diff options
Diffstat (limited to 'bignum.c')
-rw-r--r-- | bignum.c | 34 |
1 files changed, 22 insertions, 12 deletions
@@ -2151,29 +2151,39 @@ rb_big_aref(x, y) VALUE x, y; { BDIGIT *xds; - int shift; - long s1, s2; + BDIGIT_DBL num; + unsigned long shift; + long i, s1, s2; if (TYPE(y) == T_BIGNUM) { - if (!RBIGNUM(y)->sign || RBIGNUM(x)->sign) + if (!RBIGNUM(y)->sign) return INT2FIX(0); - return INT2FIX(1); + if (RBIGNUM(bigtrunc(y))->len > SIZEOF_LONG/SIZEOF_BDIGITS) { + out_of_range: + return RBIGNUM(x)->sign ? INT2FIX(0) : INT2FIX(1); + } + shift = big2ulong(y, "long", Qfalse); + } + else { + i = NUM2LONG(y); + if (i < 0) return INT2FIX(0); + shift = (VALUE)i; } - shift = NUM2INT(y); - if (shift < 0) return INT2FIX(0); s1 = shift/BITSPERDIG; s2 = shift%BITSPERDIG; + if (s1 >= RBIGNUM(x)->len) goto out_of_range; if (!RBIGNUM(x)->sign) { - if (s1 >= RBIGNUM(x)->len) return INT2FIX(1); - x = rb_big_clone(x); - get2comp(x); + xds = BDIGITS(x); + i = 0; num = 1; + while (num += ~xds[i], ++i <= s1) { + num = BIGDN(num); + } } else { - if (s1 >= RBIGNUM(x)->len) return INT2FIX(0); + num = BDIGITS(x)[s1]; } - xds = BDIGITS(x); - if (xds[s1] & (1<<s2)) + if (num & ((BDIGIT_DBL)1<<s2)) return INT2FIX(1); return INT2FIX(0); } |