1 files changed, 546 insertions, 0 deletions

diff --git a/moon-abe/pbc-0.5.14/arith/fasterfp.c b/moon-abe/pbc-0.5.14/arith/fasterfp.c
new file mode 100644
index 00000000..5ce8243a
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/arith/fasterfp.c
@@ -0,0 +1,546 @@
+// Naive implementation of F_p.
+// It uses lowlevel GMP routines (mpn_* functions) like fastfp.c, but also
+// has a flag for the value 0, avoiding many memsets.
+//
+// I'm thinking of using the flag to also represent 1, -1,
+// but that complicates the logic even more, and I believe I need more
+// control than GMP is willing to give in order to avoid expensive
+// checks for 1, -1 everywhere.
+//
+// NOTE: does not work for moduli of the form:
+//   2^(something * 8 * sizeof(mp_limb_t))
+// See comments in add, double code.
+// (This kind of integer mod ring deserves its own implementation anyway.)
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdint.h> // for intptr_t
+#include <stdlib.h>
+#include <string.h>
+#include <gmp.h>
+#include "pbc_utils.h"
+#include "pbc_field.h"
+#include "pbc_random.h"
+#include "pbc_fp.h"
+#include "pbc_memory.h"
+
+struct fp_field_data_s {
+  size_t limbs;
+  size_t bytes;
+  mp_limb_t *primelimbs;
+};
+typedef struct fp_field_data_s fp_field_data_t[1];
+typedef struct fp_field_data_s *fp_field_data_ptr;
+
+struct data_s {
+  int flag;
+  mp_limb_t *d;
+};
+typedef struct data_s *dataptr;
+
+static void fp_init(element_ptr e) {
+  fp_field_data_ptr p = e->field->data;
+  dataptr dp = e->data = pbc_malloc(sizeof(struct data_s));
+  dp->flag = 0;
+  dp->d = pbc_malloc(p->bytes);
+}
+
+static void fp_clear(element_ptr e) {
+  dataptr dp = e->data;
+  pbc_free(dp->d);
+  pbc_free(e->data);
+}
+
+//assumes z is nonzero
+static inline void from_mpz(element_ptr e, mpz_ptr z) {
+  fp_field_data_ptr p = e->field->data;
+  size_t count;
+  dataptr dp = e->data;
+  mpz_export(dp->d, &count, -1, sizeof(mp_limb_t), 0, 0, z);
+  memset((void *) (((unsigned char *) dp->d) + count * sizeof(mp_limb_t)),
+         0, (p->limbs - count) * sizeof(mp_limb_t));
+}
+
+static void fp_set_mpz(element_ptr e, mpz_ptr z) {
+  dataptr dp = e->data;
+  if (!mpz_sgn(z)) {
+    dp->flag = 0;
+  } else {
+    mpz_t tmp;
+    mpz_init(tmp);
+    mpz_mod(tmp, z, e->field->order);
+    from_mpz(e, tmp);
+    mpz_clear(tmp);
+    dp->flag = 2;
+  }
+}
+
+static void fp_set_si(element_ptr e, signed long int op) {
+  dataptr dp = e->data;
+  if (!op) {
+    dp->flag = 0;
+  } else {
+    const fp_field_data_ptr p = e->field->data;
+    const size_t t = p->limbs;
+    if (op < 0) {
+      mpn_sub_1(dp->d, p->primelimbs, t, -op);
+    } else {
+      dp->d[0] = op;
+      memset(&dp->d[1], 0, sizeof(mp_limb_t) * (t - 1));
+    }
+    dp->flag = 2;
+  }
+}
+
+static void fp_to_mpz(mpz_ptr z, element_ptr e) {
+  dataptr dp = e->data;
+  if (!dp->flag) {
+    mpz_set_ui(z, 0);
+  } else {
+    fp_field_data_ptr p = e->field->data;
+    mpz_import(z, p->limbs, -1, sizeof(mp_limb_t), 0, 0, dp->d);
+  }
+}
+
+static void fp_set0(element_ptr e) {
+  dataptr dp = e->data;
+  dp->flag = 0;
+}
+
+static void fp_set1(element_ptr e) {
+  fp_field_data_ptr p = e->field->data;
+  dataptr dp = e->data;
+  dp->flag = 2;
+  memset(&dp->d[1], 0, p->bytes - sizeof(mp_limb_t));
+  dp->d[0] = 1;
+}
+
+static int fp_is1(element_ptr e) {
+  dataptr dp = e->data;
+  if (!dp->flag) return 0;
+  else {
+    fp_field_data_ptr p = e->field->data;
+    size_t i, t = p->limbs;
+    if (dp->d[0] != 1) return 0;
+    for (i = 1; i < t; i++) if (dp->d[i]) return 0;
+    return 1;
+  }
+}
+
+static int fp_is0(element_ptr e) {
+  dataptr dp = e->data;
+  return !dp->flag;
+}
+
+static size_t fp_out_str(FILE * stream, int base, element_ptr e) {
+  size_t result;
+  mpz_t z;
+  mpz_init(z);
+  fp_to_mpz(z, e);
+  result = mpz_out_str(stream, base, z);
+  mpz_clear(z);
+  return result;
+}
+
+static void fp_set(element_ptr c, element_ptr a) {
+  dataptr ad = a->data;
+  dataptr cd = c->data;
+  if (a == c) return;
+  if (!ad->flag) {
+    cd->flag = 0;
+  } else {
+    fp_field_data_ptr p = a->field->data;
+
+    //Assembly is faster here, but I don't want to stoop to that level.
+    //Instead of calling slower memcpy, wrap stuff so that GMP assembly
+    //gets called.
+    /*
+       memcpy(cd->d, ad->d, p->bytes);
+     */
+    mpz_t z1, z2;
+    z1->_mp_d = cd->d;
+    z2->_mp_d = ad->d;
+    z1->_mp_size = z1->_mp_alloc = z2->_mp_size = z2->_mp_alloc = p->limbs;
+    mpz_set(z1, z2);
+
+    cd->flag = 2;
+  }
+}
+
+static void fp_add(element_ptr c, element_ptr a, element_ptr b) {
+  dataptr ad = a->data, bd = b->data;
+
+  if (!ad->flag) {
+    fp_set(c, b);
+  } else if (!bd->flag) {
+    fp_set(c, a);
+  } else {
+    dataptr cd = c->data;
+    fp_field_data_ptr p = a->field->data;
+    const size_t t = p->limbs;
+    mp_limb_t carry;
+    carry = mpn_add_n(cd->d, ad->d, bd->d, t);
+
+    if (carry) {
+      //assumes result of following sub is not zero,
+      //i.e. modulus cannot be 2^(n * bits_per_limb)
+      mpn_sub_n(cd->d, cd->d, p->primelimbs, t);
+      cd->flag = 2;
+    } else {
+      int i = mpn_cmp(cd->d, p->primelimbs, t);
+      if (!i) {
+        cd->flag = 0;
+      } else {
+        cd->flag = 2;
+        if (i > 0) {
+          mpn_sub_n(cd->d, cd->d, p->primelimbs, t);
+        }
+      }
+    }
+  }
+}
+
+static void fp_double(element_ptr c, element_ptr a) {
+  dataptr ad = a->data, cd = c->data;
+  if (!ad->flag) {
+    cd->flag = 0;
+  } else {
+    fp_field_data_ptr p = c->field->data;
+    const size_t t = p->limbs;
+    if (mpn_lshift(cd->d, ad->d, t, 1)) {
+      cd->flag = 2;
+      //again, assumes result is not zero:
+      mpn_sub_n(cd->d, cd->d, p->primelimbs, t);
+    } else {
+      int i = mpn_cmp(cd->d, p->primelimbs, t);
+      if (!i) {
+        cd->flag = 0;
+      } else {
+        cd->flag = 2;
+        if (i > 0) {
+          mpn_sub_n(cd->d, cd->d, p->primelimbs, t);
+        }
+      }
+    }
+  }
+}
+
+static void fp_halve(element_ptr c, element_ptr a) {
+  dataptr ad = a->data, cd = c->data;
+  if (!ad->flag) {
+    cd->flag = 0;
+  } else {
+    fp_field_data_ptr p = c->field->data;
+    const size_t t = p->limbs;
+    int carry = 0;
+    mp_limb_t *alimb = ad->d;
+    mp_limb_t *climb = cd->d;
+    if (alimb[0] & 1) {
+      carry = mpn_add_n(climb, alimb, p->primelimbs, t);
+    } else fp_set(c, a);
+
+    mpn_rshift(climb, climb, t, 1);
+    if (carry) climb[t - 1] |= ((mp_limb_t) 1) << (sizeof(mp_limb_t) * 8 - 1);
+  }
+}
+
+static void fp_neg(element_ptr c, element_ptr a) {
+  dataptr ad = a->data, cd = c->data;
+  if (!ad->flag) cd->flag = 0;
+  else {
+    fp_field_data_ptr p = a->field->data;
+    mpn_sub_n(cd->d, p->primelimbs, ad->d, p->limbs);
+    cd->flag = 2;
+  }
+}
+
+static void fp_sub(element_ptr c, element_ptr a, element_ptr b) {
+  dataptr ad = a->data, bd = b->data;
+
+  if (!ad->flag) {
+    fp_neg(c, b);
+  } else if (!bd->flag) {
+    fp_set(c, a);
+  } else {
+    fp_field_data_ptr p = c->field->data;
+    size_t t = p->limbs;
+    dataptr cd = c->data;
+    int i = mpn_cmp(ad->d, bd->d, t);
+
+    if (i == 0) {
+      cd->flag = 0;
+    } else {
+      cd->flag = 2;
+      mpn_sub_n(cd->d, ad->d, bd->d, t);
+      if (i < 0) {
+        mpn_add_n(cd->d, cd->d, p->primelimbs, t);
+      }
+    }
+  }
+}
+
+static void fp_mul(element_ptr c, element_ptr a, element_ptr b) {
+  dataptr ad = a->data, bd = b->data;
+  dataptr cd = c->data;
+
+  if (!ad->flag || !bd->flag) {
+    cd->flag = 0;
+  } else {
+    fp_field_data_ptr p = c->field->data;
+    size_t t = p->limbs;
+    //mp_limb_t tmp[3 * t + 1];
+    //mp_limb_t *qp = &tmp[2 * t];
+    mp_limb_t tmp[2 * t];
+    mp_limb_t qp[t + 1];
+    //static mp_limb_t tmp[2 * 100];
+    //static mp_limb_t qp[100 + 1];
+
+    mpn_mul_n(tmp, ad->d, bd->d, t);
+
+    mpn_tdiv_qr(qp, cd->d, 0, tmp, 2 * t, p->primelimbs, t);
+    cd->flag = 2;
+  }
+}
+
+static void fp_square(element_ptr c, element_ptr a) {
+  const fp_field_data_ptr p = c->field->data;
+  mpz_t z1, z2;
+  size_t diff;
+  dataptr ad = a->data;
+  dataptr cd = c->data;
+
+  if (!ad->flag) {
+    cd->flag = 0;
+  } else {
+    cd->flag = 2;
+    z1->_mp_d = cd->d;
+    z1->_mp_size = z1->_mp_alloc = p->limbs;
+    if (c == a) {
+      mpz_powm_ui(z1, z1, 2, c->field->order);
+    } else {
+      z2->_mp_d = ad->d;
+      z2->_mp_size = z2->_mp_alloc = p->limbs;
+      mpz_powm_ui(z1, z2, 2, c->field->order);
+    }
+
+    diff = p->limbs - z1->_mp_size;
+    if (diff) memset(&z1->_mp_d[z1->_mp_size], 0, diff * sizeof(mp_limb_t));
+
+    //mpn_sqr_n() might make the code below faster than the code above
+    //but GMP doesn't expose this function
+    /*
+       const fp_field_data_ptr p = c->field->data;
+       const size_t t = p->limbs;
+       mp_limb_t tmp[2 * t];
+       mp_limb_t qp[t + 1];
+
+       mpn_mul_n(tmp, ad->d, ad->d, t);
+
+       mpn_tdiv_qr(qp, cd->d, 0, tmp, 2 * t, p->primelimbs, t);
+     */
+  }
+}
+
+static void fp_mul_si(element_ptr c, element_ptr a, signed long int op) {
+  dataptr ad = a->data;
+  dataptr cd = c->data;
+
+  if (!ad->flag || !op) {
+    cd->flag = 0;
+  } else {
+    cd->flag = 2;
+    fp_field_data_ptr p = a->field->data;
+    size_t t = p->limbs;
+    mp_limb_t tmp[t + 1];
+    mp_limb_t qp[2];
+
+    tmp[t] = mpn_mul_1(tmp, ad->d, t, labs(op));
+    mpn_tdiv_qr(qp, cd->d, 0, tmp, t + 1, p->primelimbs, t);
+    if (op < 0) {               //TODO: don't need to check c != 0 this time
+      fp_neg(c, c);
+    }
+  }
+}
+
+static void fp_pow_mpz(element_ptr c, element_ptr a, mpz_ptr op) {
+  dataptr ad = a->data;
+  dataptr cd = c->data;
+  if (!ad->flag) cd->flag = 0;
+  else {
+    mpz_t z;
+    mpz_init(z);
+    fp_to_mpz(z, a);
+    mpz_powm(z, z, op, a->field->order);
+    from_mpz(c, z);
+    mpz_clear(z);
+    cd->flag = 2;
+  }
+}
+
+static void fp_invert(element_ptr c, element_ptr a) {
+  //assumes a is invertible
+  dataptr cd = c->data;
+  mpz_t z;
+  mpz_init(z);
+  fp_to_mpz(z, a);
+  mpz_invert(z, z, a->field->order);
+  from_mpz(c, z);
+  mpz_clear(z);
+  cd->flag = 2;
+}
+
+static void fp_random(element_ptr a) {
+  dataptr ad = a->data;
+  mpz_t z;
+  mpz_init(z);
+  pbc_mpz_random(z, a->field->order);
+  if (mpz_sgn(z)) {
+    from_mpz(a, z);
+    ad->flag = 2;
+  } else {
+    ad->flag = 0;
+  }
+  mpz_clear(z);
+}
+
+static void fp_from_hash(element_ptr a, void *data, int len) {
+  mpz_t z;
+
+  mpz_init(z);
+  pbc_mpz_from_hash(z, a->field->order, data, len);
+  fp_set_mpz(a, z);
+  mpz_clear(z);
+}
+
+static int fp_cmp(element_ptr a, element_ptr b) {
+  dataptr ad = a->data, bd = b->data;
+  if (!ad->flag) {
+    return bd->flag;
+  } else {
+    fp_field_data_ptr p = a->field->data;
+    return mpn_cmp(ad->d, bd->d, p->limbs);
+    //return memcmp(ad->d, bd->d, p->limbs);
+  }
+}
+
+static int fp_sgn_odd(element_ptr a) {
+  dataptr ad = a->data;
+  if (!ad->flag) return 0;
+  return ad->d[0] & 1 ? 1 : -1;
+}
+
+static int fp_sgn_even(element_ptr a) {
+  fp_field_data_ptr p = a->field->data;
+  dataptr ad = a->data;
+  if (!ad->flag) return 0;
+  mp_limb_t sum[p->limbs];
+
+  int carry = mpn_add_n(sum, ad->d, ad->d, p->limbs);
+  if (carry) return 1;
+  return mpn_cmp(sum, p->primelimbs, p->limbs);
+}
+
+
+static int fp_is_sqr(element_ptr a) {
+  dataptr ad = a->data;
+  int res;
+  mpz_t z;
+  mpz_init(z);
+  //0 is a square
+  if (!ad->flag) return 1;
+  fp_to_mpz(z, a);
+  res = mpz_legendre(z, a->field->order) == 1;
+  mpz_clear(z);
+  return res;
+}
+
+static int fp_to_bytes(unsigned char *data, element_t a) {
+  dataptr ad = a->data;
+  int n = a->field->fixed_length_in_bytes;
+  if (!ad->flag) {
+    memset(data, 0, n);
+  } else {
+    mpz_t z;
+
+    mpz_init(z);
+    fp_to_mpz(z, a);
+    pbc_mpz_out_raw_n(data, n, z);
+    mpz_clear(z);
+  }
+  return n;
+}
+
+static int fp_from_bytes(element_t a, unsigned char *data) {
+  dataptr ad = a->data;
+  int n;
+  mpz_t z;
+
+  mpz_init(z);
+
+  n = a->field->fixed_length_in_bytes;
+  mpz_import(z, n, 1, 1, 1, 0, data);
+  if (!mpz_sgn(z)) ad->flag = 0;
+  else {
+    ad->flag = 2;
+    from_mpz(a, z);
+  }
+  mpz_clear(z);
+  return n;
+}
+
+static void fp_out_info(FILE* str, field_ptr f) {
+  element_fprintf(str, "GF(%Zd): zero flag + mpn", f->order);
+}
+
+static void fp_field_clear(field_t f) {
+  fp_field_data_ptr p = f->data;
+  pbc_free(p->primelimbs);
+  pbc_free(p);
+}
+
+void field_init_faster_fp(field_ptr f, mpz_t prime) {
+  PBC_ASSERT(!mpz_fits_ulong_p(prime), "modulus too small");
+  fp_field_data_ptr p;
+  field_init(f);
+  f->init = fp_init;
+  f->clear = fp_clear;
+  f->set_si = fp_set_si;
+  f->set_mpz = fp_set_mpz;
+  f->out_str = fp_out_str;
+  f->add = fp_add;
+  f->sub = fp_sub;
+  f->set = fp_set;
+  f->mul = fp_mul;
+  f->mul_si = fp_mul_si;
+  f->square = fp_square;
+  f->doub = fp_double;
+  f->halve = fp_halve;
+  f->pow_mpz = fp_pow_mpz;
+  f->neg = fp_neg;
+  f->cmp = fp_cmp;
+  f->sign = mpz_odd_p(prime) ? fp_sgn_odd : fp_sgn_even;
+  f->invert = fp_invert;
+  f->random = fp_random;
+  f->from_hash = fp_from_hash;
+  f->is1 = fp_is1;
+  f->is0 = fp_is0;
+  f->set0 = fp_set0;
+  f->set1 = fp_set1;
+  f->is_sqr = fp_is_sqr;
+  f->sqrt = element_tonelli;
+  f->field_clear = fp_field_clear;
+  f->to_bytes = fp_to_bytes;
+  f->from_bytes = fp_from_bytes;
+  f->to_mpz = fp_to_mpz;
+
+  f->out_info = fp_out_info;
+
+  p = f->data = pbc_malloc(sizeof(fp_field_data_t));
+  p->limbs = mpz_size(prime);
+  p->bytes = p->limbs * sizeof(mp_limb_t);
+  p->primelimbs = pbc_malloc(p->bytes);
+  mpz_export(p->primelimbs, &p->limbs, -1, sizeof(mp_limb_t), 0, 0, prime);
+
+  mpz_set(f->order, prime);
+  f->fixed_length_in_bytes = (mpz_sizeinbase(prime, 2) + 7) / 8;
+}