feat: Add definitions for basic structures.

projects/mini-gmp.c

@@ -0,0 +1,275 @@
+#include "mini-gmp.h"
+
+mp_size_t gmp_abs(mp_size_t x) {
+  return x >= 0 ? x : -x;
+}
+
+mp_size_t gmp_max(mp_size_t a, mp_size_t b) {
+  return a > b ? a : b;
+}
+
+int gmp_cmp(mp_size_t a, mp_size_t b) {
+  return (a > b) - (a < b);
+}
+
+/* MPN interface */
+
+/* 从 低地址向高地址 顺序复制 */
+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];
+}
+
+/* 大于返回1，小于返回-1，等于返回0 */
+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;
+}
+
+/*处理位数不同的情况*/
+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);
+}
+
+/*返回非0的位数*/
+static mp_size_t
+mpn_normalized_size (mp_srcptr xp, mp_size_t n)
+{
+  while (n > 0 && xp[n-1] == 0)
+    --n;
+  return n;
+}
+
+/* 多精度数ap 加上单精度数b，返回最后产生的进位 */
+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;
+}
+
+/* 位数相同的多精度数ap 加上多精度数bp，返回最后产生的进位 */
+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;
+}
+
+/*不同位数的多精度数相加，返回最后的进位*/
+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;
+}
+
+/* MPZ interface */
+
+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.  */
+mp_ptr mrz_realloc_if(mpz_t z,mp_size_t n) {
+  return n > z->_mp_alloc ? mpz_realloc(z, n) : z->_mp_d;
+}
+
+/* MPZ comparisons and the like. */
+int
+mpz_sgn (const mpz_t u)
+{
+  return gmp_cmp (u->_mp_size, 0);
+}
+
+void
+mpz_swap (mpz_t u, mpz_t v)
+{
+  mp_size_t_swap (u->_mp_alloc, v->_mp_alloc);
+  mp_ptr_swap(u->_mp_d, v->_mp_d);
+  mp_size_t_swap (u->_mp_size, v->_mp_size);
+}
+
+/* MPZ addition and subtraction */
+
+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 = mrz_realloc_if (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 = mrz_realloc_if (r, an);
+      mpn_sub (rp, a->_mp_d, an, b->_mp_d, bn);
+      return mpn_normalized_size (rp, an);
+    }
+  else if (cmp < 0)
+    {
+      rp = mrz_realloc_if (r, bn);
+      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;
+}