log10: Remove support for OSF/1.

* m4/log10.m4 (gl_FUNC_LOG10_WORKS): Remove macro.
(gl_FUNC_LOG10): Don't invoke it.
* lib/log10.c (log10): Assume that log10 (±0.0) is correct.

diff --git a/ChangeLog b/ChangeLog
index a0cb819fd19d21f650b42f57060e89c10e746096..00070e7e72757b043305d4c2f385a1fe44aa742b 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2025-09-09  Bruno Haible  <bruno@clisp.org>
 
+       log10: Remove support for OSF/1.
+       * m4/log10.m4 (gl_FUNC_LOG10_WORKS): Remove macro.
+       (gl_FUNC_LOG10): Don't invoke it.
+       * lib/log10.c (log10): Assume that log10 (±0.0) is correct.
+
        logl: Remove support for OSF/1.
        * m4/logl.m4 (gl_FUNC_LOGL_WORKS): Remove test regarding logl (-0.0L).
        * lib/logl.c (logl): Remove workaround for OSF/1.

diff --git a/lib/log10.c b/lib/log10.c
index 84d0b44eb31eefe331c4c2d7157ab80671811616..2b2599b6fdf201fe3b61380eaee0fd95def2e9e8 100644 (file)
--- a/lib/log10.c
+++ b/lib/log10.c
@@ -23,16 +23,11 @@ double
 log10 (double x)
 #undef log10
 {
-  if (x <= 0.0)
+  if (x < 0.0)
     {
-      /* Work around the OSF/1 5.1 bug.  */
-      if (x == 0.0)
-        /* Return -Infinity.  */
-        return -1.0 / 0.0;
       /* Work around the NetBSD 5.1, Solaris 11.0 bug.  */
-      else /* x < 0.0 */
-        /* Return NaN.  */
-        return 0.0 / 0.0;
+      /* Return NaN.  */
+      return 0.0 / 0.0;
     }
   return log10 (x);
 }

diff --git a/m4/log10.m4 b/m4/log10.m4
index 82e23a5d953791b5c91c355b34c621dc736619f9..9bf58551b309bf47a2cff0bca611168ca5f5f5a2 100644 (file)
--- a/m4/log10.m4
+++ b/m4/log10.m4
@@ -1,5 +1,5 @@
 # log10.m4
-# serial 14
+# serial 15
 dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -14,17 +14,8 @@ AC_DEFUN([gl_FUNC_LOG10],
   dnl Determine LOG10_LIBM.
   gl_COMMON_DOUBLE_MATHFUNC([log10])
 
-  saved_LIBS="$LIBS"
-  LIBS="$LIBS $LOG10_LIBM"
-  gl_FUNC_LOG10_WORKS
-  LIBS="$saved_LIBS"
-  case "$gl_cv_func_log10_works" in
-    *yes) ;;
-    *) REPLACE_LOG10=1 ;;
-  esac
-
   m4_ifdef([gl_FUNC_LOG10_IEEE], [
-    if test $gl_log10_required = ieee && test $REPLACE_LOG10 = 0; then
+    if test $gl_log10_required = ieee; then
       AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
       AC_CACHE_CHECK([whether log10 works according to ISO C 99 with IEC 60559],
         [gl_cv_func_log10_ieee],
@@ -79,37 +70,3 @@ int main (int argc, char *argv[])
     fi
   ])
 ])
-
-dnl Test whether log10() works.
-dnl On OSF/1 5.1, log10(-0.0) is NaN.
-AC_DEFUN([gl_FUNC_LOG10_WORKS],
-[
-  AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  AC_CACHE_CHECK([whether log10 works], [gl_cv_func_log10_works],
-    [
-      AC_RUN_IFELSE(
-        [AC_LANG_SOURCE([[
-#include <math.h>
-volatile double x;
-double y;
-int main ()
-{
-  x = -0.0;
-  y = log10 (x);
-  if (!(y + y == y))
-    return 1;
-  return 0;
-}
-]])],
-        [gl_cv_func_log10_works=yes],
-        [gl_cv_func_log10_works=no],
-        [case "$host_os" in
-           osf*)              gl_cv_func_log10_works="guessing no" ;;
-                              # Guess yes on native Windows.
-           mingw* | windows*) gl_cv_func_log10_works="guessing yes" ;;
-           *)                 gl_cv_func_log10_works="guessing yes" ;;
-         esac
-        ])
-    ])
-])