From 1ffdd828b32ecb81fd3fd8541df1edcb8c5673a8 Mon Sep 17 00:00:00 2001 From: akr Date: Mon, 8 Jul 2013 13:44:34 +0000 Subject: [PATCH] * bignum.c (bary_mul): Arguments for work memory added. (bary_mul_balance): Ditto. (bary_mul_karatsuba): Ditto. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41833 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ChangeLog | 6 ++++++ bignum.c | 50 +++++++++++++++++++++++++++----------------------- 2 files changed, 33 insertions(+), 23 deletions(-) diff --git a/ChangeLog b/ChangeLog index 3443867365..06c9daf03d 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +Mon Jul 8 22:41:12 2013 Tanaka Akira + + * bignum.c (bary_mul): Arguments for work memory added. + (bary_mul_balance): Ditto. + (bary_mul_karatsuba): Ditto. + Mon Jul 8 22:03:30 2013 Tanaka Akira * bignum.c (rb_big_sq_fast): New function for testing. diff --git a/bignum.c b/bignum.c index 1e87b2e519..6e2758bae6 100644 --- a/bignum.c +++ b/bignum.c @@ -101,7 +101,7 @@ static VALUE big_three = Qnil; static BDIGIT bary_small_lshift(BDIGIT *zds, BDIGIT *xds, long n, int shift); static void bary_small_rshift(BDIGIT *zds, BDIGIT *xds, long n, int shift, int sign_bit); -static void bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl); +static void bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl, BDIGIT *wds, size_t wl); static void bary_divmod(BDIGIT *qds, size_t nq, BDIGIT *rds, size_t nr, BDIGIT *xds, size_t nx, BDIGIT *yds, size_t ny); static VALUE bigmul0(VALUE x, VALUE y); @@ -1552,13 +1552,11 @@ rb_big_sq_fast(VALUE x) /* balancing multiplication by slicing larger argument */ static void -bary_mul_balance(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) +bary_mul_balance(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl, BDIGIT *wds, size_t wl) { VALUE work = 0; - BDIGIT *wds = NULL; size_t yl0 = yl; size_t r, n; - size_t wl = 0; assert(xl + yl <= zl); assert(2 * xl <= yl || 3 * xl <= 2*(yl+2)); @@ -1573,7 +1571,7 @@ bary_mul_balance(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, si tl = xl + r; if (2 * (xl + r) <= zl - n) { tds = zds + n + xl + r; - bary_mul(tds, tl, xds, xl, yds + n, r); + bary_mul(tds, tl, xds, xl, yds + n, r, wds, wl); MEMZERO(zds + n + xl, BDIGIT, r); bary_add(zds + n, tl, zds + n, tl, @@ -1586,7 +1584,7 @@ bary_mul_balance(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, si } tds = zds + n; MEMCPY(wds, zds + n, BDIGIT, xl); - bary_mul(tds, tl, xds, xl, yds + n, r); + bary_mul(tds, tl, xds, xl, yds + n, r, wds-xl, wl-xl); bary_add(zds + n, tl, zds + n, tl, wds, xl); @@ -1607,7 +1605,7 @@ rb_big_mul_balance(VALUE x, VALUE y) VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); if (!(2 * xn <= yn || 3 * xn <= 2*(yn+2))) rb_raise(rb_eArgError, "invalid bignum length"); - bary_mul_balance(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn); + bary_mul_balance(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, NULL, 0); RB_GC_GUARD(x); RB_GC_GUARD(y); return z; @@ -1615,11 +1613,9 @@ rb_big_mul_balance(VALUE x, VALUE y) /* multiplication by karatsuba method */ static void -bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) +bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl, BDIGIT *wds, size_t wl) { VALUE work = 0; - BDIGIT *wds; - size_t wl; size_t n; int sub_p, borrow, carry1, carry2, carry3; @@ -1646,8 +1642,16 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, assert(n < xl); - wl = n; - wds = ALLOCV_N(BDIGIT, work, wl); + if (wl < n) { + /* This function itself needs only n BDIGITs for work area. + * However this function calls bary_mul_karatsuba and + * bary_mul_balance recursively. + * 2n BDIGITs are enough to avoid allocations in + * the recursively called functions. + */ + wl = 2*n; + wds = ALLOCV_N(BDIGIT, work, wl); + } /* Karatsuba algorithm: * @@ -1687,7 +1691,7 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, /* zds0:|x1-x0| zds1:? zds2:? zds3:? wds:|y1-y0| */ - bary_mul(zds1, 2*n, zds0, n, wds, n); + bary_mul(zds1, 2*n, zds0, n, wds, n, wds+n, wl-n); /* zds0:|x1-x0| zds1,zds2:|x1-x0|*|y1-y0| zds3:? wds:|y1-y0| */ @@ -1701,7 +1705,7 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, /* zds0:|x1-x0| zds1,zds2:-?|x1-x0|*|y1-y0| zds3:? wds:lo(-?|x1-x0|*|y1-y0|) */ - bary_mul(zds0, 2*n, xds0, n, yds0, n); + bary_mul(zds0, 2*n, xds0, n, yds0, n, wds+n, wl-n); /* zds0,zds1:x0*y0 zds2:hi(-?|x1-x0|*|y1-y0|) zds3:? wds:lo(-?|x1-x0|*|y1-y0|) */ @@ -1718,7 +1722,7 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, /* zds0:lo(x0*y0) zds1:hi(x0*y0)+lo(x0*y0-?|x1-x0|*|y1-y0|) zds2:_ zds3:? wds:hi(x0*y0-?|x1-x0|*|y1-y0|) */ - bary_mul(zds2, zl-2*n, xds1, xl-n, yds1, n); + bary_mul(zds2, zl-2*n, xds1, xl-n, yds1, n, wds+n, wl-n); /* zds0:lo(x0*y0) zds1:hi(x0*y0)+lo(x0*y0-?|x1-x0|*|y1-y0|) zds2,zds3:x1*y1 wds:hi(x0*y0-?|x1-x0|*|y1-y0|) */ @@ -1774,7 +1778,7 @@ rb_big_mul_karatsuba(VALUE x, VALUE y) VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); if (!(xn <= yn && yn < 2 * xn)) rb_raise(rb_eArgError, "invalid bignum length"); - bary_mul_karatsuba(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn); + bary_mul_karatsuba(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, NULL, 0); RB_GC_GUARD(x); RB_GC_GUARD(y); return z; @@ -1813,7 +1817,7 @@ bary_sparse_p(BDIGIT *ds, size_t n) } static void -bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) +bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl, BDIGIT *wds, size_t wl) { size_t nlsz; /* number of least significant zero BDIGITs */ @@ -1874,18 +1878,18 @@ bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) /* balance multiplication by slicing y when x is much smaller than y */ if (2 * xl <= yl) { - bary_mul_balance(zds, zl, xds, xl, yds, yl); + bary_mul_balance(zds, zl, xds, xl, yds, yl, wds, wl); return; } if (xl < TOOM3_MUL_DIGITS) { /* multiplication by karatsuba method */ - bary_mul_karatsuba(zds, zl, xds, xl, yds, yl); + bary_mul_karatsuba(zds, zl, xds, xl, yds, yl, wds, wl); return; } if (3*xl <= 2*(yl + 2)) { - bary_mul_balance(zds, zl, xds, xl, yds, yl); + bary_mul_balance(zds, zl, xds, xl, yds, yl, wds, wl); return; } @@ -2955,11 +2959,11 @@ rb_cstr_to_inum(const char *str, int base, int badcheck) for (unit = 2; unit < num_bdigits; unit *= 2) { for (i = 0; i < num_bdigits; i += unit*2) { if (2*unit <= num_bdigits - i) { - bary_mul(vds+i, unit*2, BDIGITS(powerv), RBIGNUM_LEN(powerv), uds+i+unit, unit); + bary_mul(vds+i, unit*2, BDIGITS(powerv), RBIGNUM_LEN(powerv), uds+i+unit, unit, NULL, 0); bary_add(vds+i, unit*2, vds+i, unit*2, uds+i, unit); } else if (unit <= num_bdigits - i) { - bary_mul(vds+i, num_bdigits-i, BDIGITS(powerv), RBIGNUM_LEN(powerv), uds+i+unit, num_bdigits-(i+unit)); + bary_mul(vds+i, num_bdigits-i, BDIGITS(powerv), RBIGNUM_LEN(powerv), uds+i+unit, num_bdigits-(i+unit), NULL, 0); bary_add(vds+i, num_bdigits-i, vds+i, num_bdigits-i, uds+i, unit); } else { @@ -4662,7 +4666,7 @@ bigmul0(VALUE x, VALUE y) yds = BDIGITS(y); zds = BDIGITS(z); - bary_mul(zds, zn, xds, xn, yds, yn); + bary_mul(zds, zn, xds, xn, yds, yn, NULL, 0); RB_GC_GUARD(x); RB_GC_GUARD(y);