Changeset: 4d0e87f34f62 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=4d0e87f34f62
Modified Files:
gdk/gdk_aggr.c
Branch: Jul2017
Log Message:
Be less resource hungry during floating point summation.
We use smaller types where we can, especially when we need lots of
them. Also preallocate fewer spaces for partial results.
This should fix bug 6458.
diffs (154 lines):
diff --git a/gdk/gdk_aggr.c b/gdk/gdk_aggr.c
--- a/gdk/gdk_aggr.c
+++ b/gdk/gdk_aggr.c
@@ -199,8 +199,13 @@ dofsum(const void *restrict values, oid
struct pergroup {
int npartials;
int maxpartials;
+ int valseen;
+#ifdef INFINITES_ALLOWED
+ float infs;
+#else
+ int infs;
+#endif
double *partials;
- int valseen;
} *pergroup;
BUN listi;
int parti;
@@ -228,9 +233,10 @@ dofsum(const void *restrict values, oid
if (pergroup == NULL)
return BUN_NONE;
for (grp = 0; grp < ngrp; grp++) {
- pergroup[grp].npartials = 1;
+ pergroup[grp].npartials = 0;
pergroup[grp].valseen = 0;
- pergroup[grp].maxpartials = 32;
+ pergroup[grp].maxpartials = 2;
+ pergroup[grp].infs = 0;
pergroup[grp].partials = GDKmalloc(pergroup[grp].maxpartials *
sizeof(double));
if (pergroup[grp].partials == NULL) {
while (grp > 0)
@@ -238,7 +244,6 @@ dofsum(const void *restrict values, oid
GDKfree(pergroup);
return BUN_NONE;
}
- pergroup[grp].partials[0] = 0;
}
for (;;) {
if (cand) {
@@ -274,8 +279,14 @@ dofsum(const void *restrict values, oid
continue;
}
pergroup[grp].valseen = 1;
- i = 1;
- for (parti = 1; parti < pergroup[grp].npartials; parti++) {
+#ifdef INFINITES_ALLOWED
+ if (isinf(x)) {
+ pergroup[grp].infs += x;
+ continue;
+ }
+#endif
+ i = 0;
+ for (parti = 0; parti < pergroup[grp].npartials; parti++) {
y = pergroup[grp].partials[parti];
if (fabs(x) < fabs(y))
exchange(&x, &y);
@@ -284,7 +295,7 @@ dofsum(const void *restrict values, oid
int sign = hi > 0 ? 1 : -1;
hi = x - twopow * sign;
x = hi - twopow * sign;
- pergroup[grp].partials[0] += sign;
+ pergroup[grp].infs += sign;
if (fabs(x) < fabs(y))
exchange(&x, &y);
twosum(&hi, &lo, x, y);
@@ -294,9 +305,7 @@ dofsum(const void *restrict values, oid
x = hi;
}
if (x != 0) {
- if (i == pergroup[grp].maxpartials - 1) {
- /* -1 to make sure we have one spare
- * for the final step below */
+ if (i == pergroup[grp].maxpartials) {
double *temp;
pergroup[grp].maxpartials +=
pergroup[grp].maxpartials;
temp = GDKrealloc(pergroup[grp].partials,
pergroup[grp].maxpartials * sizeof(double));
@@ -322,10 +331,8 @@ dofsum(const void *restrict values, oid
pergroup[grp].partials = NULL;
continue;
}
- if (isinf(pergroup[grp].partials[0]) ||
- isnan(pergroup[grp].partials[0])) {
- /* isnan: cannot happen: infinities of both
- * signs in summands */
+#ifdef INFINITES_ALLOWED
+ if (isinf(pergroup[grp].infs) || isnan(pergroup[grp].infs)) {
if (abort_on_error) {
goto overflow;
}
@@ -338,17 +345,18 @@ dofsum(const void *restrict values, oid
pergroup[grp].partials = NULL;
continue;
}
+#endif
- if (fabs(pergroup[grp].partials[0]) == 1.0 &&
- pergroup[grp].npartials > 1 &&
- !samesign(pergroup[grp].partials[0],
pergroup[grp].partials[pergroup[grp].npartials - 1])) {
- twosum(&hi, &lo, pergroup[grp].partials[0] * twopow,
pergroup[grp].partials[pergroup[grp].npartials - 1] / 2);
+ if ((pergroup[grp].infs == 1 || pergroup[grp].infs == -1) &&
+ pergroup[grp].npartials > 0 &&
+ !samesign(pergroup[grp].infs,
pergroup[grp].partials[pergroup[grp].npartials - 1])) {
+ twosum(&hi, &lo, pergroup[grp].infs * twopow,
pergroup[grp].partials[pergroup[grp].npartials - 1] / 2);
if (isinf(2 * hi)) {
y = 2 * lo;
x = hi + y;
x -= hi;
if (x == y &&
- pergroup[grp].npartials > 2 &&
+ pergroup[grp].npartials > 1 &&
samesign(lo,
pergroup[grp].partials[pergroup[grp].npartials - 2])) {
GDKfree(pergroup[grp].partials);
pergroup[grp].partials = NULL;
@@ -373,18 +381,27 @@ dofsum(const void *restrict values, oid
}
} else {
if (lo) {
- /* we made sure above that we
- * have space for one more
- * partial */
+ if (pergroup[grp].npartials ==
pergroup[grp].maxpartials) {
+ double *temp;
+ /* we need space for one more */
+ pergroup[grp].maxpartials++;
+ temp =
GDKrealloc(pergroup[grp].partials, pergroup[grp].maxpartials * sizeof(double));
+ if (temp == NULL)
+ goto bailout;
+ pergroup[grp].partials = temp;
+ }
pergroup[grp].partials[pergroup[grp].npartials - 1] = 2 * lo;
pergroup[grp].partials[pergroup[grp].npartials++] = 2 * hi;
} else {
pergroup[grp].partials[pergroup[grp].npartials - 1] = 2 * hi;
}
- pergroup[grp].partials[0] = 0;
+ pergroup[grp].infs = 0;
}
}
+ if (pergroup[grp].infs != 0)
+ goto overflow;
+
if (pergroup[grp].npartials == 0) {
GDKfree(pergroup[grp].partials);
pergroup[grp].partials = NULL;
@@ -394,8 +411,6 @@ dofsum(const void *restrict values, oid
((dbl *) results)[grp] = 0;
continue;
}
- if (pergroup[grp].partials[0] != 0)
- goto overflow;
/* accumulate into hi */
hi = pergroup[grp].partials[--pergroup[grp].npartials];
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