Re: new module 'fenv-rounding'

[Bruno Haible]

On NetBSD 8.0/sparc64, I see a test failure of the fenv-rounding test for
'long double' operations. On this platform, 'long double' operations are
implemented by a software floating-point library. Apparently this library
code ignores the rounding direction.

This patch avoids the test failure and documents the problem.


2023-11-04  Bruno Haible  <br...@clisp.org>

        fenv-rounding: Avoid a test failure on NetBSD/sparc64.
        * tests/test-fenv-round.c (test_towardzero, test_upward, test_downward):
        Skip the 'long double' tests on NetBSD/sparc64.
        * doc/posix-functions/fesetround.texi: Mention the problem with
        'long double' operations on some platforms.

diff --git a/doc/posix-functions/fesetround.texi 
b/doc/posix-functions/fesetround.texi
index f0c74c3467..73d6c034fa 100644
--- a/doc/posix-functions/fesetround.texi
+++ b/doc/posix-functions/fesetround.texi
@@ -18,4 +18,7 @@
 
 Portability problems not fixed by Gnulib:
 @itemize
+@item
+The rounding mode has no effect on @code{long double} operations on some 
platforms:
+FreeBSD/arm64, NetBSD/sparc64.
 @end itemize
diff --git a/tests/test-fenv-round.c b/tests/test-fenv-round.c
index aba783cc79..b697fb1301 100644
--- a/tests/test-fenv-round.c
+++ b/tests/test-fenv-round.c
@@ -45,7 +45,7 @@ test_towardzero ()
     a = -1; b = 3; q = a / b; p = b * q;
     ASSERT (p > a);
   }
-#if !(defined __FreeBSD__ && defined __aarch64__)
+#if !((defined __FreeBSD__ && defined __aarch64__) || (defined __NetBSD__ && 
defined __sparcv9 /* sparc64 */))
   {
     long double volatile a, b, q, p;
 
@@ -80,7 +80,7 @@ test_upward ()
     a = -1; b = 3; q = a / b; p = b * q;
     ASSERT (p > a);
   }
-#if !(defined __FreeBSD__ && defined __aarch64__)
+#if !((defined __FreeBSD__ && defined __aarch64__) || (defined __NetBSD__ && 
defined __sparcv9 /* sparc64 */))
   {
     long double volatile a, b, q, p;
 
@@ -115,7 +115,7 @@ test_downward ()
     a = -1; b = 3; q = a / b; p = b * q;
     ASSERT (p < a);
   }
-#if !(defined __FreeBSD__ && defined __aarch64__)
+#if !((defined __FreeBSD__ && defined __aarch64__) || (defined __NetBSD__ && 
defined __sparcv9 /* sparc64 */))
   {
     long double volatile a, b, q, p;