[test] Improve testing logging and accuracy

Author: serge-sans-paille

test/test_complex_trigonometric.cpp

@@ -148,15 +148,14 @@ struct complex_trigonometric_test
         std::transform(atan_input.cbegin(), atan_input.cend(), expected.begin(),
                        [](const value_type& v)
                        { using std::atan; return atan(v); });
-        batch_type in, out;
+        batch_type in, out, ref;
         for (size_t i = 0; i < nb_input; i += size)
         {
             detail::load_batch(in, atan_input, i);
             out = atan(in);
-            detail::store_batch(out, res, i);
+            detail::load_batch(ref, expected, i);
+            CHECK_BATCH_EQ(ref, out);
         }
-        size_t diff = detail::get_nb_diff(res, expected);
-        CHECK_EQ(diff, 0);
     }
 
 private:

test/test_xsimd_api.cpp

@@ -740,9 +740,13 @@ struct xsimd_api_float_types_functions
     {
         value_type val0(2);
         value_type val1(2);
+        value_type nval1(-3);
         int ival1 = 4;
+        int nival1 = -5;
         CHECK_EQ(extract(xsimd::pow(T(val0), T(val1))), std::pow(val0, val1));
         CHECK_EQ(extract(xsimd::pow(T(val0), ival1)), std::pow(val0, ival1));
+        CHECK_EQ(extract(xsimd::pow(T(val0), T(nval1))), doctest::Approx(std::pow(val0, nval1)));
+        CHECK_EQ(extract(xsimd::pow(T(val0), nival1)), doctest::Approx(std::pow(val0, nival1)));
     }
     void test_reciprocal()
     {
@@ -784,7 +788,7 @@ struct xsimd_api_float_types_functions
     void test_sqrt()
     {
         value_type val(1);
-        CHECK_EQ(extract(xsimd::sqrt(T(val))), std::sqrt(val));
+        CHECK_EQ(extract(xsimd::sqrt(T(val))), doctest::Approx(std::sqrt(val)));
     }
     void test_tan()
     {
@@ -1183,7 +1187,7 @@ struct xsimd_api_all_signed_types_functions
     void test_abs()
     {
         value_type val(-1);
-        CHECK_EQ(extract(xsimd::abs(T(val))), std::abs(val));
+        CHECK_EQ(extract(xsimd::abs(T(val))), doctest::Approx(std::abs(val)));
     }
 
     void test_fnms()