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authormatz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2005-07-01 08:54:04 +0000
committermatz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2005-07-01 08:54:04 +0000
commit1453dc92e4934bdc85b0759a98ee99fba1ab9fb2 (patch)
treeff7d61b858462f8b699fc1010cd146c42dd641b5 /bignum.c
parent32d0d609e9fa68c43a6e269e9e3149009f517617 (diff)
* bignum.c (get2comp): revert all prior changes, and calculate
proper 2's complement for negative numbers. backported from HEAD. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@8693 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'bignum.c')
-rw-r--r--bignum.c45
1 files changed, 22 insertions, 23 deletions
diff --git a/bignum.c b/bignum.c
index 9272816..ae748fc 100644
--- a/bignum.c
+++ b/bignum.c
@@ -65,10 +65,10 @@ rb_big_clone(x)
return z;
}
+/* modify a bignum by 2's complement */
static void
-get2comp(x, carry) /* get 2's complement */
+get2comp(x)
VALUE x;
- int carry;
{
long i = RBIGNUM(x)->len;
BDIGIT *ds = BDIGITS(x);
@@ -81,8 +81,7 @@ get2comp(x, carry) /* get 2's complement */
ds[i++] = BIGLO(num);
num = BIGDN(num);
} while (i < RBIGNUM(x)->len);
- if (!carry) return;
- if ((ds[RBIGNUM(x)->len-1] & (1<<(BITSPERDIG-1))) == 0) {
+ if (num != 0) {
REALLOC_N(RBIGNUM(x)->digits, BDIGIT, ++RBIGNUM(x)->len);
ds = BDIGITS(x);
ds[RBIGNUM(x)->len-1] = RBIGNUM(x)->sign ? ~0 : 1;
@@ -93,7 +92,7 @@ void
rb_big_2comp(x) /* get 2's complement */
VALUE x;
{
- get2comp(x, Qtrue);
+ get2comp(x);
}
static VALUE
@@ -1050,13 +1049,15 @@ rb_big_neg(x)
VALUE x;
{
VALUE z = rb_big_clone(x);
- long i = RBIGNUM(x)->len;
- BDIGIT *ds = BDIGITS(z);
+ long i;
+ BDIGIT *ds;
- if (!RBIGNUM(x)->sign) get2comp(z, Qtrue);
+ if (!RBIGNUM(x)->sign) get2comp(z);
+ ds = BDIGITS(z);
+ i = RBIGNUM(x)->len;
while (i--) ds[i] = ~ds[i];
RBIGNUM(z)->sign = !RBIGNUM(z)->sign;
- if (RBIGNUM(x)->sign) get2comp(z, Qtrue);
+ if (RBIGNUM(x)->sign) get2comp(z);
return bignorm(z);
}
@@ -1648,11 +1649,11 @@ rb_big_and(xx, yy)
}
if (!RBIGNUM(y)->sign) {
y = rb_big_clone(y);
- get2comp(y, Qtrue);
+ get2comp(y);
}
if (!RBIGNUM(x)->sign) {
x = rb_big_clone(x);
- get2comp(x, Qtrue);
+ get2comp(x);
}
if (RBIGNUM(x)->len > RBIGNUM(y)->len) {
l1 = RBIGNUM(y)->len;
@@ -1677,7 +1678,7 @@ rb_big_and(xx, yy)
for (; i<l2; i++) {
zds[i] = sign?0:ds2[i];
}
- if (!RBIGNUM(z)->sign) get2comp(z, Qtrue);
+ if (!RBIGNUM(z)->sign) get2comp(z);
return bignorm(z);
}
@@ -1702,14 +1703,13 @@ rb_big_or(xx, yy)
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
-
if (!RBIGNUM(y)->sign) {
y = rb_big_clone(y);
- get2comp(y, Qtrue);
+ get2comp(y);
}
if (!RBIGNUM(x)->sign) {
x = rb_big_clone(x);
- get2comp(x, Qtrue);
+ get2comp(x);
}
if (RBIGNUM(x)->len > RBIGNUM(y)->len) {
l1 = RBIGNUM(y)->len;
@@ -1734,7 +1734,7 @@ rb_big_or(xx, yy)
for (; i<l2; i++) {
zds[i] = sign?ds2[i]:(BIGRAD-1);
}
- if (!RBIGNUM(z)->sign) get2comp(z, Qtrue);
+ if (!RBIGNUM(z)->sign) get2comp(z);
return bignorm(z);
}
@@ -1761,14 +1761,13 @@ rb_big_xor(xx, yy)
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
-
if (!RBIGNUM(y)->sign) {
y = rb_big_clone(y);
- get2comp(y, Qtrue);
+ get2comp(y);
}
if (!RBIGNUM(x)->sign) {
x = rb_big_clone(x);
- get2comp(x, Qtrue);
+ get2comp(x);
}
if (RBIGNUM(x)->len > RBIGNUM(y)->len) {
l1 = RBIGNUM(y)->len;
@@ -1795,7 +1794,7 @@ rb_big_xor(xx, yy)
for (; i<l2; i++) {
zds[i] = sign?ds2[i]:~ds2[i];
}
- if (!RBIGNUM(z)->sign) get2comp(z, Qtrue);
+ if (!RBIGNUM(z)->sign) get2comp(z);
return bignorm(z);
}
@@ -1867,7 +1866,7 @@ rb_big_rshift(x, y)
}
if (!RBIGNUM(x)->sign) {
x = rb_big_clone(x);
- get2comp(x, Qtrue);
+ get2comp(x);
}
xds = BDIGITS(x);
i = RBIGNUM(x)->len; j = i - s1;
@@ -1882,7 +1881,7 @@ rb_big_rshift(x, y)
num = BIGUP(xds[i]);
}
if (!RBIGNUM(x)->sign) {
- get2comp(z, Qfalse);
+ get2comp(z);
}
return bignorm(z);
}
@@ -1927,7 +1926,7 @@ rb_big_aref(x, y)
if (!RBIGNUM(x)->sign) {
if (s1 >= RBIGNUM(x)->len) return INT2FIX(1);
x = rb_big_clone(x);
- get2comp(x, Qtrue);
+ get2comp(x);
}
else {
if (s1 >= RBIGNUM(x)->len) return INT2FIX(0);