Merge pull request #1898 from flintlib/mpnmod

mpn representation of integers mod n
flintlib · Mar 28, 2024 · 2c3b759 · 2c3b759
2 parents a146a88 + 32c4d71
commit 2c3b759
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Showing 7 changed files with 1,650 additions and 3 deletions.
diff --git a/doc/source/gr_domains.rst b/doc/source/gr_domains.rst
@@ -128,8 +128,18 @@ Base rings and fields
     of integers modulo *n* where
     elements have type :type:`fmpz`. The modulus must be positive.
 
+.. function:: int gr_ctx_init_mpn_mod(gr_ctx_t ctx, const fmpz_t n)
+
+    Initializes *ctx* to the ring `\mathbb{Z}/n\mathbb{Z}`
+    of integers modulo *n* where
+    elements are flat ``mpn`` arrays with the same number of limbs as
+    *n*. We currently require that the number of limbs *s* satisfies
+    `2 \le s \le 16`. This constructor does no initialization and returns
+    ``GR_UNABLE`` if the modulus is not in bounds.
+
 .. function:: void gr_ctx_nmod_set_primality(gr_ctx_t ctx, truth_t is_prime)
               void gr_ctx_fmpz_mod_set_primality(gr_ctx_t ctx, truth_t is_prime)
+              void gr_ctx_mpn_mod_set_primality(gr_ctx_t ctx, truth_t is_prime)
 
     For a ring initialized with :func:`gr_ctx_init_nmod`
     or :func:`gr_ctx_init_fmpz_mod` respectively,

diff --git a/src/gr.h b/src/gr.h
@@ -716,7 +716,7 @@ void gr_method_tab_init(gr_funcptr * methods, gr_method_tab_input * tab);
 typedef enum
 {
     GR_CTX_FMPZ, GR_CTX_FMPQ, GR_CTX_FMPZI,
-    GR_CTX_FMPZ_MOD, GR_CTX_NMOD, GR_CTX_NMOD8, GR_CTX_NMOD32,
+    GR_CTX_FMPZ_MOD, GR_CTX_NMOD, GR_CTX_NMOD8, GR_CTX_NMOD32, GR_CTX_MPN_MOD,
     GR_CTX_FQ, GR_CTX_FQ_NMOD, GR_CTX_FQ_ZECH,
     GR_CTX_NF,
     GR_CTX_REAL_ALGEBRAIC_QQBAR, GR_CTX_COMPLEX_ALGEBRAIC_QQBAR,
@@ -1367,6 +1367,9 @@ void gr_ctx_nmod_set_primality(gr_ctx_t ctx, truth_t is_prime);
 void gr_ctx_init_nmod8(gr_ctx_t ctx, unsigned char n);
 void gr_ctx_init_nmod32(gr_ctx_t ctx, unsigned int n);
 
+int gr_ctx_init_mpn_mod(gr_ctx_t ctx, const fmpz_t n);
+void gr_ctx_mpn_mod_set_primality(gr_ctx_t ctx, truth_t is_prime);
+
 void gr_ctx_init_real_qqbar(gr_ctx_t ctx);
 void gr_ctx_init_complex_qqbar(gr_ctx_t ctx);
 void _gr_ctx_qqbar_set_limits(gr_ctx_t ctx, slong deg_limit, slong bits_limit);

diff --git a/src/gr/fmpz_mod.c b/src/gr/fmpz_mod.c
@@ -483,6 +483,20 @@ _gr_fmpz_mod_vec_dot_rev(fmpz_t res, const fmpz_t initial, int subtract, const f
     return GR_SUCCESS;
 }
 
+int
+_gr_fmpz_mod_vec_mul_scalar(fmpz * res, const fmpz * vec, slong len, const fmpz_t c, gr_ctx_t ctx)
+{
+    _fmpz_mod_vec_scalar_mul_fmpz_mod(res, vec, len, c, FMPZ_MOD_CTX(ctx));
+    return GR_SUCCESS;
+}
+
+int
+_gr_fmpz_mod_scalar_mul_vec(fmpz * res, fmpz_t c, const fmpz * vec, slong len, gr_ctx_t ctx)
+{
+    _fmpz_mod_vec_scalar_mul_fmpz_mod(res, vec, len, c, FMPZ_MOD_CTX(ctx));
+    return GR_SUCCESS;
+}
+
 int
 _gr_fmpz_mod_vec_addmul_scalar(fmpz * res, const fmpz * vec, slong len, const fmpz_t c, gr_ctx_t ctx)
 {
@@ -697,7 +711,7 @@ gr_method_tab_input _fmpz_mod_methods_input[] =
     {GR_METHOD_CTX_IS_FINITE,
                                 (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_FINITE_CHARACTERISTIC,
-                                (gr_funcptr) gr_generic_ctx_predicate_false},
+                                (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_EXACT,    (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_CANONICAL,
                                 (gr_funcptr) gr_generic_ctx_predicate_true},
@@ -738,9 +752,24 @@ gr_method_tab_input _fmpz_mod_methods_input[] =
     {GR_METHOD_POW_FMPZ,        (gr_funcptr) _gr_fmpz_mod_pow_fmpz},
     {GR_METHOD_SQRT,            (gr_funcptr) _gr_fmpz_mod_sqrt},
     {GR_METHOD_IS_SQUARE,       (gr_funcptr) _gr_fmpz_mod_is_square},
+
+/*
+    {GR_METHOD_VEC_INIT,        (gr_funcptr) _gr_mpn_mod_vec_zero},
+    {GR_METHOD_VEC_CLEAR,       (gr_funcptr) _gr_mpn_mod_vec_clear},
+    {GR_METHOD_VEC_SET,         (gr_funcptr) _gr_mpn_mod_vec_set},
+    {GR_METHOD_VEC_SWAP,        (gr_funcptr) _gr_mpn_mod_vec_swap},
+    {GR_METHOD_VEC_ZERO,        (gr_funcptr) _gr_mpn_mod_vec_zero},
+    {GR_METHOD_VEC_NEG,         (gr_funcptr) _gr_mpn_mod_vec_neg},
+    {GR_METHOD_VEC_ADD,         (gr_funcptr) _gr_mpn_mod_vec_add},
+    {GR_METHOD_VEC_SUB,         (gr_funcptr) _gr_mpn_mod_vec_sub},
+    {GR_METHOD_VEC_MUL,         (gr_funcptr) _gr_mpn_mod_vec_mul},
+*/
+    {GR_METHOD_VEC_MUL_SCALAR,  (gr_funcptr) _gr_fmpz_mod_vec_mul_scalar},
+    {GR_METHOD_SCALAR_MUL_VEC,  (gr_funcptr) _gr_fmpz_mod_scalar_mul_vec},
+    {GR_METHOD_VEC_ADDMUL_SCALAR,    (gr_funcptr) _gr_fmpz_mod_vec_addmul_scalar},
+
     {GR_METHOD_VEC_DOT,         (gr_funcptr) _gr_fmpz_mod_vec_dot},
     {GR_METHOD_VEC_DOT_REV,     (gr_funcptr) _gr_fmpz_mod_vec_dot_rev},
-    {GR_METHOD_VEC_ADDMUL_SCALAR,    (gr_funcptr) _gr_fmpz_mod_vec_addmul_scalar},
     {GR_METHOD_POLY_MULLOW,     (gr_funcptr) _gr_fmpz_mod_poly_mullow},
     {GR_METHOD_POLY_INV_SERIES, (gr_funcptr) _gr_fmpz_mod_poly_inv_series},
     {GR_METHOD_POLY_DIV_SERIES, (gr_funcptr) _gr_fmpz_mod_poly_div_series},