Merge pull request #1195 from boostorg/1194

Fix removed tgamma error handling path
boostorg · Sep 9, 2024 · 84a7bdd · 84a7bdd
2 parents cb06899 + 9d13307
commit 84a7bdd
Show file tree

Hide file tree

Showing 3 changed files with 64 additions and 17 deletions.
diff --git a/include/boost/math/special_functions/gamma.hpp b/include/boost/math/special_functions/gamma.hpp
@@ -197,25 +197,30 @@ BOOST_MATH_GPU_ENABLED BOOST_MATH_FORCEINLINE T gamma_imp(T z, const Policy& pol
 {
  BOOST_MATH_STD_USING
 
- if(z <= -20)
- {
- constexpr auto function = "boost::math::tgamma<%1%>(%1%)";
- T result = gamma_imp_final(T(-z), pol, l) * sinpx(z);
- BOOST_MATH_INSTRUMENT_VARIABLE(result);
- if((fabs(result) < 1) && (tools::max_value<T>() * fabs(result) < boost::math::constants::pi<T>()))
- return -boost::math::sign(result) * policies::raise_overflow_error<T>(function, "Result of tgamma is too large to represent.", pol);
- result = -boost::math::constants::pi<T>() / result;
- if(result == 0)
- return policies::raise_underflow_error<T>(function, "Result of tgamma is too small to represent.", pol);
- if((boost::math::fpclassify)(result) == (int)BOOST_MATH_FP_SUBNORMAL)
- return policies::raise_denorm_error<T>(function, "Result of tgamma is denormalized.", result, pol);
- BOOST_MATH_INSTRUMENT_VARIABLE(result);
- return result;
- }
- else
+ T result = 1;
+ constexpr auto function = "boost::math::tgamma<%1%>(%1%)";
+
+ if(z <= 0)
  {
- return gamma_imp_final(T(z), pol, l);
+ if(floor(z) == z)
+ return policies::raise_pole_error<T>(function, "Evaluation of tgamma at a negative integer %1%.", z, pol);
+ if(z <= -20)
+ {
+ result = gamma_imp_final(T(-z), pol, l) * sinpx(z);
+ BOOST_MATH_INSTRUMENT_VARIABLE(result);
+ if((fabs(result) < 1) && (tools::max_value<T>() * fabs(result) < boost::math::constants::pi<T>()))
+ return -boost::math::sign(result) * policies::raise_overflow_error<T>(function, "Result of tgamma is too large to represent.", pol);
+ result = -boost::math::constants::pi<T>() / result;
+ if(result == 0)
+ return policies::raise_underflow_error<T>(function, "Result of tgamma is too small to represent.", pol);
+ if((boost::math::fpclassify)(result) == BOOST_MATH_FP_SUBNORMAL)
+ return policies::raise_denorm_error<T>(function, "Result of tgamma is denormalized.", result, pol);
+ BOOST_MATH_INSTRUMENT_VARIABLE(result);
+ return result;
+ }
  }
+
+ return gamma_imp_final(T(z), pol, l);
 }
 
 #ifdef BOOST_MATH_ENABLE_CUDA

diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
@@ -193,6 +193,7 @@ test-suite special_fun :
  [ run git_issue_1137.cpp ]
  [ run git_issue_1139.cpp ]
  [ run git_issue_1175.cpp ]
+ [ run git_issue_1194.cpp ]
  [ run special_functions_test.cpp /boost/test//boost_unit_test_framework ]
  [ run test_airy.cpp test_instances//test_instances pch_light /boost/test//boost_unit_test_framework ]
  [ run test_bessel_j.cpp test_instances//test_instances pch_light /boost/test//boost_unit_test_framework ]

diff --git a/test/git_issue_1194.cpp b/test/git_issue_1194.cpp
@@ -0,0 +1,41 @@
+// (C) Copyright Matt Borland 2024.
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include "math_unit_test.hpp"
+#include <boost/math/special_functions/gamma.hpp>
+#include <cerrno>
+
+int main()
+{
+ using c99_error_policy = ::boost::math::policies::policy<
+ ::boost::math::policies::domain_error< ::boost::math::policies::errno_on_error>,
+ ::boost::math::policies::pole_error< ::boost::math::policies::errno_on_error>,
+ ::boost::math::policies::overflow_error< ::boost::math::policies::errno_on_error>,
+ ::boost::math::policies::evaluation_error< ::boost::math::policies::errno_on_error>,
+ ::boost::math::policies::rounding_error< ::boost::math::policies::errno_on_error> >;
+
+ double val = -std::numeric_limits<double>::infinity();
+
+ val = boost::math::tgamma(val, c99_error_policy());
+ CHECK_EQUAL(errno, EDOM);
+
+ val = std::numeric_limits<double>::quiet_NaN();
+ val = boost::math::tgamma(val, c99_error_policy());
+ CHECK_EQUAL(errno, EDOM);
+
+ val = std::numeric_limits<double>::infinity();
+ val = boost::math::tgamma(val, c99_error_policy());
+ CHECK_EQUAL(errno, ERANGE);
+
+ val = 0;
+ val = boost::math::tgamma(val, c99_error_policy());
+ CHECK_EQUAL(errno, EDOM); // OK
+
+ val = -2;
+ val = boost::math::tgamma(val, c99_error_policy());
+ CHECK_EQUAL(errno, EDOM); // OK
+
+ return boost::math::test::report_errors();
+}