1 files changed, 11 insertions, 7 deletions

diff --git a/gl/m4/floorf.m4 b/gl/m4/floorf.m4
index c892ff9c..f5214378 100644
--- a/gl/m4/floorf.m4
+++ b/gl/m4/floorf.m4
@@ -1,5 +1,5 @@
-# floorf.m4 serial 13
-dnl Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc.
+# floorf.m4 serial 18
+dnl Copyright (C) 2007, 2009-2021 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -39,7 +39,7 @@ AC_DEFUN([gl_FUNC_FLOORF],
 static float dummy (float f) { return 0; }
 int main (int argc, char *argv[])
 {
-  float (*my_floorf) (float) = argc ? floorf : dummy;
+  float (* volatile my_floorf) (float) = argc ? floorf : dummy;
   /* Test whether floorf (-0.0f) is -0.0f.  */
   if (signbitf (minus_zerof) && !signbitf (my_floorf (minus_zerof)))
     return 1;
@@ -49,10 +49,14 @@ int main (int argc, char *argv[])
               [gl_cv_func_floorf_ieee=yes],
               [gl_cv_func_floorf_ieee=no],
               [case "$host_os" in
-                         # Guess yes on glibc systems.
-                 *-gnu*) gl_cv_func_floorf_ieee="guessing yes" ;;
-                         # If we don't know, assume the worst.
-                 *)      gl_cv_func_floorf_ieee="guessing no" ;;
+                                # Guess yes on glibc systems.
+                 *-gnu* | gnu*) gl_cv_func_floorf_ieee="guessing yes" ;;
+                                # Guess yes on musl systems.
+                 *-musl*)       gl_cv_func_floorf_ieee="guessing yes" ;;
+                                # Guess yes on native Windows.
+                 mingw*)        gl_cv_func_floorf_ieee="guessing yes" ;;
+                                # If we don't know, obey --enable-cross-guesses.
+                 *)             gl_cv_func_floorf_ieee="$gl_cross_guess_normal" ;;
                esac
               ])
             LIBS="$save_LIBS"