Merge pull request #2047 from GiacomoPope/fix_fq_default_poly_evaluat…

…e_fq_default

Correct FQ_DEFAULT_TYPE comparison in evaluation

src/fq_default_poly.h

@@ -2050,7 +2050,7 @@ void fq_default_poly_evaluate_fq_default(fq_default_t res,
     {
         res->nmod = nmod_poly_evaluate_nmod(f->nmod, a->nmod);
     }
-    else if (_FQ_DEFAULT_TYPE(ctx) == _FQ_DEFAULT_NMOD)
+    else if (_FQ_DEFAULT_TYPE(ctx) == _FQ_DEFAULT_FMPZ_MOD)
     {
         fmpz_mod_poly_evaluate_fmpz(res->fmpz_mod, f->fmpz_mod, a->fmpz_mod,
                                                         FQ_DEFAULT_CTX_FMPZ_MOD(ctx));

src/fq_default_poly/test/main.c

@@ -14,14 +14,16 @@
 #include "t-init.c"
 #include "t-inlines.c"
 #include "t-set_fmpz_poly.c"
+#include "t-evaluate_fq_default.c"
 
 /* Array of test functions ***************************************************/
 
 test_struct tests[] =
 {
     TEST_FUNCTION(fq_default_poly_init),
     TEST_FUNCTION(fq_default_poly_inlines),
-    TEST_FUNCTION(fq_default_poly_set_fmpz_poly)
+    TEST_FUNCTION(fq_default_poly_set_fmpz_poly),
+    TEST_FUNCTION(fq_default_poly_evaluate)
 };
 
 /* main function *************************************************************/

src/fq_default_poly/test/t-evaluate_fq_default.c

@@ -0,0 +1,82 @@
+/*
+    Copyright (C) 2021 William Hart
+
+    This file is part of FLINT.
+
+    FLINT is free software: you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.  See <https://www.gnu.org/licenses/>.
+*/
+
+#include "test_helpers.h"
+#include "fq_default_poly.h"
+
+TEST_FUNCTION_START(fq_default_poly_evaluate, state)
+{
+    int i, result;
+    fmpz_t p;
+    fq_default_ctx_t ctx;
+
+    fmpz_init(p);
+
+    /* Given a random fq_default_ctx, compute two random polynomials f1, f2 
+       and a random element a. Ensure f1(a) * f2(b) == (f1 * f2)(a). */
+    for (i = 0; i < 100 * flint_test_multiplier(); i++)
+    {
+        fq_default_t a, b, c;
+        fq_default_poly_t f1, f2, f3;
+
+        /* Initalise a random fq_context */
+        fq_default_ctx_init_randtest(ctx, state);
+
+        /* Initalise fq_default elements */
+        fq_default_init(a, ctx);
+        fq_default_init(b, ctx);
+        fq_default_init(c, ctx);
+        fq_default_poly_init(f1, ctx);
+        fq_default_poly_init(f2, ctx);
+        fq_default_poly_init(f3, ctx);
+
+        /* Set a to be a random element */
+        fq_default_randtest(a, state, ctx);
+
+        /* Set f1, f2 to be random polynomials and f3 their product */
+        fq_default_poly_randtest(f1, state, n_randint(state, 10), ctx);
+        fq_default_poly_randtest(f2, state, n_randint(state, 10), ctx);
+        fq_default_poly_mul(f3, f1, f2, ctx);
+
+        /* Evaluate the polynomials f1, f2, f3 = f1 * f2 on the element a */
+        fq_default_poly_evaluate_fq_default(c, f3, a, ctx);
+        fq_default_poly_evaluate_fq_default(b, f2, a, ctx);
+        fq_default_poly_evaluate_fq_default(a, f1, a, ctx);
+
+        /* Ensure that f1(a) * f2(a) = f3(a) = (f1 * f2)(a) */
+        fq_default_mul(a, a, b, ctx); // a = f1(a) * f2(a)
+        result = (fq_default_equal(a, c, ctx));
+        if (!result)
+        {
+            flint_printf("FAIL:\n");
+            fq_default_ctx_print(ctx), flint_printf("\n\n");
+            fq_default_poly_print(f1, ctx), flint_printf("\n\n");
+            fq_default_poly_print(f2, ctx), flint_printf("\n\n");
+            fq_default_poly_print(f3, ctx), flint_printf("\n\n");
+            fq_default_print(a, ctx), flint_printf("\n\n");
+            fflush(stdout);
+            flint_abort();
+        }
+
+        /* Clear everything */
+        fq_default_poly_clear(f1, ctx);
+        fq_default_poly_clear(f2, ctx);
+        fq_default_poly_clear(f3, ctx);
+        fq_default_clear(a, ctx);
+        fq_default_clear(b, ctx);
+        fq_default_clear(c, ctx);
+        fq_default_ctx_clear(ctx);
+    }
+
+    fmpz_clear(p);
+
+    TEST_FUNCTION_END(state);
+}