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* bignum.c (LOG2_KARATSUBA_BIG2STR_DIGITS): Removed. 

(KARATSUBA_BIG2STR_DIGITS): Removed.
  (big2str_numdigits_cache): New variable.
  (power_cache_get_power): Merged with power_cache_get_power0.
  This function returns maxpow_in_bdigit_dbl(base)**(2**power_level).
  (rb_big2str1): use power_cache_get_power.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42295 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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akr 2013-07-31 16:20:26 +00:00
Родитель d28913b4b9
Коммит 4f1b07e9eb
2 изменённых файлов: 52 добавлений и 37 удалений
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9
ChangeLog
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@ -1,3 +1,12 @@
Thu Aug 1 01:09:02 2013 Tanaka Akira <akr@fsij.org>
* bignum.c (LOG2_KARATSUBA_BIG2STR_DIGITS): Removed.
(KARATSUBA_BIG2STR_DIGITS): Removed.
(big2str_numdigits_cache): New variable.
(power_cache_get_power): Merged with power_cache_get_power0.
This function returns maxpow_in_bdigit_dbl(base)**(2**power_level).
(rb_big2str1): use power_cache_get_power.
Wed Jul 31 23:59:28 2013 Tanaka Akira <akr@fsij.org>
* bignum.c (big2str_find_n1): Change the return type to size_t.

80
bignum.c
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@ -4100,11 +4100,10 @@ big_rshift(VALUE x, unsigned long shift)
return big_shift3(x, 0, s1, s2);
}
#define LOG2_KARATSUBA_BIG2STR_DIGITS 7
#define KARATSUBA_BIG2STR_DIGITS (1L<<LOG2_KARATSUBA_BIG2STR_DIGITS)
#define MAX_BIG2STR_TABLE_ENTRIES (SIZEOF_SIZE_T * CHAR_BIT)
#define MAX_BIG2STR_TABLE_ENTRIES (SIZEOF_SIZE_T * CHAR_BIT + 1)
static VALUE big2str_power_cache[35][MAX_BIG2STR_TABLE_ENTRIES];
static size_t big2str_numdigits_cache[35][MAX_BIG2STR_TABLE_ENTRIES];
static void
power_cache_init(void)
@ -4118,40 +4117,47 @@ power_cache_init(void)
}
static inline VALUE
power_cache_get_power0(int base, int i)
{
/* MAX_BIG2STR_TABLE_ENTRIES is big enough to that
* big2str_power_cache[base][MAX_BIG2STR_TABLE_ENTRIES-1] fills whole memory.
* So MAX_BIG2STR_TABLE_ENTRIES <= i is not possible to calculate.
*
* big2str_power_cache[base][MAX_BIG2STR_TABLE_ENTRIES-1] =
* (base**KARATSUBA_BIG2STR_DIGITS)**(MAX_BIG2STR_TABLE_ENTRIES-1) =
* (base**KARATSUBA_BIG2STR_DIGITS)**(SIZEOF_SIZE_T*CHAR_BIT-1) =
* base**(KARATSUBA_BIG2STR_DIGITS*(SIZEOF_SIZE_T*CHAR_BIT-1)) > 2**(SIZEOF_SIZE_T*CHAR_BIT-1)
* where
* 2 <= base
* 1 < KARATSUBA_BIG2STR_DIGITS
*/
if (MAX_BIG2STR_TABLE_ENTRIES <= i)
rb_bug("too big power number requested: (%d**%ld)**(2**%d)", base, KARATSUBA_BIG2STR_DIGITS, i);
if (NIL_P(big2str_power_cache[base - 2][i])) {
big2str_power_cache[base - 2][i] =
i == 0 ? rb_big_pow(rb_int2big(base), INT2FIX(KARATSUBA_BIG2STR_DIGITS))
: bigsq(power_cache_get_power0(base, i - 1));
rb_gc_register_mark_object(big2str_power_cache[base - 2][i]);
}
return big2str_power_cache[base - 2][i];
}
static VALUE
power_cache_get_power(int base, int power_level, size_t *numdigits_ret)
{
VALUE power;
power = power_cache_get_power0(base, power_level);
/*
* MAX_BIG2STR_TABLE_ENTRIES is big enough to that
* big2str_power_cache[base][MAX_BIG2STR_TABLE_ENTRIES-1] fills whole memory.
* So MAX_BIG2STR_TABLE_ENTRIES <= power_level is not possible to calculate.
*
* number-of-bytes =
* log256(big2str_power_cache[base][MAX_BIG2STR_TABLE_ENTRIES-1]) =
* log256(maxpow_in_bdigit_dbl(base)**(2**(MAX_BIG2STR_TABLE_ENTRIES-1))) =
* log256(maxpow_in_bdigit_dbl(base)**(2**(SIZEOF_SIZE_T*CHAR_BIT))) =
* (2**(SIZEOF_SIZE_T*CHAR_BIT))*log256(maxpow_in_bdigit_dbl(base)) =
* (256**SIZEOF_SIZE_T)*log256(maxpow_in_bdigit_dbl(base)) >
* (256**SIZEOF_SIZE_T)*(sizeof(BDIGIT_DBL)-1) >
* 256**SIZEOF_SIZE_T
*/
if (MAX_BIG2STR_TABLE_ENTRIES <= power_level)
rb_bug("too big power number requested: maxpow_in_bdigit_dbl(%d)**(2**%d)", base, power_level);
if (NIL_P(big2str_power_cache[base - 2][power_level])) {
VALUE power;
size_t numdigits;
if (power_level == 0) {
int numdigits0;
BDIGIT_DBL dd = maxpow_in_bdigit_dbl(base, &numdigits0);
power = bignew(2, 1);
BDIGITS(power)[0] = BIGLO(dd);
BDIGITS(power)[1] = (BDIGIT)BIGDN(dd);
numdigits = numdigits0;
}
else {
power = bigsq(power_cache_get_power(base, power_level - 1, &numdigits));
numdigits *= 2;
}
big2str_power_cache[base - 2][power_level] = power;
big2str_numdigits_cache[base - 2][power_level] = numdigits;
rb_gc_register_mark_object(power);
}
if (numdigits_ret)
*numdigits_ret = KARATSUBA_BIG2STR_DIGITS * ((size_t)1 << power_level);
return power;
*numdigits_ret = big2str_numdigits_cache[base - 2][power_level];
return big2str_power_cache[base - 2][power_level];
}
/* big2str_muraken_find_n1
@ -4345,18 +4351,18 @@ rb_big2str1(VALUE x, int base, int trim)
ptr[0] = RBIGNUM_SIGN(x) ? '+' : '-';
power_level = 0;
power = power_cache_get_power0(base, power_level);
power = power_cache_get_power(base, power_level, NULL);
while (power_level < MAX_BIG2STR_TABLE_ENTRIES &&
RBIGNUM_LEN(power) <= (RBIGNUM_LEN(x)+1)/2) {
power_level++;
power = power_cache_get_power0(base, power_level);
power = power_cache_get_power(base, power_level, NULL);
}
assert(power_level != MAX_BIG2STR_TABLE_ENTRIES);
if (FIX2LONG(bary_cmp(BDIGITS(x), RBIGNUM_LEN(x), BDIGITS(power), RBIGNUM_LEN(power))) < 0) {
power_level--;
#ifndef NDEBUG
if (0 <= power_level) {
VALUE power0 = power_cache_get_power0(base, power_level);
VALUE power0 = power_cache_get_power(base, power_level, NULL);
assert(FIX2LONG(bary_cmp(BDIGITS(x), RBIGNUM_LEN(x), BDIGITS(power0), RBIGNUM_LEN(power0))) >= 0);
}
#endif