diff options
Diffstat (limited to 'bignum.c')
| -rw-r--r-- | bignum.c | 157 |
1 files changed, 74 insertions, 83 deletions
@@ -65,9 +65,17 @@ big_2comp(x) /* get 2's complement */ ds[i++] = BIGLO(num); num = BIGDN(num); } while (i < x->len); + if (ds[0] == 1 || ds[0] == 0) { + for (i=1;i<x->len;i++) { + if (ds[i] != 0) return; + } + REALLOC_N(BDIGITS(x), USHORT, x->len++); + ds = BDIGITS(x); + ds[x->len-1] = 1; + } } -VALUE +static VALUE bignorm(x) struct RBignum *x; { @@ -150,7 +158,7 @@ int2inum(n) VALUE str2inum(str, base) - char *str; + UCHAR *str; int base; { char sign = 1, c; @@ -189,7 +197,7 @@ str2inum(str, base) } if (len <= (sizeof(VALUE)*CHAR_BIT)) { - UINT val = strtoul(str, 0, base); + UINT val = strtoul((char*)str, 0, base); if (POSFIXABLE(val)) { if (sign) return INT2FIX(val); @@ -256,7 +264,7 @@ big2str(x, base) USHORT *ds; UINT i, j, hbase; VALUE ss; - char *s, c; + UCHAR *s, c; if (FIXNUM_P(x)) { return fix2str(x, base); @@ -431,6 +439,14 @@ big_cmp(x, y) } static VALUE +big_eq(x, y) + VALUE x, y; +{ + if (big_cmp(x, y) == INT2FIX(0)) return TRUE; + return FALSE; +} + +static VALUE big_uminus(x) struct RBignum *x; { @@ -487,35 +503,20 @@ bigsub(x, y) z = (struct RBignum*)bignew(x->len, (z == 0)?1:0); zds = BDIGITS(z); - i = x->len; - while (i--) zds[i] = BDIGITS(x)[i]; - - i = 0; num = 0; - do { - num += (long)zds[i] - BDIGITS(y)[i]; - if (num < 0) { - zds[i] = num + BIGRAD; - num = -1; - } - else { - zds[i] = BIGLO(num); - num = 0; - } - } while (++i < y->len); - if (num) { - while (num && i < x->len) { - num += zds[i]; - if (num < 0) { - zds[i++] = num + BIGRAD; - num = -1; - } - else { - zds[i++] = BIGLO(num); - num = 0; - } - } + for (i = 0, num = 0; i < y->len; i++) { + num += (long)BDIGITS(x)[i] - BDIGITS(y)[i]; + zds[i] = BIGLO(num); + num = BIGDN(num); + } + while (num && i < x->len) { + num += BDIGITS(x)[i]; + zds[i++] = BIGLO(num); + num = BIGDN(num); } - + while (i < x->len) { + zds[i++] = BDIGITS(x)[i]; + } + return bignorm(z); } @@ -525,10 +526,8 @@ bigadd(x, y, sign) char sign; { struct RBignum *z; - USHORT *zds; long num; UINT i, len; - if (x->sign == (y->sign ^ sign)) { if (y->sign == sign) return bigsub(y, x); return bigsub(x, y); @@ -541,27 +540,24 @@ bigadd(x, y, sign) len = y->len + 1; } z = (struct RBignum*)bignew(len, sign==y->sign); - zds = BDIGITS(z); - - i = len; - while (i--) zds[i] = 0; - i = y->len; - while (i--) zds[i] = BDIGITS(y)[i]; - i = 0; num = 0; - do { - num += (long)zds[i] + BDIGITS(x)[i]; - zds[i++] = BIGLO(num); - num = BIGDN(num); - } while (i < x->len); - if (num) { - while (i < y->len) { - num += zds[i]; - zds[i++] = BIGLO(num); - num = BIGDN(num); - } - BDIGITS(z)[i] = num; + if (x->len > y->len) { + struct RBignum* t = x; x = y; y = t; + } + for (i = 0, num = 0; i < x->len; i++) { + num += (long)(BDIGITS(x)[i]) + BDIGITS(y)[i]; + BDIGITS(z)[i] = BIGLO(num); + num = BIGDN(num); } + while (num && i < y->len) { + num += BDIGITS(y)[i]; + BDIGITS(z)[i++] = BIGLO(num); + num = BIGDN(num); + } + while (i < y->len) { + BDIGITS(z)[i++] = BDIGITS(y)[i]; + } + BDIGITS(z)[i] = num; return bignorm(z); } @@ -570,8 +566,6 @@ VALUE big_plus(x, y) VALUE x, y; { - VALUE z; - switch (TYPE(y)) { case T_FIXNUM: y = int2big(FIX2INT(y)); @@ -591,8 +585,6 @@ VALUE big_minus(x, y) VALUE x, y; { - VALUE cmp; - switch (TYPE(y)) { case T_FIXNUM: y = int2big(FIX2INT(y)); @@ -637,20 +629,20 @@ big_mul(x, y) z = bignew(j, x->sign==y->sign); zds = BDIGITS(z); while (j--) zds[j] = 0; - do { - j = 0; - if (BDIGITS(x)[i]) { - do { - n += zds[i + j] + ((unsigned long)BDIGITS(x)[i]*BDIGITS(y)[j]); - zds[i + j++] = BIGLO(n); - n = BIGDN(n); - } while (j < y->len); - if (n) { - zds[i + j] = n; - n = 0; - } + for (i = 0; i < x->len; i++) { + unsigned long dd = BDIGITS(x)[i]; + if (dd == 0) continue; + n = 0; + for (j = 0; j < y->len; j++) { + int ee = n + dd * BDIGITS(y)[j]; + n = zds[i + j] + ee; + if (ee) zds[i + j] = BIGLO(n); + n = BIGDN(n); } - } while (++i < x->len); + if (n) { + zds[i + j] = n; + } + } return bignorm(z); } @@ -669,7 +661,7 @@ bigdivmod(x, y, div, mod) yds = BDIGITS(y); if (ny == 0 && yds[0] == 0) num_zerodiv(); - if (nx < ny) { + if (nx < ny || nx == ny && BDIGITS(x)[nx - 1] < BDIGITS(y)[ny - 1]) { if (div) *div = INT2FIX(0); if (mod) *mod = bignorm(x); return; @@ -680,7 +672,7 @@ bigdivmod(x, y, div, mod) z = big_clone(x); zds = BDIGITS(z); t2 = 0; i = nx; - while(i--) { + while (i--) { t2 = BIGUP(t2) + zds[i]; zds[i] = t2 / dd; t2 %= dd; @@ -728,24 +720,21 @@ bigdivmod(x, y, div, mod) if (q) { i = 0; num = 0; t2 = 0; do { /* multiply and subtract */ + int ee; t2 += (unsigned long)yds[i] * q; - num += zds[j - ny + i] - BIGLO(t2); - if (num < 0) { - zds[j - ny + i] = num + BIGRAD; - num = -1; - } - else { - zds[j - ny + i] = num; - num = 0; - } + ee = num - BIGLO(t2); + num = zds[j - ny + i] + ee; + if (ee) zds[j - ny + i] = BIGLO(num); + num = BIGDN(num); t2 = BIGDN(t2); } while (++i < ny); num += zds[j - ny + i] - t2; /* borrow from high digit; don't update */ while (num) { /* "add back" required */ i = 0; num = 0; q--; do { - num += (long) zds[j - ny + i] + yds[i]; - zds[j - ny + i] = BIGLO(num); + int ee = num + yds[i]; + num = (long) zds[j - ny + i] + ee; + if (ee) zds[j - ny + i] = BIGLO(num); num = BIGDN(num); } while (++i < ny); num--; @@ -1241,6 +1230,8 @@ Init_Bignum() rb_define_method(cBignum, "[]", big_aref, 1); rb_define_method(cBignum, "<=>", big_cmp, 1); + rb_define_method(cBignum, "==", big_eq, 1); + rb_define_method(cBignum, "eql?", big_eq, 1); rb_define_method(cBignum, "hash", big_hash, 0); rb_define_method(cBignum, "to_i", big_to_i, 0); rb_define_method(cBignum, "to_f", big_to_f, 0); |