Merge pull request #1181 from fsb4000/fix_warnings

Fix warning C4701: "potentially uninitialized local variable used"

Author: jzmaddock

include/boost/math/special_functions/detail/bessel_ik.hpp

@@ -330,6 +330,11 @@ BOOST_MATH_GPU_ENABLED int bessel_ik(T v, T x, T* result_I, T* result_K, int kin
     T scale = 1;
     T scale_sign = 1;
 
+    n = iround(v, pol);
+    u = v - n;                              // -1/2 <= u < 1/2
+    BOOST_MATH_INSTRUMENT_VARIABLE(n);
+    BOOST_MATH_INSTRUMENT_VARIABLE(u);
+
     if (((kind & need_i) == 0) && (fabs(4 * v * v - 25) / (8 * x) < tools::forth_root_epsilon<T>()))
     {
        // A&S 9.7.2
@@ -341,11 +346,6 @@ BOOST_MATH_GPU_ENABLED int bessel_ik(T v, T x, T* result_I, T* result_K, int kin
     }
     else
     {
-       n = iround(v, pol);
-       u = v - n;                              // -1/2 <= u < 1/2
-       BOOST_MATH_INSTRUMENT_VARIABLE(n);
-       BOOST_MATH_INSTRUMENT_VARIABLE(u);
-
        BOOST_MATH_ASSERT(x > 0); // Error handling for x <= 0 handled in cyl_bessel_i and cyl_bessel_k
 
        // x is positive until reflection
@@ -418,6 +418,7 @@ BOOST_MATH_GPU_ENABLED int bessel_ik(T v, T x, T* result_I, T* result_K, int kin
     }
     if (reflect)
     {
+        BOOST_MATH_ASSERT(fabs(v - n - u) < tools::forth_root_epsilon<T>());
         T z = (u + n % 2);
         T fact = (2 / pi<T>()) * (boost::math::sin_pi(z, pol) * Kv);
         if(fact == 0)

test/test_bessel_j.hpp

@@ -291,6 +291,7 @@ void test_bessel(T, const char* name)
        BOOST_CHECK_EQUAL(boost::math::cyl_bessel_j(T(0), std::numeric_limits<T>::infinity()), T(0));
        BOOST_CHECK_EQUAL(boost::math::cyl_bessel_j(T(2), std::numeric_limits<T>::infinity()), T(0));
        BOOST_CHECK_EQUAL(boost::math::cyl_bessel_j(T(1.25), std::numeric_limits<T>::infinity()), T(0));
+       BOOST_CHECK_EQUAL(boost::math::cyl_bessel_j(T(-1.25), std::numeric_limits<T>::infinity()), T(0));
        BOOST_CHECK_EQUAL(boost::math::sph_bessel(0, std::numeric_limits<T>::infinity()), T(0));
        BOOST_CHECK_EQUAL(boost::math::sph_bessel(1, std::numeric_limits<T>::infinity()), T(0));
        BOOST_CHECK_EQUAL(boost::math::sph_bessel(2, std::numeric_limits<T>::infinity()), T(0));