Remove configure check LOG1P_DROPS_ZERO_SIGN. (GH-9193)

It is unused.

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1 files changed, 0 insertions, 30 deletions

diff --git a/configure.ac b/configure.ac
index e47586bd40..4b34bad35a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4384,36 +4384,6 @@ then
   AC_DEFINE(TANH_PRESERVES_ZERO_SIGN, 1,
   [Define if tanh(-0.) is -0., or if platform doesn't have signed zeros])
 fi
-
-if test "$ac_cv_func_log1p" = yes
-then
-    # On some versions of AIX, log1p(-0.) returns 0. instead of
-    # -0.  See issue #9920.
-    AC_MSG_CHECKING(whether log1p drops the sign of negative zero)
-    AC_CACHE_VAL(ac_cv_log1p_drops_zero_sign, [
-    AC_RUN_IFELSE([AC_LANG_SOURCE([[
-    #include <math.h>
-    #include <stdlib.h>
-    int main() {
-        /* Fail if the signs of log1p(-0.) and -0. can be
-	   distinguished. */
-        if (atan2(log1p(-0.), -1.) == atan2(-0., -1.))
-            return 0;
-        else
-            return 1;
-    }
-    ]])],
-    [ac_cv_log1p_drops_zero_sign=no],
-    [ac_cv_log1p_drops_zero_sign=yes],
-    [ac_cv_log1p_drops_zero_sign=no])])
-    AC_MSG_RESULT($ac_cv_log1p_drops_zero_sign)
-fi
-if test "$ac_cv_log1p_drops_zero_sign" = yes
-then
-  AC_DEFINE(LOG1P_DROPS_ZERO_SIGN, 1,
-  [Define if log1p(-0.) is 0. rather than -0.])
-fi
-
 LIBS=$LIBS_SAVE
 
 # For multiprocessing module, check that sem_open