1) Use _mpd_basedivmod() regardless of the length of the dividend. This is
required for a corner case in dec_hash() in the following commit and also
usually faster. dec_hash() needs some extra precision above MPD_MAX_PREC,
and _mpd_base_ndivmod() is not audited for that.
2) Use _mpd_basemul() if the length of the smaller operand is less than
or equal to 256. While this is technically an optimization, it is
required for *testing* corner cases in dec_hash() in reasonable time.
diff --git a/Modules/_decimal/libmpdec/mpdecimal.c b/Modules/_decimal/libmpdec/mpdecimal.c
index d7ae41c..9bdb03d 100644
--- a/Modules/_decimal/libmpdec/mpdecimal.c
+++ b/Modules/_decimal/libmpdec/mpdecimal.c
@@ -3513,8 +3513,7 @@
if (b->len == 1) {
rem = _mpd_shortdiv(q->data, a->data, a->len, b->data[0]);
}
- else if (a->len < 2*MPD_NEWTONDIV_CUTOFF &&
- b->len < MPD_NEWTONDIV_CUTOFF) {
+ else if (b->len <= MPD_NEWTONDIV_CUTOFF) {
int ret = _mpd_basedivmod(q->data, NULL, a->data, b->data,
a->len, b->len);
if (ret < 0) {
@@ -3667,8 +3666,7 @@
r->data[0] = _mpd_shortdiv(q->data, a->data, a->len, b->data[0]);
}
}
- else if (a->len < 2*MPD_NEWTONDIV_CUTOFF &&
- b->len < MPD_NEWTONDIV_CUTOFF) {
+ else if (b->len <= MPD_NEWTONDIV_CUTOFF) {
int ret;
ret = _mpd_basedivmod(q->data, r->data, a->data, b->data,
a->len, b->len);
@@ -5544,10 +5542,15 @@
}
- if (small->len == 1) {
+ if (small->len <= 256) {
rdata = mpd_calloc(rsize, sizeof *rdata);
if (rdata != NULL) {
- _mpd_shortmul(rdata, big->data, big->len, small->data[0]);
+ if (small->len == 1) {
+ _mpd_shortmul(rdata, big->data, big->len, small->data[0]);
+ }
+ else {
+ _mpd_basemul(rdata, small->data, big->data, small->len, big->len);
+ }
}
}
else if (rsize <= 1024) {