diff options
| -rw-r--r-- | ChangeLog | 12 | ||||
| -rw-r--r-- | bignum.c | 42 |
2 files changed, 31 insertions, 23 deletions
@@ -1,3 +1,15 @@ +Sun Aug 4 01:54:45 2013 Tanaka Akira <akr@fsij.org> + + * bignum.c (BARY_TRUNC): New macro. + (bary_cmp): Use BARY_TRUNC. + (bary_mul_toom3): Ditto. + (bary_divmod): Ditto. + (abs2twocomp): Ditto. + (bigfixize): Ditto. + (rb_cstr_to_inum): Ditto. + (big2str_karatsuba): Ditto. + (bigdivrem): Ditto. + Sun Aug 4 00:57:58 2013 Tanaka Akira <akr@fsij.org> * bignum.c (big2str_karatsuba): Don't allocate new temporary buffer @@ -121,6 +121,11 @@ STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_BDIGITS % SIZEOF_LONG == 0); } \ } while (0) +#define BARY_TRUNC(ds, n) do { \ + while (0 < (n) && (ds)[(n)-1] == 0) \ + (n)--; \ + } while (0) + #define KARATSUBA_BALANCED(xn, yn) ((yn)/2 < (xn)) #define TOOM3_BALANCED(xn, yn) (((yn)+2)/3 * 2 < (xn)) @@ -506,10 +511,8 @@ bdigitdbl2bary(BDIGIT *ds, size_t n, BDIGIT_DBL num) static int bary_cmp(const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn) { - while (0 < xn && xds[xn-1] == 0) - xn--; - while (0 < yn && yds[yn-1] == 0) - yn--; + BARY_TRUNC(xds, xn); + BARY_TRUNC(yds, yn); if (xn < yn) return -1; @@ -2364,8 +2367,7 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI else bary_sub(zzds + 4*n, zzn - 4*n, zzds + 4*n, zzn - 4*n, z4ds, z4n); - while (0 < zzn && zzds[zzn-1] == 0) - zzn--; + BARY_TRUNC(zzds, zzn); MEMCPY(zds, zzds, BDIGIT, zzn); BDIGITS_ZERO(zds + zzn, zn - zzn); @@ -2720,11 +2722,11 @@ bary_divmod(BDIGIT *qds, size_t nq, BDIGIT *rds, size_t nr, const BDIGIT *xds, s assert(nx <= nq); assert(ny <= nr); - while (0 < ny && !yds[ny-1]) ny--; + BARY_TRUNC(yds, ny); if (ny == 0) rb_num_zerodiv(); - while (0 < nx && !xds[nx-1]) nx--; + BARY_TRUNC(xds, nx); if (nx == 0) { BDIGITS_ZERO(qds, nq); BDIGITS_ZERO(rds, nr); @@ -2973,8 +2975,7 @@ abs2twocomp(VALUE *xp, long *n_ret) BDIGIT *ds = BDIGITS(x); BDIGIT hibits = 0; - while (0 < n && ds[n-1] == 0) - n--; + BARY_TRUNC(ds, n); if (n != 0 && RBIGNUM_NEGATIVE_P(x)) { VALUE z = bignew_1(CLASS_OF(x), n, 0); @@ -3021,8 +3022,7 @@ bigfixize(VALUE x) BDIGIT u; #endif - while (0 < len && ds[len-1] == 0) - len--; + BARY_TRUNC(ds, len); if (len == 0) return INT2FIX(0); @@ -3911,8 +3911,7 @@ rb_cstr_to_inum(const char *str, int base, int badcheck) vds = uds; uds = tds; } - while (0 < num_bdigits && uds[num_bdigits-1] == 0) - num_bdigits--; + BARY_TRUNC(uds, num_bdigits); z = bignew(num_bdigits, sign); MEMCPY(BDIGITS(z), uds, BDIGIT, num_bdigits); @@ -4393,12 +4392,10 @@ big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, rds = wds; qds = wds+rn; bary_divmod(qds, qn, rds, rn, xds, xn, bds, bn); - while (0 < qn && qds[qn-1] == 0) - qn--; + BARY_TRUNC(qds, qn); assert(qn <= bn); big2str_karatsuba(b2s, qds, qn, lower_power_level, lower_numdigits+taillen, qds+qn, wn-(rn+qn)); - while (0 < rn && rds[rn-1] == 0) - rn--; + BARY_TRUNC(rds, rn); big2str_karatsuba(b2s, rds, rn, lower_power_level, taillen, rds+rn, wn-rn); if (tmpw) ALLOCV_END(tmpw); @@ -5564,12 +5561,12 @@ bigdivrem(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp) BDIGIT dd; yds = BDIGITS(y); - while (0 < ny && !yds[ny-1]) ny--; + BARY_TRUNC(yds, ny); if (ny == 0) rb_num_zerodiv(); xds = BDIGITS(x); - while (0 < nx && !xds[nx-1]) nx--; + BARY_TRUNC(xds, nx); if (nx < ny || (nx == ny && xds[nx - 1] < yds[ny - 1])) { if (divp) *divp = rb_int2big(0); @@ -5623,13 +5620,12 @@ bigdivrem(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp) if (divp) { /* move quotient down in z */ j = nz - ny; - while (0 < j && !zds[j-1+ny]) - j--; + BARY_TRUNC(zds+ny, j); *divp = zz = bignew(j, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); MEMCPY(BDIGITS(zz), zds+ny, BDIGIT, j); } if (modp) { /* normalize remainder */ - while (ny > 0 && !zds[ny-1]) --ny; + BARY_TRUNC(zds, ny); *modp = zz = bignew(ny, RBIGNUM_SIGN(x)); MEMCPY(BDIGITS(zz), zds, BDIGIT, ny); } |