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* bignum.c (bary_mul): Use simple multiplication if yl is small.

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(rb_cstr_to_inum): Invoke bigsq instead of bigmul0.
  (bigsq): Re-implemented.
  (bigmul0): Invoke bigsq if two arguments are identical.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42096 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit is contained in:
akr 2013-07-21 12:13:47 +00:00
parent a2116ef2cd
commit 5cf931d65e
2 changed files with 36 additions and 8 deletions
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7
ChangeLog
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@ -1,3 +1,10 @@
Sun Jul 21 21:08:59 2013 Tanaka Akira <akr@fsij.org>
* bignum.c (bary_mul): Use simple multiplication if yl is small.
(rb_cstr_to_inum): Invoke bigsq instead of bigmul0.
(bigsq): Re-implemented.
(bigmul0): Invoke bigsq if two arguments are identical.
Sun Jul 21 09:58:19 2013 Tanaka Akira <akr@fsij.org>
* bignum.c (bary_mul_toom3): New function based on bigmul1_toom3.

37
bignum.c
View File

@ -2496,7 +2496,7 @@ bary_mul_toom3_start(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds
static void
bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl)
{
if (xl < KARATSUBA_MUL_DIGITS) {
if (xl < KARATSUBA_MUL_DIGITS || yl < KARATSUBA_MUL_DIGITS) {
if (xds == yds && xl == yl)
bary_sq_fast(zds, zl, xds, xl);
else
@ -3586,7 +3586,7 @@ rb_cstr_to_inum(const char *str, int base, int badcheck)
MEMCPY(vds+i, uds+i, BDIGIT, num_bdigits-i);
}
}
powerv = bigtrunc(bigmul0(powerv, powerv));
powerv = bigtrunc(bigsq(powerv));
tds = vds;
vds = uds;
uds = tds;
@ -5012,6 +5012,30 @@ rb_big_minus(VALUE x, VALUE y)
static VALUE bigdivrem(VALUE, VALUE, volatile VALUE*, volatile VALUE*);
static VALUE
bigsq(VALUE x)
{
long xn, zn;
VALUE z;
BDIGIT *xds, *zds;
xn = RBIGNUM_LEN(x);
zn = 2 * xn;
z = bignew(zn, 1);
xds = BDIGITS(x);
zds = BDIGITS(z);
if (xn < KARATSUBA_MUL_DIGITS)
bary_sq_fast(zds, zn, xds, xn);
else
bary_mul(zds, zn, xds, xn, xds, xn);
RB_GC_GUARD(x);
return z;
}
static VALUE
bigmul0(VALUE x, VALUE y)
{
@ -5019,6 +5043,9 @@ bigmul0(VALUE x, VALUE y)
VALUE z;
BDIGIT *xds, *yds, *zds;
if (x == y)
return bigsq(x);
xn = RBIGNUM_LEN(x);
yn = RBIGNUM_LEN(y);
zn = xn + yn;
@ -5590,12 +5617,6 @@ rb_big_fdiv(VALUE x, VALUE y)
return DBL2NUM(dx / dy);
}
static VALUE
bigsq(VALUE x)
{
return bigtrunc(bigmul0(x, x));
}
/*
* call-seq:
* big ** exponent -> numeric