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Diffstat (limited to 'vendor/gmp-6.3.0/mini-gmp/mini-gmp.c')
-rw-r--r-- | vendor/gmp-6.3.0/mini-gmp/mini-gmp.c | 4627 |
1 files changed, 4627 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/mini-gmp/mini-gmp.c b/vendor/gmp-6.3.0/mini-gmp/mini-gmp.c new file mode 100644 index 0000000..69a72bf --- /dev/null +++ b/vendor/gmp-6.3.0/mini-gmp/mini-gmp.c @@ -0,0 +1,4627 @@ +/* mini-gmp, a minimalistic implementation of a GNU GMP subset. + + Contributed to the GNU project by Niels Möller + Additional functionalities and improvements by Marco Bodrato. + +Copyright 1991-1997, 1999-2022 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +The GNU MP Library is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://www.gnu.org/licenses/. */ + +/* NOTE: All functions in this file which are not declared in + mini-gmp.h are internal, and are not intended to be compatible + with GMP or with future versions of mini-gmp. */ + +/* Much of the material copied from GMP files, including: gmp-impl.h, + longlong.h, mpn/generic/add_n.c, mpn/generic/addmul_1.c, + mpn/generic/lshift.c, mpn/generic/mul_1.c, + mpn/generic/mul_basecase.c, mpn/generic/rshift.c, + mpn/generic/sbpi1_div_qr.c, mpn/generic/sub_n.c, + mpn/generic/submul_1.c. */ + +#include <assert.h> +#include <ctype.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "mini-gmp.h" + +#if !defined(MINI_GMP_DONT_USE_FLOAT_H) +#include <float.h> +#endif + + +/* Macros */ +#define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT) + +#define GMP_LIMB_MAX ((mp_limb_t) ~ (mp_limb_t) 0) +#define GMP_LIMB_HIGHBIT ((mp_limb_t) 1 << (GMP_LIMB_BITS - 1)) + +#define GMP_HLIMB_BIT ((mp_limb_t) 1 << (GMP_LIMB_BITS / 2)) +#define GMP_LLIMB_MASK (GMP_HLIMB_BIT - 1) + +#define GMP_ULONG_BITS (sizeof(unsigned long) * CHAR_BIT) +#define GMP_ULONG_HIGHBIT ((unsigned long) 1 << (GMP_ULONG_BITS - 1)) + +#define GMP_ABS(x) ((x) >= 0 ? (x) : -(x)) +#define GMP_NEG_CAST(T,x) (-((T)((x) + 1) - 1)) + +#define GMP_MIN(a, b) ((a) < (b) ? (a) : (b)) +#define GMP_MAX(a, b) ((a) > (b) ? (a) : (b)) + +#define GMP_CMP(a,b) (((a) > (b)) - ((a) < (b))) + +#if defined(DBL_MANT_DIG) && FLT_RADIX == 2 +#define GMP_DBL_MANT_BITS DBL_MANT_DIG +#else +#define GMP_DBL_MANT_BITS (53) +#endif + +/* Return non-zero if xp,xsize and yp,ysize overlap. + If xp+xsize<=yp there's no overlap, or if yp+ysize<=xp there's no + overlap. If both these are false, there's an overlap. */ +#define GMP_MPN_OVERLAP_P(xp, xsize, yp, ysize) \ + ((xp) + (xsize) > (yp) && (yp) + (ysize) > (xp)) + +#define gmp_assert_nocarry(x) do { \ + mp_limb_t __cy = (x); \ + assert (__cy == 0); \ + (void) (__cy); \ + } while (0) + +#define gmp_clz(count, x) do { \ + mp_limb_t __clz_x = (x); \ + unsigned __clz_c = 0; \ + int LOCAL_SHIFT_BITS = 8; \ + if (GMP_LIMB_BITS > LOCAL_SHIFT_BITS) \ + for (; \ + (__clz_x & ((mp_limb_t) 0xff << (GMP_LIMB_BITS - 8))) == 0; \ + __clz_c += 8) \ + { __clz_x <<= LOCAL_SHIFT_BITS; } \ + for (; (__clz_x & GMP_LIMB_HIGHBIT) == 0; __clz_c++) \ + __clz_x <<= 1; \ + (count) = __clz_c; \ + } while (0) + +#define gmp_ctz(count, x) do { \ + mp_limb_t __ctz_x = (x); \ + unsigned __ctz_c = 0; \ + gmp_clz (__ctz_c, __ctz_x & - __ctz_x); \ + (count) = GMP_LIMB_BITS - 1 - __ctz_c; \ + } while (0) + +#define gmp_add_ssaaaa(sh, sl, ah, al, bh, bl) \ + do { \ + mp_limb_t __x; \ + __x = (al) + (bl); \ + (sh) = (ah) + (bh) + (__x < (al)); \ + (sl) = __x; \ + } while (0) + +#define gmp_sub_ddmmss(sh, sl, ah, al, bh, bl) \ + do { \ + mp_limb_t __x; \ + __x = (al) - (bl); \ + (sh) = (ah) - (bh) - ((al) < (bl)); \ + (sl) = __x; \ + } while (0) + +#define gmp_umul_ppmm(w1, w0, u, v) \ + do { \ + int LOCAL_GMP_LIMB_BITS = GMP_LIMB_BITS; \ + if (sizeof(unsigned int) * CHAR_BIT >= 2 * GMP_LIMB_BITS) \ + { \ + unsigned int __ww = (unsigned int) (u) * (v); \ + w0 = (mp_limb_t) __ww; \ + w1 = (mp_limb_t) (__ww >> LOCAL_GMP_LIMB_BITS); \ + } \ + else if (GMP_ULONG_BITS >= 2 * GMP_LIMB_BITS) \ + { \ + unsigned long int __ww = (unsigned long int) (u) * (v); \ + w0 = (mp_limb_t) __ww; \ + w1 = (mp_limb_t) (__ww >> LOCAL_GMP_LIMB_BITS); \ + } \ + else { \ + mp_limb_t __x0, __x1, __x2, __x3; \ + unsigned __ul, __vl, __uh, __vh; \ + mp_limb_t __u = (u), __v = (v); \ + assert (sizeof (unsigned) * 2 >= sizeof (mp_limb_t)); \ + \ + __ul = __u & GMP_LLIMB_MASK; \ + __uh = __u >> (GMP_LIMB_BITS / 2); \ + __vl = __v & GMP_LLIMB_MASK; \ + __vh = __v >> (GMP_LIMB_BITS / 2); \ + \ + __x0 = (mp_limb_t) __ul * __vl; \ + __x1 = (mp_limb_t) __ul * __vh; \ + __x2 = (mp_limb_t) __uh * __vl; \ + __x3 = (mp_limb_t) __uh * __vh; \ + \ + __x1 += __x0 >> (GMP_LIMB_BITS / 2);/* this can't give carry */ \ + __x1 += __x2; /* but this indeed can */ \ + if (__x1 < __x2) /* did we get it? */ \ + __x3 += GMP_HLIMB_BIT; /* yes, add it in the proper pos. */ \ + \ + (w1) = __x3 + (__x1 >> (GMP_LIMB_BITS / 2)); \ + (w0) = (__x1 << (GMP_LIMB_BITS / 2)) + (__x0 & GMP_LLIMB_MASK); \ + } \ + } while (0) + +/* If mp_limb_t is of size smaller than int, plain u*v implies + automatic promotion to *signed* int, and then multiply may overflow + and cause undefined behavior. Explicitly cast to unsigned int for + that case. */ +#define gmp_umullo_limb(u, v) \ + ((sizeof(mp_limb_t) >= sizeof(int)) ? (u)*(v) : (unsigned int)(u) * (v)) + +#define gmp_udiv_qrnnd_preinv(q, r, nh, nl, d, di) \ + do { \ + mp_limb_t _qh, _ql, _r, _mask; \ + gmp_umul_ppmm (_qh, _ql, (nh), (di)); \ + gmp_add_ssaaaa (_qh, _ql, _qh, _ql, (nh) + 1, (nl)); \ + _r = (nl) - gmp_umullo_limb (_qh, (d)); \ + _mask = -(mp_limb_t) (_r > _ql); /* both > and >= are OK */ \ + _qh += _mask; \ + _r += _mask & (d); \ + if (_r >= (d)) \ + { \ + _r -= (d); \ + _qh++; \ + } \ + \ + (r) = _r; \ + (q) = _qh; \ + } while (0) + +#define gmp_udiv_qr_3by2(q, r1, r0, n2, n1, n0, d1, d0, dinv) \ + do { \ + mp_limb_t _q0, _t1, _t0, _mask; \ + gmp_umul_ppmm ((q), _q0, (n2), (dinv)); \ + gmp_add_ssaaaa ((q), _q0, (q), _q0, (n2), (n1)); \ + \ + /* Compute the two most significant limbs of n - q'd */ \ + (r1) = (n1) - gmp_umullo_limb ((d1), (q)); \ + gmp_sub_ddmmss ((r1), (r0), (r1), (n0), (d1), (d0)); \ + gmp_umul_ppmm (_t1, _t0, (d0), (q)); \ + gmp_sub_ddmmss ((r1), (r0), (r1), (r0), _t1, _t0); \ + (q)++; \ + \ + /* Conditionally adjust q and the remainders */ \ + _mask = - (mp_limb_t) ((r1) >= _q0); \ + (q) += _mask; \ + gmp_add_ssaaaa ((r1), (r0), (r1), (r0), _mask & (d1), _mask & (d0)); \ + if ((r1) >= (d1)) \ + { \ + if ((r1) > (d1) || (r0) >= (d0)) \ + { \ + (q)++; \ + gmp_sub_ddmmss ((r1), (r0), (r1), (r0), (d1), (d0)); \ + } \ + } \ + } while (0) + +/* Swap macros. */ +#define MP_LIMB_T_SWAP(x, y) \ + do { \ + mp_limb_t __mp_limb_t_swap__tmp = (x); \ + (x) = (y); \ + (y) = __mp_limb_t_swap__tmp; \ + } while (0) +#define MP_SIZE_T_SWAP(x, y) \ + do { \ + mp_size_t __mp_size_t_swap__tmp = (x); \ + (x) = (y); \ + (y) = __mp_size_t_swap__tmp; \ + } while (0) +#define MP_BITCNT_T_SWAP(x,y) \ + do { \ + mp_bitcnt_t __mp_bitcnt_t_swap__tmp = (x); \ + (x) = (y); \ + (y) = __mp_bitcnt_t_swap__tmp; \ + } while (0) +#define MP_PTR_SWAP(x, y) \ + do { \ + mp_ptr __mp_ptr_swap__tmp = (x); \ + (x) = (y); \ + (y) = __mp_ptr_swap__tmp; \ + } while (0) +#define MP_SRCPTR_SWAP(x, y) \ + do { \ + mp_srcptr __mp_srcptr_swap__tmp = (x); \ + (x) = (y); \ + (y) = __mp_srcptr_swap__tmp; \ + } while (0) + +#define MPN_PTR_SWAP(xp,xs, yp,ys) \ + do { \ + MP_PTR_SWAP (xp, yp); \ + MP_SIZE_T_SWAP (xs, ys); \ + } while(0) +#define MPN_SRCPTR_SWAP(xp,xs, yp,ys) \ + do { \ + MP_SRCPTR_SWAP (xp, yp); \ + MP_SIZE_T_SWAP (xs, ys); \ + } while(0) + +#define MPZ_PTR_SWAP(x, y) \ + do { \ + mpz_ptr __mpz_ptr_swap__tmp = (x); \ + (x) = (y); \ + (y) = __mpz_ptr_swap__tmp; \ + } while (0) +#define MPZ_SRCPTR_SWAP(x, y) \ + do { \ + mpz_srcptr __mpz_srcptr_swap__tmp = (x); \ + (x) = (y); \ + (y) = __mpz_srcptr_swap__tmp; \ + } while (0) + +const int mp_bits_per_limb = GMP_LIMB_BITS; + + +/* Memory allocation and other helper functions. */ +static void +gmp_die (const char *msg) +{ + fprintf (stderr, "%s\n", msg); + abort(); +} + +static void * +gmp_default_alloc (size_t size) +{ + void *p; + + assert (size > 0); + + p = malloc (size); + if (!p) + gmp_die("gmp_default_alloc: Virtual memory exhausted."); + + return p; +} + +static void * +gmp_default_realloc (void *old, size_t unused_old_size, size_t new_size) +{ + void * p; + + p = realloc (old, new_size); + + if (!p) + gmp_die("gmp_default_realloc: Virtual memory exhausted."); + + return p; +} + +static void +gmp_default_free (void *p, size_t unused_size) +{ + free (p); +} + +static void * (*gmp_allocate_func) (size_t) = gmp_default_alloc; +static void * (*gmp_reallocate_func) (void *, size_t, size_t) = gmp_default_realloc; +static void (*gmp_free_func) (void *, size_t) = gmp_default_free; + +void +mp_get_memory_functions (void *(**alloc_func) (size_t), + void *(**realloc_func) (void *, size_t, size_t), + void (**free_func) (void *, size_t)) +{ + if (alloc_func) + *alloc_func = gmp_allocate_func; + + if (realloc_func) + *realloc_func = gmp_reallocate_func; + + if (free_func) + *free_func = gmp_free_func; +} + +void +mp_set_memory_functions (void *(*alloc_func) (size_t), + void *(*realloc_func) (void *, size_t, size_t), + void (*free_func) (void *, size_t)) +{ + if (!alloc_func) + alloc_func = gmp_default_alloc; + if (!realloc_func) + realloc_func = gmp_default_realloc; + if (!free_func) + free_func = gmp_default_free; + + gmp_allocate_func = alloc_func; + gmp_reallocate_func = realloc_func; + gmp_free_func = free_func; +} + +#define gmp_alloc(size) ((*gmp_allocate_func)((size))) +#define gmp_free(p, size) ((*gmp_free_func) ((p), (size))) +#define gmp_realloc(ptr, old_size, size) ((*gmp_reallocate_func)(ptr, old_size, size)) + +static mp_ptr +gmp_alloc_limbs (mp_size_t size) +{ + return (mp_ptr) gmp_alloc (size * sizeof (mp_limb_t)); +} + +static mp_ptr +gmp_realloc_limbs (mp_ptr old, mp_size_t old_size, mp_size_t size) +{ + assert (size > 0); + return (mp_ptr) gmp_realloc (old, old_size * sizeof (mp_limb_t), size * sizeof (mp_limb_t)); +} + +static void +gmp_free_limbs (mp_ptr old, mp_size_t size) +{ + gmp_free (old, size * sizeof (mp_limb_t)); +} + + +/* MPN interface */ + +void +mpn_copyi (mp_ptr d, mp_srcptr s, mp_size_t n) +{ + mp_size_t i; + for (i = 0; i < n; i++) + d[i] = s[i]; +} + +void +mpn_copyd (mp_ptr d, mp_srcptr s, mp_size_t n) +{ + while (--n >= 0) + d[n] = s[n]; +} + +int +mpn_cmp (mp_srcptr ap, mp_srcptr bp, mp_size_t n) +{ + while (--n >= 0) + { + if (ap[n] != bp[n]) + return ap[n] > bp[n] ? 1 : -1; + } + return 0; +} + +static int +mpn_cmp4 (mp_srcptr ap, mp_size_t an, mp_srcptr bp, mp_size_t bn) +{ + if (an != bn) + return an < bn ? -1 : 1; + else + return mpn_cmp (ap, bp, an); +} + +static mp_size_t +mpn_normalized_size (mp_srcptr xp, mp_size_t n) +{ + while (n > 0 && xp[n-1] == 0) + --n; + return n; +} + +int +mpn_zero_p(mp_srcptr rp, mp_size_t n) +{ + return mpn_normalized_size (rp, n) == 0; +} + +void +mpn_zero (mp_ptr rp, mp_size_t n) +{ + while (--n >= 0) + rp[n] = 0; +} + +mp_limb_t +mpn_add_1 (mp_ptr rp, mp_srcptr ap, mp_size_t n, mp_limb_t b) +{ + mp_size_t i; + + assert (n > 0); + i = 0; + do + { + mp_limb_t r = ap[i] + b; + /* Carry out */ + b = (r < b); + rp[i] = r; + } + while (++i < n); + + return b; +} + +mp_limb_t +mpn_add_n (mp_ptr rp, mp_srcptr ap, mp_srcptr bp, mp_size_t n) +{ + mp_size_t i; + mp_limb_t cy; + + for (i = 0, cy = 0; i < n; i++) + { + mp_limb_t a, b, r; + a = ap[i]; b = bp[i]; + r = a + cy; + cy = (r < cy); + r += b; + cy += (r < b); + rp[i] = r; + } + return cy; +} + +mp_limb_t +mpn_add (mp_ptr rp, mp_srcptr ap, mp_size_t an, mp_srcptr bp, mp_size_t bn) +{ + mp_limb_t cy; + + assert (an >= bn); + + cy = mpn_add_n (rp, ap, bp, bn); + if (an > bn) + cy = mpn_add_1 (rp + bn, ap + bn, an - bn, cy); + return cy; +} + +mp_limb_t +mpn_sub_1 (mp_ptr rp, mp_srcptr ap, mp_size_t n, mp_limb_t b) +{ + mp_size_t i; + + assert (n > 0); + + i = 0; + do + { + mp_limb_t a = ap[i]; + /* Carry out */ + mp_limb_t cy = a < b; + rp[i] = a - b; + b = cy; + } + while (++i < n); + + return b; +} + +mp_limb_t +mpn_sub_n (mp_ptr rp, mp_srcptr ap, mp_srcptr bp, mp_size_t n) +{ + mp_size_t i; + mp_limb_t cy; + + for (i = 0, cy = 0; i < n; i++) + { + mp_limb_t a, b; + a = ap[i]; b = bp[i]; + b += cy; + cy = (b < cy); + cy += (a < b); + rp[i] = a - b; + } + return cy; +} + +mp_limb_t +mpn_sub (mp_ptr rp, mp_srcptr ap, mp_size_t an, mp_srcptr bp, mp_size_t bn) +{ + mp_limb_t cy; + + assert (an >= bn); + + cy = mpn_sub_n (rp, ap, bp, bn); + if (an > bn) + cy = mpn_sub_1 (rp + bn, ap + bn, an - bn, cy); + return cy; +} + +mp_limb_t +mpn_mul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t vl) +{ + mp_limb_t ul, cl, hpl, lpl; + + assert (n >= 1); + + cl = 0; + do + { + ul = *up++; + gmp_umul_ppmm (hpl, lpl, ul, vl); + + lpl += cl; + cl = (lpl < cl) + hpl; + + *rp++ = lpl; + } + while (--n != 0); + + return cl; +} + +mp_limb_t +mpn_addmul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t vl) +{ + mp_limb_t ul, cl, hpl, lpl, rl; + + assert (n >= 1); + + cl = 0; + do + { + ul = *up++; + gmp_umul_ppmm (hpl, lpl, ul, vl); + + lpl += cl; + cl = (lpl < cl) + hpl; + + rl = *rp; + lpl = rl + lpl; + cl += lpl < rl; + *rp++ = lpl; + } + while (--n != 0); + + return cl; +} + +mp_limb_t +mpn_submul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t vl) +{ + mp_limb_t ul, cl, hpl, lpl, rl; + + assert (n >= 1); + + cl = 0; + do + { + ul = *up++; + gmp_umul_ppmm (hpl, lpl, ul, vl); + + lpl += cl; + cl = (lpl < cl) + hpl; + + rl = *rp; + lpl = rl - lpl; + cl += lpl > rl; + *rp++ = lpl; + } + while (--n != 0); + + return cl; +} + +mp_limb_t +mpn_mul (mp_ptr rp, mp_srcptr up, mp_size_t un, mp_srcptr vp, mp_size_t vn) +{ + assert (un >= vn); + assert (vn >= 1); + assert (!GMP_MPN_OVERLAP_P(rp, un + vn, up, un)); + assert (!GMP_MPN_OVERLAP_P(rp, un + vn, vp, vn)); + + /* We first multiply by the low order limb. This result can be + stored, not added, to rp. We also avoid a loop for zeroing this + way. */ + + rp[un] = mpn_mul_1 (rp, up, un, vp[0]); + + /* Now accumulate the product of up[] and the next higher limb from + vp[]. */ + + while (--vn >= 1) + { + rp += 1, vp += 1; + rp[un] = mpn_addmul_1 (rp, up, un, vp[0]); + } + return rp[un]; +} + +void +mpn_mul_n (mp_ptr rp, mp_srcptr ap, mp_srcptr bp, mp_size_t n) +{ + mpn_mul (rp, ap, n, bp, n); +} + +void +mpn_sqr (mp_ptr rp, mp_srcptr ap, mp_size_t n) +{ + mpn_mul (rp, ap, n, ap, n); +} + +mp_limb_t +mpn_lshift (mp_ptr rp, mp_srcptr up, mp_size_t n, unsigned int cnt) +{ + mp_limb_t high_limb, low_limb; + unsigned int tnc; + mp_limb_t retval; + + assert (n >= 1); + assert (cnt >= 1); + assert (cnt < GMP_LIMB_BITS); + + up += n; + rp += n; + + tnc = GMP_LIMB_BITS - cnt; + low_limb = *--up; + retval = low_limb >> tnc; + high_limb = (low_limb << cnt); + + while (--n != 0) + { + low_limb = *--up; + *--rp = high_limb | (low_limb >> tnc); + high_limb = (low_limb << cnt); + } + *--rp = high_limb; + + return retval; +} + +mp_limb_t +mpn_rshift (mp_ptr rp, mp_srcptr up, mp_size_t n, unsigned int cnt) +{ + mp_limb_t high_limb, low_limb; + unsigned int tnc; + mp_limb_t retval; + + assert (n >= 1); + assert (cnt >= 1); + assert (cnt < GMP_LIMB_BITS); + + tnc = GMP_LIMB_BITS - cnt; + high_limb = *up++; + retval = (high_limb << tnc); + low_limb = high_limb >> cnt; + + while (--n != 0) + { + high_limb = *up++; + *rp++ = low_limb | (high_limb << tnc); + low_limb = high_limb >> cnt; + } + *rp = low_limb; + + return retval; +} + +static mp_bitcnt_t +mpn_common_scan (mp_limb_t limb, mp_size_t i, mp_srcptr up, mp_size_t un, + mp_limb_t ux) +{ + unsigned cnt; + + assert (ux == 0 || ux == GMP_LIMB_MAX); + assert (0 <= i && i <= un ); + + while (limb == 0) + { + i++; + if (i == un) + return (ux == 0 ? ~(mp_bitcnt_t) 0 : un * GMP_LIMB_BITS); + limb = ux ^ up[i]; + } + gmp_ctz (cnt, limb); + return (mp_bitcnt_t) i * GMP_LIMB_BITS + cnt; +} + +mp_bitcnt_t +mpn_scan1 (mp_srcptr ptr, mp_bitcnt_t bit) +{ + mp_size_t i; + i = bit / GMP_LIMB_BITS; + + return mpn_common_scan ( ptr[i] & (GMP_LIMB_MAX << (bit % GMP_LIMB_BITS)), + i, ptr, i, 0); +} + +mp_bitcnt_t +mpn_scan0 (mp_srcptr ptr, mp_bitcnt_t bit) +{ + mp_size_t i; + i = bit / GMP_LIMB_BITS; + + return mpn_common_scan (~ptr[i] & (GMP_LIMB_MAX << (bit % GMP_LIMB_BITS)), + i, ptr, i, GMP_LIMB_MAX); +} + +void +mpn_com (mp_ptr rp, mp_srcptr up, mp_size_t n) +{ + while (--n >= 0) + *rp++ = ~ *up++; +} + +mp_limb_t +mpn_neg (mp_ptr rp, mp_srcptr up, mp_size_t n) +{ + while (*up == 0) + { + *rp = 0; + if (!--n) + return 0; + ++up; ++rp; + } + *rp = - *up; + mpn_com (++rp, ++up, --n); + return 1; +} + + +/* MPN division interface. */ + +/* The 3/2 inverse is defined as + + m = floor( (B^3-1) / (B u1 + u0)) - B +*/ +mp_limb_t +mpn_invert_3by2 (mp_limb_t u1, mp_limb_t u0) +{ + mp_limb_t r, m; + + { + mp_limb_t p, ql; + unsigned ul, uh, qh; + + assert (sizeof (unsigned) * 2 >= sizeof (mp_limb_t)); + /* For notation, let b denote the half-limb base, so that B = b^2. + Split u1 = b uh + ul. */ + ul = u1 & GMP_LLIMB_MASK; + uh = u1 >> (GMP_LIMB_BITS / 2); + + /* Approximation of the high half of quotient. Differs from the 2/1 + inverse of the half limb uh, since we have already subtracted + u0. */ + qh = (u1 ^ GMP_LIMB_MAX) / uh; + + /* Adjust to get a half-limb 3/2 inverse, i.e., we want + + qh' = floor( (b^3 - 1) / u) - b = floor ((b^3 - b u - 1) / u + = floor( (b (~u) + b-1) / u), + + and the remainder + + r = b (~u) + b-1 - qh (b uh + ul) + = b (~u - qh uh) + b-1 - qh ul + + Subtraction of qh ul may underflow, which implies adjustments. + But by normalization, 2 u >= B > qh ul, so we need to adjust by + at most 2. + */ + + r = ((~u1 - (mp_limb_t) qh * uh) << (GMP_LIMB_BITS / 2)) | GMP_LLIMB_MASK; + + p = (mp_limb_t) qh * ul; + /* Adjustment steps taken from udiv_qrnnd_c */ + if (r < p) + { + qh--; + r += u1; + if (r >= u1) /* i.e. we didn't get carry when adding to r */ + if (r < p) + { + qh--; + r += u1; + } + } + r -= p; + + /* Low half of the quotient is + + ql = floor ( (b r + b-1) / u1). + + This is a 3/2 division (on half-limbs), for which qh is a + suitable inverse. */ + + p = (r >> (GMP_LIMB_BITS / 2)) * qh + r; + /* Unlike full-limb 3/2, we can add 1 without overflow. For this to + work, it is essential that ql is a full mp_limb_t. */ + ql = (p >> (GMP_LIMB_BITS / 2)) + 1; + + /* By the 3/2 trick, we don't need the high half limb. */ + r = (r << (GMP_LIMB_BITS / 2)) + GMP_LLIMB_MASK - ql * u1; + + if (r >= (GMP_LIMB_MAX & (p << (GMP_LIMB_BITS / 2)))) + { + ql--; + r += u1; + } + m = ((mp_limb_t) qh << (GMP_LIMB_BITS / 2)) + ql; + if (r >= u1) + { + m++; + r -= u1; + } + } + + /* Now m is the 2/1 inverse of u1. If u0 > 0, adjust it to become a + 3/2 inverse. */ + if (u0 > 0) + { + mp_limb_t th, tl; + r = ~r; + r += u0; + if (r < u0) + { + m--; + if (r >= u1) + { + m--; + r -= u1; + } + r -= u1; + } + gmp_umul_ppmm (th, tl, u0, m); + r += th; + if (r < th) + { + m--; + m -= ((r > u1) | ((r == u1) & (tl > u0))); + } + } + + return m; +} + +struct gmp_div_inverse +{ + /* Normalization shift count. */ + unsigned shift; + /* Normalized divisor (d0 unused for mpn_div_qr_1) */ + mp_limb_t d1, d0; + /* Inverse, for 2/1 or 3/2. */ + mp_limb_t di; +}; + +static void +mpn_div_qr_1_invert (struct gmp_div_inverse *inv, mp_limb_t d) +{ + unsigned shift; + + assert (d > 0); + gmp_clz (shift, d); + inv->shift = shift; + inv->d1 = d << shift; + inv->di = mpn_invert_limb (inv->d1); +} + +static void +mpn_div_qr_2_invert (struct gmp_div_inverse *inv, + mp_limb_t d1, mp_limb_t d0) +{ + unsigned shift; + + assert (d1 > 0); + gmp_clz (shift, d1); + inv->shift = shift; + if (shift > 0) + { + d1 = (d1 << shift) | (d0 >> (GMP_LIMB_BITS - shift)); + d0 <<= shift; + } + inv->d1 = d1; + inv->d0 = d0; + inv->di = mpn_invert_3by2 (d1, d0); +} + +static void +mpn_div_qr_invert (struct gmp_div_inverse *inv, + mp_srcptr dp, mp_size_t dn) +{ + assert (dn > 0); + + if (dn == 1) + mpn_div_qr_1_invert (inv, dp[0]); + else if (dn == 2) + mpn_div_qr_2_invert (inv, dp[1], dp[0]); + else + { + unsigned shift; + mp_limb_t d1, d0; + + d1 = dp[dn-1]; + d0 = dp[dn-2]; + assert (d1 > 0); + gmp_clz (shift, d1); + inv->shift = shift; + if (shift > 0) + { + d1 = (d1 << shift) | (d0 >> (GMP_LIMB_BITS - shift)); + d0 = (d0 << shift) | (dp[dn-3] >> (GMP_LIMB_BITS - shift)); + } + inv->d1 = d1; + inv->d0 = d0; + inv->di = mpn_invert_3by2 (d1, d0); + } +} + +/* Not matching current public gmp interface, rather corresponding to + the sbpi1_div_* functions. */ +static mp_limb_t +mpn_div_qr_1_preinv (mp_ptr qp, mp_srcptr np, mp_size_t nn, + const struct gmp_div_inverse *inv) +{ + mp_limb_t d, di; + mp_limb_t r; + mp_ptr tp = NULL; + mp_size_t tn = 0; + + if (inv->shift > 0) + { + /* Shift, reusing qp area if possible. In-place shift if qp == np. */ + tp = qp; + if (!tp) + { + tn = nn; + tp = gmp_alloc_limbs (tn); + } + r = mpn_lshift (tp, np, nn, inv->shift); + np = tp; + } + else + r = 0; + + d = inv->d1; + di = inv->di; + while (--nn >= 0) + { + mp_limb_t q; + + gmp_udiv_qrnnd_preinv (q, r, r, np[nn], d, di); + if (qp) + qp[nn] = q; + } + if (tn) + gmp_free_limbs (tp, tn); + + return r >> inv->shift; +} + +static void +mpn_div_qr_2_preinv (mp_ptr qp, mp_ptr np, mp_size_t nn, + const struct gmp_div_inverse *inv) +{ + unsigned shift; + mp_size_t i; + mp_limb_t d1, d0, di, r1, r0; + + assert (nn >= 2); + shift = inv->shift; + d1 = inv->d1; + d0 = inv->d0; + di = inv->di; + + if (shift > 0) + r1 = mpn_lshift (np, np, nn, shift); + else + r1 = 0; + + r0 = np[nn - 1]; + + i = nn - 2; + do + { + mp_limb_t n0, q; + n0 = np[i]; + gmp_udiv_qr_3by2 (q, r1, r0, r1, r0, n0, d1, d0, di); + + if (qp) + qp[i] = q; + } + while (--i >= 0); + + if (shift > 0) + { + assert ((r0 & (GMP_LIMB_MAX >> (GMP_LIMB_BITS - shift))) == 0); + r0 = (r0 >> shift) | (r1 << (GMP_LIMB_BITS - shift)); + r1 >>= shift; + } + + np[1] = r1; + np[0] = r0; +} + +static void +mpn_div_qr_pi1 (mp_ptr qp, + mp_ptr np, mp_size_t nn, mp_limb_t n1, + mp_srcptr dp, mp_size_t dn, + mp_limb_t dinv) +{ + mp_size_t i; + + mp_limb_t d1, d0; + mp_limb_t cy, cy1; + mp_limb_t q; + + assert (dn > 2); + assert (nn >= dn); + + d1 = dp[dn - 1]; + d0 = dp[dn - 2]; + + assert ((d1 & GMP_LIMB_HIGHBIT) != 0); + /* Iteration variable is the index of the q limb. + * + * We divide <n1, np[dn-1+i], np[dn-2+i], np[dn-3+i],..., np[i]> + * by <d1, d0, dp[dn-3], ..., dp[0] > + */ + + i = nn - dn; + do + { + mp_limb_t n0 = np[dn-1+i]; + + if (n1 == d1 && n0 == d0) + { + q = GMP_LIMB_MAX; + mpn_submul_1 (np+i, dp, dn, q); + n1 = np[dn-1+i]; /* update n1, last loop's value will now be invalid */ + } + else + { + gmp_udiv_qr_3by2 (q, n1, n0, n1, n0, np[dn-2+i], d1, d0, dinv); + + cy = mpn_submul_1 (np + i, dp, dn-2, q); + + cy1 = n0 < cy; + n0 = n0 - cy; + cy = n1 < cy1; + n1 = n1 - cy1; + np[dn-2+i] = n0; + + if (cy != 0) + { + n1 += d1 + mpn_add_n (np + i, np + i, dp, dn - 1); + q--; + } + } + + if (qp) + qp[i] = q; + } + while (--i >= 0); + + np[dn - 1] = n1; +} + +static void +mpn_div_qr_preinv (mp_ptr qp, mp_ptr np, mp_size_t nn, + mp_srcptr dp, mp_size_t dn, + const struct gmp_div_inverse *inv) +{ + assert (dn > 0); + assert (nn >= dn); + + if (dn == 1) + np[0] = mpn_div_qr_1_preinv (qp, np, nn, inv); + else if (dn == 2) + mpn_div_qr_2_preinv (qp, np, nn, inv); + else + { + mp_limb_t nh; + unsigned shift; + + assert (inv->d1 == dp[dn-1]); + assert (inv->d0 == dp[dn-2]); + assert ((inv->d1 & GMP_LIMB_HIGHBIT) != 0); + + shift = inv->shift; + if (shift > 0) + nh = mpn_lshift (np, np, nn, shift); + else + nh = 0; + + mpn_div_qr_pi1 (qp, np, nn, nh, dp, dn, inv->di); + + if (shift > 0) + gmp_assert_nocarry (mpn_rshift (np, np, dn, shift)); + } +} + +static void +mpn_div_qr (mp_ptr qp, mp_ptr np, mp_size_t nn, mp_srcptr dp, mp_size_t dn) +{ + struct gmp_div_inverse inv; + mp_ptr tp = NULL; + + assert (dn > 0); + assert (nn >= dn); + + mpn_div_qr_invert (&inv, dp, dn); + if (dn > 2 && inv.shift > 0) + { + tp = gmp_alloc_limbs (dn); + gmp_assert_nocarry (mpn_lshift (tp, dp, dn, inv.shift)); + dp = tp; + } + mpn_div_qr_preinv (qp, np, nn, dp, dn, &inv); + if (tp) + gmp_free_limbs (tp, dn); +} + + +/* MPN base conversion. */ +static unsigned +mpn_base_power_of_two_p (unsigned b) +{ + switch (b) + { + case 2: return 1; + case 4: return 2; + case 8: return 3; + case 16: return 4; + case 32: return 5; + case 64: return 6; + case 128: return 7; + case 256: return 8; + default: return 0; + } +} + +struct mpn_base_info +{ + /* bb is the largest power of the base which fits in one limb, and + exp is the corresponding exponent. */ + unsigned exp; + mp_limb_t bb; +}; + +static void +mpn_get_base_info (struct mpn_base_info *info, mp_limb_t b) +{ + mp_limb_t m; + mp_limb_t p; + unsigned exp; + + m = GMP_LIMB_MAX / b; + for (exp = 1, p = b; p <= m; exp++) + p *= b; + + info->exp = exp; + info->bb = p; +} + +static mp_bitcnt_t +mpn_limb_size_in_base_2 (mp_limb_t u) +{ + unsigned shift; + + assert (u > 0); + gmp_clz (shift, u); + return GMP_LIMB_BITS - shift; +} + +static size_t +mpn_get_str_bits (unsigned char *sp, unsigned bits, mp_srcptr up, mp_size_t un) +{ + unsigned char mask; + size_t sn, j; + mp_size_t i; + unsigned shift; + + sn = ((un - 1) * GMP_LIMB_BITS + mpn_limb_size_in_base_2 (up[un-1]) + + bits - 1) / bits; + + mask = (1U << bits) - 1; + + for (i = 0, j = sn, shift = 0; j-- > 0;) + { + unsigned char digit = up[i] >> shift; + + shift += bits; + + if (shift >= GMP_LIMB_BITS && ++i < un) + { + shift -= GMP_LIMB_BITS; + digit |= up[i] << (bits - shift); + } + sp[j] = digit & mask; + } + return sn; +} + +/* We generate digits from the least significant end, and reverse at + the end. */ +static size_t +mpn_limb_get_str (unsigned char *sp, mp_limb_t w, + const struct gmp_div_inverse *binv) +{ + mp_size_t i; + for (i = 0; w > 0; i++) + { + mp_limb_t h, l, r; + + h = w >> (GMP_LIMB_BITS - binv->shift); + l = w << binv->shift; + + gmp_udiv_qrnnd_preinv (w, r, h, l, binv->d1, binv->di); + assert ((r & (GMP_LIMB_MAX >> (GMP_LIMB_BITS - binv->shift))) == 0); + r >>= binv->shift; + + sp[i] = r; + } + return i; +} + +static size_t +mpn_get_str_other (unsigned char *sp, + int base, const struct mpn_base_info *info, + mp_ptr up, mp_size_t un) +{ + struct gmp_div_inverse binv; + size_t sn; + size_t i; + + mpn_div_qr_1_invert (&binv, base); + + sn = 0; + + if (un > 1) + { + struct gmp_div_inverse bbinv; + mpn_div_qr_1_invert (&bbinv, info->bb); + + do + { + mp_limb_t w; + size_t done; + w = mpn_div_qr_1_preinv (up, up, un, &bbinv); + un -= (up[un-1] == 0); + done = mpn_limb_get_str (sp + sn, w, &binv); + + for (sn += done; done < info->exp; done++) + sp[sn++] = 0; + } + while (un > 1); + } + sn += mpn_limb_get_str (sp + sn, up[0], &binv); + + /* Reverse order */ + for (i = 0; 2*i + 1 < sn; i++) + { + unsigned char t = sp[i]; + sp[i] = sp[sn - i - 1]; + sp[sn - i - 1] = t; + } + + return sn; +} + +size_t +mpn_get_str (unsigned char *sp, int base, mp_ptr up, mp_size_t un) +{ + unsigned bits; + + assert (un > 0); + assert (up[un-1] > 0); + + bits = mpn_base_power_of_two_p (base); + if (bits) + return mpn_get_str_bits (sp, bits, up, un); + else + { + struct mpn_base_info info; + + mpn_get_base_info (&info, base); + return mpn_get_str_other (sp, base, &info, up, un); + } +} + +static mp_size_t +mpn_set_str_bits (mp_ptr rp, const unsigned char *sp, size_t sn, + unsigned bits) +{ + mp_size_t rn; + mp_limb_t limb; + unsigned shift; + + for (limb = 0, rn = 0, shift = 0; sn-- > 0; ) + { + limb |= (mp_limb_t) sp[sn] << shift; + shift += bits; + if (shift >= GMP_LIMB_BITS) + { + shift -= GMP_LIMB_BITS; + rp[rn++] = limb; + /* Next line is correct also if shift == 0, + bits == 8, and mp_limb_t == unsigned char. */ + limb = (unsigned int) sp[sn] >> (bits - shift); + } + } + if (limb != 0) + rp[rn++] = limb; + else + rn = mpn_normalized_size (rp, rn); + return rn; +} + +/* Result is usually normalized, except for all-zero input, in which + case a single zero limb is written at *RP, and 1 is returned. */ +static mp_size_t +mpn_set_str_other (mp_ptr rp, const unsigned char *sp, size_t sn, + mp_limb_t b, const struct mpn_base_info *info) +{ + mp_size_t rn; + mp_limb_t w; + unsigned k; + size_t j; + + assert (sn > 0); + + k = 1 + (sn - 1) % info->exp; + + j = 0; + w = sp[j++]; + while (--k != 0) + w = w * b + sp[j++]; + + rp[0] = w; + + for (rn = 1; j < sn;) + { + mp_limb_t cy; + + w = sp[j++]; + for (k = 1; k < info->exp; k++) + w = w * b + sp[j++]; + + cy = mpn_mul_1 (rp, rp, rn, info->bb); + cy += mpn_add_1 (rp, rp, rn, w); + if (cy > 0) + rp[rn++] = cy; + } + assert (j == sn); + + return rn; +} + +mp_size_t +mpn_set_str (mp_ptr rp, const unsigned char *sp, size_t sn, int base) +{ + unsigned bits; + + if (sn == 0) + return 0; + + bits = mpn_base_power_of_two_p (base); + if (bits) + return mpn_set_str_bits (rp, sp, sn, bits); + else + { + struct mpn_base_info info; + + mpn_get_base_info (&info, base); + return mpn_set_str_other (rp, sp, sn, base, &info); + } +} + + +/* MPZ interface */ +void +mpz_init (mpz_t r) +{ + static const mp_limb_t dummy_limb = GMP_LIMB_MAX & 0xc1a0; + + r->_mp_alloc = 0; + r->_mp_size = 0; + r->_mp_d = (mp_ptr) &dummy_limb; +} + +/* The utility of this function is a bit limited, since many functions + assigns the result variable using mpz_swap. */ +void +mpz_init2 (mpz_t r, mp_bitcnt_t bits) +{ + mp_size_t rn; + + bits -= (bits != 0); /* Round down, except if 0 */ + rn = 1 + bits / GMP_LIMB_BITS; + + r->_mp_alloc = rn; + r->_mp_size = 0; + r->_mp_d = gmp_alloc_limbs (rn); +} + +void +mpz_clear (mpz_t r) +{ + if (r->_mp_alloc) + gmp_free_limbs (r->_mp_d, r->_mp_alloc); +} + +static mp_ptr +mpz_realloc (mpz_t r, mp_size_t size) +{ + size = GMP_MAX (size, 1); + + if (r->_mp_alloc) + r->_mp_d = gmp_realloc_limbs (r->_mp_d, r->_mp_alloc, size); + else + r->_mp_d = gmp_alloc_limbs (size); + r->_mp_alloc = size; + + if (GMP_ABS (r->_mp_size) > size) + r->_mp_size = 0; + + return r->_mp_d; +} + +/* Realloc for an mpz_t WHAT if it has less than NEEDED limbs. */ +#define MPZ_REALLOC(z,n) ((n) > (z)->_mp_alloc \ + ? mpz_realloc(z,n) \ + : (z)->_mp_d) + +/* MPZ assignment and basic conversions. */ +void +mpz_set_si (mpz_t r, signed long int x) +{ + if (x >= 0) + mpz_set_ui (r, x); + else /* (x < 0) */ + if (GMP_LIMB_BITS < GMP_ULONG_BITS) + { + mpz_set_ui (r, GMP_NEG_CAST (unsigned long int, x)); + mpz_neg (r, r); + } + else + { + r->_mp_size = -1; + MPZ_REALLOC (r, 1)[0] = GMP_NEG_CAST (unsigned long int, x); + } +} + +void +mpz_set_ui (mpz_t r, unsigned long int x) +{ + if (x > 0) + { + r->_mp_size = 1; + MPZ_REALLOC (r, 1)[0] = x; + if (GMP_LIMB_BITS < GMP_ULONG_BITS) + { + int LOCAL_GMP_LIMB_BITS = GMP_LIMB_BITS; + while (x >>= LOCAL_GMP_LIMB_BITS) + { + ++ r->_mp_size; + MPZ_REALLOC (r, r->_mp_size)[r->_mp_size - 1] = x; + } + } + } + else + r->_mp_size = 0; +} + +void +mpz_set (mpz_t r, const mpz_t x) +{ + /* Allow the NOP r == x */ + if (r != x) + { + mp_size_t n; + mp_ptr rp; + + n = GMP_ABS (x->_mp_size); + rp = MPZ_REALLOC (r, n); + + mpn_copyi (rp, x->_mp_d, n); + r->_mp_size = x->_mp_size; + } +} + +void +mpz_init_set_si (mpz_t r, signed long int x) +{ + mpz_init (r); + mpz_set_si (r, x); +} + +void +mpz_init_set_ui (mpz_t r, unsigned long int x) +{ + mpz_init (r); + mpz_set_ui (r, x); +} + +void +mpz_init_set (mpz_t r, const mpz_t x) +{ + mpz_init (r); + mpz_set (r, x); +} + +int +mpz_fits_slong_p (const mpz_t u) +{ + return mpz_cmp_si (u, LONG_MAX) <= 0 && mpz_cmp_si (u, LONG_MIN) >= 0; +} + +static int +mpn_absfits_ulong_p (mp_srcptr up, mp_size_t un) +{ + int ulongsize = GMP_ULONG_BITS / GMP_LIMB_BITS; + mp_limb_t ulongrem = 0; + + if (GMP_ULONG_BITS % GMP_LIMB_BITS != 0) + ulongrem = (mp_limb_t) (ULONG_MAX >> GMP_LIMB_BITS * ulongsize) + 1; + + return un <= ulongsize || (up[ulongsize] < ulongrem && un == ulongsize + 1); +} + +int +mpz_fits_ulong_p (const mpz_t u) +{ + mp_size_t us = u->_mp_size; + + return us >= 0 && mpn_absfits_ulong_p (u->_mp_d, us); +} + +int +mpz_fits_sint_p (const mpz_t u) +{ + return mpz_cmp_si (u, INT_MAX) <= 0 && mpz_cmp_si (u, INT_MIN) >= 0; +} + +int +mpz_fits_uint_p (const mpz_t u) +{ + return u->_mp_size >= 0 && mpz_cmpabs_ui (u, UINT_MAX) <= 0; +} + +int +mpz_fits_sshort_p (const mpz_t u) +{ + return mpz_cmp_si (u, SHRT_MAX) <= 0 && mpz_cmp_si (u, SHRT_MIN) >= 0; +} + +int +mpz_fits_ushort_p (const mpz_t u) +{ + return u->_mp_size >= 0 && mpz_cmpabs_ui (u, USHRT_MAX) <= 0; +} + +long int +mpz_get_si (const mpz_t u) +{ + unsigned long r = mpz_get_ui (u); + unsigned long c = -LONG_MAX - LONG_MIN; + + if (u->_mp_size < 0) + /* This expression is necessary to properly handle -LONG_MIN */ + return -(long) c - (long) ((r - c) & LONG_MAX); + else + return (long) (r & LONG_MAX); +} + +unsigned long int +mpz_get_ui (const mpz_t u) +{ + if (GMP_LIMB_BITS < GMP_ULONG_BITS) + { + int LOCAL_GMP_LIMB_BITS = GMP_LIMB_BITS; + unsigned long r = 0; + mp_size_t n = GMP_ABS (u->_mp_size); + n = GMP_MIN (n, 1 + (mp_size_t) (GMP_ULONG_BITS - 1) / GMP_LIMB_BITS); + while (--n >= 0) + r = (r << LOCAL_GMP_LIMB_BITS) + u->_mp_d[n]; + return r; + } + + return u->_mp_size == 0 ? 0 : u->_mp_d[0]; +} + +size_t +mpz_size (const mpz_t u) +{ + return GMP_ABS (u->_mp_size); +} + +mp_limb_t +mpz_getlimbn (const mpz_t u, mp_size_t n) +{ + if (n >= 0 && n < GMP_ABS (u->_mp_size)) + return u->_mp_d[n]; + else + return 0; +} + +void +mpz_realloc2 (mpz_t x, mp_bitcnt_t n) +{ + mpz_realloc (x, 1 + (n - (n != 0)) / GMP_LIMB_BITS); +} + +mp_srcptr +mpz_limbs_read (mpz_srcptr x) +{ + return x->_mp_d; +} + +mp_ptr +mpz_limbs_modify (mpz_t x, mp_size_t n) +{ + assert (n > 0); + return MPZ_REALLOC (x, n); +} + +mp_ptr +mpz_limbs_write (mpz_t x, mp_size_t n) +{ + return mpz_limbs_modify (x, n); +} + +void +mpz_limbs_finish (mpz_t x, mp_size_t xs) +{ + mp_size_t xn; + xn = mpn_normalized_size (x->_mp_d, GMP_ABS (xs)); + x->_mp_size = xs < 0 ? -xn : xn; +} + +static mpz_srcptr +mpz_roinit_normal_n (mpz_t x, mp_srcptr xp, mp_size_t xs) +{ + x->_mp_alloc = 0; + x->_mp_d = (mp_ptr) xp; + x->_mp_size = xs; + return x; +} + +mpz_srcptr +mpz_roinit_n (mpz_t x, mp_srcptr xp, mp_size_t xs) +{ + mpz_roinit_normal_n (x, xp, xs); + mpz_limbs_finish (x, xs); + return x; +} + + +/* Conversions and comparison to double. */ +void +mpz_set_d (mpz_t r, double x) +{ + int sign; + mp_ptr rp; + mp_size_t rn, i; + double B; + double Bi; + mp_limb_t f; + + /* x != x is true when x is a NaN, and x == x * 0.5 is true when x is + zero or infinity. */ + if (x != x || x == x * 0.5) + { + r->_mp_size = 0; + return; + } + + sign = x < 0.0 ; + if (sign) + x = - x; + + if (x < 1.0) + { + r->_mp_size = 0; + return; + } + B = 4.0 * (double) (GMP_LIMB_HIGHBIT >> 1); + Bi = 1.0 / B; + for (rn = 1; x >= B; rn++) + x *= Bi; + + rp = MPZ_REALLOC (r, rn); + + f = (mp_limb_t) x; + x -= f; + assert (x < 1.0); + i = rn-1; + rp[i] = f; + while (--i >= 0) + { + x = B * x; + f = (mp_limb_t) x; + x -= f; + assert (x < 1.0); + rp[i] = f; + } + + r->_mp_size = sign ? - rn : rn; +} + +void +mpz_init_set_d (mpz_t r, double x) +{ + mpz_init (r); + mpz_set_d (r, x); +} + +double +mpz_get_d (const mpz_t u) +{ + int m; + mp_limb_t l; + mp_size_t un; + double x; + double B = 4.0 * (double) (GMP_LIMB_HIGHBIT >> 1); + + un = GMP_ABS (u->_mp_size); + + if (un == 0) + return 0.0; + + l = u->_mp_d[--un]; + gmp_clz (m, l); + m = m + GMP_DBL_MANT_BITS - GMP_LIMB_BITS; + if (m < 0) + l &= GMP_LIMB_MAX << -m; + + for (x = l; --un >= 0;) + { + x = B*x; + if (m > 0) { + l = u->_mp_d[un]; + m -= GMP_LIMB_BITS; + if (m < 0) + l &= GMP_LIMB_MAX << -m; + x += l; + } + } + + if (u->_mp_size < 0) + x = -x; + + return x; +} + +int +mpz_cmpabs_d (const mpz_t x, double d) +{ + mp_size_t xn; + double B, Bi; + mp_size_t i; + + xn = x->_mp_size; + d = GMP_ABS (d); + + if (xn != 0) + { + xn = GMP_ABS (xn); + + B = 4.0 * (double) (GMP_LIMB_HIGHBIT >> 1); + Bi = 1.0 / B; + + /* Scale d so it can be compared with the top limb. */ + for (i = 1; i < xn; i++) + d *= Bi; + + if (d >= B) + return -1; + + /* Compare floor(d) to top limb, subtract and cancel when equal. */ + for (i = xn; i-- > 0;) + { + mp_limb_t f, xl; + + f = (mp_limb_t) d; + xl = x->_mp_d[i]; + if (xl > f) + return 1; + else if (xl < f) + return -1; + d = B * (d - f); + } + } + return - (d > 0.0); +} + +int +mpz_cmp_d (const mpz_t x, double d) +{ + if (x->_mp_size < 0) + { + if (d >= 0.0) + return -1; + else + return -mpz_cmpabs_d (x, d); + } + else + { + if (d < 0.0) + return 1; + else + return mpz_cmpabs_d (x, d); + } +} + + +/* MPZ comparisons and the like. */ +int +mpz_sgn (const mpz_t u) +{ + return GMP_CMP (u->_mp_size, 0); +} + +int +mpz_cmp_si (const mpz_t u, long v) +{ + mp_size_t usize = u->_mp_size; + + if (v >= 0) + return mpz_cmp_ui (u, v); + else if (usize >= 0) + return 1; + else + return - mpz_cmpabs_ui (u, GMP_NEG_CAST (unsigned long int, v)); +} + +int +mpz_cmp_ui (const mpz_t u, unsigned long v) +{ + mp_size_t usize = u->_mp_size; + + if (usize < 0) + return -1; + else + return mpz_cmpabs_ui (u, v); +} + +int +mpz_cmp (const mpz_t a, const mpz_t b) +{ + mp_size_t asize = a->_mp_size; + mp_size_t bsize = b->_mp_size; + + if (asize != bsize) + return (asize < bsize) ? -1 : 1; + else if (asize >= 0) + return mpn_cmp (a->_mp_d, b->_mp_d, asize); + else + return mpn_cmp (b->_mp_d, a->_mp_d, -asize); +} + +int +mpz_cmpabs_ui (const mpz_t u, unsigned long v) +{ + mp_size_t un = GMP_ABS (u->_mp_size); + + if (! mpn_absfits_ulong_p (u->_mp_d, un)) + return 1; + else + { + unsigned long uu = mpz_get_ui (u); + return GMP_CMP(uu, v); + } +} + +int +mpz_cmpabs (const mpz_t u, const mpz_t v) +{ + return mpn_cmp4 (u->_mp_d, GMP_ABS (u->_mp_size), + v->_mp_d, GMP_ABS (v->_mp_size)); +} + +void +mpz_abs (mpz_t r, const mpz_t u) +{ + mpz_set (r, u); + r->_mp_size = GMP_ABS (r->_mp_size); +} + +void +mpz_neg (mpz_t r, const mpz_t u) +{ + mpz_set (r, u); + r->_mp_size = -r->_mp_size; +} + +void +mpz_swap (mpz_t u, mpz_t v) +{ + MP_SIZE_T_SWAP (u->_mp_alloc, v->_mp_alloc); + MPN_PTR_SWAP (u->_mp_d, u->_mp_size, v->_mp_d, v->_mp_size); +} + + +/* MPZ addition and subtraction */ + + +void +mpz_add_ui (mpz_t r, const mpz_t a, unsigned long b) +{ + mpz_t bb; + mpz_init_set_ui (bb, b); + mpz_add (r, a, bb); + mpz_clear (bb); +} + +void +mpz_sub_ui (mpz_t r, const mpz_t a, unsigned long b) +{ + mpz_ui_sub (r, b, a); + mpz_neg (r, r); +} + +void +mpz_ui_sub (mpz_t r, unsigned long a, const mpz_t b) +{ + mpz_neg (r, b); + mpz_add_ui (r, r, a); +} + +static mp_size_t +mpz_abs_add (mpz_t r, const mpz_t a, const mpz_t b) +{ + mp_size_t an = GMP_ABS (a->_mp_size); + mp_size_t bn = GMP_ABS (b->_mp_size); + mp_ptr rp; + mp_limb_t cy; + + if (an < bn) + { + MPZ_SRCPTR_SWAP (a, b); + MP_SIZE_T_SWAP (an, bn); + } + + rp = MPZ_REALLOC (r, an + 1); + cy = mpn_add (rp, a->_mp_d, an, b->_mp_d, bn); + + rp[an] = cy; + + return an + cy; +} + +static mp_size_t +mpz_abs_sub (mpz_t r, const mpz_t a, const mpz_t b) +{ + mp_size_t an = GMP_ABS (a->_mp_size); + mp_size_t bn = GMP_ABS (b->_mp_size); + int cmp; + mp_ptr rp; + + cmp = mpn_cmp4 (a->_mp_d, an, b->_mp_d, bn); + if (cmp > 0) + { + rp = MPZ_REALLOC (r, an); + gmp_assert_nocarry (mpn_sub (rp, a->_mp_d, an, b->_mp_d, bn)); + return mpn_normalized_size (rp, an); + } + else if (cmp < 0) + { + rp = MPZ_REALLOC (r, bn); + gmp_assert_nocarry (mpn_sub (rp, b->_mp_d, bn, a->_mp_d, an)); + return -mpn_normalized_size (rp, bn); + } + else + return 0; +} + +void +mpz_add (mpz_t r, const mpz_t a, const mpz_t b) +{ + mp_size_t rn; + + if ( (a->_mp_size ^ b->_mp_size) >= 0) + rn = mpz_abs_add (r, a, b); + else + rn = mpz_abs_sub (r, a, b); + + r->_mp_size = a->_mp_size >= 0 ? rn : - rn; +} + +void +mpz_sub (mpz_t r, const mpz_t a, const mpz_t b) +{ + mp_size_t rn; + + if ( (a->_mp_size ^ b->_mp_size) >= 0) + rn = mpz_abs_sub (r, a, b); + else + rn = mpz_abs_add (r, a, b); + + r->_mp_size = a->_mp_size >= 0 ? rn : - rn; +} + + +/* MPZ multiplication */ +void +mpz_mul_si (mpz_t r, const mpz_t u, long int v) +{ + if (v < 0) + { + mpz_mul_ui (r, u, GMP_NEG_CAST (unsigned long int, v)); + mpz_neg (r, r); + } + else + mpz_mul_ui (r, u, v); +} + +void +mpz_mul_ui (mpz_t r, const mpz_t u, unsigned long int v) +{ + mpz_t vv; + mpz_init_set_ui (vv, v); + mpz_mul (r, u, vv); + mpz_clear (vv); + return; +} + +void +mpz_mul (mpz_t r, const mpz_t u, const mpz_t v) +{ + int sign; + mp_size_t un, vn, rn; + mpz_t t; + mp_ptr tp; + + un = u->_mp_size; + vn = v->_mp_size; + + if (un == 0 || vn == 0) + { + r->_mp_size = 0; + return; + } + + sign = (un ^ vn) < 0; + + un = GMP_ABS (un); + vn = GMP_ABS (vn); + + mpz_init2 (t, (un + vn) * GMP_LIMB_BITS); + + tp = t->_mp_d; + if (un >= vn) + mpn_mul (tp, u->_mp_d, un, v->_mp_d, vn); + else + mpn_mul (tp, v->_mp_d, vn, u->_mp_d, un); + + rn = un + vn; + rn -= tp[rn-1] == 0; + + t->_mp_size = sign ? - rn : rn; + mpz_swap (r, t); + mpz_clear (t); +} + +void +mpz_mul_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t bits) +{ + mp_size_t un, rn; + mp_size_t limbs; + unsigned shift; + mp_ptr rp; + + un = GMP_ABS (u->_mp_size); + if (un == 0) + { + r->_mp_size = 0; + return; + } + + limbs = bits / GMP_LIMB_BITS; + shift = bits % GMP_LIMB_BITS; + + rn = un + limbs + (shift > 0); + rp = MPZ_REALLOC (r, rn); + if (shift > 0) + { + mp_limb_t cy = mpn_lshift (rp + limbs, u->_mp_d, un, shift); + rp[rn-1] = cy; + rn -= (cy == 0); + } + else + mpn_copyd (rp + limbs, u->_mp_d, un); + + mpn_zero (rp, limbs); + + r->_mp_size = (u->_mp_size < 0) ? - rn : rn; +} + +void +mpz_addmul_ui (mpz_t r, const mpz_t u, unsigned long int v) +{ + mpz_t t; + mpz_init_set_ui (t, v); + mpz_mul (t, u, t); + mpz_add (r, r, t); + mpz_clear (t); +} + +void +mpz_submul_ui (mpz_t r, const mpz_t u, unsigned long int v) +{ + mpz_t t; + mpz_init_set_ui (t, v); + mpz_mul (t, u, t); + mpz_sub (r, r, t); + mpz_clear (t); +} + +void +mpz_addmul (mpz_t r, const mpz_t u, const mpz_t v) +{ + mpz_t t; + mpz_init (t); + mpz_mul (t, u, v); + mpz_add (r, r, t); + mpz_clear (t); +} + +void +mpz_submul (mpz_t r, const mpz_t u, const mpz_t v) +{ + mpz_t t; + mpz_init (t); + mpz_mul (t, u, v); + mpz_sub (r, r, t); + mpz_clear (t); +} + + +/* MPZ division */ +enum mpz_div_round_mode { GMP_DIV_FLOOR, GMP_DIV_CEIL, GMP_DIV_TRUNC }; + +/* Allows q or r to be zero. Returns 1 iff remainder is non-zero. */ +static int +mpz_div_qr (mpz_t q, mpz_t r, + const mpz_t n, const mpz_t d, enum mpz_div_round_mode mode) +{ + mp_size_t ns, ds, nn, dn, qs; + ns = n->_mp_size; + ds = d->_mp_size; + + if (ds == 0) + gmp_die("mpz_div_qr: Divide by zero."); + + if (ns == 0) + { + if (q) + q->_mp_size = 0; + if (r) + r->_mp_size = 0; + return 0; + } + + nn = GMP_ABS (ns); + dn = GMP_ABS (ds); + + qs = ds ^ ns; + + if (nn < dn) + { + if (mode == GMP_DIV_CEIL && qs >= 0) + { + /* q = 1, r = n - d */ + if (r) + mpz_sub (r, n, d); + if (q) + mpz_set_ui (q, 1); + } + else if (mode == GMP_DIV_FLOOR && qs < 0) + { + /* q = -1, r = n + d */ + if (r) + mpz_add (r, n, d); + if (q) + mpz_set_si (q, -1); + } + else + { + /* q = 0, r = d */ + if (r) + mpz_set (r, n); + if (q) + q->_mp_size = 0; + } + return 1; + } + else + { + mp_ptr np, qp; + mp_size_t qn, rn; + mpz_t tq, tr; + + mpz_init_set (tr, n); + np = tr->_mp_d; + + qn = nn - dn + 1; + + if (q) + { + mpz_init2 (tq, qn * GMP_LIMB_BITS); + qp = tq->_mp_d; + } + else + qp = NULL; + + mpn_div_qr (qp, np, nn, d->_mp_d, dn); + + if (qp) + { + qn -= (qp[qn-1] == 0); + + tq->_mp_size = qs < 0 ? -qn : qn; + } + rn = mpn_normalized_size (np, dn); + tr->_mp_size = ns < 0 ? - rn : rn; + + if (mode == GMP_DIV_FLOOR && qs < 0 && rn != 0) + { + if (q) + mpz_sub_ui (tq, tq, 1); + if (r) + mpz_add (tr, tr, d); + } + else if (mode == GMP_DIV_CEIL && qs >= 0 && rn != 0) + { + if (q) + mpz_add_ui (tq, tq, 1); + if (r) + mpz_sub (tr, tr, d); + } + + if (q) + { + mpz_swap (tq, q); + mpz_clear (tq); + } + if (r) + mpz_swap (tr, r); + + mpz_clear (tr); + + return rn != 0; + } +} + +void +mpz_cdiv_qr (mpz_t q, mpz_t r, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (q, r, n, d, GMP_DIV_CEIL); +} + +void +mpz_fdiv_qr (mpz_t q, mpz_t r, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (q, r, n, d, GMP_DIV_FLOOR); +} + +void +mpz_tdiv_qr (mpz_t q, mpz_t r, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (q, r, n, d, GMP_DIV_TRUNC); +} + +void +mpz_cdiv_q (mpz_t q, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (q, NULL, n, d, GMP_DIV_CEIL); +} + +void +mpz_fdiv_q (mpz_t q, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (q, NULL, n, d, GMP_DIV_FLOOR); +} + +void +mpz_tdiv_q (mpz_t q, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (q, NULL, n, d, GMP_DIV_TRUNC); +} + +void +mpz_cdiv_r (mpz_t r, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (NULL, r, n, d, GMP_DIV_CEIL); +} + +void +mpz_fdiv_r (mpz_t r, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (NULL, r, n, d, GMP_DIV_FLOOR); +} + +void +mpz_tdiv_r (mpz_t r, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (NULL, r, n, d, GMP_DIV_TRUNC); +} + +void +mpz_mod (mpz_t r, const mpz_t n, const mpz_t d) +{ + mpz_div_qr (NULL, r, n, d, d->_mp_size >= 0 ? GMP_DIV_FLOOR : GMP_DIV_CEIL); +} + +static void +mpz_div_q_2exp (mpz_t q, const mpz_t u, mp_bitcnt_t bit_index, + enum mpz_div_round_mode mode) +{ + mp_size_t un, qn; + mp_size_t limb_cnt; + mp_ptr qp; + int adjust; + + un = u->_mp_size; + if (un == 0) + { + q->_mp_size = 0; + return; + } + limb_cnt = bit_index / GMP_LIMB_BITS; + qn = GMP_ABS (un) - limb_cnt; + bit_index %= GMP_LIMB_BITS; + + if (mode == ((un > 0) ? GMP_DIV_CEIL : GMP_DIV_FLOOR)) /* un != 0 here. */ + /* Note: Below, the final indexing at limb_cnt is valid because at + that point we have qn > 0. */ + adjust = (qn <= 0 + || !mpn_zero_p (u->_mp_d, limb_cnt) + || (u->_mp_d[limb_cnt] + & (((mp_limb_t) 1 << bit_index) - 1))); + else + adjust = 0; + + if (qn <= 0) + qn = 0; + else + { + qp = MPZ_REALLOC (q, qn); + + if (bit_index != 0) + { + mpn_rshift (qp, u->_mp_d + limb_cnt, qn, bit_index); + qn -= qp[qn - 1] == 0; + } + else + { + mpn_copyi (qp, u->_mp_d + limb_cnt, qn); + } + } + + q->_mp_size = qn; + + if (adjust) + mpz_add_ui (q, q, 1); + if (un < 0) + mpz_neg (q, q); +} + +static void +mpz_div_r_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t bit_index, + enum mpz_div_round_mode mode) +{ + mp_size_t us, un, rn; + mp_ptr rp; + mp_limb_t mask; + + us = u->_mp_size; + if (us == 0 || bit_index == 0) + { + r->_mp_size = 0; + return; + } + rn = (bit_index + GMP_LIMB_BITS - 1) / GMP_LIMB_BITS; + assert (rn > 0); + + rp = MPZ_REALLOC (r, rn); + un = GMP_ABS (us); + + mask = GMP_LIMB_MAX >> (rn * GMP_LIMB_BITS - bit_index); + + if (rn > un) + { + /* Quotient (with truncation) is zero, and remainder is + non-zero */ + if (mode == ((us > 0) ? GMP_DIV_CEIL : GMP_DIV_FLOOR)) /* us != 0 here. */ + { + /* Have to negate and sign extend. */ + mp_size_t i; + + gmp_assert_nocarry (! mpn_neg (rp, u->_mp_d, un)); + for (i = un; i < rn - 1; i++) + rp[i] = GMP_LIMB_MAX; + + rp[rn-1] = mask; + us = -us; + } + else + { + /* Just copy */ + if (r != u) + mpn_copyi (rp, u->_mp_d, un); + + rn = un; + } + } + else + { + if (r != u) + mpn_copyi (rp, u->_mp_d, rn - 1); + + rp[rn-1] = u->_mp_d[rn-1] & mask; + + if (mode == ((us > 0) ? GMP_DIV_CEIL : GMP_DIV_FLOOR)) /* us != 0 here. */ + { + /* If r != 0, compute 2^{bit_count} - r. */ + mpn_neg (rp, rp, rn); + + rp[rn-1] &= mask; + + /* us is not used for anything else, so we can modify it + here to indicate flipped sign. */ + us = -us; + } + } + rn = mpn_normalized_size (rp, rn); + r->_mp_size = us < 0 ? -rn : rn; +} + +void +mpz_cdiv_q_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t cnt) +{ + mpz_div_q_2exp (r, u, cnt, GMP_DIV_CEIL); +} + +void +mpz_fdiv_q_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t cnt) +{ + mpz_div_q_2exp (r, u, cnt, GMP_DIV_FLOOR); +} + +void +mpz_tdiv_q_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t cnt) +{ + mpz_div_q_2exp (r, u, cnt, GMP_DIV_TRUNC); +} + +void +mpz_cdiv_r_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t cnt) +{ + mpz_div_r_2exp (r, u, cnt, GMP_DIV_CEIL); +} + +void +mpz_fdiv_r_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t cnt) +{ + mpz_div_r_2exp (r, u, cnt, GMP_DIV_FLOOR); +} + +void +mpz_tdiv_r_2exp (mpz_t r, const mpz_t u, mp_bitcnt_t cnt) +{ + mpz_div_r_2exp (r, u, cnt, GMP_DIV_TRUNC); +} + +void +mpz_divexact (mpz_t q, const mpz_t n, const mpz_t d) +{ + gmp_assert_nocarry (mpz_div_qr (q, NULL, n, d, GMP_DIV_TRUNC)); +} + +int +mpz_divisible_p (const mpz_t n, const mpz_t d) +{ + return mpz_div_qr (NULL, NULL, n, d, GMP_DIV_TRUNC) == 0; +} + +int +mpz_congruent_p (const mpz_t a, const mpz_t b, const mpz_t m) +{ + mpz_t t; + int res; + + /* a == b (mod 0) iff a == b */ + if (mpz_sgn (m) == 0) + return (mpz_cmp (a, b) == 0); + + mpz_init (t); + mpz_sub (t, a, b); + res = mpz_divisible_p (t, m); + mpz_clear (t); + + return res; +} + +static unsigned long +mpz_div_qr_ui (mpz_t q, mpz_t r, + const mpz_t n, unsigned long d, enum mpz_div_round_mode mode) +{ + unsigned long ret; + mpz_t rr, dd; + + mpz_init (rr); + mpz_init_set_ui (dd, d); + mpz_div_qr (q, rr, n, dd, mode); + mpz_clear (dd); + ret = mpz_get_ui (rr); + + if (r) + mpz_swap (r, rr); + mpz_clear (rr); + + return ret; +} + +unsigned long +mpz_cdiv_qr_ui (mpz_t q, mpz_t r, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (q, r, n, d, GMP_DIV_CEIL); +} + +unsigned long +mpz_fdiv_qr_ui (mpz_t q, mpz_t r, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (q, r, n, d, GMP_DIV_FLOOR); +} + +unsigned long +mpz_tdiv_qr_ui (mpz_t q, mpz_t r, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (q, r, n, d, GMP_DIV_TRUNC); +} + +unsigned long +mpz_cdiv_q_ui (mpz_t q, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (q, NULL, n, d, GMP_DIV_CEIL); +} + +unsigned long +mpz_fdiv_q_ui (mpz_t q, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (q, NULL, n, d, GMP_DIV_FLOOR); +} + +unsigned long +mpz_tdiv_q_ui (mpz_t q, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (q, NULL, n, d, GMP_DIV_TRUNC); +} + +unsigned long +mpz_cdiv_r_ui (mpz_t r, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, r, n, d, GMP_DIV_CEIL); +} +unsigned long +mpz_fdiv_r_ui (mpz_t r, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, r, n, d, GMP_DIV_FLOOR); +} +unsigned long +mpz_tdiv_r_ui (mpz_t r, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, r, n, d, GMP_DIV_TRUNC); +} + +unsigned long +mpz_cdiv_ui (const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, NULL, n, d, GMP_DIV_CEIL); +} + +unsigned long +mpz_fdiv_ui (const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, NULL, n, d, GMP_DIV_FLOOR); +} + +unsigned long +mpz_tdiv_ui (const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, NULL, n, d, GMP_DIV_TRUNC); +} + +unsigned long +mpz_mod_ui (mpz_t r, const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, r, n, d, GMP_DIV_FLOOR); +} + +void +mpz_divexact_ui (mpz_t q, const mpz_t n, unsigned long d) +{ + gmp_assert_nocarry (mpz_div_qr_ui (q, NULL, n, d, GMP_DIV_TRUNC)); +} + +int +mpz_divisible_ui_p (const mpz_t n, unsigned long d) +{ + return mpz_div_qr_ui (NULL, NULL, n, d, GMP_DIV_TRUNC) == 0; +} + + +/* GCD */ +static mp_limb_t +mpn_gcd_11 (mp_limb_t u, mp_limb_t v) +{ + unsigned shift; + + assert ( (u | v) > 0); + + if (u == 0) + return v; + else if (v == 0) + return u; + + gmp_ctz (shift, u | v); + + u >>= shift; + v >>= shift; + + if ( (u & 1) == 0) + MP_LIMB_T_SWAP (u, v); + + while ( (v & 1) == 0) + v >>= 1; + + while (u != v) + { + if (u > v) + { + u -= v; + do + u >>= 1; + while ( (u & 1) == 0); + } + else + { + v -= u; + do + v >>= 1; + while ( (v & 1) == 0); + } + } + return u << shift; +} + +unsigned long +mpz_gcd_ui (mpz_t g, const mpz_t u, unsigned long v) +{ + mpz_t t; + mpz_init_set_ui(t, v); + mpz_gcd (t, u, t); + if (v > 0) + v = mpz_get_ui (t); + + if (g) + mpz_swap (t, g); + + mpz_clear (t); + + return v; +} + +static mp_bitcnt_t +mpz_make_odd (mpz_t r) +{ + mp_bitcnt_t shift; + + assert (r->_mp_size > 0); + /* Count trailing zeros, equivalent to mpn_scan1, because we know that there is a 1 */ + shift = mpn_scan1 (r->_mp_d, 0); + mpz_tdiv_q_2exp (r, r, shift); + + return shift; +} + +void +mpz_gcd (mpz_t g, const mpz_t u, const mpz_t v) +{ + mpz_t tu, tv; + mp_bitcnt_t uz, vz, gz; + + if (u->_mp_size == 0) + { + mpz_abs (g, v); + return; + } + if (v->_mp_size == 0) + { + mpz_abs (g, u); + return; + } + + mpz_init (tu); + mpz_init (tv); + + mpz_abs (tu, u); + uz = mpz_make_odd (tu); + mpz_abs (tv, v); + vz = mpz_make_odd (tv); + gz = GMP_MIN (uz, vz); + + if (tu->_mp_size < tv->_mp_size) + mpz_swap (tu, tv); + + mpz_tdiv_r (tu, tu, tv); + if (tu->_mp_size == 0) + { + mpz_swap (g, tv); + } + else + for (;;) + { + int c; + + mpz_make_odd (tu); + c = mpz_cmp (tu, tv); + if (c == 0) + { + mpz_swap (g, tu); + break; + } + if (c < 0) + mpz_swap (tu, tv); + + if (tv->_mp_size == 1) + { + mp_limb_t *gp; + + mpz_tdiv_r (tu, tu, tv); + gp = MPZ_REALLOC (g, 1); /* gp = mpz_limbs_modify (g, 1); */ + *gp = mpn_gcd_11 (tu->_mp_d[0], tv->_mp_d[0]); + + g->_mp_size = *gp != 0; /* mpz_limbs_finish (g, 1); */ + break; + } + mpz_sub (tu, tu, tv); + } + mpz_clear (tu); + mpz_clear (tv); + mpz_mul_2exp (g, g, gz); +} + +void +mpz_gcdext (mpz_t g, mpz_t s, mpz_t t, const mpz_t u, const mpz_t v) +{ + mpz_t tu, tv, s0, s1, t0, t1; + mp_bitcnt_t uz, vz, gz; + mp_bitcnt_t power; + + if (u->_mp_size == 0) + { + /* g = 0 u + sgn(v) v */ + signed long sign = mpz_sgn (v); + mpz_abs (g, v); + if (s) + s->_mp_size = 0; + if (t) + mpz_set_si (t, sign); + return; + } + + if (v->_mp_size == 0) + { + /* g = sgn(u) u + 0 v */ + signed long sign = mpz_sgn (u); + mpz_abs (g, u); + if (s) + mpz_set_si (s, sign); + if (t) + t->_mp_size = 0; + return; + } + + mpz_init (tu); + mpz_init (tv); + mpz_init (s0); + mpz_init (s1); + mpz_init (t0); + mpz_init (t1); + + mpz_abs (tu, u); + uz = mpz_make_odd (tu); + mpz_abs (tv, v); + vz = mpz_make_odd (tv); + gz = GMP_MIN (uz, vz); + + uz -= gz; + vz -= gz; + + /* Cofactors corresponding to odd gcd. gz handled later. */ + if (tu->_mp_size < tv->_mp_size) + { + mpz_swap (tu, tv); + MPZ_SRCPTR_SWAP (u, v); + MPZ_PTR_SWAP (s, t); + MP_BITCNT_T_SWAP (uz, vz); + } + + /* Maintain + * + * u = t0 tu + t1 tv + * v = s0 tu + s1 tv + * + * where u and v denote the inputs with common factors of two + * eliminated, and det (s0, t0; s1, t1) = 2^p. Then + * + * 2^p tu = s1 u - t1 v + * 2^p tv = -s0 u + t0 v + */ + + /* After initial division, tu = q tv + tu', we have + * + * u = 2^uz (tu' + q tv) + * v = 2^vz tv + * + * or + * + * t0 = 2^uz, t1 = 2^uz q + * s0 = 0, s1 = 2^vz + */ + + mpz_tdiv_qr (t1, tu, tu, tv); + mpz_mul_2exp (t1, t1, uz); + + mpz_setbit (s1, vz); + power = uz + vz; + + if (tu->_mp_size > 0) + { + mp_bitcnt_t shift; + shift = mpz_make_odd (tu); + mpz_setbit (t0, uz + shift); + power += shift; + + for (;;) + { + int c; + c = mpz_cmp (tu, tv); + if (c == 0) + break; + + if (c < 0) + { + /* tv = tv' + tu + * + * u = t0 tu + t1 (tv' + tu) = (t0 + t1) tu + t1 tv' + * v = s0 tu + s1 (tv' + tu) = (s0 + s1) tu + s1 tv' */ + + mpz_sub (tv, tv, tu); + mpz_add (t0, t0, t1); + mpz_add (s0, s0, s1); + + shift = mpz_make_odd (tv); + mpz_mul_2exp (t1, t1, shift); + mpz_mul_2exp (s1, s1, shift); + } + else + { + mpz_sub (tu, tu, tv); + mpz_add (t1, t0, t1); + mpz_add (s1, s0, s1); + + shift = mpz_make_odd (tu); + mpz_mul_2exp (t0, t0, shift); + mpz_mul_2exp (s0, s0, shift); + } + power += shift; + } + } + else + mpz_setbit (t0, uz); + + /* Now tv = odd part of gcd, and -s0 and t0 are corresponding + cofactors. */ + + mpz_mul_2exp (tv, tv, gz); + mpz_neg (s0, s0); + + /* 2^p g = s0 u + t0 v. Eliminate one factor of two at a time. To + adjust cofactors, we need u / g and v / g */ + + mpz_divexact (s1, v, tv); + mpz_abs (s1, s1); + mpz_divexact (t1, u, tv); + mpz_abs (t1, t1); + + while (power-- > 0) + { + /* s0 u + t0 v = (s0 - v/g) u - (t0 + u/g) v */ + if (mpz_odd_p (s0) || mpz_odd_p (t0)) + { + mpz_sub (s0, s0, s1); + mpz_add (t0, t0, t1); + } + assert (mpz_even_p (t0) && mpz_even_p (s0)); + mpz_tdiv_q_2exp (s0, s0, 1); + mpz_tdiv_q_2exp (t0, t0, 1); + } + + /* Arrange so that |s| < |u| / 2g */ + mpz_add (s1, s0, s1); + if (mpz_cmpabs (s0, s1) > 0) + { + mpz_swap (s0, s1); + mpz_sub (t0, t0, t1); + } + if (u->_mp_size < 0) + mpz_neg (s0, s0); + if (v->_mp_size < 0) + mpz_neg (t0, t0); + + mpz_swap (g, tv); + if (s) + mpz_swap (s, s0); + if (t) + mpz_swap (t, t0); + + mpz_clear (tu); + mpz_clear (tv); + mpz_clear (s0); + mpz_clear (s1); + mpz_clear (t0); + mpz_clear (t1); +} + +void +mpz_lcm (mpz_t r, const mpz_t u, const mpz_t v) +{ + mpz_t g; + + if (u->_mp_size == 0 || v->_mp_size == 0) + { + r->_mp_size = 0; + return; + } + + mpz_init (g); + + mpz_gcd (g, u, v); + mpz_divexact (g, u, g); + mpz_mul (r, g, v); + + mpz_clear (g); + mpz_abs (r, r); +} + +void +mpz_lcm_ui (mpz_t r, const mpz_t u, unsigned long v) +{ + if (v == 0 || u->_mp_size == 0) + { + r->_mp_size = 0; + return; + } + + v /= mpz_gcd_ui (NULL, u, v); + mpz_mul_ui (r, u, v); + + mpz_abs (r, r); +} + +int +mpz_invert (mpz_t r, const mpz_t u, const mpz_t m) +{ + mpz_t g, tr; + int invertible; + + if (u->_mp_size == 0 || mpz_cmpabs_ui (m, 1) <= 0) + return 0; + + mpz_init (g); + mpz_init (tr); + + mpz_gcdext (g, tr, NULL, u, m); + invertible = (mpz_cmp_ui (g, 1) == 0); + + if (invertible) + { + if (tr->_mp_size < 0) + { + if (m->_mp_size >= 0) + mpz_add (tr, tr, m); + else + mpz_sub (tr, tr, m); + } + mpz_swap (r, tr); + } + + mpz_clear (g); + mpz_clear (tr); + return invertible; +} + + +/* Higher level operations (sqrt, pow and root) */ + +void +mpz_pow_ui (mpz_t r, const mpz_t b, unsigned long e) +{ + unsigned long bit; + mpz_t tr; + mpz_init_set_ui (tr, 1); + + bit = GMP_ULONG_HIGHBIT; + do + { + mpz_mul (tr, tr, tr); + if (e & bit) + mpz_mul (tr, tr, b); + bit >>= 1; + } + while (bit > 0); + + mpz_swap (r, tr); + mpz_clear (tr); +} + +void +mpz_ui_pow_ui (mpz_t r, unsigned long blimb, unsigned long e) +{ + mpz_t b; + + mpz_init_set_ui (b, blimb); + mpz_pow_ui (r, b, e); + mpz_clear (b); +} + +void +mpz_powm (mpz_t r, const mpz_t b, const mpz_t e, const mpz_t m) +{ + mpz_t tr; + mpz_t base; + mp_size_t en, mn; + mp_srcptr mp; + struct gmp_div_inverse minv; + unsigned shift; + mp_ptr tp = NULL; + + en = GMP_ABS (e->_mp_size); + mn = GMP_ABS (m->_mp_size); + if (mn == 0) + gmp_die ("mpz_powm: Zero modulo."); + + if (en == 0) + { + mpz_set_ui (r, mpz_cmpabs_ui (m, 1)); + return; + } + + mp = m->_mp_d; + mpn_div_qr_invert (&minv, mp, mn); + shift = minv.shift; + + if (shift > 0) + { + /* To avoid shifts, we do all our reductions, except the final + one, using a *normalized* m. */ + minv.shift = 0; + + tp = gmp_alloc_limbs (mn); + gmp_assert_nocarry (mpn_lshift (tp, mp, mn, shift)); + mp = tp; + } + + mpz_init (base); + + if (e->_mp_size < 0) + { + if (!mpz_invert (base, b, m)) + gmp_die ("mpz_powm: Negative exponent and non-invertible base."); + } + else + { + mp_size_t bn; + mpz_abs (base, b); + + bn = base->_mp_size; + if (bn >= mn) + { + mpn_div_qr_preinv (NULL, base->_mp_d, base->_mp_size, mp, mn, &minv); + bn = mn; + } + + /* We have reduced the absolute value. Now take care of the + sign. Note that we get zero represented non-canonically as + m. */ + if (b->_mp_size < 0) + { + mp_ptr bp = MPZ_REALLOC (base, mn); + gmp_assert_nocarry (mpn_sub (bp, mp, mn, bp, bn)); + bn = mn; + } + base->_mp_size = mpn_normalized_size (base->_mp_d, bn); + } + mpz_init_set_ui (tr, 1); + + while (--en >= 0) + { + mp_limb_t w = e->_mp_d[en]; + mp_limb_t bit; + + bit = GMP_LIMB_HIGHBIT; + do + { + mpz_mul (tr, tr, tr); + if (w & bit) + mpz_mul (tr, tr, base); + if (tr->_mp_size > mn) + { + mpn_div_qr_preinv (NULL, tr->_mp_d, tr->_mp_size, mp, mn, &minv); + tr->_mp_size = mpn_normalized_size (tr->_mp_d, mn); + } + bit >>= 1; + } + while (bit > 0); + } + + /* Final reduction */ + if (tr->_mp_size >= mn) + { + minv.shift = shift; + mpn_div_qr_preinv (NULL, tr->_mp_d, tr->_mp_size, mp, mn, &minv); + tr->_mp_size = mpn_normalized_size (tr->_mp_d, mn); + } + if (tp) + gmp_free_limbs (tp, mn); + + mpz_swap (r, tr); + mpz_clear (tr); + mpz_clear (base); +} + +void +mpz_powm_ui (mpz_t r, const mpz_t b, unsigned long elimb, const mpz_t m) +{ + mpz_t e; + + mpz_init_set_ui (e, elimb); + mpz_powm (r, b, e, m); + mpz_clear (e); +} + +/* x=trunc(y^(1/z)), r=y-x^z */ +void +mpz_rootrem (mpz_t x, mpz_t r, const mpz_t y, unsigned long z) +{ + int sgn; + mp_bitcnt_t bc; + mpz_t t, u; + + sgn = y->_mp_size < 0; + if ((~z & sgn) != 0) + gmp_die ("mpz_rootrem: Negative argument, with even root."); + if (z == 0) + gmp_die ("mpz_rootrem: Zeroth root."); + + if (mpz_cmpabs_ui (y, 1) <= 0) { + if (x) + mpz_set (x, y); + if (r) + r->_mp_size = 0; + return; + } + + mpz_init (u); + mpz_init (t); + bc = (mpz_sizeinbase (y, 2) - 1) / z + 1; + mpz_setbit (t, bc); + + if (z == 2) /* simplify sqrt loop: z-1 == 1 */ + do { + mpz_swap (u, t); /* u = x */ + mpz_tdiv_q (t, y, u); /* t = y/x */ + mpz_add (t, t, u); /* t = y/x + x */ + mpz_tdiv_q_2exp (t, t, 1); /* x'= (y/x + x)/2 */ + } while (mpz_cmpabs (t, u) < 0); /* |x'| < |x| */ + else /* z != 2 */ { + mpz_t v; + + mpz_init (v); + if (sgn) + mpz_neg (t, t); + + do { + mpz_swap (u, t); /* u = x */ + mpz_pow_ui (t, u, z - 1); /* t = x^(z-1) */ + mpz_tdiv_q (t, y, t); /* t = y/x^(z-1) */ + mpz_mul_ui (v, u, z - 1); /* v = x*(z-1) */ + mpz_add (t, t, v); /* t = y/x^(z-1) + x*(z-1) */ + mpz_tdiv_q_ui (t, t, z); /* x'=(y/x^(z-1) + x*(z-1))/z */ + } while (mpz_cmpabs (t, u) < 0); /* |x'| < |x| */ + + mpz_clear (v); + } + + if (r) { + mpz_pow_ui (t, u, z); + mpz_sub (r, y, t); + } + if (x) + mpz_swap (x, u); + mpz_clear (u); + mpz_clear (t); +} + +int +mpz_root (mpz_t x, const mpz_t y, unsigned long z) +{ + int res; + mpz_t r; + + mpz_init (r); + mpz_rootrem (x, r, y, z); + res = r->_mp_size == 0; + mpz_clear (r); + + return res; +} + +/* Compute s = floor(sqrt(u)) and r = u - s^2. Allows r == NULL */ +void +mpz_sqrtrem (mpz_t s, mpz_t r, const mpz_t u) +{ + mpz_rootrem (s, r, u, 2); +} + +void +mpz_sqrt (mpz_t s, const mpz_t u) +{ + mpz_rootrem (s, NULL, u, 2); +} + +int +mpz_perfect_square_p (const mpz_t u) +{ + if (u->_mp_size <= 0) + return (u->_mp_size == 0); + else + return mpz_root (NULL, u, 2); +} + +int +mpn_perfect_square_p (mp_srcptr p, mp_size_t n) +{ + mpz_t t; + + assert (n > 0); + assert (p [n-1] != 0); + return mpz_root (NULL, mpz_roinit_normal_n (t, p, n), 2); +} + +mp_size_t +mpn_sqrtrem (mp_ptr sp, mp_ptr rp, mp_srcptr p, mp_size_t n) +{ + mpz_t s, r, u; + mp_size_t res; + + assert (n > 0); + assert (p [n-1] != 0); + + mpz_init (r); + mpz_init (s); + mpz_rootrem (s, r, mpz_roinit_normal_n (u, p, n), 2); + + assert (s->_mp_size == (n+1)/2); + mpn_copyd (sp, s->_mp_d, s->_mp_size); + mpz_clear (s); + res = r->_mp_size; + if (rp) + mpn_copyd (rp, r->_mp_d, res); + mpz_clear (r); + return res; +} + +/* Combinatorics */ + +void +mpz_mfac_uiui (mpz_t x, unsigned long n, unsigned long m) +{ + mpz_set_ui (x, n + (n == 0)); + if (m + 1 < 2) return; + while (n > m + 1) + mpz_mul_ui (x, x, n -= m); +} + +void +mpz_2fac_ui (mpz_t x, unsigned long n) +{ + mpz_mfac_uiui (x, n, 2); +} + +void +mpz_fac_ui (mpz_t x, unsigned long n) +{ + mpz_mfac_uiui (x, n, 1); +} + +void +mpz_bin_uiui (mpz_t r, unsigned long n, unsigned long k) +{ + mpz_t t; + + mpz_set_ui (r, k <= n); + + if (k > (n >> 1)) + k = (k <= n) ? n - k : 0; + + mpz_init (t); + mpz_fac_ui (t, k); + + for (; k > 0; --k) + mpz_mul_ui (r, r, n--); + + mpz_divexact (r, r, t); + mpz_clear (t); +} + + +/* Primality testing */ + +/* Computes Kronecker (a/b) with odd b, a!=0 and GCD(a,b) = 1 */ +/* Adapted from JACOBI_BASE_METHOD==4 in mpn/generic/jacbase.c */ +static int +gmp_jacobi_coprime (mp_limb_t a, mp_limb_t b) +{ + int c, bit = 0; + + assert (b & 1); + assert (a != 0); + /* assert (mpn_gcd_11 (a, b) == 1); */ + + /* Below, we represent a and b shifted right so that the least + significant one bit is implicit. */ + b >>= 1; + + gmp_ctz(c, a); + a >>= 1; + + for (;;) + { + a >>= c; + /* (2/b) = -1 if b = 3 or 5 mod 8 */ + bit ^= c & (b ^ (b >> 1)); + if (a < b) + { + if (a == 0) + return bit & 1 ? -1 : 1; + bit ^= a & b; + a = b - a; + b -= a; + } + else + { + a -= b; + assert (a != 0); + } + + gmp_ctz(c, a); + ++c; + } +} + +static void +gmp_lucas_step_k_2k (mpz_t V, mpz_t Qk, const mpz_t n) +{ + mpz_mod (Qk, Qk, n); + /* V_{2k} <- V_k ^ 2 - 2Q^k */ + mpz_mul (V, V, V); + mpz_submul_ui (V, Qk, 2); + mpz_tdiv_r (V, V, n); + /* Q^{2k} = (Q^k)^2 */ + mpz_mul (Qk, Qk, Qk); +} + +/* Computes V_k, Q^k (mod n) for the Lucas' sequence */ +/* with P=1, Q=Q; k = (n>>b0)|1. */ +/* Requires an odd n > 4; b0 > 0; -2*Q must not overflow a long */ +/* Returns (U_k == 0) and sets V=V_k and Qk=Q^k. */ +static int +gmp_lucas_mod (mpz_t V, mpz_t Qk, long Q, + mp_bitcnt_t b0, const mpz_t n) +{ + mp_bitcnt_t bs; + mpz_t U; + int res; + + assert (b0 > 0); + assert (Q <= - (LONG_MIN / 2)); + assert (Q >= - (LONG_MAX / 2)); + assert (mpz_cmp_ui (n, 4) > 0); + assert (mpz_odd_p (n)); + + mpz_init_set_ui (U, 1); /* U1 = 1 */ + mpz_set_ui (V, 1); /* V1 = 1 */ + mpz_set_si (Qk, Q); + + for (bs = mpz_sizeinbase (n, 2) - 1; --bs >= b0;) + { + /* U_{2k} <- U_k * V_k */ + mpz_mul (U, U, V); + /* V_{2k} <- V_k ^ 2 - 2Q^k */ + /* Q^{2k} = (Q^k)^2 */ + gmp_lucas_step_k_2k (V, Qk, n); + + /* A step k->k+1 is performed if the bit in $n$ is 1 */ + /* mpz_tstbit(n,bs) or the bit is 0 in $n$ but */ + /* should be 1 in $n+1$ (bs == b0) */ + if (b0 == bs || mpz_tstbit (n, bs)) + { + /* Q^{k+1} <- Q^k * Q */ + mpz_mul_si (Qk, Qk, Q); + /* U_{k+1} <- (U_k + V_k) / 2 */ + mpz_swap (U, V); /* Keep in V the old value of U_k */ + mpz_add (U, U, V); + /* We have to compute U/2, so we need an even value, */ + /* equivalent (mod n) */ + if (mpz_odd_p (U)) + mpz_add (U, U, n); + mpz_tdiv_q_2exp (U, U, 1); + /* V_{k+1} <-(D*U_k + V_k) / 2 = + U_{k+1} + (D-1)/2*U_k = U_{k+1} - 2Q*U_k */ + mpz_mul_si (V, V, -2*Q); + mpz_add (V, U, V); + mpz_tdiv_r (V, V, n); + } + mpz_tdiv_r (U, U, n); + } + + res = U->_mp_size == 0; + mpz_clear (U); + return res; +} + +/* Performs strong Lucas' test on x, with parameters suggested */ +/* for the BPSW test. Qk is only passed to recycle a variable. */ +/* Requires GCD (x,6) = 1.*/ +static int +gmp_stronglucas (const mpz_t x, mpz_t Qk) +{ + mp_bitcnt_t b0; + mpz_t V, n; + mp_limb_t maxD, D; /* The absolute value is stored. */ + long Q; + mp_limb_t tl; + + /* Test on the absolute value. */ + mpz_roinit_normal_n (n, x->_mp_d, GMP_ABS (x->_mp_size)); + + assert (mpz_odd_p (n)); + /* assert (mpz_gcd_ui (NULL, n, 6) == 1); */ + if (mpz_root (Qk, n, 2)) + return 0; /* A square is composite. */ + + /* Check Ds up to square root (in case, n is prime) + or avoid overflows */ + maxD = (Qk->_mp_size == 1) ? Qk->_mp_d [0] - 1 : GMP_LIMB_MAX; + + D = 3; + /* Search a D such that (D/n) = -1 in the sequence 5,-7,9,-11,.. */ + /* For those Ds we have (D/n) = (n/|D|) */ + do + { + if (D >= maxD) + return 1 + (D != GMP_LIMB_MAX); /* (1 + ! ~ D) */ + D += 2; + tl = mpz_tdiv_ui (n, D); + if (tl == 0) + return 0; + } + while (gmp_jacobi_coprime (tl, D) == 1); + + mpz_init (V); + + /* n-(D/n) = n+1 = d*2^{b0}, with d = (n>>b0) | 1 */ + b0 = mpn_common_scan (~ n->_mp_d[0], 0, n->_mp_d, n->_mp_size, GMP_LIMB_MAX); + /* b0 = mpz_scan0 (n, 0); */ + + /* D= P^2 - 4Q; P = 1; Q = (1-D)/4 */ + Q = (D & 2) ? (long) (D >> 2) + 1 : -(long) (D >> 2); + + if (! gmp_lucas_mod (V, Qk, Q, b0, n)) /* If Ud != 0 */ + while (V->_mp_size != 0 && --b0 != 0) /* while Vk != 0 */ + /* V <- V ^ 2 - 2Q^k */ + /* Q^{2k} = (Q^k)^2 */ + gmp_lucas_step_k_2k (V, Qk, n); + + mpz_clear (V); + return (b0 != 0); +} + +static int +gmp_millerrabin (const mpz_t n, const mpz_t nm1, mpz_t y, + const mpz_t q, mp_bitcnt_t k) +{ + assert (k > 0); + + /* Caller must initialize y to the base. */ + mpz_powm (y, y, q, n); + + if (mpz_cmp_ui (y, 1) == 0 || mpz_cmp (y, nm1) == 0) + return 1; + + while (--k > 0) + { + mpz_powm_ui (y, y, 2, n); + if (mpz_cmp (y, nm1) == 0) + return 1; + } + return 0; +} + +/* This product is 0xc0cfd797, and fits in 32 bits. */ +#define GMP_PRIME_PRODUCT \ + (3UL*5UL*7UL*11UL*13UL*17UL*19UL*23UL*29UL) + +/* Bit (p+1)/2 is set, for each odd prime <= 61 */ +#define GMP_PRIME_MASK 0xc96996dcUL + +int +mpz_probab_prime_p (const mpz_t n, int reps) +{ + mpz_t nm1; + mpz_t q; + mpz_t y; + mp_bitcnt_t k; + int is_prime; + int j; + + /* Note that we use the absolute value of n only, for compatibility + with the real GMP. */ + if (mpz_even_p (n)) + return (mpz_cmpabs_ui (n, 2) == 0) ? 2 : 0; + + /* Above test excludes n == 0 */ + assert (n->_mp_size != 0); + + if (mpz_cmpabs_ui (n, 64) < 0) + return (GMP_PRIME_MASK >> (n->_mp_d[0] >> 1)) & 2; + + if (mpz_gcd_ui (NULL, n, GMP_PRIME_PRODUCT) != 1) + return 0; + + /* All prime factors are >= 31. */ + if (mpz_cmpabs_ui (n, 31*31) < 0) + return 2; + + mpz_init (nm1); + mpz_init (q); + + /* Find q and k, where q is odd and n = 1 + 2**k * q. */ + mpz_abs (nm1, n); + nm1->_mp_d[0] -= 1; + /* Count trailing zeros, equivalent to mpn_scan1, because we know that there is a 1 */ + k = mpn_scan1 (nm1->_mp_d, 0); + mpz_tdiv_q_2exp (q, nm1, k); + + /* BPSW test */ + mpz_init_set_ui (y, 2); + is_prime = gmp_millerrabin (n, nm1, y, q, k) && gmp_stronglucas (n, y); + reps -= 24; /* skip the first 24 repetitions */ + + /* Use Miller-Rabin, with a deterministic sequence of bases, a[j] = + j^2 + j + 41 using Euler's polynomial. We potentially stop early, + if a[j] >= n - 1. Since n >= 31*31, this can happen only if reps > + 30 (a[30] == 971 > 31*31 == 961). */ + + for (j = 0; is_prime & (j < reps); j++) + { + mpz_set_ui (y, (unsigned long) j*j+j+41); + if (mpz_cmp (y, nm1) >= 0) + { + /* Don't try any further bases. This "early" break does not affect + the result for any reasonable reps value (<=5000 was tested) */ + assert (j >= 30); + break; + } + is_prime = gmp_millerrabin (n, nm1, y, q, k); + } + mpz_clear (nm1); + mpz_clear (q); + mpz_clear (y); + + return is_prime; +} + + +/* Logical operations and bit manipulation. */ + +/* Numbers are treated as if represented in two's complement (and + infinitely sign extended). For a negative values we get the two's + complement from -x = ~x + 1, where ~ is bitwise complement. + Negation transforms + + xxxx10...0 + + into + + yyyy10...0 + + where yyyy is the bitwise complement of xxxx. So least significant + bits, up to and including the first one bit, are unchanged, and + the more significant bits are all complemented. + + To change a bit from zero to one in a negative number, subtract the + corresponding power of two from the absolute value. This can never + underflow. To change a bit from one to zero, add the corresponding + power of two, and this might overflow. E.g., if x = -001111, the + two's complement is 110001. Clearing the least significant bit, we + get two's complement 110000, and -010000. */ + +int +mpz_tstbit (const mpz_t d, mp_bitcnt_t bit_index) +{ + mp_size_t limb_index; + unsigned shift; + mp_size_t ds; + mp_size_t dn; + mp_limb_t w; + int bit; + + ds = d->_mp_size; + dn = GMP_ABS (ds); + limb_index = bit_index / GMP_LIMB_BITS; + if (limb_index >= dn) + return ds < 0; + + shift = bit_index % GMP_LIMB_BITS; + w = d->_mp_d[limb_index]; + bit = (w >> shift) & 1; + + if (ds < 0) + { + /* d < 0. Check if any of the bits below is set: If so, our bit + must be complemented. */ + if (shift > 0 && (mp_limb_t) (w << (GMP_LIMB_BITS - shift)) > 0) + return bit ^ 1; + while (--limb_index >= 0) + if (d->_mp_d[limb_index] > 0) + return bit ^ 1; + } + return bit; +} + +static void +mpz_abs_add_bit (mpz_t d, mp_bitcnt_t bit_index) +{ + mp_size_t dn, limb_index; + mp_limb_t bit; + mp_ptr dp; + + dn = GMP_ABS (d->_mp_size); + + limb_index = bit_index / GMP_LIMB_BITS; + bit = (mp_limb_t) 1 << (bit_index % GMP_LIMB_BITS); + + if (limb_index >= dn) + { + mp_size_t i; + /* The bit should be set outside of the end of the number. + We have to increase the size of the number. */ + dp = MPZ_REALLOC (d, limb_index + 1); + + dp[limb_index] = bit; + for (i = dn; i < limb_index; i++) + dp[i] = 0; + dn = limb_index + 1; + } + else + { + mp_limb_t cy; + + dp = d->_mp_d; + + cy = mpn_add_1 (dp + limb_index, dp + limb_index, dn - limb_index, bit); + if (cy > 0) + { + dp = MPZ_REALLOC (d, dn + 1); + dp[dn++] = cy; + } + } + + d->_mp_size = (d->_mp_size < 0) ? - dn : dn; +} + +static void +mpz_abs_sub_bit (mpz_t d, mp_bitcnt_t bit_index) +{ + mp_size_t dn, limb_index; + mp_ptr dp; + mp_limb_t bit; + + dn = GMP_ABS (d->_mp_size); + dp = d->_mp_d; + + limb_index = bit_index / GMP_LIMB_BITS; + bit = (mp_limb_t) 1 << (bit_index % GMP_LIMB_BITS); + + assert (limb_index < dn); + + gmp_assert_nocarry (mpn_sub_1 (dp + limb_index, dp + limb_index, + dn - limb_index, bit)); + dn = mpn_normalized_size (dp, dn); + d->_mp_size = (d->_mp_size < 0) ? - dn : dn; +} + +void +mpz_setbit (mpz_t d, mp_bitcnt_t bit_index) +{ + if (!mpz_tstbit (d, bit_index)) + { + if (d->_mp_size >= 0) + mpz_abs_add_bit (d, bit_index); + else + mpz_abs_sub_bit (d, bit_index); + } +} + +void +mpz_clrbit (mpz_t d, mp_bitcnt_t bit_index) +{ + if (mpz_tstbit (d, bit_index)) + { + if (d->_mp_size >= 0) + mpz_abs_sub_bit (d, bit_index); + else + mpz_abs_add_bit (d, bit_index); + } +} + +void +mpz_combit (mpz_t d, mp_bitcnt_t bit_index) +{ + if (mpz_tstbit (d, bit_index) ^ (d->_mp_size < 0)) + mpz_abs_sub_bit (d, bit_index); + else + mpz_abs_add_bit (d, bit_index); +} + +void +mpz_com (mpz_t r, const mpz_t u) +{ + mpz_add_ui (r, u, 1); + mpz_neg (r, r); +} + +void +mpz_and (mpz_t r, const mpz_t u, const mpz_t v) +{ + mp_size_t un, vn, rn, i; + mp_ptr up, vp, rp; + + mp_limb_t ux, vx, rx; + mp_limb_t uc, vc, rc; + mp_limb_t ul, vl, rl; + + un = GMP_ABS (u->_mp_size); + vn = GMP_ABS (v->_mp_size); + if (un < vn) + { + MPZ_SRCPTR_SWAP (u, v); + MP_SIZE_T_SWAP (un, vn); + } + if (vn == 0) + { + r->_mp_size = 0; + return; + } + + uc = u->_mp_size < 0; + vc = v->_mp_size < 0; + rc = uc & vc; + + ux = -uc; + vx = -vc; + rx = -rc; + + /* If the smaller input is positive, higher limbs don't matter. */ + rn = vx ? un : vn; + + rp = MPZ_REALLOC (r, rn + (mp_size_t) rc); + + up = u->_mp_d; + vp = v->_mp_d; + + i = 0; + do + { + ul = (up[i] ^ ux) + uc; + uc = ul < uc; + + vl = (vp[i] ^ vx) + vc; + vc = vl < vc; + + rl = ( (ul & vl) ^ rx) + rc; + rc = rl < rc; + rp[i] = rl; + } + while (++i < vn); + assert (vc == 0); + + for (; i < rn; i++) + { + ul = (up[i] ^ ux) + uc; + uc = ul < uc; + + rl = ( (ul & vx) ^ rx) + rc; + rc = rl < rc; + rp[i] = rl; + } + if (rc) + rp[rn++] = rc; + else + rn = mpn_normalized_size (rp, rn); + + r->_mp_size = rx ? -rn : rn; +} + +void +mpz_ior (mpz_t r, const mpz_t u, const mpz_t v) +{ + mp_size_t un, vn, rn, i; + mp_ptr up, vp, rp; + + mp_limb_t ux, vx, rx; + mp_limb_t uc, vc, rc; + mp_limb_t ul, vl, rl; + + un = GMP_ABS (u->_mp_size); + vn = GMP_ABS (v->_mp_size); + if (un < vn) + { + MPZ_SRCPTR_SWAP (u, v); + MP_SIZE_T_SWAP (un, vn); + } + if (vn == 0) + { + mpz_set (r, u); + return; + } + + uc = u->_mp_size < 0; + vc = v->_mp_size < 0; + rc = uc | vc; + + ux = -uc; + vx = -vc; + rx = -rc; + + /* If the smaller input is negative, by sign extension higher limbs + don't matter. */ + rn = vx ? vn : un; + + rp = MPZ_REALLOC (r, rn + (mp_size_t) rc); + + up = u->_mp_d; + vp = v->_mp_d; + + i = 0; + do + { + ul = (up[i] ^ ux) + uc; + uc = ul < uc; + + vl = (vp[i] ^ vx) + vc; + vc = vl < vc; + + rl = ( (ul | vl) ^ rx) + rc; + rc = rl < rc; + rp[i] = rl; + } + while (++i < vn); + assert (vc == 0); + + for (; i < rn; i++) + { + ul = (up[i] ^ ux) + uc; + uc = ul < uc; + + rl = ( (ul | vx) ^ rx) + rc; + rc = rl < rc; + rp[i] = rl; + } + if (rc) + rp[rn++] = rc; + else + rn = mpn_normalized_size (rp, rn); + + r->_mp_size = rx ? -rn : rn; +} + +void +mpz_xor (mpz_t r, const mpz_t u, const mpz_t v) +{ + mp_size_t un, vn, i; + mp_ptr up, vp, rp; + + mp_limb_t ux, vx, rx; + mp_limb_t uc, vc, rc; + mp_limb_t ul, vl, rl; + + un = GMP_ABS (u->_mp_size); + vn = GMP_ABS (v->_mp_size); + if (un < vn) + { + MPZ_SRCPTR_SWAP (u, v); + MP_SIZE_T_SWAP (un, vn); + } + if (vn == 0) + { + mpz_set (r, u); + return; + } + + uc = u->_mp_size < 0; + vc = v->_mp_size < 0; + rc = uc ^ vc; + + ux = -uc; + vx = -vc; + rx = -rc; + + rp = MPZ_REALLOC (r, un + (mp_size_t) rc); + + up = u->_mp_d; + vp = v->_mp_d; + + i = 0; + do + { + ul = (up[i] ^ ux) + uc; + uc = ul < uc; + + vl = (vp[i] ^ vx) + vc; + vc = vl < vc; + + rl = (ul ^ vl ^ rx) + rc; + rc = rl < rc; + rp[i] = rl; + } + while (++i < vn); + assert (vc == 0); + + for (; i < un; i++) + { + ul = (up[i] ^ ux) + uc; + uc = ul < uc; + + rl = (ul ^ ux) + rc; + rc = rl < rc; + rp[i] = rl; + } + if (rc) + rp[un++] = rc; + else + un = mpn_normalized_size (rp, un); + + r->_mp_size = rx ? -un : un; +} + +static unsigned +gmp_popcount_limb (mp_limb_t x) +{ + unsigned c; + + /* Do 16 bits at a time, to avoid limb-sized constants. */ + int LOCAL_SHIFT_BITS = 16; + for (c = 0; x > 0;) + { + unsigned w = x - ((x >> 1) & 0x5555); + w = ((w >> 2) & 0x3333) + (w & 0x3333); + w = (w >> 4) + w; + w = ((w >> 8) & 0x000f) + (w & 0x000f); + c += w; + if (GMP_LIMB_BITS > LOCAL_SHIFT_BITS) + x >>= LOCAL_SHIFT_BITS; + else + x = 0; + } + return c; +} + +mp_bitcnt_t +mpn_popcount (mp_srcptr p, mp_size_t n) +{ + mp_size_t i; + mp_bitcnt_t c; + + for (c = 0, i = 0; i < n; i++) + c += gmp_popcount_limb (p[i]); + + return c; +} + +mp_bitcnt_t +mpz_popcount (const mpz_t u) +{ + mp_size_t un; + + un = u->_mp_size; + + if (un < 0) + return ~(mp_bitcnt_t) 0; + + return mpn_popcount (u->_mp_d, un); +} + +mp_bitcnt_t +mpz_hamdist (const mpz_t u, const mpz_t v) +{ + mp_size_t un, vn, i; + mp_limb_t uc, vc, ul, vl, comp; + mp_srcptr up, vp; + mp_bitcnt_t c; + + un = u->_mp_size; + vn = v->_mp_size; + + if ( (un ^ vn) < 0) + return ~(mp_bitcnt_t) 0; + + comp = - (uc = vc = (un < 0)); + if (uc) + { + assert (vn < 0); + un = -un; + vn = -vn; + } + + up = u->_mp_d; + vp = v->_mp_d; + + if (un < vn) + MPN_SRCPTR_SWAP (up, un, vp, vn); + + for (i = 0, c = 0; i < vn; i++) + { + ul = (up[i] ^ comp) + uc; + uc = ul < uc; + + vl = (vp[i] ^ comp) + vc; + vc = vl < vc; + + c += gmp_popcount_limb (ul ^ vl); + } + assert (vc == 0); + + for (; i < un; i++) + { + ul = (up[i] ^ comp) + uc; + uc = ul < uc; + + c += gmp_popcount_limb (ul ^ comp); + } + + return c; +} + +mp_bitcnt_t +mpz_scan1 (const mpz_t u, mp_bitcnt_t starting_bit) +{ + mp_ptr up; + mp_size_t us, un, i; + mp_limb_t limb, ux; + + us = u->_mp_size; + un = GMP_ABS (us); + i = starting_bit / GMP_LIMB_BITS; + + /* Past the end there's no 1 bits for u>=0, or an immediate 1 bit + for u<0. Notice this test picks up any u==0 too. */ + if (i >= un) + return (us >= 0 ? ~(mp_bitcnt_t) 0 : starting_bit); + + up = u->_mp_d; + ux = 0; + limb = up[i]; + + if (starting_bit != 0) + { + if (us < 0) + { + ux = mpn_zero_p (up, i); + limb = ~ limb + ux; + ux = - (mp_limb_t) (limb >= ux); + } + + /* Mask to 0 all bits before starting_bit, thus ignoring them. */ + limb &= GMP_LIMB_MAX << (starting_bit % GMP_LIMB_BITS); + } + + return mpn_common_scan (limb, i, up, un, ux); +} + +mp_bitcnt_t +mpz_scan0 (const mpz_t u, mp_bitcnt_t starting_bit) +{ + mp_ptr up; + mp_size_t us, un, i; + mp_limb_t limb, ux; + + us = u->_mp_size; + ux = - (mp_limb_t) (us >= 0); + un = GMP_ABS (us); + i = starting_bit / GMP_LIMB_BITS; + + /* When past end, there's an immediate 0 bit for u>=0, or no 0 bits for + u<0. Notice this test picks up all cases of u==0 too. */ + if (i >= un) + return (ux ? starting_bit : ~(mp_bitcnt_t) 0); + + up = u->_mp_d; + limb = up[i] ^ ux; + + if (ux == 0) + limb -= mpn_zero_p (up, i); /* limb = ~(~limb + zero_p) */ + + /* Mask all bits before starting_bit, thus ignoring them. */ + limb &= GMP_LIMB_MAX << (starting_bit % GMP_LIMB_BITS); + + return mpn_common_scan (limb, i, up, un, ux); +} + + +/* MPZ base conversion. */ + +size_t +mpz_sizeinbase (const mpz_t u, int base) +{ + mp_size_t un, tn; + mp_srcptr up; + mp_ptr tp; + mp_bitcnt_t bits; + struct gmp_div_inverse bi; + size_t ndigits; + + assert (base >= 2); + assert (base <= 62); + + un = GMP_ABS (u->_mp_size); + if (un == 0) + return 1; + + up = u->_mp_d; + + bits = (un - 1) * GMP_LIMB_BITS + mpn_limb_size_in_base_2 (up[un-1]); + switch (base) + { + case 2: + return bits; + case 4: + return (bits + 1) / 2; + case 8: + return (bits + 2) / 3; + case 16: + return (bits + 3) / 4; + case 32: + return (bits + 4) / 5; + /* FIXME: Do something more clever for the common case of base + 10. */ + } + + tp = gmp_alloc_limbs (un); + mpn_copyi (tp, up, un); + mpn_div_qr_1_invert (&bi, base); + + tn = un; + ndigits = 0; + do + { + ndigits++; + mpn_div_qr_1_preinv (tp, tp, tn, &bi); + tn -= (tp[tn-1] == 0); + } + while (tn > 0); + + gmp_free_limbs (tp, un); + return ndigits; +} + +char * +mpz_get_str (char *sp, int base, const mpz_t u) +{ + unsigned bits; + const char *digits; + mp_size_t un; + size_t i, sn, osn; + + digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; + if (base > 1) + { + if (base <= 36) + digits = "0123456789abcdefghijklmnopqrstuvwxyz"; + else if (base > 62) + return NULL; + } + else if (base >= -1) + base = 10; + else + { + base = -base; + if (base > 36) + return NULL; + } + + sn = 1 + mpz_sizeinbase (u, base); + if (!sp) + { + osn = 1 + sn; + sp = (char *) gmp_alloc (osn); + } + else + osn = 0; + un = GMP_ABS (u->_mp_size); + + if (un == 0) + { + sp[0] = '0'; + sn = 1; + goto ret; + } + + i = 0; + + if (u->_mp_size < 0) + sp[i++] = '-'; + + bits = mpn_base_power_of_two_p (base); + + if (bits) + /* Not modified in this case. */ + sn = i + mpn_get_str_bits ((unsigned char *) sp + i, bits, u->_mp_d, un); + else + { + struct mpn_base_info info; + mp_ptr tp; + + mpn_get_base_info (&info, base); + tp = gmp_alloc_limbs (un); + mpn_copyi (tp, u->_mp_d, un); + + sn = i + mpn_get_str_other ((unsigned char *) sp + i, base, &info, tp, un); + gmp_free_limbs (tp, un); + } + + for (; i < sn; i++) + sp[i] = digits[(unsigned char) sp[i]]; + +ret: + sp[sn] = '\0'; + if (osn && osn != sn + 1) + sp = (char*) gmp_realloc (sp, osn, sn + 1); + return sp; +} + +int +mpz_set_str (mpz_t r, const char *sp, int base) +{ + unsigned bits, value_of_a; + mp_size_t rn, alloc; + mp_ptr rp; + size_t dn, sn; + int sign; + unsigned char *dp; + + assert (base == 0 || (base >= 2 && base <= 62)); + + while (isspace( (unsigned char) *sp)) + sp++; + + sign = (*sp == '-'); + sp += sign; + + if (base == 0) + { + if (sp[0] == '0') + { + if (sp[1] == 'x' || sp[1] == 'X') + { + base = 16; + sp += 2; + } + else if (sp[1] == 'b' || sp[1] == 'B') + { + base = 2; + sp += 2; + } + else + base = 8; + } + else + base = 10; + } + + if (!*sp) + { + r->_mp_size = 0; + return -1; + } + sn = strlen(sp); + dp = (unsigned char *) gmp_alloc (sn); + + value_of_a = (base > 36) ? 36 : 10; + for (dn = 0; *sp; sp++) + { + unsigned digit; + + if (isspace ((unsigned char) *sp)) + continue; + else if (*sp >= '0' && *sp <= '9') + digit = *sp - '0'; + else if (*sp >= 'a' && *sp <= 'z') + digit = *sp - 'a' + value_of_a; + else if (*sp >= 'A' && *sp <= 'Z') + digit = *sp - 'A' + 10; + else + digit = base; /* fail */ + + if (digit >= (unsigned) base) + { + gmp_free (dp, sn); + r->_mp_size = 0; + return -1; + } + + dp[dn++] = digit; + } + + if (!dn) + { + gmp_free (dp, sn); + r->_mp_size = 0; + return -1; + } + bits = mpn_base_power_of_two_p (base); + + if (bits > 0) + { + alloc = (dn * bits + GMP_LIMB_BITS - 1) / GMP_LIMB_BITS; + rp = MPZ_REALLOC (r, alloc); + rn = mpn_set_str_bits (rp, dp, dn, bits); + } + else + { + struct mpn_base_info info; + mpn_get_base_info (&info, base); + alloc = (dn + info.exp - 1) / info.exp; + rp = MPZ_REALLOC (r, alloc); + rn = mpn_set_str_other (rp, dp, dn, base, &info); + /* Normalization, needed for all-zero input. */ + assert (rn > 0); + rn -= rp[rn-1] == 0; + } + assert (rn <= alloc); + gmp_free (dp, sn); + + r->_mp_size = sign ? - rn : rn; + + return 0; +} + +int +mpz_init_set_str (mpz_t r, const char *sp, int base) +{ + mpz_init (r); + return mpz_set_str (r, sp, base); +} + +size_t +mpz_out_str (FILE *stream, int base, const mpz_t x) +{ + char *str; + size_t len, n; + + str = mpz_get_str (NULL, base, x); + if (!str) + return 0; + len = strlen (str); + n = fwrite (str, 1, len, stream); + gmp_free (str, len + 1); + return n; +} + + +static int +gmp_detect_endian (void) +{ + static const int i = 2; + const unsigned char *p = (const unsigned char *) &i; + return 1 - *p; +} + +/* Import and export. Does not support nails. */ +void +mpz_import (mpz_t r, size_t count, int order, size_t size, int endian, + size_t nails, const void *src) +{ + const unsigned char *p; + ptrdiff_t word_step; + mp_ptr rp; + mp_size_t rn; + + /* The current (partial) limb. */ + mp_limb_t limb; + /* The number of bytes already copied to this limb (starting from + the low end). */ + size_t bytes; + /* The index where the limb should be stored, when completed. */ + mp_size_t i; + + if (nails != 0) + gmp_die ("mpz_import: Nails not supported."); + + assert (order == 1 || order == -1); + assert (endian >= -1 && endian <= 1); + + if (endian == 0) + endian = gmp_detect_endian (); + + p = (unsigned char *) src; + + word_step = (order != endian) ? 2 * size : 0; + + /* Process bytes from the least significant end, so point p at the + least significant word. */ + if (order == 1) + { + p += size * (count - 1); + word_step = - word_step; + } + + /* And at least significant byte of that word. */ + if (endian == 1) + p += (size - 1); + + rn = (size * count + sizeof(mp_limb_t) - 1) / sizeof(mp_limb_t); + rp = MPZ_REALLOC (r, rn); + + for (limb = 0, bytes = 0, i = 0; count > 0; count--, p += word_step) + { + size_t j; + for (j = 0; j < size; j++, p -= (ptrdiff_t) endian) + { + limb |= (mp_limb_t) *p << (bytes++ * CHAR_BIT); + if (bytes == sizeof(mp_limb_t)) + { + rp[i++] = limb; + bytes = 0; + limb = 0; + } + } + } + assert (i + (bytes > 0) == rn); + if (limb != 0) + rp[i++] = limb; + else + i = mpn_normalized_size (rp, i); + + r->_mp_size = i; +} + +void * +mpz_export (void *r, size_t *countp, int order, size_t size, int endian, + size_t nails, const mpz_t u) +{ + size_t count; + mp_size_t un; + + if (nails != 0) + gmp_die ("mpz_export: Nails not supported."); + + assert (order == 1 || order == -1); + assert (endian >= -1 && endian <= 1); + assert (size > 0 || u->_mp_size == 0); + + un = u->_mp_size; + count = 0; + if (un != 0) + { + size_t k; + unsigned char *p; + ptrdiff_t word_step; + /* The current (partial) limb. */ + mp_limb_t limb; + /* The number of bytes left to do in this limb. */ + size_t bytes; + /* The index where the limb was read. */ + mp_size_t i; + + un = GMP_ABS (un); + + /* Count bytes in top limb. */ + limb = u->_mp_d[un-1]; + assert (limb != 0); + + k = (GMP_LIMB_BITS <= CHAR_BIT); + if (!k) + { + do { + int LOCAL_CHAR_BIT = CHAR_BIT; + k++; limb >>= LOCAL_CHAR_BIT; + } while (limb != 0); + } + /* else limb = 0; */ + + count = (k + (un-1) * sizeof (mp_limb_t) + size - 1) / size; + + if (!r) + r = gmp_alloc (count * size); + + if (endian == 0) + endian = gmp_detect_endian (); + + p = (unsigned char *) r; + + word_step = (order != endian) ? 2 * size : 0; + + /* Process bytes from the least significant end, so point p at the + least significant word. */ + if (order == 1) + { + p += size * (count - 1); + word_step = - word_step; + } + + /* And at least significant byte of that word. */ + if (endian == 1) + p += (size - 1); + + for (bytes = 0, i = 0, k = 0; k < count; k++, p += word_step) + { + size_t j; + for (j = 0; j < size; ++j, p -= (ptrdiff_t) endian) + { + if (sizeof (mp_limb_t) == 1) + { + if (i < un) + *p = u->_mp_d[i++]; + else + *p = 0; + } + else + { + int LOCAL_CHAR_BIT = CHAR_BIT; + if (bytes == 0) + { + if (i < un) + limb = u->_mp_d[i++]; + bytes = sizeof (mp_limb_t); + } + *p = limb; + limb >>= LOCAL_CHAR_BIT; + bytes--; + } + } + } + assert (i == un); + assert (k == count); + } + + if (countp) + *countp = count; + + return r; +} |