closes bpo-34640: Remove the TANH_PRESERVES_ZERO_SIGN configure check. (GH-9206)

1 files changed, 0 insertions, 27 deletions

diff --git a/configure.ac b/configure.ac
index 4b34bad35a..a985ec2b00 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4359,33 +4359,6 @@ AC_CHECK_FUNCS([acosh asinh atanh copysign erf erfc expm1 finite gamma])
 AC_CHECK_FUNCS([hypot lgamma log1p log2 round tgamma])
 AC_CHECK_DECLS([isinf, isnan, isfinite], [], [], [[#include <math.h>]])
 
-# On FreeBSD 6.2, it appears that tanh(-0.) returns 0. instead of
-# -0. on some architectures.
-AC_MSG_CHECKING(whether tanh preserves the sign of zero)
-AC_CACHE_VAL(ac_cv_tanh_preserves_zero_sign, [
-AC_RUN_IFELSE([AC_LANG_SOURCE([[
-#include <math.h>
-#include <stdlib.h>
-int main() {
-    /* return 0 if either negative zeros don't exist
-       on this platform or if negative zeros exist
-       and tanh(-0.) == -0. */
-  if (atan2(0., -1.) == atan2(-0., -1.) ||
-      atan2(tanh(-0.), -1.) == atan2(-0., -1.)) exit(0);
-  else exit(1);
-}
-]])],
-[ac_cv_tanh_preserves_zero_sign=yes],
-[ac_cv_tanh_preserves_zero_sign=no],
-[ac_cv_tanh_preserves_zero_sign=no])])
-AC_MSG_RESULT($ac_cv_tanh_preserves_zero_sign)
-if test "$ac_cv_tanh_preserves_zero_sign" = yes
-then
-  AC_DEFINE(TANH_PRESERVES_ZERO_SIGN, 1,
-  [Define if tanh(-0.) is -0., or if platform doesn't have signed zeros])
-fi
-LIBS=$LIBS_SAVE
-
 # For multiprocessing module, check that sem_open
 # actually works.  For FreeBSD versions <= 7.2,
 # the kernel module that provides POSIX semaphores