* numeric.c: Extract integer rounding into int_round_0

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33185 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit is contained in:
marcandre 2011-09-04 20:14:00 +00:00
Родитель dc20068d98
Коммит 269de36cd0
1 изменённых файлов: 41 добавлений и 32 удалений

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@ -1455,6 +1455,45 @@ flo_ceil(VALUE num)
return LONG2FIX(val);
}
/*
* Assumes num is an Integer, ndigits <= 0
*/
static VALUE
int_round_0(VALUE num, int ndigits)
{
VALUE n, f, h, r;
long bytes;
ID op;
/* If 10**N / 2 > num, then return 0 */
/* We have log_256(10) > 0.415241 and log_256(1/2) = -0.125, so */
bytes = FIXNUM_P(num) ? sizeof(long) : rb_funcall(num, rb_intern("size"), 0);
if (-0.415241 * ndigits - 0.125 > bytes ) {
return INT2FIX(0);
}
f = int_pow(10, -ndigits);
if (FIXNUM_P(num) && FIXNUM_P(f)) {
SIGNED_VALUE x = FIX2LONG(num), y = FIX2LONG(f);
int neg = x < 0;
if (neg) x = -x;
x = (x + y / 2) / y * y;
if (neg) x = -x;
return LONG2NUM(x);
}
if (TYPE(f) == T_FLOAT) {
/* then int_pow overflow */
return INT2FIX(0);
}
h = rb_funcall(f, '/', 1, INT2FIX(2));
r = rb_funcall(num, '%', 1, f);
n = rb_funcall(num, '-', 1, r);
op = RTEST(rb_funcall(num, '<', 1, INT2FIX(0))) ? rb_intern("<=") : '<';
if (!RTEST(rb_funcall(r, op, 1, h))) {
n = rb_funcall(n, '+', 1, f);
}
return n;
}
/*
* call-seq:
* flt.round([ndigits]) -> integer or float
@ -3318,10 +3357,8 @@ int_dotimes(VALUE num)
static VALUE
int_round(int argc, VALUE* argv, VALUE num)
{
VALUE n, f, h, r;
VALUE n;
int ndigits;
long bytes;
ID op;
if (argc == 0) return num;
rb_scan_args(argc, argv, "1", &n);
@ -3332,35 +3369,7 @@ int_round(int argc, VALUE* argv, VALUE num)
if (ndigits == 0) {
return num;
}
/* If 10**N / 2 > num, then return 0 */
/* We have log_256(10) > 0.415241 and log_256(1/2) = -0.125, so */
bytes = FIXNUM_P(num) ? sizeof(long) : rb_funcall(num, rb_intern("size"), 0);
if (-0.415241 * ndigits - 0.125 > bytes ) {
return INT2FIX(0);
}
f = int_pow(10, -ndigits);
if (FIXNUM_P(num) && FIXNUM_P(f)) {
SIGNED_VALUE x = FIX2LONG(num), y = FIX2LONG(f);
int neg = x < 0;
if (neg) x = -x;
x = (x + y / 2) / y * y;
if (neg) x = -x;
return LONG2NUM(x);
}
if (TYPE(f) == T_FLOAT) {
/* then int_pow overflow */
return INT2FIX(0);
}
h = rb_funcall(f, '/', 1, INT2FIX(2));
r = rb_funcall(num, '%', 1, f);
n = rb_funcall(num, '-', 1, r);
op = RTEST(rb_funcall(num, '<', 1, INT2FIX(0))) ? rb_intern("<=") : '<';
if (!RTEST(rb_funcall(r, op, 1, h))) {
n = rb_funcall(n, '+', 1, f);
}
return n;
return int_round_0(num, ndigits);
}
/*