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authorJakob Kaivo <jkk@ung.org>2022-03-28 14:58:20 -0400
committerJakob Kaivo <jkk@ung.org>2022-03-28 14:58:20 -0400
commitf9a8d0b1205d3772d27c0e8e8a8dccda2f3c66ca (patch)
treeff610e896d28556ffa9cc86710e8651b0e5ec470
parent8a1de9cc709b2a9470541a229d2134f022a28301 (diff)
modernize bigpow()
-rw-r--r--big.c25
1 files changed, 17 insertions, 8 deletions
diff --git a/big.c b/big.c
index 02753f6..8fba599 100644
--- a/big.c
+++ b/big.c
@@ -585,30 +585,39 @@ word ms2d(word x)
return (digit(x) * IBASE + d);
}
-word bigpow(x, y) /* assumes y big_is_positive */
-word x, y;
+/* assumes y big_is_positive */
+word bigpow(word x, word y)
{
- word d, r = make(INT, 1, 0);
- while (rest(y)) { /* this loop has been unwrapped once, see below */
+ word d;
+ word r = make(INT, 1, 0);
+
+ /* this loop has been unwrapped once, see below */
+ while (rest(y)) {
word i = DIGITWIDTH;
d = digit(y);
while (i--) {
- if (d & 1)
+ if (d & 1) {
r = bigtimes(r, x);
+ }
x = bigtimes(x, x);
d >>= 1;
}
y = rest(y);
}
+
d = digit(y);
- if (d & 1)
+ if (d & 1) {
r = bigtimes(r, x);
+ }
+
while (d >>= 1) {
x = bigtimes(x, x);
- if (d & 1)
+ if (d & 1) {
r = bigtimes(r, x);
+ }
}
- return (r);
+
+ return r;
}
double bigtodbl(x)