-#include "config.h"
+/* Licensed under LGPLv3+ - see LICENSE file for details */
#include <ccan/tally/tally.h>
#include <ccan/build_assert/build_assert.h>
#include <ccan/likely/likely.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
+#include <stdlib.h>
#define SIZET_BITS (sizeof(size_t)*CHAR_BIT)
size_t total[2];
/* This allows limited frequency analysis. */
unsigned buckets, step_bits;
- size_t counts[1 /* [buckets] */ ];
+ size_t counts[1 /* Actually: [buckets] */ ];
};
struct tally *tally_new(unsigned buckets)
{
struct tally *tally;
- /* Check for overflow. */
- if (buckets && SIZE_MAX / buckets < sizeof(tally->counts[0]))
+ /* There is always 1 bucket. */
+ if (buckets == 0) {
+ buckets = 1;
+ }
+
+ /* Overly cautious check for overflow. */
+ if (sizeof(*tally) * buckets / sizeof(*tally) != buckets) {
+ return NULL;
+ }
+
+ tally = (struct tally *)malloc(
+ sizeof(*tally) + sizeof(tally->counts[0])*(buckets-1));
+ if (tally == NULL) {
return NULL;
- tally = malloc(sizeof(*tally) + sizeof(tally->counts[0])*buckets);
- if (tally) {
- tally->max = ((size_t)1 << (SIZET_BITS - 1));
- tally->min = ~tally->max;
- tally->total[0] = tally->total[1] = 0;
- /* There is always 1 bucket. */
- tally->buckets = buckets+1;
- tally->step_bits = 0;
- memset(tally->counts, 0, sizeof(tally->counts[0])*(buckets+1));
}
+
+ tally->max = ((size_t)1 << (SIZET_BITS - 1));
+ tally->min = ~tally->max;
+ tally->total[0] = tally->total[1] = 0;
+ tally->buckets = buckets;
+ tally->step_bits = 0;
+ memset(tally->counts, 0, sizeof(tally->counts[0])*buckets);
return tally;
}
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));
}
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. */
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:
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)]++;
}
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;
}
#endif
uint64_t r = 64;
- if (!val)
+ if (!val) {
return 0;
+ }
if (!(val & 0xffffffff00000000ull)) {
val <<= 32;
r -= 32;
/* 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];
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;
}
un[j+2] = un[j+2] + k;
}
- } // End j.
+ } /* End j. */
return q[1]*b + q[0];
}
{
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;
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. */
}
/* If result is negative, make sure we can represent it. */
- if (tally->total[1] & (1 << (SIZET_BITS-1))) {
+ if (tally->total[1] & ((size_t)1 << (SIZET_BITS-1))) {
/* Must have only underflowed once, and must be able to
* represent result at ssize_t. */
if ((~tally->total[1])+1 != 0
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;
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);
}
{
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;
}
} else {
/* We create a temporary then renormalize so < height. */
/* FIXME: Antialias properly! */
- tmp = tally_new(tally->buckets-1);
- if (!tmp)
+ tmp = tally_new(tally->buckets);
+ 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;
/* 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 = malloc(height * (width + 1) + 1);
+ p = graph = (char *)malloc(height * (width + 1) + 1);
if (!graph) {
free(tmp);
return NULL;
}
for (i = 0; i < height; i++) {
- unsigned covered = 1;
- count = (double)tally->counts[i] / largest_bucket * (width-1)+1;
+ unsigned covered = 1, row;
- if (i == 0)
+ /* People expect minimum at the bottom. */
+ row = height - i - 1;
+ count = (double)tally->counts[row] / largest_bucket * (width-1)+1;
+
+ if (row == 0) {
covered = snprintf(p, width, "%zi", tally->min);
- else if (i == height - 1)
+ } else if (row == height - 1) {
covered = snprintf(p, width, "%zi", tally->max);
- else if (i == 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++;