kotovalexarian-likes-github/ruby--ruby
1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
Code Releases Activity

* bignum.c (rb_absint_singlebit_p): New function.

Browse source 
* internal.h (rb_absint_singlebit_p): Declared.

* time.c (v2w_bignum): Use rb_absint_singlebit_p instead of
  rb_big_abs_find_minbit.
  (rb_big_abs_find_minbit): Removed.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41177 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit is contained in:
akr 2013-06-08 12:05:57 +00:00
parent af612be8e0
commit 747894a32d
4 changed files with 58 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
ChangeLog
View file

@ -1,3 +1,13 @@
Sat Jun 8 21:03:40 2013 Tanaka Akira <akr@fsij.org>
* bignum.c (rb_absint_singlebit_p): New function.
* internal.h (rb_absint_singlebit_p): Declared.
* time.c (v2w_bignum): Use rb_absint_singlebit_p instead of
rb_big_abs_find_minbit.
(rb_big_abs_find_minbit): Removed.
Sat Jun 8 20:24:23 2013 Tanaka Akira <akr@fsij.org>
* time.c (rb_big_abs_find_maxbit): Use rb_absint_size.

46
bignum.c
View file

@ -537,6 +537,52 @@ rb_absint_size_in_word(VALUE val, size_t word_numbits_arg, size_t *number_of_lea
return numwords;
}
int
rb_absint_singlebit_p(VALUE val)
{
BDIGIT *dp;
BDIGIT *de;
BDIGIT fixbuf[(sizeof(long) + SIZEOF_BDIGITS - 1) / SIZEOF_BDIGITS];
BDIGIT d;
val = rb_to_int(val);
if (FIXNUM_P(val)) {
long v = FIX2LONG(val);
if (v < 0) {
v = -v;
}
#if SIZEOF_BDIGITS == SIZEOF_LONG
fixbuf[0] = v;
#else
{
int i;
for (i = 0; i < numberof(fixbuf); i++) {
fixbuf[i] = (BDIGIT)(v & ((1L << (SIZEOF_BDIGITS * CHAR_BIT)) - 1));
v >>= SIZEOF_BDIGITS * CHAR_BIT;
}
}
#endif
dp = fixbuf;
de = fixbuf + numberof(fixbuf);
}
else {
dp = BDIGITS(val);
de = dp + RBIGNUM_LEN(val);
}
while (dp < de && de[-1] == 0)
de--;
while (dp < de && dp[0] == 0)
dp++;
if (dp == de) /* no bit set. */
return 0;
if (dp != de-1) /* two non-zero words. two bits set, at least. */
return 0;
d = *dp;
d = d & (d - 1); /* Clear the least significant bit set */
return d == 0;
}
#define INTEGER_PACK_WORDORDER_MASK \
(INTEGER_PACK_MSWORD_FIRST | \
INTEGER_PACK_LSWORD_FIRST)

1
internal.h
View file

@ -121,6 +121,7 @@ VALUE rb_integer_float_cmp(VALUE x, VALUE y);
VALUE rb_integer_float_eq(VALUE x, VALUE y);
size_t rb_absint_size(VALUE val, int *number_of_leading_zero_bits);
size_t rb_absint_size_in_word(VALUE val, size_t word_numbits, size_t *number_of_leading_zero_bits);
int rb_absint_singlebit_p(VALUE val);
/* class.c */
VALUE rb_obj_methods(int argc, VALUE *argv, VALUE obj);

22
time.c
View file

@ -313,25 +313,6 @@ rb_big_abs_find_maxbit(VALUE big)
return res;
}
static VALUE
rb_big_abs_find_minbit(VALUE big)
{
BDIGIT *ds = RBIGNUM_DIGITS(big);
BDIGIT d;
long len = RBIGNUM_LEN(big);
long i;
VALUE res;
for (i = 0; i < len; i++)
if (ds[i])
break;
if (i == len)
return Qnil;
res = mul(LONG2NUM(i), INT2FIX(SIZEOF_BDIGITS * CHAR_BIT));
d = ds[i];
res = add(res, LONG2FIX(ffs(d)-1));
return res;
}
static wideval_t
v2w_bignum(VALUE v)
{
@ -346,8 +327,7 @@ v2w_bignum(VALUE v)
return WINT2FIXWV(0);
if (lt(maxbit, INT2FIX(sizeof(wideint_t) * CHAR_BIT - 2)) ||
(eq(maxbit, INT2FIX(sizeof(wideint_t) * CHAR_BIT - 2)) &&
RBIGNUM_NEGATIVE_P(v) &&
eq(rb_big_abs_find_minbit(v), INT2FIX(sizeof(wideint_t) * CHAR_BIT - 2)))) {
RBIGNUM_NEGATIVE_P(v) && rb_absint_singlebit_p(v))) {
wideint_t i;
i = 0;
while (len)