Ticket #12173: 15-integer_to_mod.patch

module_list.py

@@ -1357 +1357 @@
     
     Extension('sage.rings.fraction_field_FpT',
               sources = ['sage/rings/fraction_field_FpT.pyx'],
+              language = 'c++',
               libraries = ["csage", "flint", "gmp", "gmpxx", "ntl", "zn_poly"],
               extra_compile_args=["-std=c99", "-D_XPG6"],
               include_dirs = [SAGE_INC + 'flint/'],
@@ -1627 +1628 @@
 
     Extension('sage.rings.polynomial.polynomial_zmod_flint',
               sources = ['sage/rings/polynomial/polynomial_zmod_flint.pyx'],
+              language = 'c++',
               libraries = ["csage", "flint", "gmp", "gmpxx", "ntl", "zn_poly"],
               extra_compile_args=["-std=c99", "-D_XPG6"],
               include_dirs = [SAGE_INC + 'flint/'],

sage/libs/flint/fmpz_poly.pxi

@@ -3 +3 @@
 
 cdef extern from "flint/fmpz_poly.h":
     
-    ctypedef void* fmpz_poly_t
-    
+    ctypedef struct fmpz_poly_struct:
+        fmpz * coeffs
+
+    ctypedef void * fmpz_poly_t
+
     void fmpz_poly_init(fmpz_poly_t poly)
     void fmpz_poly_init2(fmpz_poly_t poly, unsigned long alloc)
     void fmpz_poly_realloc(fmpz_poly_t poly, unsigned long alloc)

sage/libs/flint/zmod_poly_linkage.pxi

@@ -1 +1 @@
 r"""
-Linkage for arithmetic with FLINT's zmod_poly_t elements.
+Linkage for arithmetic with FLINT's nmod_poly_t elements.
 
 This file provides the backend for \class{Polynomial_zmod_flint} via
 templating.

sage/rings/polynomial/polynomial_zmod_flint.pxd

@@ -1 +1 @@
 from sage.libs.flint.zmod_poly cimport nmod_poly_t, nmod_poly_struct
 from sage.structure.parent cimport Parent
+from sage.rings.polynomial.polynomial_integer_dense_flint cimport Polynomial_integer_dense_flint
 
 ctypedef nmod_poly_struct celement
 
@@ -7 +8 @@
 
 cdef class Polynomial_zmod_flint(Polynomial_template):
     cdef Polynomial_template _new(self)
-    cdef _set_list(self, x)
+    cdef void _set_list(self, x)
+    cdef void _set_fmpz_poly(self, Polynomial_integer_dense_flint, bint)
     cpdef _mul_trunc(self, Polynomial_zmod_flint other, length)
     cpdef _mul_trunc_opposite(self, Polynomial_zmod_flint other, length)
     cpdef rational_reconstruct(self, m, n_deg=?, d_deg=?)

sage/rings/polynomial/polynomial_zmod_flint.pyx

@@ -36 +36 @@
 from sage.libs.ntl.ntl_lzz_pX import ntl_zz_pX
 from sage.structure.factorization import Factorization
 from sage.structure.element import coerce_binop, parent
+from sage.rings.polynomial.polynomial_integer_dense_flint cimport Polynomial_integer_dense_flint
 
 # We need to define this stuff before including the templating stuff
 # to make sure the function get_cparent is found since it is used in
@@ -62 +63 @@
     cdef void zn_mod_clear(zn_mod_struct *mod)
     cdef void zn_array_mul(unsigned long* res, unsigned long* op1, size_t n1, unsigned long* op2, size_t n2, zn_mod_struct *mod)
 
+include "../../libs/flint/fmpz.pxi"
+
+cdef extern from "flint/fmpz.h":
+    cdef unsigned long fmpz_get_ui(fmpz_t)
+    cdef unsigned long fmpz_fdiv_ui(fmpz_t, unsigned long)
+
+include "../../libs/flint/fmpz_poly.pxi"
+
 cdef class Polynomial_zmod_flint(Polynomial_template):
     def __init__(self, parent, x=None, check=True, is_gen=False, construct=False):
         """
@@ -86 +95 @@
             Polynomial_template.__init__(self, parent, 0, check, is_gen, construct)
             self._set_list(lst)
             return
+        elif PY_TYPE_CHECK(x, Polynomial_integer_dense_flint):
+            Polynomial_template.__init__(self, parent, 0, check, is_gen, construct)
+            self._set_fmpz_poly(x, check)
+            return
         else:
             if PY_TYPE_CHECK(x, ntl_zz_pX):
                 x = x.list()
@@ -139 +152 @@
         celement_set_si(&r.x, int(x), get_cparent(P))
         return r
 
-    cdef _set_list(self, x):
+    cdef void _set_list(self, x):
         """
+        Set the coefficients of ``self`` from a list of coefficients.
+
+        INPUT:
+
+        - ``x`` - a list of coefficients
+
         EXAMPLES::
 
             sage: P.<a>=GF(7)[]
@@ -164 +183 @@
         nmod_poly_realloc(&self.x, length)
         sig_off()
 
+        sig_on()
         for i from 0 <= i < length:
             nmod_poly_set_coeff_ui(&self.x, i, l_in[i])
+        sig_off()
+
+    cdef void _set_fmpz_poly(self, Polynomial_integer_dense_flint x, bint check):
+        """
+        Set the coefficients of ``self`` from the coefficients of a :class:`Polynomial_integer_dense_flint` element.
+
+        INPUT:
+
+        - ``x`` - a :class:`Polynomial_integer_dense_flint` element
+
+        - ``check`` - whether to reduce the coefficients of `x` or not
+
+        EXAMPLES::
+
+            sage: a = ZZ['x'](range(17))
+            sage: R = Integers(7)['x']
+            sage: R(a)
+            2*x^16 + x^15 + 6*x^13 + 5*x^12 + 4*x^11 + 3*x^10 + 2*x^9 + x^8 + 6*x^6 + 5*x^5 + 4*x^4 + 3*x^3 + 2*x^2 + x
+
+        TESTS:
+
+        The following test from :trac:`12173` used to be horribly slow::
+
+            sage: a = ZZ['x'](range(100000))
+            sage: R = Integers(3)['x']
+            sage: R(a)
+            2*x^99998 + ... + x
+        """
+        cdef unsigned long length = fmpz_poly_length(x.__poly)
+        cdef unsigned long modulus = nmod_poly_modulus(&self.x)
+        cdef fmpz *coeffs = (<fmpz_poly_struct>(x.__poly[0])).coeffs
+        cdef int i
+        if length == 0:
+            nmod_poly_zero(&self.x)
+            return
+
+        # resize to length of list
+        sig_on()
+        nmod_poly_realloc(&self.x, length)
+        sig_off()
+
+        if check:
+            sig_on()
+            for i from 0 <= i < length:
+                nmod_poly_set_coeff_ui(&self.x, i, fmpz_fdiv_ui(&coeffs[i], modulus))
+            sig_off()
+            return
+        else:
+            sig_on()
+            for i from 0 <= i < length:
+                nmod_poly_set_coeff_ui(&self.x, i, fmpz_get_ui(&coeffs[i]))
+            sig_off()
+            return
 
     def __getitem__(self, i):
         """