get_max_bucket(tmp)) >= height) {
 			renormalize(tmp, tmp->min, tmp->max * 2);
+		}
 		/* Restore max */
 		tmp->max = tally->max;
 		tally = tmp;
@@ -448,8 +476,9 @@ char *tally_histogram(const struct tally *tally,
 	/* Figure out longest line, for scale. */
 	largest_bucket = 0;
 	for (i = 0; i < tally->buckets; i++) {
-		if (tally->counts[i] > largest_bucket)
+		if (tally->counts[i] > largest_bucket) {
 			largest_bucket = tally->counts[i];
+		}
 	}
 
 	p = graph = (char *)malloc(height * (width + 1) + 1);
@@ -465,25 +494,28 @@ char *tally_histogram(const struct tally *tally,
 		row = height - i - 1;
 		count = (double)tally->counts[row] / largest_bucket * (width-1)+1;
 
-		if (row == 0)
+		if (row == 0) {
 			covered = snprintf(p, width, "%zi", tally->min);
-		else if (row == height - 1)
+		} else if (row == height - 1) {
 			covered = snprintf(p, width, "%zi", tally->max);
-		else if (row == bucket_of(tally->min, tally->step_bits, 0))
+		} else if (row == bucket_of(tally->min, tally->step_bits, 0)) {
 			*p = '+';
-		else
+		} else {
 			*p = '|';
+		}
 
-		if (covered > width)
+		if (covered > width) {
 			covered = width;
+		}
 		p += covered;
 
-		if (count > covered)
+		if (count > covered) {
 			count -= covered;
-		else
+			memset(p, '*', count);
+		} else {
 			count = 0;
+		}
 
-		memset(p, '*', count);
 		p += count;
 		*p = '\n';
 		p++;