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ruby--ruby/bignum.c
卜部昌平 aa44b29030 suppress uninitialized variable warnings
Starting GCC 7, warnings about uninitialized variables are issued around
them.  Such warnings could be false positives (all versions of clang do
not warn), but adding initializers there could never be bad things.
2020-03-04 12:30:42 +09:00

7214 lines
182 KiB
C

/**********************************************************************
bignum.c -
$Author$
created at: Fri Jun 10 00:48:55 JST 1994
Copyright (C) 1993-2007 Yukihiro Matsumoto
**********************************************************************/
#include "ruby/config.h"
#include <ctype.h>
#include <float.h>
#include <math.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#ifdef HAVE_IEEEFP_H
# include <ieeefp.h>
#endif
#if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
# define USE_GMP
# include <gmp.h>
#endif
#include "id.h"
#include "internal.h"
#include "internal/bignum.h"
#include "internal/complex.h"
#include "internal/gc.h"
#include "internal/numeric.h"
#include "internal/object.h"
#include "internal/sanitizers.h"
#include "internal/util.h"
#include "internal/variable.h"
#include "internal/warnings.h"
#include "ruby/thread.h"
#include "ruby/util.h"
#include "ruby_assert.h"
#define RB_BIGNUM_TYPE_P(x) RB_TYPE_P((x), T_BIGNUM)
#ifndef RUBY_INTEGER_UNIFICATION
VALUE rb_cBignum;
#endif
const char ruby_digitmap[] = "0123456789abcdefghijklmnopqrstuvwxyz";
#ifndef SIZEOF_BDIGIT_DBL
# if SIZEOF_INT*2 <= SIZEOF_LONG_LONG
# define SIZEOF_BDIGIT_DBL SIZEOF_LONG_LONG
# else
# define SIZEOF_BDIGIT_DBL SIZEOF_LONG
# endif
#endif
STATIC_ASSERT(sizeof_bdigit_dbl, sizeof(BDIGIT_DBL) == SIZEOF_BDIGIT_DBL);
STATIC_ASSERT(sizeof_bdigit_dbl_signed, sizeof(BDIGIT_DBL_SIGNED) == SIZEOF_BDIGIT_DBL);
STATIC_ASSERT(sizeof_bdigit, SIZEOF_BDIGIT <= sizeof(BDIGIT));
STATIC_ASSERT(sizeof_bdigit_and_dbl, SIZEOF_BDIGIT*2 <= SIZEOF_BDIGIT_DBL);
STATIC_ASSERT(bdigit_signedness, 0 < (BDIGIT)-1);
STATIC_ASSERT(bdigit_dbl_signedness, 0 < (BDIGIT_DBL)-1);
STATIC_ASSERT(bdigit_dbl_signed_signedness, 0 > (BDIGIT_DBL_SIGNED)-1);
STATIC_ASSERT(rbignum_embed_len_max, BIGNUM_EMBED_LEN_MAX <= (BIGNUM_EMBED_LEN_MASK >> BIGNUM_EMBED_LEN_SHIFT));
#if SIZEOF_BDIGIT < SIZEOF_LONG
STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_LONG % SIZEOF_BDIGIT == 0);
#else
STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_BDIGIT % SIZEOF_LONG == 0);
#endif
#ifdef WORDS_BIGENDIAN
# define HOST_BIGENDIAN_P 1
#else
# define HOST_BIGENDIAN_P 0
#endif
/* (!LSHIFTABLE(d, n) ? 0 : (n)) is same as n but suppress a warning, C4293, by Visual Studio. */
#define LSHIFTABLE(d, n) ((n) < sizeof(d) * CHAR_BIT)
#define LSHIFTX(d, n) (!LSHIFTABLE(d, n) ? 0 : ((d) << (!LSHIFTABLE(d, n) ? 0 : (n))))
#define CLEAR_LOWBITS(d, numbits) ((d) & LSHIFTX(~((d)*0), (numbits)))
#define FILL_LOWBITS(d, numbits) ((d) | (LSHIFTX(((d)*0+1), (numbits))-1))
#define POW2_P(x) (((x)&((x)-1))==0)
#define BDIGITS(x) (BIGNUM_DIGITS(x))
#define BITSPERDIG (SIZEOF_BDIGIT*CHAR_BIT)
#define BIGRAD ((BDIGIT_DBL)1 << BITSPERDIG)
#define BIGRAD_HALF ((BDIGIT)(BIGRAD >> 1))
#define BDIGIT_MSB(d) (((d) & BIGRAD_HALF) != 0)
#define BIGUP(x) LSHIFTX(((x) + (BDIGIT_DBL)0), BITSPERDIG)
#define BIGDN(x) RSHIFT((x),BITSPERDIG)
#define BIGLO(x) ((BDIGIT)((x) & BDIGMAX))
#define BDIGMAX ((BDIGIT)(BIGRAD-1))
#define BDIGIT_DBL_MAX (~(BDIGIT_DBL)0)
#if SIZEOF_BDIGIT == 2
# define swap_bdigit(x) swap16(x)
#elif SIZEOF_BDIGIT == 4
# define swap_bdigit(x) swap32(x)
#elif SIZEOF_BDIGIT == 8
# define swap_bdigit(x) swap64(x)
#endif
#define BIGZEROP(x) (BIGNUM_LEN(x) == 0 || \
(BDIGITS(x)[0] == 0 && \
(BIGNUM_LEN(x) == 1 || bigzero_p(x))))
#define BIGSIZE(x) (BIGNUM_LEN(x) == 0 ? (size_t)0 : \
BDIGITS(x)[BIGNUM_LEN(x)-1] ? \
(size_t)(BIGNUM_LEN(x)*SIZEOF_BDIGIT - nlz(BDIGITS(x)[BIGNUM_LEN(x)-1])/CHAR_BIT) : \
rb_absint_size(x, NULL))
#define BIGDIVREM_EXTRA_WORDS 1
#define bdigit_roomof(n) roomof(n, SIZEOF_BDIGIT)
#define BARY_ARGS(ary) ary, numberof(ary)
#define BARY_ADD(z, x, y) bary_add(BARY_ARGS(z), BARY_ARGS(x), BARY_ARGS(y))
#define BARY_SUB(z, x, y) bary_sub(BARY_ARGS(z), BARY_ARGS(x), BARY_ARGS(y))
#define BARY_SHORT_MUL(z, x, y) bary_short_mul(BARY_ARGS(z), BARY_ARGS(x), BARY_ARGS(y))
#define BARY_DIVMOD(q, r, x, y) bary_divmod(BARY_ARGS(q), BARY_ARGS(r), BARY_ARGS(x), BARY_ARGS(y))
#define BARY_ZERO_P(x) bary_zero_p(BARY_ARGS(x))
#define BIGNUM_SET_NEGATIVE_SIGN(b) BIGNUM_SET_SIGN(b, 0)
#define BIGNUM_SET_POSITIVE_SIGN(b) BIGNUM_SET_SIGN(b, 1)
#define bignew(len,sign) bignew_1(rb_cInteger,(len),(sign))
#define BDIGITS_ZERO(ptr, n) do { \
BDIGIT *bdigitz_zero_ptr = (ptr); \
size_t bdigitz_zero_n = (n); \
while (bdigitz_zero_n) { \
*bdigitz_zero_ptr++ = 0; \
bdigitz_zero_n--; \
} \
} 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))
#define GMP_MUL_DIGITS 20
#define KARATSUBA_MUL_DIGITS 70
#define TOOM3_MUL_DIGITS 150
#define GMP_DIV_DIGITS 20
#define GMP_BIG2STR_DIGITS 20
#define GMP_STR2BIG_DIGITS 20
#ifdef USE_GMP
# define NAIVE_MUL_DIGITS GMP_MUL_DIGITS
#else
# define NAIVE_MUL_DIGITS KARATSUBA_MUL_DIGITS
#endif
typedef void (mulfunc_t)(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn);
static mulfunc_t bary_mul_toom3_start;
static mulfunc_t bary_mul_karatsuba_start;
static BDIGIT bigdivrem_single(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT y);
static void bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn);
static VALUE bigmul0(VALUE x, VALUE y);
static void bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn);
static VALUE bignew_1(VALUE klass, size_t len, int sign);
static inline VALUE bigtrunc(VALUE x);
static VALUE bigsq(VALUE x);
static void bigdivmod(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp);
static inline VALUE power_cache_get_power(int base, int power_level, size_t *numdigits_ret);
#if SIZEOF_BDIGIT <= SIZEOF_INT
static int nlz(BDIGIT x) { return nlz_int((unsigned int)x) - (SIZEOF_INT-SIZEOF_BDIGIT) * CHAR_BIT; }
#elif SIZEOF_BDIGIT <= SIZEOF_LONG
static int nlz(BDIGIT x) { return nlz_long((unsigned long)x) - (SIZEOF_LONG-SIZEOF_BDIGIT) * CHAR_BIT; }
#elif SIZEOF_BDIGIT <= SIZEOF_LONG_LONG
static int nlz(BDIGIT x) { return nlz_long_long((unsigned LONG_LONG)x) - (SIZEOF_LONG_LONG-SIZEOF_BDIGIT) * CHAR_BIT; }
#elif SIZEOF_BDIGIT <= SIZEOF_INT128_T
static int nlz(BDIGIT x) { return nlz_int128((uint128_t)x) - (SIZEOF_INT128_T-SIZEOF_BDIGIT) * CHAR_BIT; }
#endif
#define U16(a) ((uint16_t)(a))
#define U32(a) ((uint32_t)(a))
#ifdef HAVE_UINT64_T
#define U64(a,b) (((uint64_t)(a) << 32) | (b))
#endif
#ifdef HAVE_UINT128_T
#define U128(a,b,c,d) (((uint128_t)U64(a,b) << 64) | U64(c,d))
#endif
/* The following script, maxpow.rb, generates the tables follows.
def big(n, bits)
ns = []
((bits+31)/32).times {
ns << sprintf("0x%08x", n & 0xffff_ffff)
n >>= 32
}
"U#{bits}(" + ns.reverse.join(",") + ")"
end
def values(ary, width, indent)
lines = [""]
ary.each {|e|
lines << "" if !ary.last.empty? && width < (lines.last + e + ", ").length
lines.last << e + ", "
}
lines.map {|line| " " * indent + line.chomp(" ") + "\n" }.join
end
[16,32,64,128].each {|bits|
max = 2**bits-1
exps = []
nums = []
2.upto(36) {|base|
exp = 0
n = 1
while n * base <= max
exp += 1
n *= base
end
exps << exp.to_s
nums << big(n, bits)
}
puts "#ifdef HAVE_UINT#{bits}_T"
puts "static const int maxpow#{bits}_exp[35] = {"
print values(exps, 70, 4)
puts "};"
puts "static const uint#{bits}_t maxpow#{bits}_num[35] = {"
print values(nums, 70, 4)
puts "};"
puts "#endif"
}
*/
#if SIZEOF_BDIGIT_DBL == 2
static const int maxpow16_exp[35] = {
15, 10, 7, 6, 6, 5, 5, 5, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
};
static const uint16_t maxpow16_num[35] = {
U16(0x00008000), U16(0x0000e6a9), U16(0x00004000), U16(0x00003d09),
U16(0x0000b640), U16(0x000041a7), U16(0x00008000), U16(0x0000e6a9),
U16(0x00002710), U16(0x00003931), U16(0x00005100), U16(0x00006f91),
U16(0x00009610), U16(0x0000c5c1), U16(0x00001000), U16(0x00001331),
U16(0x000016c8), U16(0x00001acb), U16(0x00001f40), U16(0x0000242d),
U16(0x00002998), U16(0x00002f87), U16(0x00003600), U16(0x00003d09),
U16(0x000044a8), U16(0x00004ce3), U16(0x000055c0), U16(0x00005f45),
U16(0x00006978), U16(0x0000745f), U16(0x00008000), U16(0x00008c61),
U16(0x00009988), U16(0x0000a77b), U16(0x0000b640),
};
#elif SIZEOF_BDIGIT_DBL == 4
static const int maxpow32_exp[35] = {
31, 20, 15, 13, 12, 11, 10, 10, 9, 9, 8, 8, 8, 8, 7, 7, 7, 7, 7, 7,
7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
};
static const uint32_t maxpow32_num[35] = {
U32(0x80000000), U32(0xcfd41b91), U32(0x40000000), U32(0x48c27395),
U32(0x81bf1000), U32(0x75db9c97), U32(0x40000000), U32(0xcfd41b91),
U32(0x3b9aca00), U32(0x8c8b6d2b), U32(0x19a10000), U32(0x309f1021),
U32(0x57f6c100), U32(0x98c29b81), U32(0x10000000), U32(0x18754571),
U32(0x247dbc80), U32(0x3547667b), U32(0x4c4b4000), U32(0x6b5a6e1d),
U32(0x94ace180), U32(0xcaf18367), U32(0x0b640000), U32(0x0e8d4a51),
U32(0x1269ae40), U32(0x17179149), U32(0x1cb91000), U32(0x23744899),
U32(0x2b73a840), U32(0x34e63b41), U32(0x40000000), U32(0x4cfa3cc1),
U32(0x5c13d840), U32(0x6d91b519), U32(0x81bf1000),
};
#elif SIZEOF_BDIGIT_DBL == 8 && defined HAVE_UINT64_T
static const int maxpow64_exp[35] = {
63, 40, 31, 27, 24, 22, 21, 20, 19, 18, 17, 17, 16, 16, 15, 15, 15,
15, 14, 14, 14, 14, 13, 13, 13, 13, 13, 13, 13, 12, 12, 12, 12, 12,
12,
};
static const uint64_t maxpow64_num[35] = {
U64(0x80000000,0x00000000), U64(0xa8b8b452,0x291fe821),
U64(0x40000000,0x00000000), U64(0x6765c793,0xfa10079d),
U64(0x41c21cb8,0xe1000000), U64(0x36427987,0x50226111),
U64(0x80000000,0x00000000), U64(0xa8b8b452,0x291fe821),
U64(0x8ac72304,0x89e80000), U64(0x4d28cb56,0xc33fa539),
U64(0x1eca170c,0x00000000), U64(0x780c7372,0x621bd74d),
U64(0x1e39a505,0x7d810000), U64(0x5b27ac99,0x3df97701),
U64(0x10000000,0x00000000), U64(0x27b95e99,0x7e21d9f1),
U64(0x5da0e1e5,0x3c5c8000), U64(0xd2ae3299,0xc1c4aedb),
U64(0x16bcc41e,0x90000000), U64(0x2d04b7fd,0xd9c0ef49),
U64(0x5658597b,0xcaa24000), U64(0xa0e20737,0x37609371),
U64(0x0c29e980,0x00000000), U64(0x14adf4b7,0x320334b9),
U64(0x226ed364,0x78bfa000), U64(0x383d9170,0xb85ff80b),
U64(0x5a3c23e3,0x9c000000), U64(0x8e651373,0x88122bcd),
U64(0xdd41bb36,0xd259e000), U64(0x0aee5720,0xee830681),
U64(0x10000000,0x00000000), U64(0x172588ad,0x4f5f0981),
U64(0x211e44f7,0xd02c1000), U64(0x2ee56725,0xf06e5c71),
U64(0x41c21cb8,0xe1000000),
};
#elif SIZEOF_BDIGIT_DBL == 16 && defined HAVE_UINT128_T
static const int maxpow128_exp[35] = {
127, 80, 63, 55, 49, 45, 42, 40, 38, 37, 35, 34, 33, 32, 31, 31, 30,
30, 29, 29, 28, 28, 27, 27, 27, 26, 26, 26, 26, 25, 25, 25, 25, 24,
24,
};
static const uint128_t maxpow128_num[35] = {
U128(0x80000000,0x00000000,0x00000000,0x00000000),
U128(0x6f32f1ef,0x8b18a2bc,0x3cea5978,0x9c79d441),
U128(0x40000000,0x00000000,0x00000000,0x00000000),
U128(0xd0cf4b50,0xcfe20765,0xfff4b4e3,0xf741cf6d),
U128(0x6558e2a0,0x921fe069,0x42860000,0x00000000),
U128(0x5080c7b7,0xd0e31ba7,0x5911a67d,0xdd3d35e7),
U128(0x40000000,0x00000000,0x00000000,0x00000000),
U128(0x6f32f1ef,0x8b18a2bc,0x3cea5978,0x9c79d441),
U128(0x4b3b4ca8,0x5a86c47a,0x098a2240,0x00000000),
U128(0xffd1390a,0x0adc2fb8,0xdabbb817,0x4d95c99b),
U128(0x2c6fdb36,0x4c25e6c0,0x00000000,0x00000000),
U128(0x384bacd6,0x42c343b4,0xe90c4272,0x13506d29),
U128(0x31f5db32,0xa34aced6,0x0bf13a0e,0x00000000),
U128(0x20753ada,0xfd1e839f,0x53686d01,0x3143ee01),
U128(0x10000000,0x00000000,0x00000000,0x00000000),
U128(0x68ca11d6,0xb4f6d1d1,0xfaa82667,0x8073c2f1),
U128(0x223e493b,0xb3bb69ff,0xa4b87d6c,0x40000000),
U128(0xad62418d,0x14ea8247,0x01c4b488,0x6cc66f59),
U128(0x2863c1f5,0xcdae42f9,0x54000000,0x00000000),
U128(0xa63fd833,0xb9386b07,0x36039e82,0xbe651b25),
U128(0x1d1f7a9c,0xd087a14d,0x28cdf3d5,0x10000000),
U128(0x651b5095,0xc2ea8fc1,0xb30e2c57,0x77aaf7e1),
U128(0x0ddef20e,0xff760000,0x00000000,0x00000000),
U128(0x29c30f10,0x29939b14,0x6664242d,0x97d9f649),
U128(0x786a435a,0xe9558b0e,0x6aaf6d63,0xa8000000),
U128(0x0c5afe6f,0xf302bcbf,0x94fd9829,0xd87f5079),
U128(0x1fce575c,0xe1692706,0x07100000,0x00000000),
U128(0x4f34497c,0x8597e144,0x36e91802,0x00528229),
U128(0xbf3a8e1d,0x41ef2170,0x7802130d,0x84000000),
U128(0x0e7819e1,0x7f1eb0fb,0x6ee4fb89,0x01d9531f),
U128(0x20000000,0x00000000,0x00000000,0x00000000),
U128(0x4510460d,0xd9e879c0,0x14a82375,0x2f22b321),
U128(0x91abce3c,0x4b4117ad,0xe76d35db,0x22000000),
U128(0x08973ea3,0x55d75bc2,0x2e42c391,0x727d69e1),
U128(0x10e425c5,0x6daffabc,0x35c10000,0x00000000),
};
#endif
static BDIGIT_DBL
maxpow_in_bdigit_dbl(int base, int *exp_ret)
{
BDIGIT_DBL maxpow;
int exponent;
assert(2 <= base && base <= 36);
{
#if SIZEOF_BDIGIT_DBL == 2
maxpow = maxpow16_num[base-2];
exponent = maxpow16_exp[base-2];
#elif SIZEOF_BDIGIT_DBL == 4
maxpow = maxpow32_num[base-2];
exponent = maxpow32_exp[base-2];
#elif SIZEOF_BDIGIT_DBL == 8 && defined HAVE_UINT64_T
maxpow = maxpow64_num[base-2];
exponent = maxpow64_exp[base-2];
#elif SIZEOF_BDIGIT_DBL == 16 && defined HAVE_UINT128_T
maxpow = maxpow128_num[base-2];
exponent = maxpow128_exp[base-2];
#else
maxpow = base;
exponent = 1;
while (maxpow <= BDIGIT_DBL_MAX / base) {
maxpow *= base;
exponent++;
}
#endif
}
*exp_ret = exponent;
return maxpow;
}
static inline BDIGIT_DBL
bary2bdigitdbl(const BDIGIT *ds, size_t n)
{
assert(n <= 2);
if (n == 2)
return ds[0] | BIGUP(ds[1]);
if (n == 1)
return ds[0];
return 0;
}
static inline void
bdigitdbl2bary(BDIGIT *ds, size_t n, BDIGIT_DBL num)
{
assert(n == 2);
ds[0] = BIGLO(num);
ds[1] = (BDIGIT)BIGDN(num);
}
static int
bary_cmp(const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
size_t i;
BARY_TRUNC(xds, xn);
BARY_TRUNC(yds, yn);
if (xn < yn)
return -1;
if (xn > yn)
return 1;
for (i = 0; i < xn; i++)
if (xds[xn - i - 1] != yds[yn - i - 1])
break;
if (i == xn)
return 0;
return xds[xn - i - 1] < yds[yn - i - 1] ? -1 : 1;
}
static BDIGIT
bary_small_lshift(BDIGIT *zds, const BDIGIT *xds, size_t n, int shift)
{
size_t i;
BDIGIT_DBL num = 0;
assert(0 <= shift && shift < BITSPERDIG);
for (i=0; i<n; i++) {
num = num | (BDIGIT_DBL)*xds++ << shift;
*zds++ = BIGLO(num);
num = BIGDN(num);
}
return BIGLO(num);
}
static void
bary_small_rshift(BDIGIT *zds, const BDIGIT *xds, size_t n, int shift, BDIGIT higher_bdigit)
{
size_t i;
BDIGIT_DBL num = 0;
assert(0 <= shift && shift < BITSPERDIG);
num = BIGUP(higher_bdigit);
for (i = 0; i < n; i++) {
BDIGIT x = xds[n - i - 1];
num = (num | x) >> shift;
zds[n - i - 1] = BIGLO(num);
num = BIGUP(x);
}
}
static int
bary_zero_p(const BDIGIT *xds, size_t xn)
{
if (xn == 0)
return 1;
do {
if (xds[--xn]) return 0;
} while (xn);
return 1;
}
static void
bary_neg(BDIGIT *ds, size_t n)
{
size_t i;
for (i = 0; i < n; i++)
ds[n - i - 1] = BIGLO(~ds[n - i - 1]);
}
static int
bary_2comp(BDIGIT *ds, size_t n)
{
size_t i;
i = 0;
for (i = 0; i < n; i++) {
if (ds[i] != 0) {
goto non_zero;
}
}
return 1;
non_zero:
ds[i] = BIGLO(~ds[i] + 1);
i++;
for (; i < n; i++) {
ds[i] = BIGLO(~ds[i]);
}
return 0;
}
static void
bary_swap(BDIGIT *ds, size_t num_bdigits)
{
BDIGIT *p1 = ds;
BDIGIT *p2 = ds + num_bdigits - 1;
for (; p1 < p2; p1++, p2--) {
BDIGIT tmp = *p1;
*p1 = *p2;
*p2 = tmp;
}
}
#define INTEGER_PACK_WORDORDER_MASK \
(INTEGER_PACK_MSWORD_FIRST | \
INTEGER_PACK_LSWORD_FIRST)
#define INTEGER_PACK_BYTEORDER_MASK \
(INTEGER_PACK_MSBYTE_FIRST | \
INTEGER_PACK_LSBYTE_FIRST | \
INTEGER_PACK_NATIVE_BYTE_ORDER)
static void
validate_integer_pack_format(size_t numwords, size_t wordsize, size_t nails, int flags, int supported_flags)
{
int wordorder_bits = flags & INTEGER_PACK_WORDORDER_MASK;
int byteorder_bits = flags & INTEGER_PACK_BYTEORDER_MASK;
if (flags & ~supported_flags) {
rb_raise(rb_eArgError, "unsupported flags specified");
}
if (wordorder_bits == 0) {
if (1 < numwords)
rb_raise(rb_eArgError, "word order not specified");
}
else if (wordorder_bits != INTEGER_PACK_MSWORD_FIRST &&
wordorder_bits != INTEGER_PACK_LSWORD_FIRST)
rb_raise(rb_eArgError, "unexpected word order");
if (byteorder_bits == 0) {
rb_raise(rb_eArgError, "byte order not specified");
}
else if (byteorder_bits != INTEGER_PACK_MSBYTE_FIRST &&
byteorder_bits != INTEGER_PACK_LSBYTE_FIRST &&
byteorder_bits != INTEGER_PACK_NATIVE_BYTE_ORDER)
rb_raise(rb_eArgError, "unexpected byte order");
if (wordsize == 0)
rb_raise(rb_eArgError, "invalid wordsize: %"PRI_SIZE_PREFIX"u", wordsize);
if (SSIZE_MAX < wordsize)
rb_raise(rb_eArgError, "too big wordsize: %"PRI_SIZE_PREFIX"u", wordsize);
if (wordsize <= nails / CHAR_BIT)
rb_raise(rb_eArgError, "too big nails: %"PRI_SIZE_PREFIX"u", nails);
if (SIZE_MAX / wordsize < numwords)
rb_raise(rb_eArgError, "too big numwords * wordsize: %"PRI_SIZE_PREFIX"u * %"PRI_SIZE_PREFIX"u", numwords, wordsize);
}
static void
integer_pack_loop_setup(
size_t numwords, size_t wordsize, size_t nails, int flags,
size_t *word_num_fullbytes_ret,
int *word_num_partialbits_ret,
size_t *word_start_ret,
ssize_t *word_step_ret,
size_t *word_last_ret,
size_t *byte_start_ret,
int *byte_step_ret)
{
int wordorder_bits = flags & INTEGER_PACK_WORDORDER_MASK;
int byteorder_bits = flags & INTEGER_PACK_BYTEORDER_MASK;
size_t word_num_fullbytes;
int word_num_partialbits;
size_t word_start;
ssize_t word_step;
size_t word_last;
size_t byte_start;
int byte_step;
word_num_partialbits = CHAR_BIT - (int)(nails % CHAR_BIT);
if (word_num_partialbits == CHAR_BIT)
word_num_partialbits = 0;
word_num_fullbytes = wordsize - (nails / CHAR_BIT);
if (word_num_partialbits != 0) {
word_num_fullbytes--;
}
if (wordorder_bits == INTEGER_PACK_MSWORD_FIRST) {
word_start = wordsize*(numwords-1);
word_step = -(ssize_t)wordsize;
word_last = 0;
}
else {
word_start = 0;
word_step = wordsize;
word_last = wordsize*(numwords-1);
}
if (byteorder_bits == INTEGER_PACK_NATIVE_BYTE_ORDER) {
#ifdef WORDS_BIGENDIAN
byteorder_bits = INTEGER_PACK_MSBYTE_FIRST;
#else
byteorder_bits = INTEGER_PACK_LSBYTE_FIRST;
#endif
}
if (byteorder_bits == INTEGER_PACK_MSBYTE_FIRST) {
byte_start = wordsize-1;
byte_step = -1;
}
else {
byte_start = 0;
byte_step = 1;
}
*word_num_partialbits_ret = word_num_partialbits;
*word_num_fullbytes_ret = word_num_fullbytes;
*word_start_ret = word_start;
*word_step_ret = word_step;
*word_last_ret = word_last;
*byte_start_ret = byte_start;
*byte_step_ret = byte_step;
}
static inline void
integer_pack_fill_dd(BDIGIT **dpp, BDIGIT **dep, BDIGIT_DBL *ddp, int *numbits_in_dd_p)
{
if (*dpp < *dep && BITSPERDIG <= (int)sizeof(*ddp) * CHAR_BIT - *numbits_in_dd_p) {
*ddp |= (BDIGIT_DBL)(*(*dpp)++) << *numbits_in_dd_p;
*numbits_in_dd_p += BITSPERDIG;
}
else if (*dpp == *dep) {
/* higher bits are infinity zeros */
*numbits_in_dd_p = (int)sizeof(*ddp) * CHAR_BIT;
}
}
static inline BDIGIT_DBL
integer_pack_take_lowbits(int n, BDIGIT_DBL *ddp, int *numbits_in_dd_p)
{
BDIGIT_DBL ret;
ret = (*ddp) & (((BDIGIT_DBL)1 << n) - 1);
*ddp >>= n;
*numbits_in_dd_p -= n;
return ret;
}
#if !defined(WORDS_BIGENDIAN)
static int
bytes_2comp(unsigned char *buf, size_t len)
{
size_t i;
for (i = 0; i < len; i++) {
signed char c = buf[i];
signed int d = ~c;
unsigned int e = d & 0xFF;
buf[i] = e;
}
for (i = 0; i < len; i++) {
buf[i]++;
if (buf[i] != 0)
return 0;
}
return 1;
}
#endif
static int
bary_pack(int sign, BDIGIT *ds, size_t num_bdigits, void *words, size_t numwords, size_t wordsize, size_t nails, int flags)
{
BDIGIT *dp, *de;
unsigned char *buf, *bufend;
dp = ds;
de = ds + num_bdigits;
validate_integer_pack_format(numwords, wordsize, nails, flags,
INTEGER_PACK_MSWORD_FIRST|
INTEGER_PACK_LSWORD_FIRST|
INTEGER_PACK_MSBYTE_FIRST|
INTEGER_PACK_LSBYTE_FIRST|
INTEGER_PACK_NATIVE_BYTE_ORDER|
INTEGER_PACK_2COMP|
INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION);
while (dp < de && de[-1] == 0)
de--;
if (dp == de) {
sign = 0;
}
if (!(flags & INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION)) {
if (sign == 0) {
MEMZERO(words, unsigned char, numwords * wordsize);
return 0;
}
if (nails == 0 && numwords == 1) {
int need_swap = wordsize != 1 &&
(flags & INTEGER_PACK_BYTEORDER_MASK) != INTEGER_PACK_NATIVE_BYTE_ORDER &&
((flags & INTEGER_PACK_MSBYTE_FIRST) ? !HOST_BIGENDIAN_P : HOST_BIGENDIAN_P);
if (0 < sign || !(flags & INTEGER_PACK_2COMP)) {
BDIGIT d;
if (wordsize == 1) {
*((unsigned char *)words) = (unsigned char)(d = dp[0]);
return ((1 < de - dp || CLEAR_LOWBITS(d, 8) != 0) ? 2 : 1) * sign;
}
#if defined(HAVE_UINT16_T) && 2 <= SIZEOF_BDIGIT
if (wordsize == 2 && (uintptr_t)words % RUBY_ALIGNOF(uint16_t) == 0) {
uint16_t u = (uint16_t)(d = dp[0]);
if (need_swap) u = swap16(u);
*((uint16_t *)words) = u;
return ((1 < de - dp || CLEAR_LOWBITS(d, 16) != 0) ? 2 : 1) * sign;
}
#endif
#if defined(HAVE_UINT32_T) && 4 <= SIZEOF_BDIGIT
if (wordsize == 4 && (uintptr_t)words % RUBY_ALIGNOF(uint32_t) == 0) {
uint32_t u = (uint32_t)(d = dp[0]);
if (need_swap) u = swap32(u);
*((uint32_t *)words) = u;
return ((1 < de - dp || CLEAR_LOWBITS(d, 32) != 0) ? 2 : 1) * sign;
}
#endif
#if defined(HAVE_UINT64_T) && 8 <= SIZEOF_BDIGIT
if (wordsize == 8 && (uintptr_t)words % RUBY_ALIGNOF(uint64_t) == 0) {
uint64_t u = (uint64_t)(d = dp[0]);
if (need_swap) u = swap64(u);
*((uint64_t *)words) = u;
return ((1 < de - dp || CLEAR_LOWBITS(d, 64) != 0) ? 2 : 1) * sign;
}
#endif
}
else { /* sign < 0 && (flags & INTEGER_PACK_2COMP) */
BDIGIT_DBL_SIGNED d;
if (wordsize == 1) {
*((unsigned char *)words) = (unsigned char)(d = -(BDIGIT_DBL_SIGNED)dp[0]);
return (1 < de - dp || FILL_LOWBITS(d, 8) != -1) ? -2 : -1;
}
#if defined(HAVE_UINT16_T) && 2 <= SIZEOF_BDIGIT
if (wordsize == 2 && (uintptr_t)words % RUBY_ALIGNOF(uint16_t) == 0) {
uint16_t u = (uint16_t)(d = -(BDIGIT_DBL_SIGNED)dp[0]);
if (need_swap) u = swap16(u);
*((uint16_t *)words) = u;
return (wordsize == SIZEOF_BDIGIT && de - dp == 2 && dp[1] == 1 && dp[0] == 0) ? -1 :
(1 < de - dp || FILL_LOWBITS(d, 16) != -1) ? -2 : -1;
}
#endif
#if defined(HAVE_UINT32_T) && 4 <= SIZEOF_BDIGIT
if (wordsize == 4 && (uintptr_t)words % RUBY_ALIGNOF(uint32_t) == 0) {
uint32_t u = (uint32_t)(d = -(BDIGIT_DBL_SIGNED)dp[0]);
if (need_swap) u = swap32(u);
*((uint32_t *)words) = u;
return (wordsize == SIZEOF_BDIGIT && de - dp == 2 && dp[1] == 1 && dp[0] == 0) ? -1 :
(1 < de - dp || FILL_LOWBITS(d, 32) != -1) ? -2 : -1;
}
#endif
#if defined(HAVE_UINT64_T) && 8 <= SIZEOF_BDIGIT
if (wordsize == 8 && (uintptr_t)words % RUBY_ALIGNOF(uint64_t) == 0) {
uint64_t u = (uint64_t)(d = -(BDIGIT_DBL_SIGNED)dp[0]);
if (need_swap) u = swap64(u);
*((uint64_t *)words) = u;
return (wordsize == SIZEOF_BDIGIT && de - dp == 2 && dp[1] == 1 && dp[0] == 0) ? -1 :
(1 < de - dp || FILL_LOWBITS(d, 64) != -1) ? -2 : -1;
}
#endif
}
}
#if !defined(WORDS_BIGENDIAN)
if (nails == 0 && SIZEOF_BDIGIT == sizeof(BDIGIT) &&
(flags & INTEGER_PACK_WORDORDER_MASK) == INTEGER_PACK_LSWORD_FIRST &&
(flags & INTEGER_PACK_BYTEORDER_MASK) != INTEGER_PACK_MSBYTE_FIRST) {
size_t src_size = (de - dp) * SIZEOF_BDIGIT;
size_t dst_size = numwords * wordsize;
int overflow = 0;
while (0 < src_size && ((unsigned char *)ds)[src_size-1] == 0)
src_size--;
if (src_size <= dst_size) {
MEMCPY(words, dp, char, src_size);
MEMZERO((char*)words + src_size, char, dst_size - src_size);
}
else {
MEMCPY(words, dp, char, dst_size);
overflow = 1;
}
if (sign < 0 && (flags & INTEGER_PACK_2COMP)) {
int zero_p = bytes_2comp(words, dst_size);
if (zero_p && overflow) {
unsigned char *p = (unsigned char *)dp;
if (dst_size == src_size-1 &&
p[dst_size] == 1) {
overflow = 0;
}
}
}
if (overflow)
sign *= 2;
return sign;
}
#endif
if (nails == 0 && SIZEOF_BDIGIT == sizeof(BDIGIT) &&
wordsize % SIZEOF_BDIGIT == 0 && (uintptr_t)words % RUBY_ALIGNOF(BDIGIT) == 0) {
size_t bdigits_per_word = wordsize / SIZEOF_BDIGIT;
size_t src_num_bdigits = de - dp;
size_t dst_num_bdigits = numwords * bdigits_per_word;
int overflow = 0;
int mswordfirst_p = (flags & INTEGER_PACK_MSWORD_FIRST) != 0;
int msbytefirst_p = (flags & INTEGER_PACK_NATIVE_BYTE_ORDER) ? HOST_BIGENDIAN_P :
(flags & INTEGER_PACK_MSBYTE_FIRST) != 0;
if (src_num_bdigits <= dst_num_bdigits) {
MEMCPY(words, dp, BDIGIT, src_num_bdigits);
BDIGITS_ZERO((BDIGIT*)words + src_num_bdigits, dst_num_bdigits - src_num_bdigits);
}
else {
MEMCPY(words, dp, BDIGIT, dst_num_bdigits);
overflow = 1;
}
if (sign < 0 && (flags & INTEGER_PACK_2COMP)) {
int zero_p = bary_2comp(words, dst_num_bdigits);
if (zero_p && overflow &&
dst_num_bdigits == src_num_bdigits-1 &&
dp[dst_num_bdigits] == 1)
overflow = 0;
}
if (msbytefirst_p != HOST_BIGENDIAN_P) {
size_t i;
for (i = 0; i < dst_num_bdigits; i++) {
BDIGIT d = ((BDIGIT*)words)[i];
((BDIGIT*)words)[i] = swap_bdigit(d);
}
}
if (mswordfirst_p ? !msbytefirst_p : msbytefirst_p) {
size_t i;
BDIGIT *p = words;
for (i = 0; i < numwords; i++) {
bary_swap(p, bdigits_per_word);
p += bdigits_per_word;
}
}
if (mswordfirst_p) {
bary_swap(words, dst_num_bdigits);
}
if (overflow)
sign *= 2;
return sign;
}
}
buf = words;
bufend = buf + numwords * wordsize;
if (buf == bufend) {
/* overflow if non-zero*/
if (!(flags & INTEGER_PACK_2COMP) || 0 <= sign)
sign *= 2;
else {
if (de - dp == 1 && dp[0] == 1)
sign = -1; /* val == -1 == -2**(numwords*(wordsize*CHAR_BIT-nails)) */
else
sign = -2; /* val < -1 == -2**(numwords*(wordsize*CHAR_BIT-nails)) */
}
}
else if (dp == de) {
memset(buf, '\0', bufend - buf);
}
else if (dp < de && buf < bufend) {
int word_num_partialbits;
size_t word_num_fullbytes;
ssize_t word_step;
size_t byte_start;
int byte_step;
size_t word_start, word_last;
unsigned char *wordp, *last_wordp;
BDIGIT_DBL dd;
int numbits_in_dd;
integer_pack_loop_setup(numwords, wordsize, nails, flags,
&word_num_fullbytes, &word_num_partialbits,
&word_start, &word_step, &word_last, &byte_start, &byte_step);
wordp = buf + word_start;
last_wordp = buf + word_last;
dd = 0;
numbits_in_dd = 0;
#define FILL_DD \
integer_pack_fill_dd(&dp, &de, &dd, &numbits_in_dd)
#define TAKE_LOWBITS(n) \
integer_pack_take_lowbits(n, &dd, &numbits_in_dd)
while (1) {
size_t index_in_word = 0;
unsigned char *bytep = wordp + byte_start;
while (index_in_word < word_num_fullbytes) {
FILL_DD;
*bytep = TAKE_LOWBITS(CHAR_BIT);
bytep += byte_step;
index_in_word++;
}
if (word_num_partialbits) {
FILL_DD;
*bytep = TAKE_LOWBITS(word_num_partialbits);
bytep += byte_step;
index_in_word++;
}
while (index_in_word < wordsize) {
*bytep = 0;
bytep += byte_step;
index_in_word++;
}
if (wordp == last_wordp)
break;
wordp += word_step;
}
FILL_DD;
/* overflow tests */
if (dp != de || 1 < dd) {
/* 2**(numwords*(wordsize*CHAR_BIT-nails)+1) <= abs(val) */
sign *= 2;
}
else if (dd == 1) {
/* 2**(numwords*(wordsize*CHAR_BIT-nails)) <= abs(val) < 2**(numwords*(wordsize*CHAR_BIT-nails)+1) */
if (!(flags & INTEGER_PACK_2COMP) || 0 <= sign)
sign *= 2;
else { /* overflow_2comp && sign == -1 */
/* test lower bits are all zero. */
dp = ds;
while (dp < de && *dp == 0)
dp++;
if (de - dp == 1 && /* only one non-zero word. */
POW2_P(*dp)) /* *dp contains only one bit set. */
sign = -1; /* val == -2**(numwords*(wordsize*CHAR_BIT-nails)) */
else
sign = -2; /* val < -2**(numwords*(wordsize*CHAR_BIT-nails)) */
}
}
}
if ((flags & INTEGER_PACK_2COMP) && (sign < 0 && numwords != 0)) {
int word_num_partialbits;
size_t word_num_fullbytes;
ssize_t word_step;
size_t byte_start;
int byte_step;
size_t word_start, word_last;
unsigned char *wordp, *last_wordp;
unsigned int partialbits_mask;
int carry;
integer_pack_loop_setup(numwords, wordsize, nails, flags,
&word_num_fullbytes, &word_num_partialbits,
&word_start, &word_step, &word_last, &byte_start, &byte_step);
partialbits_mask = (1 << word_num_partialbits) - 1;
buf = words;
wordp = buf + word_start;
last_wordp = buf + word_last;
carry = 1;
while (1) {
size_t index_in_word = 0;
unsigned char *bytep = wordp + byte_start;
while (index_in_word < word_num_fullbytes) {
carry += (unsigned char)~*bytep;
*bytep = (unsigned char)carry;
carry >>= CHAR_BIT;
bytep += byte_step;
index_in_word++;
}
if (word_num_partialbits) {
carry += (*bytep & partialbits_mask) ^ partialbits_mask;
*bytep = carry & partialbits_mask;
carry >>= word_num_partialbits;
bytep += byte_step;
index_in_word++;
}
if (wordp == last_wordp)
break;
wordp += word_step;
}
}
return sign;
#undef FILL_DD
#undef TAKE_LOWBITS
}
static size_t
integer_unpack_num_bdigits_small(size_t numwords, size_t wordsize, size_t nails, int *nlp_bits_ret)
{
/* nlp_bits stands for number of leading padding bits */
size_t num_bits = (wordsize * CHAR_BIT - nails) * numwords;
size_t num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG;
*nlp_bits_ret = (int)(num_bdigits * BITSPERDIG - num_bits);
return num_bdigits;
}
static size_t
integer_unpack_num_bdigits_generic(size_t numwords, size_t wordsize, size_t nails, int *nlp_bits_ret)
{
/* BITSPERDIG = SIZEOF_BDIGIT * CHAR_BIT */
/* num_bits = (wordsize * CHAR_BIT - nails) * numwords */
/* num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG */
/* num_bits = CHAR_BIT * (wordsize * numwords) - nails * numwords = CHAR_BIT * num_bytes1 - nails * numwords */
size_t num_bytes1 = wordsize * numwords;
/* q1 * CHAR_BIT + r1 = numwords */
size_t q1 = numwords / CHAR_BIT;
size_t r1 = numwords % CHAR_BIT;
/* num_bits = CHAR_BIT * num_bytes1 - nails * (q1 * CHAR_BIT + r1) = CHAR_BIT * num_bytes2 - nails * r1 */
size_t num_bytes2 = num_bytes1 - nails * q1;
/* q2 * CHAR_BIT + r2 = nails */
size_t q2 = nails / CHAR_BIT;
size_t r2 = nails % CHAR_BIT;
/* num_bits = CHAR_BIT * num_bytes2 - (q2 * CHAR_BIT + r2) * r1 = CHAR_BIT * num_bytes3 - r1 * r2 */
size_t num_bytes3 = num_bytes2 - q2 * r1;
/* q3 * BITSPERDIG + r3 = num_bytes3 */
size_t q3 = num_bytes3 / BITSPERDIG;
size_t r3 = num_bytes3 % BITSPERDIG;
/* num_bits = CHAR_BIT * (q3 * BITSPERDIG + r3) - r1 * r2 = BITSPERDIG * num_digits1 + CHAR_BIT * r3 - r1 * r2 */
size_t num_digits1 = CHAR_BIT * q3;
/*
* if CHAR_BIT * r3 >= r1 * r2
* CHAR_BIT * r3 - r1 * r2 = CHAR_BIT * BITSPERDIG - (CHAR_BIT * BITSPERDIG - (CHAR_BIT * r3 - r1 * r2))
* q4 * BITSPERDIG + r4 = CHAR_BIT * BITSPERDIG - (CHAR_BIT * r3 - r1 * r2)
* num_bits = BITSPERDIG * num_digits1 + CHAR_BIT * BITSPERDIG - (q4 * BITSPERDIG + r4) = BITSPERDIG * num_digits2 - r4
* else
* q4 * BITSPERDIG + r4 = -(CHAR_BIT * r3 - r1 * r2)
* num_bits = BITSPERDIG * num_digits1 - (q4 * BITSPERDIG + r4) = BITSPERDIG * num_digits2 - r4
* end
*/
if (CHAR_BIT * r3 >= r1 * r2) {
size_t tmp1 = CHAR_BIT * BITSPERDIG - (CHAR_BIT * r3 - r1 * r2);
size_t q4 = tmp1 / BITSPERDIG;
int r4 = (int)(tmp1 % BITSPERDIG);
size_t num_digits2 = num_digits1 + CHAR_BIT - q4;
*nlp_bits_ret = r4;
return num_digits2;
}
else {
size_t tmp1 = r1 * r2 - CHAR_BIT * r3;
size_t q4 = tmp1 / BITSPERDIG;
int r4 = (int)(tmp1 % BITSPERDIG);
size_t num_digits2 = num_digits1 - q4;
*nlp_bits_ret = r4;
return num_digits2;
}
}
static size_t
integer_unpack_num_bdigits(size_t numwords, size_t wordsize, size_t nails, int *nlp_bits_ret)
{
size_t num_bdigits;
if (numwords <= (SIZE_MAX - (BITSPERDIG-1)) / CHAR_BIT / wordsize) {
num_bdigits = integer_unpack_num_bdigits_small(numwords, wordsize, nails, nlp_bits_ret);
#ifdef DEBUG_INTEGER_PACK
{
int nlp_bits1;
size_t num_bdigits1 = integer_unpack_num_bdigits_generic(numwords, wordsize, nails, &nlp_bits1);
assert(num_bdigits == num_bdigits1);
assert(*nlp_bits_ret == nlp_bits1);
}
#endif
}
else {
num_bdigits = integer_unpack_num_bdigits_generic(numwords, wordsize, nails, nlp_bits_ret);
}
return num_bdigits;
}
static inline void
integer_unpack_push_bits(int data, int numbits, BDIGIT_DBL *ddp, int *numbits_in_dd_p, BDIGIT **dpp)
{
(*ddp) |= ((BDIGIT_DBL)data) << (*numbits_in_dd_p);
*numbits_in_dd_p += numbits;
while (BITSPERDIG <= *numbits_in_dd_p) {
*(*dpp)++ = BIGLO(*ddp);
*ddp = BIGDN(*ddp);
*numbits_in_dd_p -= BITSPERDIG;
}
}
static int
integer_unpack_single_bdigit(BDIGIT u, size_t size, int flags, BDIGIT *dp)
{
int sign;
if (flags & INTEGER_PACK_2COMP) {
sign = (flags & INTEGER_PACK_NEGATIVE) ?
((size == SIZEOF_BDIGIT && u == 0) ? -2 : -1) :
((u >> (size * CHAR_BIT - 1)) ? -1 : 1);
if (sign < 0) {
u |= LSHIFTX(BDIGMAX, size * CHAR_BIT);
u = BIGLO(1 + ~u);
}
}
else
sign = (flags & INTEGER_PACK_NEGATIVE) ? -1 : 1;
*dp = u;
return sign;
}
#ifdef HAVE_BUILTIN___BUILTIN_ASSUME_ALIGNED
#define reinterpret_cast(type, value) (type) \
__builtin_assume_aligned((value), sizeof(*(type)NULL));
#else
#define reinterpret_cast(type, value) (type)value
#endif
static int
bary_unpack_internal(BDIGIT *bdigits, size_t num_bdigits, const void *words, size_t numwords, size_t wordsize, size_t nails, int flags, int nlp_bits)
{
int sign;
const unsigned char *buf = words;
BDIGIT *dp;
BDIGIT *de;
dp = bdigits;
de = dp + num_bdigits;
if (!(flags & INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION)) {
if (nails == 0 && numwords == 1) {
int need_swap = wordsize != 1 &&
(flags & INTEGER_PACK_BYTEORDER_MASK) != INTEGER_PACK_NATIVE_BYTE_ORDER &&
((flags & INTEGER_PACK_MSBYTE_FIRST) ? !HOST_BIGENDIAN_P : HOST_BIGENDIAN_P);
if (wordsize == 1) {
return integer_unpack_single_bdigit(*(uint8_t *)buf, sizeof(uint8_t), flags, dp);
}
#if defined(HAVE_UINT16_T) && 2 <= SIZEOF_BDIGIT
if (wordsize == 2 && (uintptr_t)words % RUBY_ALIGNOF(uint16_t) == 0) {
uint16_t u = *reinterpret_cast(const uint16_t *, buf);
return integer_unpack_single_bdigit(need_swap ? swap16(u) : u, sizeof(uint16_t), flags, dp);
}
#endif
#if defined(HAVE_UINT32_T) && 4 <= SIZEOF_BDIGIT
if (wordsize == 4 && (uintptr_t)words % RUBY_ALIGNOF(uint32_t) == 0) {
uint32_t u = *reinterpret_cast(const uint32_t *, buf);
return integer_unpack_single_bdigit(need_swap ? swap32(u) : u, sizeof(uint32_t), flags, dp);
}
#endif
#if defined(HAVE_UINT64_T) && 8 <= SIZEOF_BDIGIT
if (wordsize == 8 && (uintptr_t)words % RUBY_ALIGNOF(uint64_t) == 0) {
uint64_t u = *reinterpret_cast(const uint64_t *, buf);
return integer_unpack_single_bdigit(need_swap ? swap64(u) : u, sizeof(uint64_t), flags, dp);
}
#endif
#undef reinterpret_cast
}
#if !defined(WORDS_BIGENDIAN)
if (nails == 0 && SIZEOF_BDIGIT == sizeof(BDIGIT) &&
(flags & INTEGER_PACK_WORDORDER_MASK) == INTEGER_PACK_LSWORD_FIRST &&
(flags & INTEGER_PACK_BYTEORDER_MASK) != INTEGER_PACK_MSBYTE_FIRST) {
size_t src_size = numwords * wordsize;
size_t dst_size = num_bdigits * SIZEOF_BDIGIT;
MEMCPY(dp, words, char, src_size);
if (flags & INTEGER_PACK_2COMP) {
if (flags & INTEGER_PACK_NEGATIVE) {
int zero_p;
memset((char*)dp + src_size, 0xff, dst_size - src_size);
zero_p = bary_2comp(dp, num_bdigits);
sign = zero_p ? -2 : -1;
}
else if (buf[src_size-1] >> (CHAR_BIT-1)) {
memset((char*)dp + src_size, 0xff, dst_size - src_size);
bary_2comp(dp, num_bdigits);
sign = -1;
}
else {
MEMZERO((char*)dp + src_size, char, dst_size - src_size);
sign = 1;
}
}
else {
MEMZERO((char*)dp + src_size, char, dst_size - src_size);
sign = (flags & INTEGER_PACK_NEGATIVE) ? -1 : 1;
}
return sign;
}
#endif
if (nails == 0 && SIZEOF_BDIGIT == sizeof(BDIGIT) &&
wordsize % SIZEOF_BDIGIT == 0) {
size_t bdigits_per_word = wordsize / SIZEOF_BDIGIT;
int mswordfirst_p = (flags & INTEGER_PACK_MSWORD_FIRST) != 0;
int msbytefirst_p = (flags & INTEGER_PACK_NATIVE_BYTE_ORDER) ? HOST_BIGENDIAN_P :
(flags & INTEGER_PACK_MSBYTE_FIRST) != 0;
MEMCPY(dp, words, BDIGIT, numwords*bdigits_per_word);
if (mswordfirst_p) {
bary_swap(dp, num_bdigits);
}
if (mswordfirst_p ? !msbytefirst_p : msbytefirst_p) {
size_t i;
BDIGIT *p = dp;
for (i = 0; i < numwords; i++) {
bary_swap(p, bdigits_per_word);
p += bdigits_per_word;
}
}
if (msbytefirst_p != HOST_BIGENDIAN_P) {
BDIGIT *p;
for (p = dp; p < de; p++) {
BDIGIT d = *p;
*p = swap_bdigit(d);
}
}
if (flags & INTEGER_PACK_2COMP) {
if (flags & INTEGER_PACK_NEGATIVE) {
int zero_p = bary_2comp(dp, num_bdigits);
sign = zero_p ? -2 : -1;
}
else if (BDIGIT_MSB(de[-1])) {
bary_2comp(dp, num_bdigits);
sign = -1;
}
else {
sign = 1;
}
}
else {
sign = (flags & INTEGER_PACK_NEGATIVE) ? -1 : 1;
}
return sign;
}
}
if (num_bdigits != 0) {
int word_num_partialbits;
size_t word_num_fullbytes;
ssize_t word_step;
size_t byte_start;
int byte_step;
size_t word_start, word_last;
const unsigned char *wordp, *last_wordp;
BDIGIT_DBL dd;
int numbits_in_dd;
integer_pack_loop_setup(numwords, wordsize, nails, flags,
&word_num_fullbytes, &word_num_partialbits,
&word_start, &word_step, &word_last, &byte_start, &byte_step);
wordp = buf + word_start;
last_wordp = buf + word_last;
dd = 0;
numbits_in_dd = 0;
#define PUSH_BITS(data, numbits) \
integer_unpack_push_bits(data, numbits, &dd, &numbits_in_dd, &dp)
while (1) {
size_t index_in_word = 0;
const unsigned char *bytep = wordp + byte_start;
while (index_in_word < word_num_fullbytes) {
PUSH_BITS(*bytep, CHAR_BIT);
bytep += byte_step;
index_in_word++;
}
if (word_num_partialbits) {
PUSH_BITS(*bytep & ((1 << word_num_partialbits) - 1), word_num_partialbits);
bytep += byte_step;
index_in_word++;
}
if (wordp == last_wordp)
break;
wordp += word_step;
}
if (dd)
*dp++ = (BDIGIT)dd;
assert(dp <= de);
while (dp < de)
*dp++ = 0;
#undef PUSH_BITS
}
if (!(flags & INTEGER_PACK_2COMP)) {
sign = (flags & INTEGER_PACK_NEGATIVE) ? -1 : 1;
}
else {
if (nlp_bits) {
if ((flags & INTEGER_PACK_NEGATIVE) ||
(bdigits[num_bdigits-1] >> (BITSPERDIG - nlp_bits - 1))) {
bdigits[num_bdigits-1] |= BIGLO(BDIGMAX << (BITSPERDIG - nlp_bits));
sign = -1;
}
else {
sign = 1;
}
}
else {
if (flags & INTEGER_PACK_NEGATIVE) {
sign = bary_zero_p(bdigits, num_bdigits) ? -2 : -1;
}
else {
if (num_bdigits != 0 && BDIGIT_MSB(bdigits[num_bdigits-1]))
sign = -1;
else
sign = 1;
}
}
if (sign == -1 && num_bdigits != 0) {
bary_2comp(bdigits, num_bdigits);
}
}
return sign;
}
static void
bary_unpack(BDIGIT *bdigits, size_t num_bdigits, const void *words, size_t numwords, size_t wordsize, size_t nails, int flags)
{
size_t num_bdigits0;
int nlp_bits;
int sign;
validate_integer_pack_format(numwords, wordsize, nails, flags,
INTEGER_PACK_MSWORD_FIRST|
INTEGER_PACK_LSWORD_FIRST|
INTEGER_PACK_MSBYTE_FIRST|
INTEGER_PACK_LSBYTE_FIRST|
INTEGER_PACK_NATIVE_BYTE_ORDER|
INTEGER_PACK_2COMP|
INTEGER_PACK_FORCE_BIGNUM|
INTEGER_PACK_NEGATIVE|
INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION);
num_bdigits0 = integer_unpack_num_bdigits(numwords, wordsize, nails, &nlp_bits);
assert(num_bdigits0 <= num_bdigits);
sign = bary_unpack_internal(bdigits, num_bdigits0, words, numwords, wordsize, nails, flags, nlp_bits);
if (num_bdigits0 < num_bdigits) {
BDIGITS_ZERO(bdigits + num_bdigits0, num_bdigits - num_bdigits0);
if (sign == -2) {
bdigits[num_bdigits0] = 1;
}
}
}
static int
bary_subb(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, int borrow)
{
BDIGIT_DBL_SIGNED num;
size_t i;
size_t sn;
assert(xn <= zn);
assert(yn <= zn);
sn = xn < yn ? xn : yn;
num = borrow ? -1 : 0;
for (i = 0; i < sn; i++) {
num += (BDIGIT_DBL_SIGNED)xds[i] - yds[i];
zds[i] = BIGLO(num);
num = BIGDN(num);
}
if (yn <= xn) {
for (; i < xn; i++) {
if (num == 0) goto num_is_zero;
num += xds[i];
zds[i] = BIGLO(num);
num = BIGDN(num);
}
}
else {
for (; i < yn; i++) {
num -= yds[i];
zds[i] = BIGLO(num);
num = BIGDN(num);
}
}
if (num == 0) goto num_is_zero;
for (; i < zn; i++) {
zds[i] = BDIGMAX;
}
return 1;
num_is_zero:
if (xds == zds && xn == zn)
return 0;
for (; i < xn; i++) {
zds[i] = xds[i];
}
for (; i < zn; i++) {
zds[i] = 0;
}
return 0;
}
static int
bary_sub(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
return bary_subb(zds, zn, xds, xn, yds, yn, 0);
}
static int
bary_sub_one(BDIGIT *zds, size_t zn)
{
return bary_subb(zds, zn, zds, zn, NULL, 0, 1);
}
static int
bary_addc(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, int carry)
{
BDIGIT_DBL num;
size_t i;
assert(xn <= zn);
assert(yn <= zn);
if (xn > yn) {
const BDIGIT *tds;
tds = xds; xds = yds; yds = tds;
i = xn; xn = yn; yn = i;
}
num = carry ? 1 : 0;
for (i = 0; i < xn; i++) {
num += (BDIGIT_DBL)xds[i] + yds[i];
zds[i] = BIGLO(num);
num = BIGDN(num);
}
for (; i < yn; i++) {
if (num == 0) goto num_is_zero;
num += yds[i];
zds[i] = BIGLO(num);
num = BIGDN(num);
}
for (; i < zn; i++) {
if (num == 0) goto num_is_zero;
zds[i] = BIGLO(num);
num = BIGDN(num);
}
return num != 0;
num_is_zero:
if (yds == zds && yn == zn)
return 0;
for (; i < yn; i++) {
zds[i] = yds[i];
}
for (; i < zn; i++) {
zds[i] = 0;
}
return 0;
}
static int
bary_add(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
return bary_addc(zds, zn, xds, xn, yds, yn, 0);
}
static int
bary_add_one(BDIGIT *ds, size_t n)
{
size_t i;
for (i = 0; i < n; i++) {
BDIGIT_DBL n = ds[i];
n += 1;
ds[i] = BIGLO(n);
if (ds[i] != 0)
return 0;
}
return 1;
}
static void
bary_mul_single(BDIGIT *zds, size_t zn, BDIGIT x, BDIGIT y)
{
BDIGIT_DBL n;
assert(2 <= zn);
n = (BDIGIT_DBL)x * y;
bdigitdbl2bary(zds, 2, n);
BDIGITS_ZERO(zds + 2, zn - 2);
}
static int
bary_muladd_1xN(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
{
BDIGIT_DBL n;
BDIGIT_DBL dd;
size_t j;
assert(zn > yn);
if (x == 0)
return 0;
dd = x;
n = 0;
for (j = 0; j < yn; j++) {
BDIGIT_DBL ee = n + dd * yds[j];
if (ee) {
n = zds[j] + ee;
zds[j] = BIGLO(n);
n = BIGDN(n);
}
else {
n = 0;
}
}
for (; j < zn; j++) {
if (n == 0)
break;
n += zds[j];
zds[j] = BIGLO(n);
n = BIGDN(n);
}
return n != 0;
}
static BDIGIT_DBL_SIGNED
bigdivrem_mulsub(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
{
size_t i;
BDIGIT_DBL t2;
BDIGIT_DBL_SIGNED num;
assert(zn == yn + 1);
num = 0;
t2 = 0;
i = 0;
do {
BDIGIT_DBL_SIGNED ee;
t2 += (BDIGIT_DBL)yds[i] * x;
ee = num - BIGLO(t2);
num = (BDIGIT_DBL_SIGNED)zds[i] + ee;
if (ee) zds[i] = BIGLO(num);
num = BIGDN(num);
t2 = BIGDN(t2);
} while (++i < yn);
num -= (BDIGIT_DBL_SIGNED)t2;
num += (BDIGIT_DBL_SIGNED)zds[yn]; /* borrow from high digit; don't update */
return num;
}
static int
bary_mulsub_1xN(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
{
BDIGIT_DBL_SIGNED num;
assert(zn == yn + 1);
num = bigdivrem_mulsub(zds, zn, x, yds, yn);
zds[yn] = BIGLO(num);
if (BIGDN(num))
return 1;
return 0;
}
static void
bary_mul_normal(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
size_t i;
assert(xn + yn <= zn);
BDIGITS_ZERO(zds, zn);
for (i = 0; i < xn; i++) {
bary_muladd_1xN(zds+i, zn-i, xds[i], yds, yn);
}
}
VALUE
rb_big_mul_normal(VALUE x, VALUE y)
{
size_t xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y), zn = xn + yn;
VALUE z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
bary_mul_normal(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return z;
}
/* efficient squaring (2 times faster than normal multiplication)
* ref: Handbook of Applied Cryptography, Algorithm 14.16
* http://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf
*/
static void
bary_sq_fast(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn)
{
size_t i, j;
BDIGIT_DBL c, v, w;
BDIGIT vl;
int vh;
assert(xn * 2 <= zn);
BDIGITS_ZERO(zds, zn);
if (xn == 0)
return;
for (i = 0; i < xn-1; i++) {
v = (BDIGIT_DBL)xds[i];
if (!v)
continue;
c = (BDIGIT_DBL)zds[i + i] + v * v;
zds[i + i] = BIGLO(c);
c = BIGDN(c);
v *= 2;
vl = BIGLO(v);
vh = (int)BIGDN(v);
for (j = i + 1; j < xn; j++) {
w = (BDIGIT_DBL)xds[j];
c += (BDIGIT_DBL)zds[i + j] + vl * w;
zds[i + j] = BIGLO(c);
c = BIGDN(c);
if (vh)
c += w;
}
if (c) {
c += (BDIGIT_DBL)zds[i + xn];
zds[i + xn] = BIGLO(c);
c = BIGDN(c);
if (c)
zds[i + xn + 1] += (BDIGIT)c;
}
}
/* i == xn-1 */
v = (BDIGIT_DBL)xds[i];
if (!v)
return;
c = (BDIGIT_DBL)zds[i + i] + v * v;
zds[i + i] = BIGLO(c);
c = BIGDN(c);
if (c) {
zds[i + xn] += BIGLO(c);
}
}
VALUE
rb_big_sq_fast(VALUE x)
{
size_t xn = BIGNUM_LEN(x), zn = 2 * xn;
VALUE z = bignew(zn, 1);
bary_sq_fast(BDIGITS(z), zn, BDIGITS(x), xn);
RB_GC_GUARD(x);
return z;
}
/* balancing multiplication by slicing larger argument */
static void
bary_mul_balance_with_mulfunc(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn, mulfunc_t *mulfunc)
{
VALUE work = 0;
size_t yn0 = yn;
size_t r, n;
assert(xn + yn <= zn);
assert(xn <= yn);
assert(!KARATSUBA_BALANCED(xn, yn) || !TOOM3_BALANCED(xn, yn));
BDIGITS_ZERO(zds, xn);
n = 0;
while (yn > 0) {
BDIGIT *tds;
size_t tn;
r = xn > yn ? yn : xn;
tn = xn + r;
if (2 * (xn + r) <= zn - n) {
tds = zds + n + xn + r;
mulfunc(tds, tn, xds, xn, yds + n, r, wds, wn);
BDIGITS_ZERO(zds + n + xn, r);
bary_add(zds + n, tn,
zds + n, tn,
tds, tn);
}
else {
if (wn < xn) {
wn = xn;
wds = ALLOCV_N(BDIGIT, work, wn);
}
tds = zds + n;
MEMCPY(wds, zds + n, BDIGIT, xn);
mulfunc(tds, tn, xds, xn, yds + n, r, wds+xn, wn-xn);
bary_add(zds + n, tn,
zds + n, tn,
wds, xn);
}
yn -= r;
n += r;
}
BDIGITS_ZERO(zds+xn+yn0, zn - (xn+yn0));
if (work)
ALLOCV_END(work);
}
VALUE
rb_big_mul_balance(VALUE x, VALUE y)
{
size_t xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y), zn = xn + yn;
VALUE z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
bary_mul_balance_with_mulfunc(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, NULL, 0, bary_mul_toom3_start);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return z;
}
/* multiplication by karatsuba method */
static void
bary_mul_karatsuba(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn)
{
VALUE work = 0;
size_t n;
int sub_p, borrow, carry1, carry2, carry3;
int odd_y = 0;
int odd_xy = 0;
int sq;
const BDIGIT *xds0, *xds1, *yds0, *yds1;
BDIGIT *zds0, *zds1, *zds2, *zds3;
assert(xn + yn <= zn);
assert(xn <= yn);
assert(yn < 2 * xn);
sq = xds == yds && xn == yn;
if (yn & 1) {
odd_y = 1;
yn--;
if (yn < xn) {
odd_xy = 1;
xn--;
}
}
n = yn / 2;
assert(n < xn);
if (wn < 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.
*/
wn = 2*n;
wds = ALLOCV_N(BDIGIT, work, wn);
}
/* Karatsuba algorithm:
*
* x = x0 + r*x1
* y = y0 + r*y1
* z = x*y
* = (x0 + r*x1) * (y0 + r*y1)
* = x0*y0 + r*(x1*y0 + x0*y1) + r*r*x1*y1
* = x0*y0 + r*(x0*y0 + x1*y1 - (x1-x0)*(y1-y0)) + r*r*x1*y1
* = x0*y0 + r*(x0*y0 + x1*y1 - (x0-x1)*(y0-y1)) + r*r*x1*y1
*/
xds0 = xds;
xds1 = xds + n;
yds0 = yds;
yds1 = yds + n;
zds0 = zds;
zds1 = zds + n;
zds2 = zds + 2*n;
zds3 = zds + 3*n;
sub_p = 1;
/* zds0:? zds1:? zds2:? zds3:? wds:? */
if (bary_sub(zds0, n, xds, n, xds+n, xn-n)) {
bary_2comp(zds0, n);
sub_p = !sub_p;
}
/* zds0:|x1-x0| zds1:? zds2:? zds3:? wds:? */
if (sq) {
sub_p = 1;
bary_mul_karatsuba_start(zds1, 2*n, zds0, n, zds0, n, wds, wn);
}
else {
if (bary_sub(wds, n, yds, n, yds+n, n)) {
bary_2comp(wds, n);
sub_p = !sub_p;
}
/* zds0:|x1-x0| zds1:? zds2:? zds3:? wds:|y1-y0| */
bary_mul_karatsuba_start(zds1, 2*n, zds0, n, wds, n, wds+n, wn-n);
}
/* zds0:|x1-x0| zds1,zds2:|x1-x0|*|y1-y0| zds3:? wds:|y1-y0| */
borrow = 0;
if (sub_p) {
borrow = !bary_2comp(zds1, 2*n);
}
/* zds0:|x1-x0| zds1,zds2:-?|x1-x0|*|y1-y0| zds3:? wds:|y1-y0| */
MEMCPY(wds, zds1, BDIGIT, n);
/* zds0:|x1-x0| zds1,zds2:-?|x1-x0|*|y1-y0| zds3:? wds:lo(-?|x1-x0|*|y1-y0|) */
bary_mul_karatsuba_start(zds0, 2*n, xds0, n, yds0, n, wds+n, wn-n);
/* zds0,zds1:x0*y0 zds2:hi(-?|x1-x0|*|y1-y0|) zds3:? wds:lo(-?|x1-x0|*|y1-y0|) */
carry1 = bary_add(wds, n, wds, n, zds0, n);
carry1 = bary_addc(zds2, n, zds2, n, zds1, n, carry1);
/* zds0,zds1:x0*y0 zds2:hi(x0*y0-?|x1-x0|*|y1-y0|) zds3:? wds:lo(x0*y0-?|x1-x0|*|y1-y0|) */
carry2 = bary_add(zds1, n, zds1, n, wds, n);
/* zds0:lo(x0*y0) zds1:hi(x0*y0)+lo(x0*y0-?|x1-x0|*|y1-y0|) zds2:hi(x0*y0-?|x1-x0|*|y1-y0|) zds3:? wds:lo(x0*y0-?|x1-x0|*|y1-y0|) */
MEMCPY(wds, zds2, BDIGIT, n);
/* 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_karatsuba_start(zds2, zn-2*n, xds1, xn-n, yds1, n, wds+n, wn-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|) */
carry3 = bary_add(zds1, n, zds1, n, zds2, n);
/* zds0:lo(x0*y0) zds1:hi(x0*y0)+lo(x0*y0-?|x1-x0|*|y1-y0|)+lo(x1*y1) zds2,zds3:x1*y1 wds:hi(x0*y0-?|x1-x0|*|y1-y0|) */
carry3 = bary_addc(zds2, n, zds2, n, zds3, (4*n < zn ? n : zn-3*n), carry3);
/* zds0:lo(x0*y0) zds1:hi(x0*y0)+lo(x0*y0-?|x1-x0|*|y1-y0|)+lo(x1*y1) zds2,zds3:x1*y1+hi(x1*y1) wds:hi(x0*y0-?|x1-x0|*|y1-y0|) */
bary_add(zds2, zn-2*n, zds2, zn-2*n, wds, n);
/* zds0:lo(x0*y0) zds1:hi(x0*y0)+lo(x0*y0-?|x1-x0|*|y1-y0|)+lo(x1*y1) zds2,zds3:x1*y1+hi(x1*y1)+hi(x0*y0-?|x1-x0|*|y1-y0|) wds:_ */
if (carry2)
bary_add_one(zds2, zn-2*n);
if (carry1 + carry3 - borrow < 0)
bary_sub_one(zds3, zn-3*n);
else if (carry1 + carry3 - borrow > 0) {
BDIGIT c = carry1 + carry3 - borrow;
bary_add(zds3, zn-3*n, zds3, zn-3*n, &c, 1);
}
/*
if (SIZEOF_BDIGIT * zn <= 16) {
uint128_t z, x, y;
ssize_t i;
for (x = 0, i = xn-1; 0 <= i; i--) { x <<= SIZEOF_BDIGIT*CHAR_BIT; x |= xds[i]; }
for (y = 0, i = yn-1; 0 <= i; i--) { y <<= SIZEOF_BDIGIT*CHAR_BIT; y |= yds[i]; }
for (z = 0, i = zn-1; 0 <= i; i--) { z <<= SIZEOF_BDIGIT*CHAR_BIT; z |= zds[i]; }
assert(z == x * y);
}
*/
if (odd_xy) {
bary_muladd_1xN(zds+yn, zn-yn, yds[yn], xds, xn);
bary_muladd_1xN(zds+xn, zn-xn, xds[xn], yds, yn+1);
}
else if (odd_y) {
bary_muladd_1xN(zds+yn, zn-yn, yds[yn], xds, xn);
}
if (work)
ALLOCV_END(work);
}
VALUE
rb_big_mul_karatsuba(VALUE x, VALUE y)
{
size_t xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y), zn = xn + yn;
VALUE z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
if (!((xn <= yn && yn < 2) || KARATSUBA_BALANCED(xn, yn)))
rb_raise(rb_eArgError, "unexpected bignum length for karatsuba");
bary_mul_karatsuba(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, NULL, 0);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return z;
}
static void
bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn)
{
size_t n;
size_t wnc;
VALUE work = 0;
/* "p" stands for "positive". Actually it means "non-negative", though. */
size_t x0n; const BDIGIT *x0ds;
size_t x1n; const BDIGIT *x1ds;
size_t x2n; const BDIGIT *x2ds;
size_t y0n; const BDIGIT *y0ds;
size_t y1n; const BDIGIT *y1ds;
size_t y2n; const BDIGIT *y2ds;
size_t u1n; BDIGIT *u1ds; int u1p;
size_t u2n; BDIGIT *u2ds; int u2p;
size_t u3n; BDIGIT *u3ds; int u3p;
size_t v1n; BDIGIT *v1ds; int v1p;
size_t v2n; BDIGIT *v2ds; int v2p;
size_t v3n; BDIGIT *v3ds; int v3p;
size_t t0n; BDIGIT *t0ds; int t0p;
size_t t1n; BDIGIT *t1ds; int t1p;
size_t t2n; BDIGIT *t2ds; int t2p;
size_t t3n; BDIGIT *t3ds; int t3p;
size_t t4n; BDIGIT *t4ds; int t4p;
size_t z0n; BDIGIT *z0ds;
size_t z1n; BDIGIT *z1ds; int z1p;
size_t z2n; BDIGIT *z2ds; int z2p;
size_t z3n; BDIGIT *z3ds; int z3p;
size_t z4n; BDIGIT *z4ds;
size_t zzn; BDIGIT *zzds;
int sq = xds == yds && xn == yn;
assert(xn <= yn); /* assume y >= x */
assert(xn + yn <= zn);
n = (yn + 2) / 3;
assert(2*n < xn);
wnc = 0;
wnc += (u1n = n+1); /* BITSPERDIG*n+2 bits */
wnc += (u2n = n+1); /* BITSPERDIG*n+1 bits */
wnc += (u3n = n+1); /* BITSPERDIG*n+3 bits */
wnc += (v1n = n+1); /* BITSPERDIG*n+2 bits */
wnc += (v2n = n+1); /* BITSPERDIG*n+1 bits */
wnc += (v3n = n+1); /* BITSPERDIG*n+3 bits */
wnc += (t0n = 2*n); /* BITSPERDIG*2*n bits */
wnc += (t1n = 2*n+2); /* BITSPERDIG*2*n+4 bits but bary_mul needs u1n+v1n */
wnc += (t2n = 2*n+2); /* BITSPERDIG*2*n+2 bits but bary_mul needs u2n+v2n */
wnc += (t3n = 2*n+2); /* BITSPERDIG*2*n+6 bits but bary_mul needs u3n+v3n */
wnc += (t4n = 2*n); /* BITSPERDIG*2*n bits */
wnc += (z1n = 2*n+1); /* BITSPERDIG*2*n+5 bits */
wnc += (z2n = 2*n+1); /* BITSPERDIG*2*n+6 bits */
wnc += (z3n = 2*n+1); /* BITSPERDIG*2*n+8 bits */
if (wn < wnc) {
wn = wnc * 3 / 2; /* Allocate working memory for whole recursion at once. */
wds = ALLOCV_N(BDIGIT, work, wn);
}
u1ds = wds; wds += u1n;
u2ds = wds; wds += u2n;
u3ds = wds; wds += u3n;
v1ds = wds; wds += v1n;
v2ds = wds; wds += v2n;
v3ds = wds; wds += v3n;
t0ds = wds; wds += t0n;
t1ds = wds; wds += t1n;
t2ds = wds; wds += t2n;
t3ds = wds; wds += t3n;
t4ds = wds; wds += t4n;
z1ds = wds; wds += z1n;
z2ds = wds; wds += z2n;
z3ds = wds; wds += z3n;
wn -= wnc;
zzds = u1ds;
zzn = 6*n+1;
x0n = n;
x1n = n;
x2n = xn - 2*n;
x0ds = xds;
x1ds = xds + n;
x2ds = xds + 2*n;
if (sq) {
y0n = x0n;
y1n = x1n;
y2n = x2n;
y0ds = x0ds;
y1ds = x1ds;
y2ds = x2ds;
}
else {
y0n = n;
y1n = n;
y2n = yn - 2*n;
y0ds = yds;
y1ds = yds + n;
y2ds = yds + 2*n;
}
/*
* ref. http://en.wikipedia.org/wiki/Toom%E2%80%93Cook_multiplication
*
* x(b) = x0 * b^0 + x1 * b^1 + x2 * b^2
* y(b) = y0 * b^0 + y1 * b^1 + y2 * b^2
*
* z(b) = x(b) * y(b)
* z(b) = z0 * b^0 + z1 * b^1 + z2 * b^2 + z3 * b^3 + z4 * b^4
* where:
* z0 = x0 * y0
* z1 = x0 * y1 + x1 * y0
* z2 = x0 * y2 + x1 * y1 + x2 * y0
* z3 = x1 * y2 + x2 * y1
* z4 = x2 * y2
*
* Toom3 method (a.k.a. Toom-Cook method):
* (Step1) calculating 5 points z(b0), z(b1), z(b2), z(b3), z(b4),
* where:
* b0 = 0, b1 = 1, b2 = -1, b3 = -2, b4 = inf,
* z(0) = x(0) * y(0) = x0 * y0
* z(1) = x(1) * y(1) = (x0 + x1 + x2) * (y0 + y1 + y2)
* z(-1) = x(-1) * y(-1) = (x0 - x1 + x2) * (y0 - y1 + y2)
* z(-2) = x(-2) * y(-2) = (x0 - 2 * (x1 - 2 * x2)) * (y0 - 2 * (y1 - 2 * y2))
* z(inf) = x(inf) * y(inf) = x2 * y2
*
* (Step2) interpolating z0, z1, z2, z3 and z4.
*
* (Step3) Substituting base value into b of the polynomial z(b),
*/
/*
* [Step1] calculating 5 points z(b0), z(b1), z(b2), z(b3), z(b4)
*/
/* u1 <- x0 + x2 */
bary_add(u1ds, u1n, x0ds, x0n, x2ds, x2n);
u1p = 1;
/* x(-1) : u2 <- u1 - x1 = x0 - x1 + x2 */
if (bary_sub(u2ds, u2n, u1ds, u1n, x1ds, x1n)) {
bary_2comp(u2ds, u2n);
u2p = 0;
}
else {
u2p = 1;
}
/* x(1) : u1 <- u1 + x1 = x0 + x1 + x2 */
bary_add(u1ds, u1n, u1ds, u1n, x1ds, x1n);
/* x(-2) : u3 <- 2 * (u2 + x2) - x0 = x0 - 2 * (x1 - 2 * x2) */
u3p = 1;
if (u2p) {
bary_add(u3ds, u3n, u2ds, u2n, x2ds, x2n);
}
else if (bary_sub(u3ds, u3n, x2ds, x2n, u2ds, u2n)) {
bary_2comp(u3ds, u3n);
u3p = 0;
}
bary_small_lshift(u3ds, u3ds, u3n, 1);
if (!u3p) {
bary_add(u3ds, u3n, u3ds, u3n, x0ds, x0n);
}
else if (bary_sub(u3ds, u3n, u3ds, u3n, x0ds, x0n)) {
bary_2comp(u3ds, u3n);
u3p = 0;
}
if (sq) {
v1n = u1n; v1ds = u1ds; v1p = u1p;
v2n = u2n; v2ds = u2ds; v2p = u2p;
v3n = u3n; v3ds = u3ds; v3p = u3p;
}
else {
/* v1 <- y0 + y2 */
bary_add(v1ds, v1n, y0ds, y0n, y2ds, y2n);
v1p = 1;
/* y(-1) : v2 <- v1 - y1 = y0 - y1 + y2 */
v2p = 1;
if (bary_sub(v2ds, v2n, v1ds, v1n, y1ds, y1n)) {
bary_2comp(v2ds, v2n);
v2p = 0;
}
/* y(1) : v1 <- v1 + y1 = y0 + y1 + y2 */
bary_add(v1ds, v1n, v1ds, v1n, y1ds, y1n);
/* y(-2) : v3 <- 2 * (v2 + y2) - y0 = y0 - 2 * (y1 - 2 * y2) */
v3p = 1;
if (v2p) {
bary_add(v3ds, v3n, v2ds, v2n, y2ds, y2n);
}
else if (bary_sub(v3ds, v3n, y2ds, y2n, v2ds, v2n)) {
bary_2comp(v3ds, v3n);
v3p = 0;
}
bary_small_lshift(v3ds, v3ds, v3n, 1);
if (!v3p) {
bary_add(v3ds, v3n, v3ds, v3n, y0ds, y0n);
}
else if (bary_sub(v3ds, v3n, v3ds, v3n, y0ds, y0n)) {
bary_2comp(v3ds, v3n);
v3p = 0;
}
}
/* z(0) : t0 <- x0 * y0 */
bary_mul_toom3_start(t0ds, t0n, x0ds, x0n, y0ds, y0n, wds, wn);
t0p = 1;
/* z(1) : t1 <- u1 * v1 */
bary_mul_toom3_start(t1ds, t1n, u1ds, u1n, v1ds, v1n, wds, wn);
t1p = u1p == v1p;
assert(t1ds[t1n-1] == 0);
t1n--;
/* z(-1) : t2 <- u2 * v2 */
bary_mul_toom3_start(t2ds, t2n, u2ds, u2n, v2ds, v2n, wds, wn);
t2p = u2p == v2p;
assert(t2ds[t2n-1] == 0);
t2n--;
/* z(-2) : t3 <- u3 * v3 */
bary_mul_toom3_start(t3ds, t3n, u3ds, u3n, v3ds, v3n, wds, wn);
t3p = u3p == v3p;
assert(t3ds[t3n-1] == 0);
t3n--;
/* z(inf) : t4 <- x2 * y2 */
bary_mul_toom3_start(t4ds, t4n, x2ds, x2n, y2ds, y2n, wds, wn);
t4p = 1;
/*
* [Step2] interpolating z0, z1, z2, z3 and z4.
*/
/* z0 <- z(0) == t0 */
z0n = t0n; z0ds = t0ds;
/* z4 <- z(inf) == t4 */
z4n = t4n; z4ds = t4ds;
/* z3 <- (z(-2) - z(1)) / 3 == (t3 - t1) / 3 */
if (t3p == t1p) {
z3p = t3p;
if (bary_sub(z3ds, z3n, t3ds, t3n, t1ds, t1n)) {
bary_2comp(z3ds, z3n);
z3p = !z3p;
}
}
else {
z3p = t3p;
bary_add(z3ds, z3n, t3ds, t3n, t1ds, t1n);
}
bigdivrem_single(z3ds, z3ds, z3n, 3);
/* z1 <- (z(1) - z(-1)) / 2 == (t1 - t2) / 2 */
if (t1p == t2p) {
z1p = t1p;
if (bary_sub(z1ds, z1n, t1ds, t1n, t2ds, t2n)) {
bary_2comp(z1ds, z1n);
z1p = !z1p;
}
}
else {
z1p = t1p;
bary_add(z1ds, z1n, t1ds, t1n, t2ds, t2n);
}
bary_small_rshift(z1ds, z1ds, z1n, 1, 0);
/* z2 <- z(-1) - z(0) == t2 - t0 */
if (t2p == t0p) {
z2p = t2p;
if (bary_sub(z2ds, z2n, t2ds, t2n, t0ds, t0n)) {
bary_2comp(z2ds, z2n);
z2p = !z2p;
}
}
else {
z2p = t2p;
bary_add(z2ds, z2n, t2ds, t2n, t0ds, t0n);
}
/* z3 <- (z2 - z3) / 2 + 2 * z(inf) == (z2 - z3) / 2 + 2 * t4 */
if (z2p == z3p) {
z3p = z2p;
if (bary_sub(z3ds, z3n, z2ds, z2n, z3ds, z3n)) {
bary_2comp(z3ds, z3n);
z3p = !z3p;
}
}
else {
z3p = z2p;
bary_add(z3ds, z3n, z2ds, z2n, z3ds, z3n);
}
bary_small_rshift(z3ds, z3ds, z3n, 1, 0);
if (z3p == t4p) {
bary_muladd_1xN(z3ds, z3n, 2, t4ds, t4n);
}
else {
if (bary_mulsub_1xN(z3ds, z3n, 2, t4ds, t4n)) {
bary_2comp(z3ds, z3n);
z3p = !z3p;
}
}
/* z2 <- z2 + z1 - z(inf) == z2 + z1 - t4 */
if (z2p == z1p) {
bary_add(z2ds, z2n, z2ds, z2n, z1ds, z1n);
}
else {
if (bary_sub(z2ds, z2n, z2ds, z2n, z1ds, z1n)) {
bary_2comp(z2ds, z2n);
z2p = !z2p;
}
}
if (z2p == t4p) {
if (bary_sub(z2ds, z2n, z2ds, z2n, t4ds, t4n)) {
bary_2comp(z2ds, z2n);
z2p = !z2p;
}
}
else {
bary_add(z2ds, z2n, z2ds, z2n, t4ds, t4n);
}
/* z1 <- z1 - z3 */
if (z1p == z3p) {
if (bary_sub(z1ds, z1n, z1ds, z1n, z3ds, z3n)) {
bary_2comp(z1ds, z1n);
z1p = !z1p;
}
}
else {
bary_add(z1ds, z1n, z1ds, z1n, z3ds, z3n);
}
/*
* [Step3] Substituting base value into b of the polynomial z(b),
*/
MEMCPY(zzds, z0ds, BDIGIT, z0n);
BDIGITS_ZERO(zzds + z0n, 4*n - z0n);
MEMCPY(zzds + 4*n, z4ds, BDIGIT, z4n);
BDIGITS_ZERO(zzds + 4*n + z4n, zzn - (4*n + z4n));
if (z1p)
bary_add(zzds + n, zzn - n, zzds + n, zzn - n, z1ds, z1n);
else
bary_sub(zzds + n, zzn - n, zzds + n, zzn - n, z1ds, z1n);
if (z2p)
bary_add(zzds + 2*n, zzn - 2*n, zzds + 2*n, zzn - 2*n, z2ds, z2n);
else
bary_sub(zzds + 2*n, zzn - 2*n, zzds + 2*n, zzn - 2*n, z2ds, z2n);
if (z3p)
bary_add(zzds + 3*n, zzn - 3*n, zzds + 3*n, zzn - 3*n, z3ds, z3n);
else
bary_sub(zzds + 3*n, zzn - 3*n, zzds + 3*n, zzn - 3*n, z3ds, z3n);
BARY_TRUNC(zzds, zzn);
MEMCPY(zds, zzds, BDIGIT, zzn);
BDIGITS_ZERO(zds + zzn, zn - zzn);
if (work)
ALLOCV_END(work);
}
VALUE
rb_big_mul_toom3(VALUE x, VALUE y)
{
size_t xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y), zn = xn + yn;
VALUE z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
if (xn > yn || yn < 3 || !TOOM3_BALANCED(xn,yn))
rb_raise(rb_eArgError, "unexpected bignum length for toom3");
bary_mul_toom3(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, NULL, 0);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return z;
}
#ifdef USE_GMP
static inline void
bdigits_to_mpz(mpz_t mp, const BDIGIT *digits, size_t len)
{
const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
mpz_import(mp, len, -1, sizeof(BDIGIT), 0, nails, digits);
}
static inline void
bdigits_from_mpz(mpz_t mp, BDIGIT *digits, size_t *len)
{
const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
mpz_export(digits, len, -1, sizeof(BDIGIT), 0, nails, mp);
}
static void
bary_mul_gmp(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
mpz_t x, y, z;
size_t count;
assert(xn + yn <= zn);
mpz_init(x);
mpz_init(y);
mpz_init(z);
bdigits_to_mpz(x, xds, xn);
if (xds == yds && xn == yn) {
mpz_mul(z, x, x);
}
else {
bdigits_to_mpz(y, yds, yn);
mpz_mul(z, x, y);
}
bdigits_from_mpz(z, zds, &count);
BDIGITS_ZERO(zds+count, zn-count);
mpz_clear(x);
mpz_clear(y);
mpz_clear(z);
}
VALUE
rb_big_mul_gmp(VALUE x, VALUE y)
{
size_t xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y), zn = xn + yn;
VALUE z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
bary_mul_gmp(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return z;
}
#endif
static void
bary_short_mul(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
assert(xn + yn <= zn);
if (xn == 1 && yn == 1) {
bary_mul_single(zds, zn, xds[0], yds[0]);
}
else {
bary_mul_normal(zds, zn, xds, xn, yds, yn);
rb_thread_check_ints();
}
}
/* determine whether a bignum is sparse or not by random sampling */
static inline int
bary_sparse_p(const BDIGIT *ds, size_t n)
{
long c = 0;
if ( ds[rb_genrand_ulong_limited(n / 2) + n / 4]) c++;
if (c <= 1 && ds[rb_genrand_ulong_limited(n / 2) + n / 4]) c++;
if (c <= 1 && ds[rb_genrand_ulong_limited(n / 2) + n / 4]) c++;
return (c <= 1) ? 1 : 0;
}
static int
bary_mul_precheck(BDIGIT **zdsp, size_t *znp, const BDIGIT **xdsp, size_t *xnp, const BDIGIT **ydsp, size_t *ynp)
{
size_t nlsz; /* number of least significant zero BDIGITs */
BDIGIT *zds = *zdsp;
size_t zn = *znp;
const BDIGIT *xds = *xdsp;
size_t xn = *xnp;
const BDIGIT *yds = *ydsp;
size_t yn = *ynp;
assert(xn + yn <= zn);
nlsz = 0;
while (0 < xn) {
if (xds[xn-1] == 0) {
xn--;
}
else {
do {
if (xds[0] != 0)
break;
xds++;
xn--;
nlsz++;
} while (0 < xn);
break;
}
}
while (0 < yn) {
if (yds[yn-1] == 0) {
yn--;
}
else {
do {
if (yds[0] != 0)
break;
yds++;
yn--;
nlsz++;
} while (0 < yn);
break;
}
}
if (nlsz) {
BDIGITS_ZERO(zds, nlsz);
zds += nlsz;
zn -= nlsz;
}
/* make sure that y is longer than x */
if (xn > yn) {
const BDIGIT *tds;
size_t tn;
tds = xds; xds = yds; yds = tds;
tn = xn; xn = yn; yn = tn;
}
assert(xn <= yn);
if (xn <= 1) {
if (xn == 0) {
BDIGITS_ZERO(zds, zn);
return 1;
}
if (xds[0] == 1) {
MEMCPY(zds, yds, BDIGIT, yn);
BDIGITS_ZERO(zds+yn, zn-yn);
return 1;
}
if (POW2_P(xds[0])) {
zds[yn] = bary_small_lshift(zds, yds, yn, bit_length(xds[0])-1);
BDIGITS_ZERO(zds+yn+1, zn-yn-1);
return 1;
}
if (yn == 1 && yds[0] == 1) {
zds[0] = xds[0];
BDIGITS_ZERO(zds+1, zn-1);
return 1;
}
bary_mul_normal(zds, zn, xds, xn, yds, yn);
return 1;
}
*zdsp = zds;
*znp = zn;
*xdsp = xds;
*xnp = xn;
*ydsp = yds;
*ynp = yn;
return 0;
}
static void
bary_mul_karatsuba_branch(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn)
{
/* normal multiplication when x is small */
if (xn < KARATSUBA_MUL_DIGITS) {
normal:
if (xds == yds && xn == yn)
bary_sq_fast(zds, zn, xds, xn);
else
bary_short_mul(zds, zn, xds, xn, yds, yn);
return;
}
/* normal multiplication when x or y is a sparse bignum */
if (bary_sparse_p(xds, xn)) goto normal;
if (bary_sparse_p(yds, yn)) {
bary_short_mul(zds, zn, yds, yn, xds, xn);
return;
}
/* balance multiplication by slicing y when x is much smaller than y */
if (!KARATSUBA_BALANCED(xn, yn)) {
bary_mul_balance_with_mulfunc(zds, zn, xds, xn, yds, yn, wds, wn, bary_mul_karatsuba_start);
return;
}
/* multiplication by karatsuba method */
bary_mul_karatsuba(zds, zn, xds, xn, yds, yn, wds, wn);
}
static void
bary_mul_karatsuba_start(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn)
{
if (bary_mul_precheck(&zds, &zn, &xds, &xn, &yds, &yn))
return;
bary_mul_karatsuba_branch(zds, zn, xds, xn, yds, yn, wds, wn);
}
static void
bary_mul_toom3_branch(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn)
{
if (xn < TOOM3_MUL_DIGITS) {
bary_mul_karatsuba_branch(zds, zn, xds, xn, yds, yn, wds, wn);
return;
}
if (!TOOM3_BALANCED(xn, yn)) {
bary_mul_balance_with_mulfunc(zds, zn, xds, xn, yds, yn, wds, wn, bary_mul_toom3_start);
return;
}
bary_mul_toom3(zds, zn, xds, xn, yds, yn, wds, wn);
}
static void
bary_mul_toom3_start(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn)
{
if (bary_mul_precheck(&zds, &zn, &xds, &xn, &yds, &yn))
return;
bary_mul_toom3_branch(zds, zn, xds, xn, yds, yn, wds, wn);
}
static void
bary_mul(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
if (xn <= yn) {
if (xn < NAIVE_MUL_DIGITS) {
if (xds == yds && xn == yn)
bary_sq_fast(zds, zn, xds, xn);
else
bary_short_mul(zds, zn, xds, xn, yds, yn);
return;
}
}
else {
if (yn < NAIVE_MUL_DIGITS) {
bary_short_mul(zds, zn, yds, yn, xds, xn);
return;
}
}
#ifdef USE_GMP
bary_mul_gmp(zds, zn, xds, xn, yds, yn);
#else
bary_mul_toom3_start(zds, zn, xds, xn, yds, yn, NULL, 0);
#endif
}
struct big_div_struct {
size_t yn, zn;
BDIGIT *yds, *zds;
volatile VALUE stop;
};
static void *
bigdivrem1(void *ptr)
{
struct big_div_struct *bds = (struct big_div_struct*)ptr;
size_t yn = bds->yn;
size_t zn = bds->zn;
BDIGIT *yds = bds->yds, *zds = bds->zds;
BDIGIT_DBL_SIGNED num;
BDIGIT q;
do {
if (bds->stop) {
bds->zn = zn;
return 0;
}
if (zds[zn-1] == yds[yn-1]) q = BDIGMAX;
else q = (BDIGIT)((BIGUP(zds[zn-1]) + zds[zn-2])/yds[yn-1]);
if (q) {
num = bigdivrem_mulsub(zds+zn-(yn+1), yn+1,
q,
yds, yn);
while (num) { /* "add back" required */
q--;
num = bary_add(zds+zn-(yn+1), yn,
zds+zn-(yn+1), yn,
yds, yn);
num--;
}
}
zn--;
zds[zn] = q;
} while (zn > yn);
return 0;
}
/* async-signal-safe */
static void
rb_big_stop(void *ptr)
{
struct big_div_struct *bds = ptr;
bds->stop = Qtrue;
}
static BDIGIT
bigdivrem_single1(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT x_higher_bdigit, BDIGIT y)
{
assert(0 < xn);
assert(x_higher_bdigit < y);
if (POW2_P(y)) {
BDIGIT r;
r = xds[0] & (y-1);
bary_small_rshift(qds, xds, xn, bit_length(y)-1, x_higher_bdigit);
return r;
}
else {
size_t i;
BDIGIT_DBL t2;
t2 = x_higher_bdigit;
for (i = 0; i < xn; i++) {
t2 = BIGUP(t2) + xds[xn - i - 1];
qds[xn - i - 1] = (BDIGIT)(t2 / y);
t2 %= y;
}
return (BDIGIT)t2;
}
}
static BDIGIT
bigdivrem_single(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT y)
{
return bigdivrem_single1(qds, xds, xn, 0, y);
}
static void
bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn)
{
struct big_div_struct bds;
size_t ynzero;
assert(yn < zn);
assert(BDIGIT_MSB(yds[yn-1]));
assert(zds[zn-1] < yds[yn-1]);
for (ynzero = 0; !yds[ynzero]; ynzero++);
if (ynzero+1 == yn) {
BDIGIT r;
r = bigdivrem_single1(zds+yn, zds+ynzero, zn-yn, zds[zn-1], yds[ynzero]);
zds[ynzero] = r;
return;
}
bds.yn = yn - ynzero;
bds.zds = zds + ynzero;
bds.yds = yds + ynzero;
bds.stop = Qfalse;
bds.zn = zn - ynzero;
if (bds.zn > 10000 || bds.yn > 10000) {
retry:
bds.stop = Qfalse;
rb_nogvl(bigdivrem1, &bds, rb_big_stop, &bds, RB_NOGVL_UBF_ASYNC_SAFE);
if (bds.stop == Qtrue) {
/* execute trap handler, but exception was not raised. */
goto retry;
}
}
else {
bigdivrem1(&bds);
}
}
static void
bary_divmod_normal(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
int shift;
BDIGIT *zds, *yyds;
size_t zn;
VALUE tmpyz = 0;
assert(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
assert(qds ? (xn - yn + 1) <= qn : 1);
assert(rds ? yn <= rn : 1);
zn = xn + BIGDIVREM_EXTRA_WORDS;
shift = nlz(yds[yn-1]);
if (shift) {
int alloc_y = !rds;
int alloc_z = !qds || qn < zn;
if (alloc_y && alloc_z) {
yyds = ALLOCV_N(BDIGIT, tmpyz, yn+zn);
zds = yyds + yn;
}
else {
yyds = alloc_y ? ALLOCV_N(BDIGIT, tmpyz, yn) : rds;
zds = alloc_z ? ALLOCV_N(BDIGIT, tmpyz, zn) : qds;
}
zds[xn] = bary_small_lshift(zds, xds, xn, shift);
bary_small_lshift(yyds, yds, yn, shift);
}
else {
if (qds && zn <= qn)
zds = qds;
else
zds = ALLOCV_N(BDIGIT, tmpyz, zn);
MEMCPY(zds, xds, BDIGIT, xn);
zds[xn] = 0;
/* bigdivrem_restoring will not modify y.
* So use yds directly. */
yyds = (BDIGIT *)yds;
}
bigdivrem_restoring(zds, zn, yyds, yn);
if (rds) {
if (shift)
bary_small_rshift(rds, zds, yn, shift, 0);
else
MEMCPY(rds, zds, BDIGIT, yn);
BDIGITS_ZERO(rds+yn, rn-yn);
}
if (qds) {
size_t j = zn - yn;
MEMMOVE(qds, zds+yn, BDIGIT, j);
BDIGITS_ZERO(qds+j, qn-j);
}
if (tmpyz)
ALLOCV_END(tmpyz);
}
VALUE
rb_big_divrem_normal(VALUE x, VALUE y)
{
size_t xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y), qn, rn;
BDIGIT *xds = BDIGITS(x), *yds = BDIGITS(y), *qds, *rds;
VALUE q, r;
BARY_TRUNC(yds, yn);
if (yn == 0)
rb_num_zerodiv();
BARY_TRUNC(xds, xn);
if (xn < yn || (xn == yn && xds[xn - 1] < yds[yn - 1]))
return rb_assoc_new(LONG2FIX(0), x);
qn = xn + BIGDIVREM_EXTRA_WORDS;
q = bignew(qn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
qds = BDIGITS(q);
rn = yn;
r = bignew(rn, BIGNUM_SIGN(x));
rds = BDIGITS(r);
bary_divmod_normal(qds, qn, rds, rn, xds, xn, yds, yn);
bigtrunc(q);
bigtrunc(r);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return rb_assoc_new(q, r);
}
#ifdef USE_GMP
static void
bary_divmod_gmp(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
mpz_t x, y, q, r;
size_t count;
assert(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
assert(qds ? (xn - yn + 1) <= qn : 1);
assert(rds ? yn <= rn : 1);
assert(qds || rds);
mpz_init(x);
mpz_init(y);
if (qds) mpz_init(q);
if (rds) mpz_init(r);
bdigits_to_mpz(x, xds, xn);
bdigits_to_mpz(y, yds, yn);
if (!rds) {
mpz_fdiv_q(q, x, y);
}
else if (!qds) {
mpz_fdiv_r(r, x, y);
}
else {
mpz_fdiv_qr(q, r, x, y);
}
mpz_clear(x);
mpz_clear(y);
if (qds) {
bdigits_from_mpz(q, qds, &count);
BDIGITS_ZERO(qds+count, qn-count);
mpz_clear(q);
}
if (rds) {
bdigits_from_mpz(r, rds, &count);
BDIGITS_ZERO(rds+count, rn-count);
mpz_clear(r);
}
}
VALUE
rb_big_divrem_gmp(VALUE x, VALUE y)
{
size_t xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y), qn, rn;
BDIGIT *xds = BDIGITS(x), *yds = BDIGITS(y), *qds, *rds;
VALUE q, r;
BARY_TRUNC(yds, yn);
if (yn == 0)
rb_num_zerodiv();
BARY_TRUNC(xds, xn);
if (xn < yn || (xn == yn && xds[xn - 1] < yds[yn - 1]))
return rb_assoc_new(LONG2FIX(0), x);
qn = xn - yn + 1;
q = bignew(qn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
qds = BDIGITS(q);
rn = yn;
r = bignew(rn, BIGNUM_SIGN(x));
rds = BDIGITS(r);
bary_divmod_gmp(qds, qn, rds, rn, xds, xn, yds, yn);
bigtrunc(q);
bigtrunc(r);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return rb_assoc_new(q, r);
}
#endif
static void
bary_divmod_branch(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
#ifdef USE_GMP
if (GMP_DIV_DIGITS < xn) {
bary_divmod_gmp(qds, qn, rds, rn, xds, xn, yds, yn);
return;
}
#endif
bary_divmod_normal(qds, qn, rds, rn, xds, xn, yds, yn);
}
static void
bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
{
assert(xn <= qn);
assert(yn <= rn);
BARY_TRUNC(yds, yn);
if (yn == 0)
rb_num_zerodiv();
BARY_TRUNC(xds, xn);
if (xn == 0) {
BDIGITS_ZERO(qds, qn);
BDIGITS_ZERO(rds, rn);
return;
}
if (xn < yn || (xn == yn && xds[xn - 1] < yds[yn - 1])) {
MEMCPY(rds, xds, BDIGIT, xn);
BDIGITS_ZERO(rds+xn, rn-xn);
BDIGITS_ZERO(qds, qn);
}
else if (yn == 1) {
MEMCPY(qds, xds, BDIGIT, xn);
BDIGITS_ZERO(qds+xn, qn-xn);
rds[0] = bigdivrem_single(qds, xds, xn, yds[0]);
BDIGITS_ZERO(rds+1, rn-1);
}
else if (xn == 2 && yn == 2) {
BDIGIT_DBL x = bary2bdigitdbl(xds, 2);
BDIGIT_DBL y = bary2bdigitdbl(yds, 2);
BDIGIT_DBL q = x / y;
BDIGIT_DBL r = x % y;
qds[0] = BIGLO(q);
qds[1] = BIGLO(BIGDN(q));
BDIGITS_ZERO(qds+2, qn-2);
rds[0] = BIGLO(r);
rds[1] = BIGLO(BIGDN(r));
BDIGITS_ZERO(rds+2, rn-2);
}
else {
bary_divmod_branch(qds, qn, rds, rn, xds, xn, yds, yn);
}
}
#define BIGNUM_DEBUG 0
#if BIGNUM_DEBUG
#define ON_DEBUG(x) do { x; } while (0)
static void
dump_bignum(VALUE x)
{
long i;
printf("%c0x0", BIGNUM_SIGN(x) ? '+' : '-');
for (i = BIGNUM_LEN(x); i--; ) {
printf("_%0*"PRIxBDIGIT, SIZEOF_BDIGIT*2, BDIGITS(x)[i]);
}
printf(", len=%"PRIuSIZE, BIGNUM_LEN(x));
puts("");
}
static VALUE
rb_big_dump(VALUE x)
{
dump_bignum(x);
return x;
}
#else
#define ON_DEBUG(x)
#endif
static int
bigzero_p(VALUE x)
{
return bary_zero_p(BDIGITS(x), BIGNUM_LEN(x));
}
int
rb_bigzero_p(VALUE x)
{
return BIGZEROP(x);
}
int
rb_cmpint(VALUE val, VALUE a, VALUE b)
{
if (NIL_P(val)) {
rb_cmperr(a, b);
}
if (FIXNUM_P(val)) {
long l = FIX2LONG(val);
if (l > 0) return 1;
if (l < 0) return -1;
return 0;
}
if (RB_BIGNUM_TYPE_P(val)) {
if (BIGZEROP(val)) return 0;
if (BIGNUM_SIGN(val)) return 1;
return -1;
}
if (RTEST(rb_funcall(val, '>', 1, INT2FIX(0)))) return 1;
if (RTEST(rb_funcall(val, '<', 1, INT2FIX(0)))) return -1;
return 0;
}
#define BIGNUM_SET_LEN(b,l) \
(BIGNUM_EMBED_P(b) ? \
(void)(RBASIC(b)->flags = \
(RBASIC(b)->flags & ~BIGNUM_EMBED_LEN_MASK) | \
((l) << BIGNUM_EMBED_LEN_SHIFT)) : \
(void)(RBIGNUM(b)->as.heap.len = (l)))
static void
rb_big_realloc(VALUE big, size_t len)
{
BDIGIT *ds;
if (BIGNUM_EMBED_P(big)) {
if (BIGNUM_EMBED_LEN_MAX < len) {
ds = ALLOC_N(BDIGIT, len);
MEMCPY(ds, RBIGNUM(big)->as.ary, BDIGIT, BIGNUM_EMBED_LEN_MAX);
RBIGNUM(big)->as.heap.len = BIGNUM_LEN(big);
RBIGNUM(big)->as.heap.digits = ds;
FL_UNSET_RAW(big, BIGNUM_EMBED_FLAG);
}
}
else {
if (len <= BIGNUM_EMBED_LEN_MAX) {
ds = RBIGNUM(big)->as.heap.digits;
FL_SET_RAW(big, BIGNUM_EMBED_FLAG);
BIGNUM_SET_LEN(big, len);
(void)VALGRIND_MAKE_MEM_UNDEFINED((void*)RBIGNUM(big)->as.ary, sizeof(RBIGNUM(big)->as.ary));
if (ds) {
MEMCPY(RBIGNUM(big)->as.ary, ds, BDIGIT, len);
xfree(ds);
}
}
else {
if (BIGNUM_LEN(big) == 0) {
RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);
}
else {
REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len);
}
}
}
}
void
rb_big_resize(VALUE big, size_t len)
{
rb_big_realloc(big, len);
BIGNUM_SET_LEN(big, len);
}
static VALUE
bignew_1(VALUE klass, size_t len, int sign)
{
NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM | (RGENGC_WB_PROTECTED_BIGNUM ? FL_WB_PROTECTED : 0));
BIGNUM_SET_SIGN((VALUE)big, sign);
if (len <= BIGNUM_EMBED_LEN_MAX) {
FL_SET_RAW(big, BIGNUM_EMBED_FLAG);
BIGNUM_SET_LEN((VALUE)big, len);
(void)VALGRIND_MAKE_MEM_UNDEFINED((void*)RBIGNUM(big)->as.ary, sizeof(RBIGNUM(big)->as.ary));
}
else {
RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);
RBIGNUM(big)->as.heap.len = len;
}
OBJ_FREEZE(big);
return (VALUE)big;
}
VALUE
rb_big_new(size_t len, int sign)
{
return bignew(len, sign != 0);
}
VALUE
rb_big_clone(VALUE x)
{
size_t len = BIGNUM_LEN(x);
VALUE z = bignew_1(CLASS_OF(x), len, BIGNUM_SIGN(x));
MEMCPY(BDIGITS(z), BDIGITS(x), BDIGIT, len);
return z;
}
static void
big_extend_carry(VALUE x)
{
rb_big_resize(x, BIGNUM_LEN(x)+1);
BDIGITS(x)[BIGNUM_LEN(x)-1] = 1;
}
/* modify a bignum by 2's complement */
static void
get2comp(VALUE x)
{
long i = BIGNUM_LEN(x);
BDIGIT *ds = BDIGITS(x);
if (bary_2comp(ds, i)) {
big_extend_carry(x);
}
}
void
rb_big_2comp(VALUE x) /* get 2's complement */
{
get2comp(x);
}
static BDIGIT
abs2twocomp(VALUE *xp, long *n_ret)
{
VALUE x = *xp;
long n = BIGNUM_LEN(x);
BDIGIT *ds = BDIGITS(x);
BDIGIT hibits = 0;
BARY_TRUNC(ds, n);
if (n != 0 && BIGNUM_NEGATIVE_P(x)) {
VALUE z = bignew_1(CLASS_OF(x), n, 0);
MEMCPY(BDIGITS(z), ds, BDIGIT, n);
bary_2comp(BDIGITS(z), n);
hibits = BDIGMAX;
*xp = z;
}
*n_ret = n;
return hibits;
}
static void
twocomp2abs_bang(VALUE x, int hibits)
{
BIGNUM_SET_SIGN(x, !hibits);
if (hibits) {
get2comp(x);
}
}
static inline VALUE
bigtrunc(VALUE x)
{
size_t len = BIGNUM_LEN(x);
BDIGIT *ds = BDIGITS(x);
if (len == 0) return x;
while (--len && !ds[len]);
if (BIGNUM_LEN(x) > len+1) {
rb_big_resize(x, len+1);
}
return x;
}
static inline VALUE
bigfixize(VALUE x)
{
size_t n = BIGNUM_LEN(x);
BDIGIT *ds = BDIGITS(x);
#if SIZEOF_BDIGIT < SIZEOF_LONG
unsigned long u;
#else
BDIGIT u;
#endif
BARY_TRUNC(ds, n);
if (n == 0) return INT2FIX(0);
#if SIZEOF_BDIGIT < SIZEOF_LONG
if (sizeof(long)/SIZEOF_BDIGIT < n)
goto return_big;
else {
int i = (int)n;
u = 0;
while (i--) {
u = (unsigned long)(BIGUP(u) + ds[i]);
}
}
#else /* SIZEOF_BDIGIT >= SIZEOF_LONG */
if (1 < n)
goto return_big;
else
u = ds[0];
#endif
if (BIGNUM_POSITIVE_P(x)) {
if (POSFIXABLE(u)) return LONG2FIX((long)u);
}
else {
if (u <= -FIXNUM_MIN) return LONG2FIX(-(long)u);
}
return_big:
rb_big_resize(x, n);
return x;
}
static VALUE
bignorm(VALUE x)
{
if (RB_BIGNUM_TYPE_P(x)) {
x = bigfixize(x);
}
return x;
}
VALUE
rb_big_norm(VALUE x)
{
return bignorm(x);
}
VALUE
rb_uint2big(uintptr_t n)
{
long i;
VALUE big = bignew(bdigit_roomof(SIZEOF_VALUE), 1);
BDIGIT *digits = BDIGITS(big);
#if SIZEOF_BDIGIT >= SIZEOF_VALUE
digits[0] = n;
#else
for (i = 0; i < bdigit_roomof(SIZEOF_VALUE); i++) {
digits[i] = BIGLO(n);
n = BIGDN(n);
}
#endif
i = bdigit_roomof(SIZEOF_VALUE);
while (--i && !digits[i]) ;
BIGNUM_SET_LEN(big, i+1);
return big;
}
VALUE
rb_int2big(intptr_t n)
{
long neg = 0;
VALUE u;
VALUE big;
if (n < 0) {
u = 1 + (VALUE)(-(n + 1)); /* u = -n avoiding overflow */
neg = 1;
}
else {
u = n;
}
big = rb_uint2big(u);
if (neg) {
BIGNUM_SET_NEGATIVE_SIGN(big);
}
return big;
}
VALUE
rb_uint2inum(uintptr_t n)
{
if (POSFIXABLE(n)) return LONG2FIX(n);
return rb_uint2big(n);
}
VALUE
rb_int2inum(intptr_t n)
{
if (FIXABLE(n)) return LONG2FIX(n);
return rb_int2big(n);
}
void
rb_big_pack(VALUE val, unsigned long *buf, long num_longs)
{
rb_integer_pack(val, buf, num_longs, sizeof(long), 0,
INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER|
INTEGER_PACK_2COMP);
}
VALUE
rb_big_unpack(unsigned long *buf, long num_longs)
{
return rb_integer_unpack(buf, num_longs, sizeof(long), 0,
INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER|
INTEGER_PACK_2COMP);
}
/*
* Calculate the number of bytes to be required to represent
* the absolute value of the integer given as _val_.
*
* [val] an integer.
* [nlz_bits_ret] number of leading zero bits in the most significant byte is returned if not NULL.
*
* This function returns ((val_numbits * CHAR_BIT + CHAR_BIT - 1) / CHAR_BIT)
* where val_numbits is the number of bits of abs(val).
* This function should not overflow.
*
* If nlz_bits_ret is not NULL,
* (return_value * CHAR_BIT - val_numbits) is stored in *nlz_bits_ret.
* In this case, 0 <= *nlz_bits_ret < CHAR_BIT.
*
*/
size_t
rb_absint_size(VALUE val, int *nlz_bits_ret)
{
BDIGIT *dp;
BDIGIT *de;
BDIGIT fixbuf[bdigit_roomof(sizeof(long))];
int num_leading_zeros;
val = rb_to_int(val);
if (FIXNUM_P(val)) {
long v = FIX2LONG(val);
if (v < 0) {
v = -v;
}
#if SIZEOF_BDIGIT >= SIZEOF_LONG
fixbuf[0] = v;
#else
{
int i;
for (i = 0; i < numberof(fixbuf); i++) {
fixbuf[i] = BIGLO(v);
v = BIGDN(v);
}
}
#endif
dp = fixbuf;
de = fixbuf + numberof(fixbuf);
}
else {
dp = BDIGITS(val);
de = dp + BIGNUM_LEN(val);
}
while (dp < de && de[-1] == 0)
de--;
if (dp == de) {
if (nlz_bits_ret)
*nlz_bits_ret = 0;
return 0;
}
num_leading_zeros = nlz(de[-1]);
if (nlz_bits_ret)
*nlz_bits_ret = num_leading_zeros % CHAR_BIT;
return (de - dp) * SIZEOF_BDIGIT - num_leading_zeros / CHAR_BIT;
}
static size_t
absint_numwords_small(size_t numbytes, int nlz_bits_in_msbyte, size_t word_numbits, size_t *nlz_bits_ret)
{
size_t val_numbits = numbytes * CHAR_BIT - nlz_bits_in_msbyte;
size_t div = val_numbits / word_numbits;
size_t mod = val_numbits % word_numbits;
size_t numwords;
size_t nlz_bits;
numwords = mod == 0 ? div : div + 1;
nlz_bits = mod == 0 ? 0 : word_numbits - mod;
*nlz_bits_ret = nlz_bits;
return numwords;
}
static size_t
absint_numwords_generic(size_t numbytes, int nlz_bits_in_msbyte, size_t word_numbits, size_t *nlz_bits_ret)
{
static const BDIGIT char_bit[1] = { CHAR_BIT };
BDIGIT numbytes_bary[bdigit_roomof(sizeof(numbytes))];
BDIGIT val_numbits_bary[bdigit_roomof(sizeof(numbytes) + 1)];
BDIGIT nlz_bits_in_msbyte_bary[1];
BDIGIT word_numbits_bary[bdigit_roomof(sizeof(word_numbits))];
BDIGIT div_bary[numberof(val_numbits_bary) + BIGDIVREM_EXTRA_WORDS];
BDIGIT mod_bary[numberof(word_numbits_bary)];
BDIGIT one[1] = { 1 };
size_t nlz_bits;
size_t mod;
int sign;
size_t numwords;
nlz_bits_in_msbyte_bary[0] = nlz_bits_in_msbyte;
/*
* val_numbits = numbytes * CHAR_BIT - nlz_bits_in_msbyte
* div, mod = val_numbits.divmod(word_numbits)
* numwords = mod == 0 ? div : div + 1
* nlz_bits = mod == 0 ? 0 : word_numbits - mod
*/
bary_unpack(BARY_ARGS(numbytes_bary), &numbytes, 1, sizeof(numbytes), 0,
INTEGER_PACK_NATIVE_BYTE_ORDER);
BARY_SHORT_MUL(val_numbits_bary, numbytes_bary, char_bit);
if (nlz_bits_in_msbyte)
BARY_SUB(val_numbits_bary, val_numbits_bary, nlz_bits_in_msbyte_bary);
bary_unpack(BARY_ARGS(word_numbits_bary), &word_numbits, 1, sizeof(word_numbits), 0,
INTEGER_PACK_NATIVE_BYTE_ORDER);
BARY_DIVMOD(div_bary, mod_bary, val_numbits_bary, word_numbits_bary);
if (BARY_ZERO_P(mod_bary)) {
nlz_bits = 0;
}
else {
BARY_ADD(div_bary, div_bary, one);
bary_pack(+1, BARY_ARGS(mod_bary), &mod, 1, sizeof(mod), 0,
INTEGER_PACK_NATIVE_BYTE_ORDER);
nlz_bits = word_numbits - mod;
}
sign = bary_pack(+1, BARY_ARGS(div_bary), &numwords, 1, sizeof(numwords), 0,
INTEGER_PACK_NATIVE_BYTE_ORDER);
if (sign == 2) {
#if defined __GNUC__ && (__GNUC__ == 4 && __GNUC_MINOR__ == 4)
*nlz_bits_ret = 0;
#endif
return (size_t)-1;
}
*nlz_bits_ret = nlz_bits;
return numwords;
}
/*
* Calculate the number of words to be required to represent
* the absolute value of the integer given as _val_.
*
* [val] an integer.
* [word_numbits] number of bits in a word.
* [nlz_bits_ret] number of leading zero bits in the most significant word is returned if not NULL.
*
* This function returns ((val_numbits * CHAR_BIT + word_numbits - 1) / word_numbits)
* where val_numbits is the number of bits of abs(val).
*
* This function can overflow.
* When overflow occur, (size_t)-1 is returned.
*
* If nlz_bits_ret is not NULL and overflow is not occur,
* (return_value * word_numbits - val_numbits) is stored in *nlz_bits_ret.
* In this case, 0 <= *nlz_bits_ret < word_numbits.
*
*/
size_t
rb_absint_numwords(VALUE val, size_t word_numbits, size_t *nlz_bits_ret)
{
size_t numbytes;
int nlz_bits_in_msbyte;
size_t numwords;
size_t nlz_bits = 0;
if (word_numbits == 0)
return (size_t)-1;
numbytes = rb_absint_size(val, &nlz_bits_in_msbyte);
if (numbytes <= SIZE_MAX / CHAR_BIT) {
numwords = absint_numwords_small(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits);
#ifdef DEBUG_INTEGER_PACK
{
size_t numwords0, nlz_bits0;
numwords0 = absint_numwords_generic(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits0);
assert(numwords0 == numwords);
assert(nlz_bits0 == nlz_bits);
}
#endif
}
else {
numwords = absint_numwords_generic(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits);
}
if (numwords == (size_t)-1)
return numwords;
if (nlz_bits_ret)
*nlz_bits_ret = nlz_bits;
return numwords;
}
/* Test abs(val) consists only a bit or not.
*
* Returns 1 if abs(val) == 1 << n for some n >= 0.
* Returns 0 otherwise.
*
* rb_absint_singlebit_p can be used to determine required buffer size
* for rb_integer_pack used with INTEGER_PACK_2COMP (two's complement).
*
* Following example calculates number of bits required to
* represent val in two's complement number, without sign bit.
*
* size_t size;
* int neg = FIXNUM_P(val) ? FIX2LONG(val) < 0 : BIGNUM_NEGATIVE_P(val);
* size = rb_absint_numwords(val, 1, NULL)
* if (size == (size_t)-1) ...overflow...
* if (neg && rb_absint_singlebit_p(val))
* size--;
*
* Following example calculates number of bytes required to
* represent val in two's complement number, with sign bit.
*
* size_t size;
* int neg = FIXNUM_P(val) ? FIX2LONG(val) < 0 : BIGNUM_NEGATIVE_P(val);
* int nlz_bits;
* size = rb_absint_size(val, &nlz_bits);
* if (nlz_bits == 0 && !(neg && rb_absint_singlebit_p(val)))
* size++;
*/
int
rb_absint_singlebit_p(VALUE val)
{
BDIGIT *dp;
BDIGIT *de;
BDIGIT fixbuf[bdigit_roomof(sizeof(long))];
BDIGIT d;
val = rb_to_int(val);
if (FIXNUM_P(val)) {
long v = FIX2LONG(val);
if (v < 0) {
v = -v;
}
#if SIZEOF_BDIGIT >= SIZEOF_LONG
fixbuf[0] = v;
#else
{
int i;
for (i = 0; i < numberof(fixbuf); i++) {
fixbuf[i] = BIGLO(v);
v = BIGDN(v);
}
}
#endif
dp = fixbuf;
de = fixbuf + numberof(fixbuf);
}
else {
dp = BDIGITS(val);
de = dp + BIGNUM_LEN(val);
}
while (dp < de && de[-1] == 0)
de--;
while (dp < de && dp[0] == 0)
dp++;
if (dp == de) /* no bit set. */
return 0;
if (dp != de-1) /* two non-zero words. two bits set, at least. */
return 0;
d = *dp;
return POW2_P(d);
}
/*
* Export an integer into a buffer.
*
* This function fills the buffer specified by _words_ and _numwords_ as
* val in the format specified by _wordsize_, _nails_ and _flags_.
*
* [val] Fixnum, Bignum or another integer like object which has to_int method.
* [words] buffer to export abs(val).
* [numwords] the size of given buffer as number of words.
* [wordsize] the size of word as number of bytes.
* [nails] number of padding bits in a word.
* Most significant nails bits of each word are filled by zero.
* [flags] bitwise or of constants which name starts "INTEGER_PACK_".
*
* flags:
* [INTEGER_PACK_MSWORD_FIRST] Store the most significant word as the first word.
* [INTEGER_PACK_LSWORD_FIRST] Store the least significant word as the first word.
* [INTEGER_PACK_MSBYTE_FIRST] Store the most significant byte in a word as the first byte in the word.
* [INTEGER_PACK_LSBYTE_FIRST] Store the least significant byte in a word as the first byte in the word.
* [INTEGER_PACK_NATIVE_BYTE_ORDER] INTEGER_PACK_MSBYTE_FIRST or INTEGER_PACK_LSBYTE_FIRST corresponding to the host's endian.
* [INTEGER_PACK_2COMP] Use 2's complement representation.
* [INTEGER_PACK_LITTLE_ENDIAN] Same as INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_LSBYTE_FIRST
* [INTEGER_PACK_BIG_ENDIAN] Same as INTEGER_PACK_MSWORD_FIRST|INTEGER_PACK_MSBYTE_FIRST
* [INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION] Use generic implementation (for test and debug).
*
* This function fills the buffer specified by _words_
* as abs(val) if INTEGER_PACK_2COMP is not specified in _flags_.
* If INTEGER_PACK_2COMP is specified, 2's complement representation of val is
* filled in the buffer.
*
* This function returns the signedness and overflow condition.
* The overflow condition depends on INTEGER_PACK_2COMP.
*
* INTEGER_PACK_2COMP is not specified:
* -2 : negative overflow. val <= -2**(numwords*(wordsize*CHAR_BIT-nails))
* -1 : negative without overflow. -2**(numwords*(wordsize*CHAR_BIT-nails)) < val < 0
* 0 : zero. val == 0
* 1 : positive without overflow. 0 < val < 2**(numwords*(wordsize*CHAR_BIT-nails))
* 2 : positive overflow. 2**(numwords*(wordsize*CHAR_BIT-nails)) <= val
*
* INTEGER_PACK_2COMP is specified:
* -2 : negative overflow. val < -2**(numwords*(wordsize*CHAR_BIT-nails))
* -1 : negative without overflow. -2**(numwords*(wordsize*CHAR_BIT-nails)) <= val < 0
* 0 : zero. val == 0
* 1 : positive without overflow. 0 < val < 2**(numwords*(wordsize*CHAR_BIT-nails))
* 2 : positive overflow. 2**(numwords*(wordsize*CHAR_BIT-nails)) <= val
*
* The value, -2**(numwords*(wordsize*CHAR_BIT-nails)), is representable
* in 2's complement representation but not representable in absolute value.
* So -1 is returned for the value if INTEGER_PACK_2COMP is specified
* but returns -2 if INTEGER_PACK_2COMP is not specified.
*
* The least significant words are filled in the buffer when overflow occur.
*/
int
rb_integer_pack(VALUE val, void *words, size_t numwords, size_t wordsize, size_t nails, int flags)
{
int sign;
BDIGIT *ds;
size_t num_bdigits;
BDIGIT fixbuf[bdigit_roomof(sizeof(long))];
RB_GC_GUARD(val) = rb_to_int(val);
if (FIXNUM_P(val)) {
long v = FIX2LONG(val);
if (v < 0) {
sign = -1;
v = -v;
}
else {
sign = 1;
}
#if SIZEOF_BDIGIT >= SIZEOF_LONG
fixbuf[0] = v;
#else
{
int i;
for (i = 0; i < numberof(fixbuf); i++) {
fixbuf[i] = BIGLO(v);
v = BIGDN(v);
}
}
#endif
ds = fixbuf;
num_bdigits = numberof(fixbuf);
}
else {
sign = BIGNUM_POSITIVE_P(val) ? 1 : -1;
ds = BDIGITS(val);
num_bdigits = BIGNUM_LEN(val);
}
return bary_pack(sign, ds, num_bdigits, words, numwords, wordsize, nails, flags);
}
/*
* Import an integer from a buffer.
*
* [words] buffer to import.
* [numwords] the size of given buffer as number of words.
* [wordsize] the size of word as number of bytes.
* [nails] number of padding bits in a word.
* Most significant nails bits of each word are ignored.
* [flags] bitwise or of constants which name starts "INTEGER_PACK_".
*
* flags:
* [INTEGER_PACK_MSWORD_FIRST] Interpret the first word as the most significant word.
* [INTEGER_PACK_LSWORD_FIRST] Interpret the first word as the least significant word.
* [INTEGER_PACK_MSBYTE_FIRST] Interpret the first byte in a word as the most significant byte in the word.
* [INTEGER_PACK_LSBYTE_FIRST] Interpret the first byte in a word as the least significant byte in the word.
* [INTEGER_PACK_NATIVE_BYTE_ORDER] INTEGER_PACK_MSBYTE_FIRST or INTEGER_PACK_LSBYTE_FIRST corresponding to the host's endian.
* [INTEGER_PACK_2COMP] Use 2's complement representation.
* [INTEGER_PACK_LITTLE_ENDIAN] Same as INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_LSBYTE_FIRST
* [INTEGER_PACK_BIG_ENDIAN] Same as INTEGER_PACK_MSWORD_FIRST|INTEGER_PACK_MSBYTE_FIRST
* [INTEGER_PACK_FORCE_BIGNUM] the result will be a Bignum
* even if it is representable as a Fixnum.
* [INTEGER_PACK_NEGATIVE] Returns non-positive value.
* (Returns non-negative value if not specified.)
* [INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION] Use generic implementation (for test and debug).
*
* This function returns the imported integer as Fixnum or Bignum.
*
* The range of the result value depends on INTEGER_PACK_2COMP and INTEGER_PACK_NEGATIVE.
*
* INTEGER_PACK_2COMP is not set:
* 0 <= val < 2**(numwords*(wordsize*CHAR_BIT-nails)) if !INTEGER_PACK_NEGATIVE
* -2**(numwords*(wordsize*CHAR_BIT-nails)) < val <= 0 if INTEGER_PACK_NEGATIVE
*
* INTEGER_PACK_2COMP is set:
* -2**(numwords*(wordsize*CHAR_BIT-nails)-1) <= val <= 2**(numwords*(wordsize*CHAR_BIT-nails)-1)-1 if !INTEGER_PACK_NEGATIVE
* -2**(numwords*(wordsize*CHAR_BIT-nails)) <= val <= -1 if INTEGER_PACK_NEGATIVE
*
* INTEGER_PACK_2COMP without INTEGER_PACK_NEGATIVE means sign extension.
* INTEGER_PACK_2COMP with INTEGER_PACK_NEGATIVE mean assuming the higher bits are 1.
*
* Note that this function returns 0 when numwords is zero and
* INTEGER_PACK_2COMP is set but INTEGER_PACK_NEGATIVE is not set.
*/
VALUE
rb_integer_unpack(const void *words, size_t numwords, size_t wordsize, size_t nails, int flags)
{
VALUE val;
size_t num_bdigits;
int sign;
int nlp_bits;
BDIGIT *ds;
BDIGIT fixbuf[2] = { 0, 0 };
validate_integer_pack_format(numwords, wordsize, nails, flags,
INTEGER_PACK_MSWORD_FIRST|
INTEGER_PACK_LSWORD_FIRST|
INTEGER_PACK_MSBYTE_FIRST|
INTEGER_PACK_LSBYTE_FIRST|
INTEGER_PACK_NATIVE_BYTE_ORDER|
INTEGER_PACK_2COMP|
INTEGER_PACK_FORCE_BIGNUM|
INTEGER_PACK_NEGATIVE|
INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION);
num_bdigits = integer_unpack_num_bdigits(numwords, wordsize, nails, &nlp_bits);
if (LONG_MAX-1 < num_bdigits)
rb_raise(rb_eArgError, "too big to unpack as an integer");
if (num_bdigits <= numberof(fixbuf) && !(flags & INTEGER_PACK_FORCE_BIGNUM)) {
val = Qfalse;
ds = fixbuf;
}
else {
val = bignew((long)num_bdigits, 0);
ds = BDIGITS(val);
}
sign = bary_unpack_internal(ds, num_bdigits, words, numwords, wordsize, nails, flags, nlp_bits);
if (sign == -2) {
if (val) {
big_extend_carry(val);
}
else if (num_bdigits == numberof(fixbuf)) {
val = bignew((long)num_bdigits+1, 0);
MEMCPY(BDIGITS(val), fixbuf, BDIGIT, num_bdigits);
BDIGITS(val)[num_bdigits++] = 1;
}
else {
ds[num_bdigits++] = 1;
}
}
if (!val) {
BDIGIT_DBL u = fixbuf[0] + BIGUP(fixbuf[1]);
if (u == 0)
return LONG2FIX(0);
if (0 < sign && POSFIXABLE(u))
return LONG2FIX(u);
if (sign < 0 && BDIGIT_MSB(fixbuf[1]) == 0 &&
NEGFIXABLE(-(BDIGIT_DBL_SIGNED)u))
return LONG2FIX(-(BDIGIT_DBL_SIGNED)u);
val = bignew((long)num_bdigits, 0 <= sign);
MEMCPY(BDIGITS(val), fixbuf, BDIGIT, num_bdigits);
}
if ((flags & INTEGER_PACK_FORCE_BIGNUM) && sign != 0 &&
bary_zero_p(BDIGITS(val), BIGNUM_LEN(val)))
sign = 0;
BIGNUM_SET_SIGN(val, 0 <= sign);
if (flags & INTEGER_PACK_FORCE_BIGNUM)
return bigtrunc(val);
return bignorm(val);
}
#define conv_digit(c) (ruby_digit36_to_number_table[(unsigned char)(c)])
NORETURN(static inline void invalid_radix(int base));
NORETURN(static inline void invalid_integer(VALUE s));
static inline int
valid_radix_p(int base)
{
return (1 < base && base <= 36);
}
static inline void
invalid_radix(int base)
{
rb_raise(rb_eArgError, "invalid radix %d", base);
}
static inline void
invalid_integer(VALUE s)
{
rb_raise(rb_eArgError, "invalid value for Integer(): %+"PRIsVALUE, s);
}
static int
str2big_scan_digits(const char *s, const char *str, int base, int badcheck, size_t *num_digits_p, ssize_t *len_p)
{
char nondigit = 0;
size_t num_digits = 0;
const char *digits_start = str;
const char *digits_end = str;
ssize_t len = *len_p;
int c;
if (!len) {
*num_digits_p = 0;
*len_p = 0;
return TRUE;
}
if (badcheck && *str == '_') goto bad;
while ((c = *str++) != 0) {
if (c == '_') {
if (nondigit) {
if (badcheck) goto bad;
break;
}
nondigit = (char) c;
}
else if ((c = conv_digit(c)) < 0 || c >= base) {
break;
}
else {
nondigit = 0;
num_digits++;
digits_end = str;
}
if (len > 0 && !--len) break;
}
if (badcheck && nondigit) goto bad;
if (badcheck && len) {
str--;
while (*str && ISSPACE(*str)) {
str++;
if (len > 0 && !--len) break;
}
if (len && *str) {
bad:
return FALSE;
}
}
*num_digits_p = num_digits;
*len_p = digits_end - digits_start;
return TRUE;
}
static VALUE
str2big_poweroftwo(
int sign,
const char *digits_start,
const char *digits_end,
size_t num_digits,
int bits_per_digit)
{
BDIGIT *dp;
BDIGIT_DBL dd;
int numbits;
size_t num_bdigits;
const char *p;
int c;
VALUE z;
num_bdigits = (num_digits / BITSPERDIG) * bits_per_digit + roomof((num_digits % BITSPERDIG) * bits_per_digit, BITSPERDIG);
z = bignew(num_bdigits, sign);
dp = BDIGITS(z);
dd = 0;
numbits = 0;
for (p = digits_end; digits_start < p; p--) {
if ((c = conv_digit(p[-1])) < 0)
continue;
dd |= (BDIGIT_DBL)c << numbits;
numbits += bits_per_digit;
if (BITSPERDIG <= numbits) {
*dp++ = BIGLO(dd);
dd = BIGDN(dd);
numbits -= BITSPERDIG;
}
}
if (numbits) {
*dp++ = BIGLO(dd);
}
assert((size_t)(dp - BDIGITS(z)) == num_bdigits);
return z;
}
static VALUE
str2big_normal(
int sign,
const char *digits_start,
const char *digits_end,
size_t num_bdigits,
int base)
{
size_t blen = 1;
BDIGIT *zds;
BDIGIT_DBL num;
size_t i;
const char *p;
int c;
VALUE z;
z = bignew(num_bdigits, sign);
zds = BDIGITS(z);
BDIGITS_ZERO(zds, num_bdigits);
for (p = digits_start; p < digits_end; p++) {
if ((c = conv_digit(*p)) < 0)
continue;
num = c;
i = 0;
for (;;) {
while (i<blen) {
num += (BDIGIT_DBL)zds[i]*base;
zds[i++] = BIGLO(num);
num = BIGDN(num);
}
if (num) {
blen++;
continue;
}
break;
}
assert(blen <= num_bdigits);
}
return z;
}
static VALUE
str2big_karatsuba(
int sign,
const char *digits_start,
const char *digits_end,
size_t num_digits,
size_t num_bdigits,
int digits_per_bdigits_dbl,
int base)
{
VALUE powerv;
size_t unit;
VALUE tmpuv = 0;
BDIGIT *uds, *vds, *tds;
BDIGIT_DBL dd;
BDIGIT_DBL current_base;
int m;
int power_level = 0;
size_t i;
const char *p;
int c;
VALUE z;
uds = ALLOCV_N(BDIGIT, tmpuv, 2*num_bdigits);
vds = uds + num_bdigits;
powerv = power_cache_get_power(base, power_level, NULL);
i = 0;
dd = 0;
current_base = 1;
m = digits_per_bdigits_dbl;
if (num_digits < (size_t)m)
m = (int)num_digits;
for (p = digits_end; digits_start < p; p--) {
if ((c = conv_digit(p[-1])) < 0)
continue;
dd = dd + c * current_base;
current_base *= base;
num_digits--;
m--;
if (m == 0) {
uds[i++] = BIGLO(dd);
uds[i++] = (BDIGIT)BIGDN(dd);
dd = 0;
m = digits_per_bdigits_dbl;
if (num_digits < (size_t)m)
m = (int)num_digits;
current_base = 1;
}
}
assert(i == num_bdigits);
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), BIGNUM_LEN(powerv), uds+i+unit, unit);
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), BIGNUM_LEN(powerv), uds+i+unit, num_bdigits-(i+unit));
bary_add(vds+i, num_bdigits-i, vds+i, num_bdigits-i, uds+i, unit);
}
else {
MEMCPY(vds+i, uds+i, BDIGIT, num_bdigits-i);
}
}
power_level++;
powerv = power_cache_get_power(base, power_level, NULL);
tds = vds;
vds = uds;
uds = tds;
}
BARY_TRUNC(uds, num_bdigits);
z = bignew(num_bdigits, sign);
MEMCPY(BDIGITS(z), uds, BDIGIT, num_bdigits);
if (tmpuv)
ALLOCV_END(tmpuv);
return z;
}
#ifdef USE_GMP
static VALUE
str2big_gmp(
int sign,
const char *digits_start,
const char *digits_end,
size_t num_digits,
size_t num_bdigits,
int base)
{
char *buf, *p;
const char *q;
VALUE tmps;
mpz_t mz;
VALUE z;
BDIGIT *zds;
size_t zn, count;
buf = ALLOCV_N(char, tmps, num_digits+1);
p = buf;
for (q = digits_start; q < digits_end; q++) {
if (conv_digit(*q) < 0)
continue;
*p++ = *q;
}
*p = '\0';
mpz_init(mz);
mpz_set_str(mz, buf, base);
zn = num_bdigits;
z = bignew(zn, sign);
zds = BDIGITS(z);
bdigits_from_mpz(mz, BDIGITS(z), &count);
BDIGITS_ZERO(zds+count, zn-count);
mpz_clear(mz);
if (tmps)
ALLOCV_END(tmps);
return z;
}
#endif
static VALUE rb_cstr_parse_inum(const char *str, ssize_t len, char **endp, int base);
/*
* Parse +str+ as Ruby Integer, i.e., underscores, 0d and 0b prefixes.
*
* str: pointer to the string to be parsed.
* should be NUL-terminated.
* base: base of conversion, must be 2..36, or -36..0.
* if +base+ > 0, the conversion is done according to the +base+
* and unmatched prefix is parsed as a part of the result if
* present.
* if +base+ <= 0, the conversion is done according to the
* prefix if present, in base <code>-base</code> if +base+ < -1,
* or in base 10.
* badcheck: if non-zero, +ArgumentError+ is raised when +str+ is not
* valid as an Integer. if zero, Fixnum 0 is returned in
* that case.
*/
VALUE
rb_cstr_to_inum(const char *str, int base, int badcheck)
{
char *end;
VALUE ret = rb_cstr_parse_inum(str, -1, (badcheck ? NULL : &end), base);
if (NIL_P(ret)) {
if (badcheck) rb_invalid_str(str, "Integer()");
ret = INT2FIX(0);
}
return ret;
}
/*
* Parse +str+ as Ruby Integer, i.e., underscores, 0d and 0b prefixes.
*
* str: pointer to the string to be parsed.
* should be NUL-terminated if +len+ is negative.
* len: length of +str+ if >= 0. if +len+ is negative, +str+ should
* be NUL-terminated.
* endp: if non-NULL, the address after parsed part is stored. if
* NULL, Qnil is returned when +str+ is not valid as an Integer.
* ndigits: if non-NULL, the number of parsed digits is stored.
* base: see +rb_cstr_to_inum+
* flags: bitwise OR of below flags:
* RB_INT_PARSE_SIGN: allow preceding spaces and +/- sign
* RB_INT_PARSE_UNDERSCORE: allow an underscore between digits
* RB_INT_PARSE_PREFIX: allow preceding prefix
*/
VALUE
rb_int_parse_cstr(const char *str, ssize_t len, char **endp, size_t *ndigits,
int base, int flags)
{
const char *const s = str;
char sign = 1;
int c;
VALUE z = Qnil;
unsigned long val;
int ov;
const char *digits_start, *digits_end;
size_t num_digits = 0;
size_t num_bdigits;
const ssize_t len0 = len;
const int badcheck = !endp;
#define ADV(n) do {\
if (len > 0 && len <= (n)) goto bad; \
str += (n); \
len -= (n); \
} while (0)
#define ASSERT_LEN() do {\
assert(len != 0); \
if (len0 >= 0) assert(s + len0 == str + len); \
} while (0)
if (!str) {
bad:
if (endp) *endp = (char *)str;
if (ndigits) *ndigits = num_digits;
return z;
}
if (len && (flags & RB_INT_PARSE_SIGN)) {
while (ISSPACE(*str)) ADV(1);
if (str[0] == '+') {
ADV(1);
}
else if (str[0] == '-') {
ADV(1);
sign = 0;
}
ASSERT_LEN();
}
if (base <= 0) {
if (str[0] == '0' && len > 1) {
switch (str[1]) {
case 'x': case 'X':
base = 16;
ADV(2);
break;
case 'b': case 'B':
base = 2;
ADV(2);
break;
case 'o': case 'O':
base = 8;
ADV(2);
break;
case 'd': case 'D':
base = 10;
ADV(2);
break;
default:
base = 8;
}
}
else if (base < -1) {
base = -base;
}
else {
base = 10;
}
}
else if (len == 1 || !(flags & RB_INT_PARSE_PREFIX)) {
/* no prefix */
}
else if (base == 2) {
if (str[0] == '0' && (str[1] == 'b'||str[1] == 'B')) {
ADV(2);
}
}
else if (base == 8) {
if (str[0] == '0' && (str[1] == 'o'||str[1] == 'O')) {
ADV(2);
}
}
else if (base == 10) {
if (str[0] == '0' && (str[1] == 'd'||str[1] == 'D')) {
ADV(2);
}
}
else if (base == 16) {
if (str[0] == '0' && (str[1] == 'x'||str[1] == 'X')) {
ADV(2);
}
}
if (!valid_radix_p(base)) {
invalid_radix(base);
}
if (!len) goto bad;
num_digits = str - s;
if (*str == '0' && len != 1) { /* squeeze preceding 0s */
int us = 0;
const char *end = len < 0 ? NULL : str + len;
++num_digits;
while ((c = *++str) == '0' ||
((flags & RB_INT_PARSE_UNDERSCORE) && c == '_')) {
if (c == '_') {
if (++us >= 2)
break;
}
else {
++num_digits;
us = 0;
}
if (str == end) break;
}
if (!c || ISSPACE(c)) --str;
if (end) len = end - str;
ASSERT_LEN();
}
c = *str;
c = conv_digit(c);
if (c < 0 || c >= base) {
if (!badcheck && num_digits) z = INT2FIX(0);
goto bad;
}
if (ndigits) *ndigits = num_digits;
val = ruby_scan_digits(str, len, base, &num_digits, &ov);
if (!ov) {
const char *end = &str[num_digits];
if (num_digits > 0 && *end == '_' && (flags & RB_INT_PARSE_UNDERSCORE))
goto bigparse;
if (endp) *endp = (char *)end;
if (ndigits) *ndigits += num_digits;
if (badcheck) {
if (num_digits == 0) return Qnil; /* no number */
while (len < 0 ? *end : end < str + len) {
if (!ISSPACE(*end)) return Qnil; /* trailing garbage */
end++;
}
}
if (POSFIXABLE(val)) {
if (sign) return LONG2FIX(val);
else {
long result = -(long)val;
return LONG2FIX(result);
}
}
else {
VALUE big = rb_uint2big(val);
BIGNUM_SET_SIGN(big, sign);
return bignorm(big);
}
}
bigparse:
digits_start = str;
if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
goto bad;
if (endp) *endp = (char *)(str + len);
if (ndigits) *ndigits += num_digits;
digits_end = digits_start + len;
if (POW2_P(base)) {
z = str2big_poweroftwo(sign, digits_start, digits_end, num_digits,
bit_length(base-1));
}
else {
int digits_per_bdigits_dbl;
maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
num_bdigits = roomof(num_digits, digits_per_bdigits_dbl)*2;
#ifdef USE_GMP
if (GMP_STR2BIG_DIGITS < num_bdigits) {
z = str2big_gmp(sign, digits_start, digits_end, num_digits,
num_bdigits, base);
}
else
#endif
if (num_bdigits < KARATSUBA_MUL_DIGITS) {
z = str2big_normal(sign, digits_start, digits_end,
num_bdigits, base);
}
else {
z = str2big_karatsuba(sign, digits_start, digits_end, num_digits,
num_bdigits, digits_per_bdigits_dbl, base);
}
}
return bignorm(z);
}
static VALUE
rb_cstr_parse_inum(const char *str, ssize_t len, char **endp, int base)
{
return rb_int_parse_cstr(str, len, endp, NULL, base,
RB_INT_PARSE_DEFAULT);
}
VALUE
rb_str_convert_to_inum(VALUE str, int base, int badcheck, int raise_exception)
{
VALUE ret;
const char *s;
long len;
char *end;
StringValue(str);
rb_must_asciicompat(str);
RSTRING_GETMEM(str, s, len);
ret = rb_cstr_parse_inum(s, len, (badcheck ? NULL : &end), base);
if (NIL_P(ret)) {
if (badcheck) {
if (!raise_exception) return Qnil;
invalid_integer(str);
}
ret = INT2FIX(0);
}
return ret;
}
VALUE
rb_str_to_inum(VALUE str, int base, int badcheck)
{
return rb_str_convert_to_inum(str, base, badcheck, TRUE);
}
VALUE
rb_str2big_poweroftwo(VALUE arg, int base, int badcheck)
{
int positive_p = 1;
const char *s, *str;
const char *digits_start, *digits_end;
size_t num_digits;
ssize_t len;
VALUE z;
if (!valid_radix_p(base) || !POW2_P(base)) {
invalid_radix(base);
}
rb_must_asciicompat(arg);
s = str = StringValueCStr(arg);
len = RSTRING_LEN(arg);
if (*str == '-') {
len--;
str++;
positive_p = 0;
}
digits_start = str;
if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
invalid_integer(arg);
digits_end = digits_start + len;
z = str2big_poweroftwo(positive_p, digits_start, digits_end, num_digits,
bit_length(base-1));
RB_GC_GUARD(arg);
return bignorm(z);
}
VALUE
rb_str2big_normal(VALUE arg, int base, int badcheck)
{
int positive_p = 1;
const char *s, *str;
const char *digits_start, *digits_end;
size_t num_digits;
ssize_t len;
VALUE z;
int digits_per_bdigits_dbl;
size_t num_bdigits;
if (!valid_radix_p(base)) {
invalid_radix(base);
}
rb_must_asciicompat(arg);
s = str = StringValuePtr(arg);
len = RSTRING_LEN(arg);
if (len > 0 && *str == '-') {
len--;
str++;
positive_p = 0;
}
digits_start = str;
if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
invalid_integer(arg);
digits_end = digits_start + len;
maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
num_bdigits = roomof(num_digits, digits_per_bdigits_dbl)*2;
z = str2big_normal(positive_p, digits_start, digits_end,
num_bdigits, base);
RB_GC_GUARD(arg);
return bignorm(z);
}
VALUE
rb_str2big_karatsuba(VALUE arg, int base, int badcheck)
{
int positive_p = 1;
const char *s, *str;
const char *digits_start, *digits_end;
size_t num_digits;
ssize_t len;
VALUE z;
int digits_per_bdigits_dbl;
size_t num_bdigits;
if (!valid_radix_p(base)) {
invalid_radix(base);
}
rb_must_asciicompat(arg);
s = str = StringValuePtr(arg);
len = RSTRING_LEN(arg);
if (len > 0 && *str == '-') {
len--;
str++;
positive_p = 0;
}
digits_start = str;
if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
invalid_integer(arg);
digits_end = digits_start + len;
maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
num_bdigits = roomof(num_digits, digits_per_bdigits_dbl)*2;
z = str2big_karatsuba(positive_p, digits_start, digits_end, num_digits,
num_bdigits, digits_per_bdigits_dbl, base);
RB_GC_GUARD(arg);
return bignorm(z);
}
#ifdef USE_GMP
VALUE
rb_str2big_gmp(VALUE arg, int base, int badcheck)
{
int positive_p = 1;
const char *s, *str;
const char *digits_start, *digits_end;
size_t num_digits;
ssize_t len;
VALUE z;
int digits_per_bdigits_dbl;
size_t num_bdigits;
if (!valid_radix_p(base)) {
invalid_radix(base);
}
rb_must_asciicompat(arg);
s = str = StringValuePtr(arg);
len = RSTRING_LEN(arg);
if (len > 0 && *str == '-') {
len--;
str++;
positive_p = 0;
}
digits_start = str;
if (!str2big_scan_digits(s, str, base, badcheck, &num_digits, &len))
invalid_integer(arg);
digits_end = digits_start + len;
maxpow_in_bdigit_dbl(base, &digits_per_bdigits_dbl);
num_bdigits = roomof(num_digits, digits_per_bdigits_dbl)*2;
z = str2big_gmp(positive_p, digits_start, digits_end, num_digits, num_bdigits, base);
RB_GC_GUARD(arg);
return bignorm(z);
}
#endif
#if HAVE_LONG_LONG
static VALUE
rb_ull2big(unsigned LONG_LONG n)
{
long i;
VALUE big = bignew(bdigit_roomof(SIZEOF_LONG_LONG), 1);
BDIGIT *digits = BDIGITS(big);
#if SIZEOF_BDIGIT >= SIZEOF_LONG_LONG
digits[0] = n;
#else
for (i = 0; i < bdigit_roomof(SIZEOF_LONG_LONG); i++) {
digits[i] = BIGLO(n);
n = BIGDN(n);
}
#endif
i = bdigit_roomof(SIZEOF_LONG_LONG);
while (i-- && !digits[i]) ;
BIGNUM_SET_LEN(big, i+1);
return big;
}
static VALUE
rb_ll2big(LONG_LONG n)
{
long neg = 0;
unsigned LONG_LONG u;
VALUE big;
if (n < 0) {
u = 1 + (unsigned LONG_LONG)(-(n + 1)); /* u = -n avoiding overflow */
neg = 1;
}
else {
u = n;
}
big = rb_ull2big(u);
if (neg) {
BIGNUM_SET_NEGATIVE_SIGN(big);
}
return big;
}
VALUE
rb_ull2inum(unsigned LONG_LONG n)
{
if (POSFIXABLE(n)) return LONG2FIX(n);
return rb_ull2big(n);
}
VALUE
rb_ll2inum(LONG_LONG n)
{
if (FIXABLE(n)) return LONG2FIX(n);
return rb_ll2big(n);
}
#endif /* HAVE_LONG_LONG */
#ifdef HAVE_INT128_T
static VALUE
rb_uint128t2big(uint128_t n)
{
long i;
VALUE big = bignew(bdigit_roomof(SIZEOF_INT128_T), 1);
BDIGIT *digits = BDIGITS(big);
for (i = 0; i < bdigit_roomof(SIZEOF_INT128_T); i++) {
digits[i] = BIGLO(RSHIFT(n ,BITSPERDIG*i));
}
i = bdigit_roomof(SIZEOF_INT128_T);
while (i-- && !digits[i]) ;
BIGNUM_SET_LEN(big, i+1);
return big;
}
MJIT_FUNC_EXPORTED VALUE
rb_int128t2big(int128_t n)
{
int neg = 0;
uint128_t u;
VALUE big;
if (n < 0) {
u = 1 + (uint128_t)(-(n + 1)); /* u = -n avoiding overflow */
neg = 1;
}
else {
u = n;
}
big = rb_uint128t2big(u);
if (neg) {
BIGNUM_SET_NEGATIVE_SIGN(big);
}
return big;
}
#endif
VALUE
rb_cstr2inum(const char *str, int base)
{
return rb_cstr_to_inum(str, base, base==0);
}
VALUE
rb_str2inum(VALUE str, int base)
{
return rb_str_to_inum(str, base, base==0);
}
static VALUE
big_shift3(VALUE x, int lshift_p, size_t shift_numdigits, int shift_numbits)
{
BDIGIT *xds, *zds;
long s1;
int s2;
VALUE z;
long xn;
if (lshift_p) {
if (LONG_MAX < shift_numdigits) {
rb_raise(rb_eArgError, "too big number");
}
s1 = shift_numdigits;
s2 = shift_numbits;
xn = BIGNUM_LEN(x);
z = bignew(xn+s1+1, BIGNUM_SIGN(x));
zds = BDIGITS(z);
BDIGITS_ZERO(zds, s1);
xds = BDIGITS(x);
zds[xn+s1] = bary_small_lshift(zds+s1, xds, xn, s2);
}
else {
long zn;
BDIGIT hibitsx;
if (LONG_MAX < shift_numdigits || (size_t)BIGNUM_LEN(x) <= shift_numdigits) {
if (BIGNUM_POSITIVE_P(x) ||
bary_zero_p(BDIGITS(x), BIGNUM_LEN(x)))
return INT2FIX(0);
else
return INT2FIX(-1);
}
s1 = shift_numdigits;
s2 = shift_numbits;
hibitsx = abs2twocomp(&x, &xn);
xds = BDIGITS(x);
if (xn <= s1) {
return hibitsx ? INT2FIX(-1) : INT2FIX(0);
}
zn = xn - s1;
z = bignew(zn, 0);
zds = BDIGITS(z);
bary_small_rshift(zds, xds+s1, zn, s2, hibitsx != 0 ? BDIGMAX : 0);
twocomp2abs_bang(z, hibitsx != 0);
}
RB_GC_GUARD(x);
return z;
}
static VALUE
big_shift2(VALUE x, int lshift_p, VALUE y)
{
int sign;
size_t lens[2];
size_t shift_numdigits;
int shift_numbits;
assert(POW2_P(CHAR_BIT));
assert(POW2_P(BITSPERDIG));
if (BIGZEROP(x))
return INT2FIX(0);
sign = rb_integer_pack(y, lens, numberof(lens), sizeof(size_t), 0,
INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER);
if (sign < 0) {
lshift_p = !lshift_p;
sign = -sign;
}
if (lshift_p) {
if (1 < sign || CHAR_BIT <= lens[1])
rb_raise(rb_eRangeError, "shift width too big");
}
else {
if (1 < sign || CHAR_BIT <= lens[1])
return BIGNUM_POSITIVE_P(x) ? INT2FIX(0) : INT2FIX(-1);
}
shift_numbits = (int)(lens[0] & (BITSPERDIG-1));
shift_numdigits = (lens[0] >> bit_length(BITSPERDIG-1)) |
(lens[1] << (CHAR_BIT*SIZEOF_SIZE_T - bit_length(BITSPERDIG-1)));
return big_shift3(x, lshift_p, shift_numdigits, shift_numbits);
}
static VALUE
big_lshift(VALUE x, unsigned long shift)
{
long s1 = shift/BITSPERDIG;
int s2 = (int)(shift%BITSPERDIG);
return big_shift3(x, 1, s1, s2);
}
static VALUE
big_rshift(VALUE x, unsigned long shift)
{
long s1 = shift/BITSPERDIG;
int s2 = (int)(shift%BITSPERDIG);
return big_shift3(x, 0, s1, s2);
}
#define MAX_BASE36_POWER_TABLE_ENTRIES (SIZEOF_SIZE_T * CHAR_BIT + 1)
static VALUE base36_power_cache[35][MAX_BASE36_POWER_TABLE_ENTRIES];
static size_t base36_numdigits_cache[35][MAX_BASE36_POWER_TABLE_ENTRIES];
static void
power_cache_init(void)
{
int i, j;
for (i = 0; i < 35; ++i) {
for (j = 0; j < MAX_BASE36_POWER_TABLE_ENTRIES; ++j) {
base36_power_cache[i][j] = Qnil;
}
}
}
static inline VALUE
power_cache_get_power(int base, int power_level, size_t *numdigits_ret)
{
/*
* MAX_BASE36_POWER_TABLE_ENTRIES is big enough to that
* base36_power_cache[base][MAX_BASE36_POWER_TABLE_ENTRIES-1] fills whole memory.
* So MAX_BASE36_POWER_TABLE_ENTRIES <= power_level is not possible to calculate.
*
* number-of-bytes =
* log256(base36_power_cache[base][MAX_BASE36_POWER_TABLE_ENTRIES-1]) =
* log256(maxpow_in_bdigit_dbl(base)**(2**(MAX_BASE36_POWER_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_BASE36_POWER_TABLE_ENTRIES <= power_level)
rb_bug("too big power number requested: maxpow_in_bdigit_dbl(%d)**(2**%d)", base, power_level);
if (NIL_P(base36_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);
bdigitdbl2bary(BDIGITS(power), 2, dd);
numdigits = numdigits0;
}
else {
power = bigtrunc(bigsq(power_cache_get_power(base, power_level - 1, &numdigits)));
numdigits *= 2;
}
rb_obj_hide(power);
base36_power_cache[base - 2][power_level] = power;
base36_numdigits_cache[base - 2][power_level] = numdigits;
rb_gc_register_mark_object(power);
}
if (numdigits_ret)
*numdigits_ret = base36_numdigits_cache[base - 2][power_level];
return base36_power_cache[base - 2][power_level];
}
struct big2str_struct {
int negative;
int base;
BDIGIT_DBL hbase2;
int hbase2_numdigits;
VALUE result;
char *ptr;
};
static void
big2str_alloc(struct big2str_struct *b2s, size_t len)
{
if (LONG_MAX-1 < len)
rb_raise(rb_eArgError, "too big number");
b2s->result = rb_usascii_str_new(0, (long)(len + 1)); /* plus one for sign */
b2s->ptr = RSTRING_PTR(b2s->result);
if (b2s->negative)
*b2s->ptr++ = '-';
}
static void
big2str_2bdigits(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t taillen)
{
size_t j;
BDIGIT_DBL num;
char buf[SIZEOF_BDIGIT_DBL*CHAR_BIT], *p;
int beginning = !b2s->ptr;
size_t len = 0;
assert(xn <= 2);
num = bary2bdigitdbl(xds, xn);
if (beginning) {
if (num == 0)
return;
p = buf;
j = sizeof(buf);
do {
BDIGIT_DBL idx = num % b2s->base;
num /= b2s->base;
p[--j] = ruby_digitmap[idx];
} while (num);
len = sizeof(buf) - j;
big2str_alloc(b2s, len + taillen);
MEMCPY(b2s->ptr, buf + j, char, len);
}
else {
p = b2s->ptr;
j = b2s->hbase2_numdigits;
do {
BDIGIT_DBL idx = num % b2s->base;
num /= b2s->base;
p[--j] = ruby_digitmap[idx];
} while (j);
len = b2s->hbase2_numdigits;
}
b2s->ptr += len;
}
static void
big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
int power_level, size_t taillen)
{
VALUE b;
size_t half_numdigits, lower_numdigits;
int lower_power_level;
size_t bn;
const BDIGIT *bds;
size_t len;
/*
* Precondition:
* abs(x) < maxpow**(2**power_level)
* where
* maxpow = maxpow_in_bdigit_dbl(base, &numdigits)
*
* This function generates sequence of zeros, and then stringized abs(x) into b2s->ptr.
*
* b2s->ptr can be NULL.
* It is allocated when the first character is generated via big2str_alloc.
*
* The prefix zeros should be generated if and only if b2s->ptr is not NULL.
* When the zeros are generated, the zeros and abs(x) consists
* numdigits*(2**power_level) characters at total.
*
* Note:
* power_cache_get_power(base, power_level, &len) may not be cached yet. It should not be called.
* power_cache_get_power(base, power_level-1, &len) should be cached already if 0 <= power_level-1.
*/
if (xn == 0 || bary_zero_p(xds, xn)) {
if (b2s->ptr) {
/* When x is zero, power_cache_get_power(base, power_level) should be cached already. */
power_cache_get_power(b2s->base, power_level, &len);
memset(b2s->ptr, '0', len);
b2s->ptr += len;
}
return;
}
if (power_level == 0) {
big2str_2bdigits(b2s, xds, xn, taillen);
return;
}
lower_power_level = power_level-1;
b = power_cache_get_power(b2s->base, lower_power_level, &lower_numdigits);
bn = BIGNUM_LEN(b);
bds = BDIGITS(b);
half_numdigits = lower_numdigits;
while (0 < lower_power_level &&
(xn < bn ||
(xn == bn && bary_cmp(xds, xn, bds, bn) < 0))) {
lower_power_level--;
b = power_cache_get_power(b2s->base, lower_power_level, &lower_numdigits);
bn = BIGNUM_LEN(b);
bds = BDIGITS(b);
}
if (lower_power_level == 0 &&
(xn < bn ||
(xn == bn && bary_cmp(xds, xn, bds, bn) < 0))) {
if (b2s->ptr) {
len = half_numdigits * 2 - lower_numdigits;
memset(b2s->ptr, '0', len);
b2s->ptr += len;
}
big2str_2bdigits(b2s, xds, xn, taillen);
}
else {
BDIGIT *qds, *rds;
size_t qn, rn;
BDIGIT *tds;
int shift;
if (lower_power_level != power_level-1 && b2s->ptr) {
len = (half_numdigits - lower_numdigits) * 2;
memset(b2s->ptr, '0', len);
b2s->ptr += len;
}
shift = nlz(bds[bn-1]);
qn = xn + BIGDIVREM_EXTRA_WORDS;
if (shift == 0) {
/* bigdivrem_restoring will not modify y.
* So use bds directly. */
tds = (BDIGIT *)bds;
xds[xn] = 0;
}
else {
/* bigdivrem_restoring will modify y.
* So use temporary buffer. */
tds = xds + qn;
assert(qn + bn <= xn + wn);
bary_small_lshift(tds, bds, bn, shift);
xds[xn] = bary_small_lshift(xds, xds, xn, shift);
}
bigdivrem_restoring(xds, qn, tds, bn);
rds = xds;
rn = bn;
qds = xds + bn;
qn = qn - bn;
if (shift) {
bary_small_rshift(rds, rds, rn, shift, 0);
}
BARY_TRUNC(qds, qn);
assert(qn <= bn);
big2str_karatsuba(b2s, qds, qn, xn+wn - (rn+qn), lower_power_level, lower_numdigits+taillen);
BARY_TRUNC(rds, rn);
big2str_karatsuba(b2s, rds, rn, xn+wn - rn, lower_power_level, taillen);
}
}
static VALUE
big2str_base_poweroftwo(VALUE x, int base)
{
int word_numbits = ffs(base) - 1;
size_t numwords;
VALUE result;
char *ptr;
numwords = rb_absint_numwords(x, word_numbits, NULL);
if (BIGNUM_NEGATIVE_P(x)) {
if (LONG_MAX-1 < numwords)
rb_raise(rb_eArgError, "too big number");
result = rb_usascii_str_new(0, 1+numwords);
ptr = RSTRING_PTR(result);
*ptr++ = BIGNUM_POSITIVE_P(x) ? '+' : '-';
}
else {
if (LONG_MAX < numwords)
rb_raise(rb_eArgError, "too big number");
result = rb_usascii_str_new(0, numwords);
ptr = RSTRING_PTR(result);
}
rb_integer_pack(x, ptr, numwords, 1, CHAR_BIT-word_numbits,
INTEGER_PACK_BIG_ENDIAN);
while (0 < numwords) {
*ptr = ruby_digitmap[*(unsigned char *)ptr];
ptr++;
numwords--;
}
return result;
}
VALUE
rb_big2str_poweroftwo(VALUE x, int base)
{
return big2str_base_poweroftwo(x, base);
}
static VALUE
big2str_generic(VALUE x, int base)
{
BDIGIT *xds;
size_t xn;
struct big2str_struct b2s_data;
int power_level;
VALUE power;
xds = BDIGITS(x);
xn = BIGNUM_LEN(x);
BARY_TRUNC(xds, xn);
if (xn == 0) {
return rb_usascii_str_new2("0");
}
if (!valid_radix_p(base))
invalid_radix(base);
if (xn >= LONG_MAX/BITSPERDIG) {
rb_raise(rb_eRangeError, "bignum too big to convert into `string'");
}
power_level = 0;
power = power_cache_get_power(base, power_level, NULL);
while (power_level < MAX_BASE36_POWER_TABLE_ENTRIES &&
(size_t)BIGNUM_LEN(power) <= (xn+1)/2) {
power_level++;
power = power_cache_get_power(base, power_level, NULL);
}
assert(power_level != MAX_BASE36_POWER_TABLE_ENTRIES);
if ((size_t)BIGNUM_LEN(power) <= xn) {
/*
* This increment guarantees x < power_cache_get_power(base, power_level)
* without invoking it actually.
* (power_cache_get_power(base, power_level) can be slow and not used
* in big2str_karatsuba.)
*
* Although it is possible that x < power_cache_get_power(base, power_level-1),
* it is no problem because big2str_karatsuba checks it and
* doesn't affect the result when b2s_data.ptr is NULL.
*/
power_level++;
}
b2s_data.negative = BIGNUM_NEGATIVE_P(x);
b2s_data.base = base;
b2s_data.hbase2 = maxpow_in_bdigit_dbl(base, &b2s_data.hbase2_numdigits);
b2s_data.result = Qnil;
b2s_data.ptr = NULL;
if (power_level == 0) {
big2str_2bdigits(&b2s_data, xds, xn, 0);
}
else {
VALUE tmpw = 0;
BDIGIT *wds;
size_t wn;
wn = power_level * BIGDIVREM_EXTRA_WORDS + BIGNUM_LEN(power);
wds = ALLOCV_N(BDIGIT, tmpw, xn + wn);
MEMCPY(wds, xds, BDIGIT, xn);
big2str_karatsuba(&b2s_data, wds, xn, wn, power_level, 0);
if (tmpw)
ALLOCV_END(tmpw);
}
RB_GC_GUARD(x);
*b2s_data.ptr = '\0';
rb_str_resize(b2s_data.result, (long)(b2s_data.ptr - RSTRING_PTR(b2s_data.result)));
RB_GC_GUARD(x);
return b2s_data.result;
}
VALUE
rb_big2str_generic(VALUE x, int base)
{
return big2str_generic(x, base);
}
#ifdef USE_GMP
static VALUE
big2str_gmp(VALUE x, int base)
{
mpz_t mx;
size_t size;
VALUE str;
BDIGIT *xds = BDIGITS(x);
size_t xn = BIGNUM_LEN(x);
mpz_init(mx);
bdigits_to_mpz(mx, xds, xn);
size = mpz_sizeinbase(mx, base);
if (BIGNUM_NEGATIVE_P(x)) {
mpz_neg(mx, mx);
str = rb_usascii_str_new(0, size+1);
}
else {
str = rb_usascii_str_new(0, size);
}
mpz_get_str(RSTRING_PTR(str), base, mx);
mpz_clear(mx);
if (RSTRING_PTR(str)[RSTRING_LEN(str)-1] == '\0') {
rb_str_set_len(str, RSTRING_LEN(str)-1);
}
RB_GC_GUARD(x);
return str;
}
VALUE
rb_big2str_gmp(VALUE x, int base)
{
return big2str_gmp(x, base);
}
#endif
static VALUE
rb_big2str1(VALUE x, int base)
{
BDIGIT *xds;
size_t xn;
if (FIXNUM_P(x)) {
return rb_fix2str(x, base);
}
bigtrunc(x);
xds = BDIGITS(x);
xn = BIGNUM_LEN(x);
BARY_TRUNC(xds, xn);
if (xn == 0) {
return rb_usascii_str_new2("0");
}
if (!valid_radix_p(base))
invalid_radix(base);
if (xn >= LONG_MAX/BITSPERDIG) {
rb_raise(rb_eRangeError, "bignum too big to convert into `string'");
}
if (POW2_P(base)) {
/* base == 2 || base == 4 || base == 8 || base == 16 || base == 32 */
return big2str_base_poweroftwo(x, base);
}
#ifdef USE_GMP
if (GMP_BIG2STR_DIGITS < xn) {
return big2str_gmp(x, base);
}
#endif
return big2str_generic(x, base);
}
VALUE
rb_big2str(VALUE x, int base)
{
return rb_big2str1(x, base);
}
static unsigned long
big2ulong(VALUE x, const char *type)
{
#if SIZEOF_LONG > SIZEOF_BDIGIT
size_t i;
#endif
size_t len = BIGNUM_LEN(x);
unsigned long num;
BDIGIT *ds;
if (len == 0)
return 0;
if (BIGSIZE(x) > sizeof(long)) {
rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type);
}
ds = BDIGITS(x);
#if SIZEOF_LONG <= SIZEOF_BDIGIT
num = (unsigned long)ds[0];
#else
num = 0;
for (i = 0; i < len; i++) {
num <<= BITSPERDIG;
num += (unsigned long)ds[len - i - 1]; /* overflow is already checked */
}
#endif
return num;
}
unsigned long
rb_big2ulong(VALUE x)
{
unsigned long num = big2ulong(x, "unsigned long");
if (BIGNUM_POSITIVE_P(x)) {
return num;
}
else {
if (num <= 1+(unsigned long)(-(LONG_MIN+1)))
return -(long)(num-1)-1;
}
rb_raise(rb_eRangeError, "bignum out of range of unsigned long");
}
long
rb_big2long(VALUE x)
{
unsigned long num = big2ulong(x, "long");
if (BIGNUM_POSITIVE_P(x)) {
if (num <= LONG_MAX)
return num;
}
else {
if (num <= 1+(unsigned long)(-(LONG_MIN+1)))
return -(long)(num-1)-1;
}
rb_raise(rb_eRangeError, "bignum too big to convert into `long'");
}
#if HAVE_LONG_LONG
static unsigned LONG_LONG
big2ull(VALUE x, const char *type)
{
#if SIZEOF_LONG_LONG > SIZEOF_BDIGIT
size_t i;
#endif
size_t len = BIGNUM_LEN(x);
unsigned LONG_LONG num;
BDIGIT *ds = BDIGITS(x);
if (len == 0)
return 0;
if (BIGSIZE(x) > SIZEOF_LONG_LONG)
rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type);
#if SIZEOF_LONG_LONG <= SIZEOF_BDIGIT
num = (unsigned LONG_LONG)ds[0];
#else
num = 0;
for (i = 0; i < len; i++) {
num = BIGUP(num);
num += ds[len - i - 1];
}
#endif
return num;
}
unsigned LONG_LONG
rb_big2ull(VALUE x)
{
unsigned LONG_LONG num = big2ull(x, "unsigned long long");
if (BIGNUM_POSITIVE_P(x)) {
return num;
}
else {
if (num <= 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
return -(LONG_LONG)(num-1)-1;
}
rb_raise(rb_eRangeError, "bignum out of range of unsigned long long");
}
LONG_LONG
rb_big2ll(VALUE x)
{
unsigned LONG_LONG num = big2ull(x, "long long");
if (BIGNUM_POSITIVE_P(x)) {
if (num <= LLONG_MAX)
return num;
}
else {
if (num <= 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
return -(LONG_LONG)(num-1)-1;
}
rb_raise(rb_eRangeError, "bignum too big to convert into `long long'");
}
#endif /* HAVE_LONG_LONG */
static VALUE
dbl2big(double d)
{
long i = 0;
BDIGIT c;
BDIGIT *digits;
VALUE z;
double u = (d < 0)?-d:d;
if (isinf(d)) {
rb_raise(rb_eFloatDomainError, d < 0 ? "-Infinity" : "Infinity");
}
if (isnan(d)) {
rb_raise(rb_eFloatDomainError, "NaN");
}
while (1.0 <= u) {
u /= (double)(BIGRAD);
i++;
}
z = bignew(i, d>=0);
digits = BDIGITS(z);
while (i--) {
u *= BIGRAD;
c = (BDIGIT)u;
u -= c;
digits[i] = c;
}
return z;
}
VALUE
rb_dbl2big(double d)
{
return bignorm(dbl2big(d));
}
static double
big2dbl(VALUE x)
{
double d = 0.0;
long i = (bigtrunc(x), BIGNUM_LEN(x)), lo = 0, bits;
BDIGIT *ds = BDIGITS(x), dl;
if (i) {
bits = i * BITSPERDIG - nlz(ds[i-1]);
if (bits > DBL_MANT_DIG+DBL_MAX_EXP) {
d = HUGE_VAL;
}
else {
if (bits > DBL_MANT_DIG+1)
lo = (bits -= DBL_MANT_DIG+1) / BITSPERDIG;
else
bits = 0;
while (--i > lo) {
d = ds[i] + BIGRAD*d;
}
dl = ds[i];
if (bits && (dl & ((BDIGIT)1 << (bits %= BITSPERDIG)))) {
int carry = (dl & ~(BDIGMAX << bits)) != 0;
if (!carry) {
while (i-- > 0) {
carry = ds[i] != 0;
if (carry) break;
}
}
if (carry) {
BDIGIT mask = BDIGMAX;
BDIGIT bit = 1;
mask <<= bits;
bit <<= bits;
dl &= mask;
dl += bit;
dl = BIGLO(dl);
if (!dl) d += 1;
}
}
d = dl + BIGRAD*d;
if (lo) {
if (lo > INT_MAX / BITSPERDIG)
d = HUGE_VAL;
else if (lo < INT_MIN / BITSPERDIG)
d = 0.0;
else
d = ldexp(d, (int)(lo * BITSPERDIG));
}
}
}
if (BIGNUM_NEGATIVE_P(x)) d = -d;
return d;
}
double
rb_big2dbl(VALUE x)
{
double d = big2dbl(x);
if (isinf(d)) {
rb_warning("Bignum out of Float range");
if (d < 0.0)
d = -HUGE_VAL;
else
d = HUGE_VAL;
}
return d;
}
VALUE
rb_integer_float_cmp(VALUE x, VALUE y)
{
double yd = RFLOAT_VALUE(y);
double yi, yf;
VALUE rel;
if (isnan(yd))
return Qnil;
if (isinf(yd)) {
if (yd > 0.0) return INT2FIX(-1);
else return INT2FIX(1);
}
yf = modf(yd, &yi);
if (FIXNUM_P(x)) {
#if SIZEOF_LONG * CHAR_BIT < DBL_MANT_DIG /* assume FLT_RADIX == 2 */
double xd = (double)FIX2LONG(x);
if (xd < yd)
return INT2FIX(-1);
if (xd > yd)
return INT2FIX(1);
return INT2FIX(0);
#else
long xn, yn;
if (yi < FIXNUM_MIN)
return INT2FIX(1);
if (FIXNUM_MAX+1 <= yi)
return INT2FIX(-1);
xn = FIX2LONG(x);
yn = (long)yi;
if (xn < yn)
return INT2FIX(-1);
if (xn > yn)
return INT2FIX(1);
if (yf < 0.0)
return INT2FIX(1);
if (0.0 < yf)
return INT2FIX(-1);
return INT2FIX(0);
#endif
}
y = rb_dbl2big(yi);
rel = rb_big_cmp(x, y);
if (yf == 0.0 || rel != INT2FIX(0))
return rel;
if (yf < 0.0)
return INT2FIX(1);
return INT2FIX(-1);
}
#if SIZEOF_LONG * CHAR_BIT >= DBL_MANT_DIG /* assume FLT_RADIX == 2 */
COMPILER_WARNING_PUSH
#if __has_warning("-Wimplicit-int-float-conversion")
COMPILER_WARNING_IGNORED(-Wimplicit-int-float-conversion)
#endif
static const double LONG_MAX_as_double = LONG_MAX;
COMPILER_WARNING_POP
#endif
VALUE
rb_integer_float_eq(VALUE x, VALUE y)
{
double yd = RFLOAT_VALUE(y);
double yi, yf;
if (isnan(yd) || isinf(yd))
return Qfalse;
yf = modf(yd, &yi);
if (yf != 0)
return Qfalse;
if (FIXNUM_P(x)) {
#if SIZEOF_LONG * CHAR_BIT < DBL_MANT_DIG /* assume FLT_RADIX == 2 */
double xd = (double)FIX2LONG(x);
if (xd != yd)
return Qfalse;
return Qtrue;
#else
long xn, yn;
if (yi < LONG_MIN || LONG_MAX_as_double <= yi)
return Qfalse;
xn = FIX2LONG(x);
yn = (long)yi;
if (xn != yn)
return Qfalse;
return Qtrue;
#endif
}
y = rb_dbl2big(yi);
return rb_big_eq(x, y);
}
VALUE
rb_big_cmp(VALUE x, VALUE y)
{
if (FIXNUM_P(y)) {
x = bigfixize(x);
if (FIXNUM_P(x)) {
/* SIGNED_VALUE and Fixnum have same sign-bits, same
* order */
SIGNED_VALUE sx = (SIGNED_VALUE)x, sy = (SIGNED_VALUE)y;
if (sx < sy) return INT2FIX(-1);
return INT2FIX(sx > sy);
}
}
else if (RB_BIGNUM_TYPE_P(y)) {
if (BIGNUM_SIGN(x) == BIGNUM_SIGN(y)) {
int cmp = bary_cmp(BDIGITS(x), BIGNUM_LEN(x), BDIGITS(y), BIGNUM_LEN(y));
return INT2FIX(BIGNUM_SIGN(x) ? cmp : -cmp);
}
}
else if (RB_FLOAT_TYPE_P(y)) {
return rb_integer_float_cmp(x, y);
}
else {
return rb_num_coerce_cmp(x, y, idCmp);
}
return INT2FIX(BIGNUM_SIGN(x) ? 1 : -1);
}
enum big_op_t {
big_op_gt,
big_op_ge,
big_op_lt,
big_op_le
};
static VALUE
big_op(VALUE x, VALUE y, enum big_op_t op)
{
VALUE rel;
int n;
if (RB_INTEGER_TYPE_P(y)) {
rel = rb_big_cmp(x, y);
}
else if (RB_FLOAT_TYPE_P(y)) {
rel = rb_integer_float_cmp(x, y);
}
else {
ID id = 0;
switch (op) {
case big_op_gt: id = '>'; break;
case big_op_ge: id = idGE; break;
case big_op_lt: id = '<'; break;
case big_op_le: id = idLE; break;
}
return rb_num_coerce_relop(x, y, id);
}
if (NIL_P(rel)) return Qfalse;
n = FIX2INT(rel);
switch (op) {
case big_op_gt: return n > 0 ? Qtrue : Qfalse;
case big_op_ge: return n >= 0 ? Qtrue : Qfalse;
case big_op_lt: return n < 0 ? Qtrue : Qfalse;
case big_op_le: return n <= 0 ? Qtrue : Qfalse;
}
return Qundef;
}
VALUE
rb_big_gt(VALUE x, VALUE y)
{
return big_op(x, y, big_op_gt);
}
VALUE
rb_big_ge(VALUE x, VALUE y)
{
return big_op(x, y, big_op_ge);
}
VALUE
rb_big_lt(VALUE x, VALUE y)
{
return big_op(x, y, big_op_lt);
}
VALUE
rb_big_le(VALUE x, VALUE y)
{
return big_op(x, y, big_op_le);
}
/*
* call-seq:
* big == obj -> true or false
*
* Returns <code>true</code> only if <i>obj</i> has the same value
* as <i>big</i>. Contrast this with Integer#eql?, which requires
* <i>obj</i> to be a Integer.
*
* 68719476736 == 68719476736.0 #=> true
*/
VALUE
rb_big_eq(VALUE x, VALUE y)
{
if (FIXNUM_P(y)) {
return bignorm(x) == y ? Qtrue : Qfalse;
}
else if (RB_BIGNUM_TYPE_P(y)) {
}
else if (RB_FLOAT_TYPE_P(y)) {
return rb_integer_float_eq(x, y);
}
else {
return rb_equal(y, x);
}
if (BIGNUM_SIGN(x) != BIGNUM_SIGN(y)) return Qfalse;
if (BIGNUM_LEN(x) != BIGNUM_LEN(y)) return Qfalse;
if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,BIGNUM_LEN(y)) != 0) return Qfalse;
return Qtrue;
}
VALUE
rb_big_eql(VALUE x, VALUE y)
{
if (!RB_BIGNUM_TYPE_P(y)) return Qfalse;
if (BIGNUM_SIGN(x) != BIGNUM_SIGN(y)) return Qfalse;
if (BIGNUM_LEN(x) != BIGNUM_LEN(y)) return Qfalse;
if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,BIGNUM_LEN(y)) != 0) return Qfalse;
return Qtrue;
}
VALUE
rb_big_uminus(VALUE x)
{
VALUE z = rb_big_clone(x);
BIGNUM_NEGATE(z);
return bignorm(z);
}
VALUE
rb_big_comp(VALUE x)
{
VALUE z = rb_big_clone(x);
BDIGIT *ds = BDIGITS(z);
long n = BIGNUM_LEN(z);
if (!n) return INT2FIX(-1);
if (BIGNUM_POSITIVE_P(z)) {
if (bary_add_one(ds, n)) {
big_extend_carry(z);
}
BIGNUM_SET_NEGATIVE_SIGN(z);
}
else {
bary_neg(ds, n);
if (bary_add_one(ds, n))
return INT2FIX(-1);
bary_neg(ds, n);
BIGNUM_SET_POSITIVE_SIGN(z);
}
return bignorm(z);
}
static VALUE
bigsub(VALUE x, VALUE y)
{
VALUE z;
BDIGIT *xds, *yds, *zds;
long xn, yn, zn;
xn = BIGNUM_LEN(x);
yn = BIGNUM_LEN(y);
zn = xn < yn ? yn : xn;
z = bignew(zn, 1);
xds = BDIGITS(x);
yds = BDIGITS(y);
zds = BDIGITS(z);
if (bary_sub(zds, zn, xds, xn, yds, yn)) {
bary_2comp(zds, zn);
BIGNUM_SET_NEGATIVE_SIGN(z);
}
return z;
}
static VALUE bigadd_int(VALUE x, long y);
static VALUE
bigsub_int(VALUE x, long y0)
{
VALUE z;
BDIGIT *xds, *zds;
long xn, zn;
BDIGIT_DBL_SIGNED num;
long i, y;
y = y0;
xds = BDIGITS(x);
xn = BIGNUM_LEN(x);
if (xn == 0)
return LONG2NUM(-y0);
zn = xn;
#if SIZEOF_BDIGIT < SIZEOF_LONG
if (zn < bdigit_roomof(SIZEOF_LONG))
zn = bdigit_roomof(SIZEOF_LONG);
#endif
z = bignew(zn, BIGNUM_SIGN(x));
zds = BDIGITS(z);
#if SIZEOF_BDIGIT >= SIZEOF_LONG
assert(xn == zn);
num = (BDIGIT_DBL_SIGNED)xds[0] - y;
if (xn == 1 && num < 0) {
BIGNUM_NEGATE(z);
zds[0] = (BDIGIT)-num;
RB_GC_GUARD(x);
return bignorm(z);
}
zds[0] = BIGLO(num);
num = BIGDN(num);
i = 1;
if (i < xn)
goto y_is_zero_x;
goto finish;
#else
num = 0;
for (i=0; i < xn; i++) {
if (y == 0) goto y_is_zero_x;
num += (BDIGIT_DBL_SIGNED)xds[i] - BIGLO(y);
zds[i] = BIGLO(num);
num = BIGDN(num);
y = BIGDN(y);
}
for (; i < zn; i++) {
if (y == 0) goto y_is_zero_z;
num -= BIGLO(y);
zds[i] = BIGLO(num);
num = BIGDN(num);
y = BIGDN(y);
}
goto finish;
#endif
for (; i < xn; i++) {
y_is_zero_x:
if (num == 0) goto num_is_zero_x;
num += xds[i];
zds[i] = BIGLO(num);
num = BIGDN(num);
}
#if SIZEOF_BDIGIT < SIZEOF_LONG
for (; i < zn; i++) {
y_is_zero_z:
if (num == 0) goto num_is_zero_z;
zds[i] = BIGLO(num);
num = BIGDN(num);
}
#endif
goto finish;
for (; i < xn; i++) {
num_is_zero_x:
zds[i] = xds[i];
}
#if SIZEOF_BDIGIT < SIZEOF_LONG
for (; i < zn; i++) {
num_is_zero_z:
zds[i] = 0;
}
#endif
goto finish;
finish:
assert(num == 0 || num == -1);
if (num < 0) {
get2comp(z);
BIGNUM_NEGATE(z);
}
RB_GC_GUARD(x);
return bignorm(z);
}
static VALUE
bigadd_int(VALUE x, long y)
{
VALUE z;
BDIGIT *xds, *zds;
long xn, zn;
BDIGIT_DBL num;
long i;
xds = BDIGITS(x);
xn = BIGNUM_LEN(x);
if (xn == 0)
return LONG2NUM(y);
zn = xn;
#if SIZEOF_BDIGIT < SIZEOF_LONG
if (zn < bdigit_roomof(SIZEOF_LONG))
zn = bdigit_roomof(SIZEOF_LONG);
#endif
zn++;
z = bignew(zn, BIGNUM_SIGN(x));
zds = BDIGITS(z);
#if SIZEOF_BDIGIT >= SIZEOF_LONG
num = (BDIGIT_DBL)xds[0] + y;
zds[0] = BIGLO(num);
num = BIGDN(num);
i = 1;
if (i < xn)
goto y_is_zero_x;
goto y_is_zero_z;
#else
num = 0;
for (i=0; i < xn; i++) {
if (y == 0) goto y_is_zero_x;
num += (BDIGIT_DBL)xds[i] + BIGLO(y);
zds[i] = BIGLO(num);
num = BIGDN(num);
y = BIGDN(y);
}
for (; i < zn; i++) {
if (y == 0) goto y_is_zero_z;
num += BIGLO(y);
zds[i] = BIGLO(num);
num = BIGDN(num);
y = BIGDN(y);
}
goto finish;
#endif
for (;i < xn; i++) {
y_is_zero_x:
if (num == 0) goto num_is_zero_x;
num += (BDIGIT_DBL)xds[i];
zds[i] = BIGLO(num);
num = BIGDN(num);
}
for (; i < zn; i++) {
y_is_zero_z:
if (num == 0) goto num_is_zero_z;
zds[i] = BIGLO(num);
num = BIGDN(num);
}
goto finish;
for (;i < xn; i++) {
num_is_zero_x:
zds[i] = xds[i];
}
for (; i < zn; i++) {
num_is_zero_z:
zds[i] = 0;
}
goto finish;
finish:
RB_GC_GUARD(x);
return bignorm(z);
}
static VALUE
bigadd(VALUE x, VALUE y, int sign)
{
VALUE z;
size_t len;
sign = (sign == BIGNUM_SIGN(y));
if (BIGNUM_SIGN(x) != sign) {
if (sign) return bigsub(y, x);
return bigsub(x, y);
}
if (BIGNUM_LEN(x) > BIGNUM_LEN(y)) {
len = BIGNUM_LEN(x) + 1;
}
else {
len = BIGNUM_LEN(y) + 1;
}
z = bignew(len, sign);
bary_add(BDIGITS(z), BIGNUM_LEN(z),
BDIGITS(x), BIGNUM_LEN(x),
BDIGITS(y), BIGNUM_LEN(y));
return z;
}
VALUE
rb_big_plus(VALUE x, VALUE y)
{
long n;
if (FIXNUM_P(y)) {
n = FIX2LONG(y);
if ((n > 0) != BIGNUM_SIGN(x)) {
if (n < 0) {
n = -n;
}
return bigsub_int(x, n);
}
if (n < 0) {
n = -n;
}
return bigadd_int(x, n);
}
else if (RB_BIGNUM_TYPE_P(y)) {
return bignorm(bigadd(x, y, 1));
}
else if (RB_FLOAT_TYPE_P(y)) {
return DBL2NUM(rb_big2dbl(x) + RFLOAT_VALUE(y));
}
else {
return rb_num_coerce_bin(x, y, '+');
}
}
VALUE
rb_big_minus(VALUE x, VALUE y)
{
long n;
if (FIXNUM_P(y)) {
n = FIX2LONG(y);
if ((n > 0) != BIGNUM_SIGN(x)) {
if (n < 0) {
n = -n;
}
return bigadd_int(x, n);
}
if (n < 0) {
n = -n;
}
return bigsub_int(x, n);
}
else if (RB_BIGNUM_TYPE_P(y)) {
return bignorm(bigadd(x, y, 0));
}
else if (RB_FLOAT_TYPE_P(y)) {
return DBL2NUM(rb_big2dbl(x) - RFLOAT_VALUE(y));
}
else {
return rb_num_coerce_bin(x, y, '-');
}
}
static VALUE
bigsq(VALUE x)
{
long xn, zn;
VALUE z;
BDIGIT *xds, *zds;
xn = BIGNUM_LEN(x);
zn = 2 * xn;
z = bignew(zn, 1);
xds = BDIGITS(x);
zds = BDIGITS(z);
if (xn < NAIVE_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)
{
long xn, yn, zn;
VALUE z;
BDIGIT *xds, *yds, *zds;
if (x == y)
return bigsq(x);
xn = BIGNUM_LEN(x);
yn = BIGNUM_LEN(y);
zn = xn + yn;
z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
xds = BDIGITS(x);
yds = BDIGITS(y);
zds = BDIGITS(z);
bary_mul(zds, zn, xds, xn, yds, yn);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return z;
}
VALUE
rb_big_mul(VALUE x, VALUE y)
{
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
else if (RB_BIGNUM_TYPE_P(y)) {
}
else if (RB_FLOAT_TYPE_P(y)) {
return DBL2NUM(rb_big2dbl(x) * RFLOAT_VALUE(y));
}
else {
return rb_num_coerce_bin(x, y, '*');
}
return bignorm(bigmul0(x, y));
}
static VALUE
bigdivrem(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp)
{
long xn = BIGNUM_LEN(x), yn = BIGNUM_LEN(y);
VALUE z;
BDIGIT *xds, *yds, *zds;
BDIGIT dd;
VALUE q = Qnil, r = Qnil;
BDIGIT *qds, *rds;
long qn, rn;
yds = BDIGITS(y);
BARY_TRUNC(yds, yn);
if (yn == 0)
rb_num_zerodiv();
xds = BDIGITS(x);
BARY_TRUNC(xds, xn);
if (xn < yn || (xn == yn && xds[xn - 1] < yds[yn - 1])) {
if (divp) *divp = rb_int2big(0);
if (modp) *modp = x;
return Qnil;
}
if (yn == 1) {
dd = yds[0];
z = bignew(xn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
zds = BDIGITS(z);
dd = bigdivrem_single(zds, xds, xn, dd);
if (modp) {
*modp = rb_uint2big((uintptr_t)dd);
BIGNUM_SET_SIGN(*modp, BIGNUM_SIGN(x));
}
if (divp) *divp = z;
return Qnil;
}
if (xn == 2 && yn == 2) {
BDIGIT_DBL x0 = bary2bdigitdbl(xds, 2);
BDIGIT_DBL y0 = bary2bdigitdbl(yds, 2);
BDIGIT_DBL q0 = x0 / y0;
BDIGIT_DBL r0 = x0 % y0;
if (divp) {
z = bignew(bdigit_roomof(sizeof(BDIGIT_DBL)), BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
zds = BDIGITS(z);
zds[0] = BIGLO(q0);
zds[1] = BIGLO(BIGDN(q0));
*divp = z;
}
if (modp) {
z = bignew(bdigit_roomof(sizeof(BDIGIT_DBL)), BIGNUM_SIGN(x));
zds = BDIGITS(z);
zds[0] = BIGLO(r0);
zds[1] = BIGLO(BIGDN(r0));
*modp = z;
}
return Qnil;
}
if (divp) {
qn = xn + BIGDIVREM_EXTRA_WORDS;
q = bignew(qn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
qds = BDIGITS(q);
}
else {
qn = 0;
qds = NULL;
}
if (modp) {
rn = yn;
r = bignew(rn, BIGNUM_SIGN(x));
rds = BDIGITS(r);
}
else {
rn = 0;
rds = NULL;
}
bary_divmod_branch(qds, qn, rds, rn, xds, xn, yds, yn);
if (divp) {
bigtrunc(q);
*divp = q;
}
if (modp) {
bigtrunc(r);
*modp = r;
}
return Qnil;
}
static void
bigdivmod(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp)
{
VALUE mod;
bigdivrem(x, y, divp, &mod);
if (BIGNUM_SIGN(x) != BIGNUM_SIGN(y) && !BIGZEROP(mod)) {
if (divp) *divp = bigadd(*divp, rb_int2big(1), 0);
if (modp) *modp = bigadd(mod, y, 1);
}
else if (modp) {
*modp = mod;
}
}
static VALUE
rb_big_divide(VALUE x, VALUE y, ID op)
{
VALUE z;
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
else if (RB_BIGNUM_TYPE_P(y)) {
}
else if (RB_FLOAT_TYPE_P(y)) {
if (op == '/') {
double dx = rb_big2dbl(x);
return rb_flo_div_flo(DBL2NUM(dx), y);
}
else {
VALUE v;
double dy = RFLOAT_VALUE(y);
if (dy == 0.0) rb_num_zerodiv();
v = rb_big_divide(x, y, '/');
return rb_dbl2big(RFLOAT_VALUE(v));
}
}
else {
return rb_num_coerce_bin(x, y, op);
}
bigdivmod(x, y, &z, 0);
return bignorm(z);
}
VALUE
rb_big_div(VALUE x, VALUE y)
{
return rb_big_divide(x, y, '/');
}
VALUE
rb_big_idiv(VALUE x, VALUE y)
{
return rb_big_divide(x, y, idDiv);
}
VALUE
rb_big_modulo(VALUE x, VALUE y)
{
VALUE z;
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
else if (!RB_BIGNUM_TYPE_P(y)) {
return rb_num_coerce_bin(x, y, '%');
}
bigdivmod(x, y, 0, &z);
return bignorm(z);
}
VALUE
rb_big_remainder(VALUE x, VALUE y)
{
VALUE z;
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
else if (!RB_BIGNUM_TYPE_P(y)) {
return rb_num_coerce_bin(x, y, rb_intern("remainder"));
}
bigdivrem(x, y, 0, &z);
return bignorm(z);
}
VALUE
rb_big_divmod(VALUE x, VALUE y)
{
VALUE div, mod;
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
else if (!RB_BIGNUM_TYPE_P(y)) {
return rb_num_coerce_bin(x, y, idDivmod);
}
bigdivmod(x, y, &div, &mod);
return rb_assoc_new(bignorm(div), bignorm(mod));
}
static VALUE
big_shift(VALUE x, long n)
{
if (n < 0)
return big_lshift(x, 1+(unsigned long)(-(n+1)));
else if (n > 0)
return big_rshift(x, (unsigned long)n);
return x;
}
enum {DBL_BIGDIG = ((DBL_MANT_DIG + BITSPERDIG) / BITSPERDIG)};
static double
big_fdiv(VALUE x, VALUE y, long ey)
{
VALUE z;
long l, ex;
bigtrunc(x);
l = BIGNUM_LEN(x);
ex = l * BITSPERDIG - nlz(BDIGITS(x)[l-1]);
ex -= 2 * DBL_BIGDIG * BITSPERDIG;
if (ex > BITSPERDIG) ex -= BITSPERDIG;
else if (ex > 0) ex = 0;
if (ex) x = big_shift(x, ex);
bigdivrem(x, y, &z, 0);
l = ex - ey;
#if SIZEOF_LONG > SIZEOF_INT
{
/* Visual C++ can't be here */
if (l > INT_MAX) return HUGE_VAL;
if (l < INT_MIN) return 0.0;
}
#endif
return ldexp(big2dbl(z), (int)l);
}
static double
big_fdiv_int(VALUE x, VALUE y)
{
long l, ey;
bigtrunc(y);
l = BIGNUM_LEN(y);
ey = l * BITSPERDIG - nlz(BDIGITS(y)[l-1]);
ey -= DBL_BIGDIG * BITSPERDIG;
if (ey) y = big_shift(y, ey);
return big_fdiv(x, y, ey);
}
static double
big_fdiv_float(VALUE x, VALUE y)
{
int i;
y = dbl2big(ldexp(frexp(RFLOAT_VALUE(y), &i), DBL_MANT_DIG));
return big_fdiv(x, y, i - DBL_MANT_DIG);
}
double
rb_big_fdiv_double(VALUE x, VALUE y)
{
double dx, dy;
VALUE v;
dx = big2dbl(x);
if (FIXNUM_P(y)) {
dy = (double)FIX2LONG(y);
if (isinf(dx))
return big_fdiv_int(x, rb_int2big(FIX2LONG(y)));
}
else if (RB_BIGNUM_TYPE_P(y)) {
return big_fdiv_int(x, y);
}
else if (RB_FLOAT_TYPE_P(y)) {
dy = RFLOAT_VALUE(y);
if (isnan(dy))
return dy;
if (isinf(dx))
return big_fdiv_float(x, y);
}
else {
return NUM2DBL(rb_num_coerce_bin(x, y, idFdiv));
}
v = rb_flo_div_flo(DBL2NUM(dx), DBL2NUM(dy));
return NUM2DBL(v);
}
VALUE
rb_big_fdiv(VALUE x, VALUE y)
{
return DBL2NUM(rb_big_fdiv_double(x, y));
}
VALUE
rb_big_pow(VALUE x, VALUE y)
{
double d;
SIGNED_VALUE yy;
again:
if (y == INT2FIX(0)) return INT2FIX(1);
if (y == INT2FIX(1)) return x;
if (RB_FLOAT_TYPE_P(y)) {
d = RFLOAT_VALUE(y);
if ((BIGNUM_NEGATIVE_P(x) && !BIGZEROP(x))) {
return rb_dbl_complex_new_polar_pi(pow(-rb_big2dbl(x), d), d);
}
}
else if (RB_BIGNUM_TYPE_P(y)) {
y = bignorm(y);
if (FIXNUM_P(y))
goto again;
rb_warn("in a**b, b may be too big");
d = rb_big2dbl(y);
}
else if (FIXNUM_P(y)) {
yy = FIX2LONG(y);
if (yy < 0) {
x = rb_big_pow(x, INT2NUM(-yy));
if (RB_INTEGER_TYPE_P(x))
return rb_rational_raw(INT2FIX(1), x);
else
return DBL2NUM(1.0 / NUM2DBL(x));
}
else {
VALUE z = 0;
SIGNED_VALUE mask;
const size_t xbits = rb_absint_numwords(x, 1, NULL);
const size_t BIGLEN_LIMIT = 32*1024*1024;
if (xbits == (size_t)-1 ||
(xbits > BIGLEN_LIMIT) ||
(xbits * yy > BIGLEN_LIMIT)) {
rb_warn("in a**b, b may be too big");
d = (double)yy;
}
else {
for (mask = FIXNUM_MAX + 1; mask; mask >>= 1) {
if (z) z = bigsq(z);
if (yy & mask) {
z = z ? bigtrunc(bigmul0(z, x)) : x;
}
}
return bignorm(z);
}
}
}
else {
return rb_num_coerce_bin(x, y, idPow);
}
return DBL2NUM(pow(rb_big2dbl(x), d));
}
static VALUE
bigand_int(VALUE x, long xn, BDIGIT hibitsx, long y)
{
VALUE z;
BDIGIT *xds, *zds;
long zn;
long i;
BDIGIT hibitsy;
if (y == 0) return INT2FIX(0);
if (xn == 0) return hibitsx ? LONG2NUM(y) : 0;
hibitsy = 0 <= y ? 0 : BDIGMAX;
xds = BDIGITS(x);
#if SIZEOF_BDIGIT >= SIZEOF_LONG
if (!hibitsy) {
y &= xds[0];
return LONG2NUM(y);
}
#endif
zn = xn;
#if SIZEOF_BDIGIT < SIZEOF_LONG
if (hibitsx && zn < bdigit_roomof(SIZEOF_LONG))
zn = bdigit_roomof(SIZEOF_LONG);
#endif
z = bignew(zn, 0);
zds = BDIGITS(z);
#if SIZEOF_BDIGIT >= SIZEOF_LONG
i = 1;
zds[0] = xds[0] & BIGLO(y);
#else
for (i=0; i < xn; i++) {
if (y == 0 || y == -1) break;
zds[i] = xds[i] & BIGLO(y);
y = BIGDN(y);
}
for (; i < zn; i++) {
if (y == 0 || y == -1) break;
zds[i] = hibitsx & BIGLO(y);
y = BIGDN(y);
}
#endif
for (;i < xn; i++) {
zds[i] = xds[i] & hibitsy;
}
for (;i < zn; i++) {
zds[i] = hibitsx & hibitsy;
}
twocomp2abs_bang(z, hibitsx && hibitsy);
RB_GC_GUARD(x);
return bignorm(z);
}
VALUE
rb_big_and(VALUE x, VALUE y)
{
VALUE z;
BDIGIT *ds1, *ds2, *zds;
long i, xn, yn, n1, n2;
BDIGIT hibitsx, hibitsy;
BDIGIT hibits1, hibits2;
VALUE tmpv;
BDIGIT tmph;
long tmpn;
if (!RB_INTEGER_TYPE_P(y)) {
return rb_num_coerce_bit(x, y, '&');
}
hibitsx = abs2twocomp(&x, &xn);
if (FIXNUM_P(y)) {
return bigand_int(x, xn, hibitsx, FIX2LONG(y));
}
hibitsy = abs2twocomp(&y, &yn);
if (xn > yn) {
tmpv = x; x = y; y = tmpv;
tmpn = xn; xn = yn; yn = tmpn;
tmph = hibitsx; hibitsx = hibitsy; hibitsy = tmph;
}
n1 = xn;
n2 = yn;
ds1 = BDIGITS(x);
ds2 = BDIGITS(y);
hibits1 = hibitsx;
hibits2 = hibitsy;
if (!hibits1)
n2 = n1;
z = bignew(n2, 0);
zds = BDIGITS(z);
for (i=0; i<n1; i++) {
zds[i] = ds1[i] & ds2[i];
}
for (; i<n2; i++) {
zds[i] = hibits1 & ds2[i];
}
twocomp2abs_bang(z, hibits1 && hibits2);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return bignorm(z);
}
static VALUE
bigor_int(VALUE x, long xn, BDIGIT hibitsx, long y)
{
VALUE z;
BDIGIT *xds, *zds;
long zn;
long i;
BDIGIT hibitsy;
if (y == -1) return INT2FIX(-1);
if (xn == 0) return hibitsx ? INT2FIX(-1) : LONG2FIX(y);
hibitsy = 0 <= y ? 0 : BDIGMAX;
xds = BDIGITS(x);
zn = BIGNUM_LEN(x);
#if SIZEOF_BDIGIT < SIZEOF_LONG
if (zn < bdigit_roomof(SIZEOF_LONG))
zn = bdigit_roomof(SIZEOF_LONG);
#endif
z = bignew(zn, 0);
zds = BDIGITS(z);
#if SIZEOF_BDIGIT >= SIZEOF_LONG
i = 1;
zds[0] = xds[0] | BIGLO(y);
if (i < zn)
goto y_is_fixed_point;
goto finish;
#else
for (i=0; i < xn; i++) {
if (y == 0 || y == -1) goto y_is_fixed_point;
zds[i] = xds[i] | BIGLO(y);
y = BIGDN(y);
}
if (hibitsx)
goto fill_hibits;
for (; i < zn; i++) {
if (y == 0 || y == -1) goto y_is_fixed_point;
zds[i] = BIGLO(y);
y = BIGDN(y);
}
goto finish;
#endif
y_is_fixed_point:
if (hibitsy)
goto fill_hibits;
for (; i < xn; i++) {
zds[i] = xds[i];
}
if (hibitsx)
goto fill_hibits;
for (; i < zn; i++) {
zds[i] = 0;
}
goto finish;
fill_hibits:
for (; i < zn; i++) {
zds[i] = BDIGMAX;
}
finish:
twocomp2abs_bang(z, hibitsx || hibitsy);
RB_GC_GUARD(x);
return bignorm(z);
}
VALUE
rb_big_or(VALUE x, VALUE y)
{
VALUE z;
BDIGIT *ds1, *ds2, *zds;
long i, xn, yn, n1, n2;
BDIGIT hibitsx, hibitsy;
BDIGIT hibits1, hibits2;
VALUE tmpv;
BDIGIT tmph;
long tmpn;
if (!RB_INTEGER_TYPE_P(y)) {
return rb_num_coerce_bit(x, y, '|');
}
hibitsx = abs2twocomp(&x, &xn);
if (FIXNUM_P(y)) {
return bigor_int(x, xn, hibitsx, FIX2LONG(y));
}
hibitsy = abs2twocomp(&y, &yn);
if (xn > yn) {
tmpv = x; x = y; y = tmpv;
tmpn = xn; xn = yn; yn = tmpn;
tmph = hibitsx; hibitsx = hibitsy; hibitsy = tmph;
}
n1 = xn;
n2 = yn;
ds1 = BDIGITS(x);
ds2 = BDIGITS(y);
hibits1 = hibitsx;
hibits2 = hibitsy;
if (hibits1)
n2 = n1;
z = bignew(n2, 0);
zds = BDIGITS(z);
for (i=0; i<n1; i++) {
zds[i] = ds1[i] | ds2[i];
}
for (; i<n2; i++) {
zds[i] = hibits1 | ds2[i];
}
twocomp2abs_bang(z, hibits1 || hibits2);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return bignorm(z);
}
static VALUE
bigxor_int(VALUE x, long xn, BDIGIT hibitsx, long y)
{
VALUE z;
BDIGIT *xds, *zds;
long zn;
long i;
BDIGIT hibitsy;
hibitsy = 0 <= y ? 0 : BDIGMAX;
xds = BDIGITS(x);
zn = BIGNUM_LEN(x);
#if SIZEOF_BDIGIT < SIZEOF_LONG
if (zn < bdigit_roomof(SIZEOF_LONG))
zn = bdigit_roomof(SIZEOF_LONG);
#endif
z = bignew(zn, 0);
zds = BDIGITS(z);
#if SIZEOF_BDIGIT >= SIZEOF_LONG
i = 1;
zds[0] = xds[0] ^ BIGLO(y);
#else
for (i = 0; i < xn; i++) {
zds[i] = xds[i] ^ BIGLO(y);
y = BIGDN(y);
}
for (; i < zn; i++) {
zds[i] = hibitsx ^ BIGLO(y);
y = BIGDN(y);
}
#endif
for (; i < xn; i++) {
zds[i] = xds[i] ^ hibitsy;
}
for (; i < zn; i++) {
zds[i] = hibitsx ^ hibitsy;
}
twocomp2abs_bang(z, (hibitsx ^ hibitsy) != 0);
RB_GC_GUARD(x);
return bignorm(z);
}
VALUE
rb_big_xor(VALUE x, VALUE y)
{
VALUE z;
BDIGIT *ds1, *ds2, *zds;
long i, xn, yn, n1, n2;
BDIGIT hibitsx, hibitsy;
BDIGIT hibits1, hibits2;
VALUE tmpv;
BDIGIT tmph;
long tmpn;
if (!RB_INTEGER_TYPE_P(y)) {
return rb_num_coerce_bit(x, y, '^');
}
hibitsx = abs2twocomp(&x, &xn);
if (FIXNUM_P(y)) {
return bigxor_int(x, xn, hibitsx, FIX2LONG(y));
}
hibitsy = abs2twocomp(&y, &yn);
if (xn > yn) {
tmpv = x; x = y; y = tmpv;
tmpn = xn; xn = yn; yn = tmpn;
tmph = hibitsx; hibitsx = hibitsy; hibitsy = tmph;
}
n1 = xn;
n2 = yn;
ds1 = BDIGITS(x);
ds2 = BDIGITS(y);
hibits1 = hibitsx;
hibits2 = hibitsy;
z = bignew(n2, 0);
zds = BDIGITS(z);
for (i=0; i<n1; i++) {
zds[i] = ds1[i] ^ ds2[i];
}
for (; i<n2; i++) {
zds[i] = hibitsx ^ ds2[i];
}
twocomp2abs_bang(z, (hibits1 ^ hibits2) != 0);
RB_GC_GUARD(x);
RB_GC_GUARD(y);
return bignorm(z);
}
VALUE
rb_big_lshift(VALUE x, VALUE y)
{
int lshift_p;
size_t shift_numdigits;
int shift_numbits;
for (;;) {
if (FIXNUM_P(y)) {
long l = FIX2LONG(y);
unsigned long shift;
if (0 <= l) {
lshift_p = 1;
shift = l;
}
else {
lshift_p = 0;
shift = 1+(unsigned long)(-(l+1));
}
shift_numbits = (int)(shift & (BITSPERDIG-1));
shift_numdigits = shift >> bit_length(BITSPERDIG-1);
return bignorm(big_shift3(x, lshift_p, shift_numdigits, shift_numbits));
}
else if (RB_BIGNUM_TYPE_P(y)) {
return bignorm(big_shift2(x, 1, y));
}
y = rb_to_int(y);
}
}
VALUE
rb_big_rshift(VALUE x, VALUE y)
{
int lshift_p;
size_t shift_numdigits;
int shift_numbits;
for (;;) {
if (FIXNUM_P(y)) {
long l = FIX2LONG(y);
unsigned long shift;
if (0 <= l) {
lshift_p = 0;
shift = l;
}
else {
lshift_p = 1;
shift = 1+(unsigned long)(-(l+1));
}
shift_numbits = (int)(shift & (BITSPERDIG-1));
shift_numdigits = shift >> bit_length(BITSPERDIG-1);
return bignorm(big_shift3(x, lshift_p, shift_numdigits, shift_numbits));
}
else if (RB_BIGNUM_TYPE_P(y)) {
return bignorm(big_shift2(x, 0, y));
}
y = rb_to_int(y);
}
}
VALUE
rb_big_aref(VALUE x, VALUE y)
{
BDIGIT *xds;
size_t shift;
size_t i, s1, s2;
long l;
BDIGIT bit;
if (RB_BIGNUM_TYPE_P(y)) {
if (BIGNUM_NEGATIVE_P(y))
return INT2FIX(0);
bigtrunc(y);
if (BIGSIZE(y) > sizeof(size_t)) {
out_of_range:
return BIGNUM_SIGN(x) ? INT2FIX(0) : INT2FIX(1);
}
#if SIZEOF_SIZE_T <= SIZEOF_LONG
shift = big2ulong(y, "long");
#else
shift = big2ull(y, "long long");
#endif
}
else {
l = NUM2LONG(y);
if (l < 0) return INT2FIX(0);
shift = (size_t)l;
}
s1 = shift/BITSPERDIG;
s2 = shift%BITSPERDIG;
bit = (BDIGIT)1 << s2;
if (s1 >= BIGNUM_LEN(x)) goto out_of_range;
xds = BDIGITS(x);
if (BIGNUM_POSITIVE_P(x))
return (xds[s1] & bit) ? INT2FIX(1) : INT2FIX(0);
if (xds[s1] & (bit-1))
return (xds[s1] & bit) ? INT2FIX(0) : INT2FIX(1);
for (i = 0; i < s1; i++)
if (xds[i])
return (xds[s1] & bit) ? INT2FIX(0) : INT2FIX(1);
return (xds[s1] & bit) ? INT2FIX(1) : INT2FIX(0);
}
VALUE
rb_big_hash(VALUE x)
{
st_index_t hash;
hash = rb_memhash(BDIGITS(x), sizeof(BDIGIT)*BIGNUM_LEN(x)) ^ BIGNUM_SIGN(x);
return ST2FIX(hash);
}
/*
* call-seq:
* big.coerce(numeric) -> array
*
* Returns an array with both a +numeric+ and a +big+ represented as Bignum
* objects.
*
* This is achieved by converting +numeric+ to a Bignum.
*
* A TypeError is raised if the +numeric+ is not a Fixnum or Bignum type.
*
* (0x3FFFFFFFFFFFFFFF+1).coerce(42) #=> [42, 4611686018427387904]
*/
static VALUE
rb_int_coerce(VALUE x, VALUE y)
{
if (RB_INTEGER_TYPE_P(y)) {
return rb_assoc_new(y, x);
}
else {
x = rb_Float(x);
y = rb_Float(y);
return rb_assoc_new(y, x);
}
}
VALUE
rb_big_abs(VALUE x)
{
if (BIGNUM_NEGATIVE_P(x)) {
x = rb_big_clone(x);
BIGNUM_SET_POSITIVE_SIGN(x);
}
return x;
}
int
rb_big_sign(VALUE x)
{
return BIGNUM_SIGN(x);
}
size_t
rb_big_size(VALUE big)
{
return BIGSIZE(big);
}
VALUE
rb_big_size_m(VALUE big)
{
return SIZET2NUM(rb_big_size(big));
}
VALUE
rb_big_bit_length(VALUE big)
{
int nlz_bits;
size_t numbytes;
static const BDIGIT char_bit[1] = { CHAR_BIT };
BDIGIT numbytes_bary[bdigit_roomof(sizeof(size_t))];
BDIGIT nlz_bary[1];
BDIGIT result_bary[bdigit_roomof(sizeof(size_t)+1)];
numbytes = rb_absint_size(big, &nlz_bits);
if (numbytes == 0)
return LONG2FIX(0);
if (BIGNUM_NEGATIVE_P(big) && rb_absint_singlebit_p(big)) {
if (nlz_bits != CHAR_BIT-1) {
nlz_bits++;
}
else {
nlz_bits = 0;
numbytes--;
}
}
if (numbytes <= SIZE_MAX / CHAR_BIT) {
return SIZET2NUM(numbytes * CHAR_BIT - nlz_bits);
}
nlz_bary[0] = nlz_bits;
bary_unpack(BARY_ARGS(numbytes_bary), &numbytes, 1, sizeof(numbytes), 0,
INTEGER_PACK_NATIVE_BYTE_ORDER);
BARY_SHORT_MUL(result_bary, numbytes_bary, char_bit);
BARY_SUB(result_bary, result_bary, nlz_bary);
return rb_integer_unpack(result_bary, numberof(result_bary), sizeof(BDIGIT), 0,
INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER);
}
VALUE
rb_big_odd_p(VALUE num)
{
if (BIGNUM_LEN(num) != 0 && BDIGITS(num)[0] & 1) {
return Qtrue;
}
return Qfalse;
}
VALUE
rb_big_even_p(VALUE num)
{
if (BIGNUM_LEN(num) != 0 && BDIGITS(num)[0] & 1) {
return Qfalse;
}
return Qtrue;
}
unsigned long rb_ulong_isqrt(unsigned long);
#if SIZEOF_BDIGIT*2 > SIZEOF_LONG
BDIGIT rb_bdigit_dbl_isqrt(BDIGIT_DBL);
# ifdef ULL_TO_DOUBLE
# define BDIGIT_DBL_TO_DOUBLE(n) ULL_TO_DOUBLE(n)
# endif
#else
# define rb_bdigit_dbl_isqrt(x) (BDIGIT)rb_ulong_isqrt(x)
#endif
#ifndef BDIGIT_DBL_TO_DOUBLE
# define BDIGIT_DBL_TO_DOUBLE(n) (double)(n)
#endif
static BDIGIT *
estimate_initial_sqrt(VALUE *xp, const size_t xn, const BDIGIT *nds, size_t len)
{
enum {dbl_per_bdig = roomof(DBL_MANT_DIG,BITSPERDIG)};
const int zbits = nlz(nds[len-1]);
VALUE x = *xp = bignew_1(0, xn, 1); /* division may release the GVL */
BDIGIT *xds = BDIGITS(x);
BDIGIT_DBL d = bary2bdigitdbl(nds+len-dbl_per_bdig, dbl_per_bdig);
BDIGIT lowbits = 1;
int rshift = (int)((BITSPERDIG*2-zbits+(len&BITSPERDIG&1) - DBL_MANT_DIG + 1) & ~1);
double f;
if (rshift > 0) {
lowbits = (BDIGIT)d & ~(~(BDIGIT)1U << rshift);
d >>= rshift;
}
else if (rshift < 0) {
d <<= -rshift;
d |= nds[len-dbl_per_bdig-1] >> (BITSPERDIG+rshift);
}
f = sqrt(BDIGIT_DBL_TO_DOUBLE(d));
d = (BDIGIT_DBL)ceil(f);
if (BDIGIT_DBL_TO_DOUBLE(d) == f) {
if (lowbits || (lowbits = !bary_zero_p(nds, len-dbl_per_bdig)))
++d;
}
else {
lowbits = 1;
}
rshift /= 2;
rshift += (2-(len&1))*BITSPERDIG/2;
if (rshift >= 0) {
if (nlz((BDIGIT)d) + rshift >= BITSPERDIG) {
/* (d << rshift) does cause overflow.
* example: Integer.sqrt(0xffff_ffff_ffff_ffff ** 2)
*/
d = ~(BDIGIT_DBL)0;
}
else {
d <<= rshift;
}
}
BDIGITS_ZERO(xds, xn-2);
bdigitdbl2bary(&xds[xn-2], 2, d);
if (!lowbits) return NULL; /* special case, exact result */
return xds;
}
VALUE
rb_big_isqrt(VALUE n)
{
BDIGIT *nds = BDIGITS(n);
size_t len = BIGNUM_LEN(n);
size_t xn = (len+1) / 2;
VALUE x;
BDIGIT *xds;
if (len <= 2) {
BDIGIT sq = rb_bdigit_dbl_isqrt(bary2bdigitdbl(nds, len));
#if SIZEOF_BDIGIT > SIZEOF_LONG
return ULL2NUM(sq);
#else
return ULONG2NUM(sq);
#endif
}
else if ((xds = estimate_initial_sqrt(&x, xn, nds, len)) != 0) {
size_t tn = xn + BIGDIVREM_EXTRA_WORDS;
VALUE t = bignew_1(0, tn, 1);
BDIGIT *tds = BDIGITS(t);
tn = BIGNUM_LEN(t);
/* t = n/x */
while (bary_divmod_branch(tds, tn, NULL, 0, nds, len, xds, xn),
bary_cmp(tds, tn, xds, xn) < 0) {
int carry;
BARY_TRUNC(tds, tn);
/* x = (x+t)/2 */
carry = bary_add(xds, xn, xds, xn, tds, tn);
bary_small_rshift(xds, xds, xn, 1, carry);
tn = BIGNUM_LEN(t);
}
rb_big_realloc(t, 0);
rb_gc_force_recycle(t);
}
RBASIC_SET_CLASS_RAW(x, rb_cInteger);
return x;
}
#ifdef USE_GMP
static void
bary_powm_gmp(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, const BDIGIT *mds, size_t mn)
{
mpz_t z, x, y, m;
size_t count;
mpz_init(x);
mpz_init(y);
mpz_init(m);
mpz_init(z);
bdigits_to_mpz(x, xds, xn);
bdigits_to_mpz(y, yds, yn);
bdigits_to_mpz(m, mds, mn);
mpz_powm(z, x, y, m);
bdigits_from_mpz(z, zds, &count);
BDIGITS_ZERO(zds+count, zn-count);
mpz_clear(x);
mpz_clear(y);
mpz_clear(m);
mpz_clear(z);
}
#endif
static VALUE
int_pow_tmp3(VALUE x, VALUE y, VALUE m, int nega_flg)
{
#ifdef USE_GMP
VALUE z;
size_t xn, yn, mn, zn;
if (FIXNUM_P(x)) {
x = rb_int2big(FIX2LONG(x));
}
if (FIXNUM_P(y)) {
y = rb_int2big(FIX2LONG(y));
}
assert(RB_BIGNUM_TYPE_P(m));
xn = BIGNUM_LEN(x);
yn = BIGNUM_LEN(y);
mn = BIGNUM_LEN(m);
zn = mn;
z = bignew(zn, 1);
bary_powm_gmp(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, BDIGITS(m), mn);
if (nega_flg & BIGNUM_POSITIVE_P(z)) {
z = rb_big_minus(z, m);
}
RB_GC_GUARD(x);
RB_GC_GUARD(y);
RB_GC_GUARD(m);
return rb_big_norm(z);
#else
VALUE tmp = LONG2FIX(1L);
long yy;
for (/*NOP*/; ! FIXNUM_P(y); y = rb_big_rshift(y, LONG2FIX(1L))) {
if (RTEST(rb_int_odd_p(y))) {
tmp = rb_int_mul(tmp, x);
tmp = rb_int_modulo(tmp, m);
}
x = rb_int_mul(x, x);
x = rb_int_modulo(x, m);
}
for (yy = FIX2LONG(y); yy; yy >>= 1L) {
if (yy & 1L) {
tmp = rb_int_mul(tmp, x);
tmp = rb_int_modulo(tmp, m);
}
x = rb_int_mul(x, x);
x = rb_int_modulo(x, m);
}
if (nega_flg && rb_int_positive_p(tmp)) {
tmp = rb_int_minus(tmp, m);
}
return tmp;
#endif
}
/*
* Integer#pow
*/
static VALUE
int_pow_tmp1(VALUE x, VALUE y, long mm, int nega_flg)
{
long xx = FIX2LONG(x);
long tmp = 1L;
long yy;
for (/*NOP*/; ! FIXNUM_P(y); y = rb_big_rshift(y, LONG2FIX(1L))) {
if (RTEST(rb_int_odd_p(y))) {
tmp = (tmp * xx) % mm;
}
xx = (xx * xx) % mm;
}
for (yy = FIX2LONG(y); yy; yy >>= 1L) {
if (yy & 1L) {
tmp = (tmp * xx) % mm;
}
xx = (xx * xx) % mm;
}
if (nega_flg && tmp) {
tmp -= mm;
}
return LONG2FIX(tmp);
}
static VALUE
int_pow_tmp2(VALUE x, VALUE y, long mm, int nega_flg)
{
long tmp = 1L;
long yy;
#ifdef DLONG
const DLONG m = mm;
long tmp2 = tmp;
long xx = FIX2LONG(x);
# define MUL_MODULO(a, b, c) (long)(((DLONG)(a) * (DLONG)(b)) % (c))
#else
const VALUE m = LONG2FIX(mm);
VALUE tmp2 = LONG2FIX(tmp);
VALUE xx = x;
# define MUL_MODULO(a, b, c) rb_int_modulo(rb_fix_mul_fix((a), (b)), (c))
#endif
for (/*NOP*/; ! FIXNUM_P(y); y = rb_big_rshift(y, LONG2FIX(1L))) {
if (RTEST(rb_int_odd_p(y))) {
tmp2 = MUL_MODULO(tmp2, xx, m);
}
xx = MUL_MODULO(xx, xx, m);
}
for (yy = FIX2LONG(y); yy; yy >>= 1L) {
if (yy & 1L) {
tmp2 = MUL_MODULO(tmp2, xx, m);
}
xx = MUL_MODULO(xx, xx, m);
}
#ifdef DLONG
tmp = tmp2;
#else
tmp = FIX2LONG(tmp2);
#endif
if (nega_flg && tmp) {
tmp -= mm;
}
return LONG2FIX(tmp);
}
/*
* Document-method: Integer#pow
* call-seq:
* integer.pow(numeric) -> numeric
* integer.pow(integer, integer) -> integer
*
* Returns (modular) exponentiation as:
*
* a.pow(b) #=> same as a**b
* a.pow(b, m) #=> same as (a**b) % m, but avoids huge temporary values
*/
VALUE
rb_int_powm(int const argc, VALUE * const argv, VALUE const num)
{
rb_check_arity(argc, 1, 2);
if (argc == 1) {
return rb_int_pow(num, argv[0]);
}
else {
VALUE const a = num;
VALUE const b = argv[0];
VALUE m = argv[1];
int nega_flg = 0;
if ( ! RB_INTEGER_TYPE_P(b)) {
rb_raise(rb_eTypeError, "Integer#pow() 2nd argument not allowed unless a 1st argument is integer");
}
if (rb_int_negative_p(b)) {
rb_raise(rb_eRangeError, "Integer#pow() 1st argument cannot be negative when 2nd argument specified");
}
if (!RB_INTEGER_TYPE_P(m)) {
rb_raise(rb_eTypeError, "Integer#pow() 2nd argument not allowed unless all arguments are integers");
}
if (rb_int_negative_p(m)) {
m = rb_int_uminus(m);
nega_flg = 1;
}
if (FIXNUM_P(m)) {
long const half_val = (long)HALF_LONG_MSB;
long const mm = FIX2LONG(m);
if (!mm) rb_num_zerodiv();
if (mm <= half_val) {
return int_pow_tmp1(rb_int_modulo(a, m), b, mm, nega_flg);
}
else {
return int_pow_tmp2(rb_int_modulo(a, m), b, mm, nega_flg);
}
}
else {
if (rb_bigzero_p(m)) rb_num_zerodiv();
return int_pow_tmp3(rb_int_modulo(a, m), b, m, nega_flg);
}
}
UNREACHABLE_RETURN(Qnil);
}
/*
* Bignum objects hold integers outside the range of
* Fixnum. Bignum objects are created
* automatically when integer calculations would otherwise overflow a
* Fixnum. When a calculation involving
* Bignum objects returns a result that will fit in a
* Fixnum, the result is automatically converted.
*
* For the purposes of the bitwise operations and <code>[]</code>, a
* Bignum is treated as if it were an infinite-length
* bitstring with 2's complement representation.
*
* While Fixnum values are immediate, Bignum
* objects are not---assignment and parameter passing work with
* references to objects, not the objects themselves.
*
*/
void
Init_Bignum(void)
{
#ifndef RUBY_INTEGER_UNIFICATION
rb_cBignum = rb_cInteger;
#endif
/* An obsolete class, use Integer */
rb_define_const(rb_cObject, "Bignum", rb_cInteger);
rb_deprecate_constant(rb_cObject, "Bignum");
rb_define_method(rb_cInteger, "coerce", rb_int_coerce, 1);
#ifdef USE_GMP
/* The version of loaded GMP. */
rb_define_const(rb_cInteger, "GMP_VERSION", rb_sprintf("GMP %s", gmp_version));
#endif
power_cache_init();
}