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authorJakob Kaivo <jkk@ung.org>2022-03-28 16:23:49 -0400
committerJakob Kaivo <jkk@ung.org>2022-03-28 16:23:49 -0400
commitfcea3028a0b5249c8908a0c3ed797c5a4eb32c5b (patch)
tree76e6792f2a171ea0d8cbd2178d4497dfc10a66a4 /big.c
parented29c791d3c58ef126c47b34921b3816db3f1d96 (diff)
move and rename len(), msd(), and ms2d()
Diffstat (limited to 'big.c')
-rw-r--r--big.c84
1 files changed, 41 insertions, 43 deletions
diff --git a/big.c b/big.c
index 5bf1772..6f7b261 100644
--- a/big.c
+++ b/big.c
@@ -40,14 +40,46 @@ struct big_div {
word big_one;
-static word len(word);
static struct big_div big__longdiv(word, word);
static struct big_div shortdiv(word, word);
-static word ms2d(word);
-static word msd(word);
static word shift(word, word);
static word stimes(word, word);
+/* no of digits in big x */
+word big__len(word x)
+{
+ word n = 1;
+ while ((x = rest(x)) != 0) {
+ n++;
+ }
+
+ return n;
+}
+
+/* most significant digit of big x */
+word big__msd(word x)
+{
+ while (rest(x)) {
+ x = rest(x);
+ }
+
+ return digit(x); /* sign? */
+}
+
+/* most significant 2 digits of big x (len>=2) */
+word big__ms2d(word x)
+{
+ word d = digit(x);
+ x = rest(x);
+ while (rest(x)) {
+ d = digit(x);
+ x = rest(x);
+ }
+
+ return (digit(x) * IBASE + d);
+}
+
+
/* ignore input signs, treat x,y as positive */
static word big__plus(word x, word y, int signbit)
{
@@ -316,7 +348,7 @@ int bigcmp(word x, word y)
word bigtimes(word x, word y)
{
/* important optimisation */
- if (len(x) < len(y)) {
+ if (big__len(x) < big__len(y)) {
word hold = x;
x = y;
y = hold;
@@ -505,19 +537,19 @@ struct big_div big__longdiv(word x, word y)
return bd;
}
- word y1 = msd(y);
+ word y1 = big__msd(y);
/* rescale if necessary */
word scale = IBASE / (y1 + 1);
if (scale > 1) {
x = stimes(x, scale);
y = stimes(y, scale);
- y1 = msd(y);
+ y1 = big__msd(y);
}
word n = 0;
word q = 0;
- word ly = len(y);
+ word ly = big__len(y);
while (bigcmp(x, y = make(INT, 0, y)) >= 0) {
n++;
}
@@ -525,7 +557,7 @@ struct big_div big__longdiv(word x, word y)
y = rest(y); /* want largest y not exceeding x */
ly += n;
for (;;) {
- word d, lx = len(x);
+ word d, lx = big__len(x);
if (lx < ly) {
d = 0;
@@ -538,7 +570,7 @@ struct big_div big__longdiv(word x, word y)
}
} else {
- d = ms2d(x) / y1;
+ d = big__ms2d(x) / y1;
if (d > MAXDIGIT) {
d = MAXDIGIT;
}
@@ -571,40 +603,6 @@ struct big_div big__longdiv(word x, word y)
}
} /* see Bird & Wadler p82 for explanation */
-/* no of digits in big x */
-word len(word x)
-{
- word n = 1;
- while ((x = rest(x)) != 0) {
- n++;
- }
-
- return n;
-}
-
-/* most significant digit of big x */
-word msd(word x)
-{
- while (rest(x)) {
- x = rest(x);
- }
-
- return digit(x); /* sign? */
-}
-
-/* most significant 2 digits of big x (len>=2) */
-word ms2d(word x)
-{
- word d = digit(x);
- x = rest(x);
- while (rest(x)) {
- d = digit(x);
- x = rest(x);
- }
-
- return (digit(x) * IBASE + d);
-}
-
/* assumes y big_is_positive */
word bigpow(word x, word y)
{