Update Gnulib to v0.1-4379-g2ef5a9b4b

Also bump required autoconf version to 2.64, as required by Gnulib.

1 files changed, 24 insertions, 10 deletions

diff --git a/m4/exponentl.m4 b/m4/exponentl.m4
index c9cb81dd8..508fe9315 100644
--- a/m4/exponentl.m4
+++ b/m4/exponentl.m4
@@ -1,11 +1,12 @@
-# exponentl.m4 serial 3
-dnl Copyright (C) 2007-2017 Free Software Foundation, Inc.
+# exponentl.m4 serial 5
+dnl Copyright (C) 2007-2021 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.
 AC_DEFUN([gl_LONG_DOUBLE_EXPONENT_LOCATION],
 [
   AC_REQUIRE([gl_BIGENDIAN])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CACHE_CHECK([where to find the exponent in a 'long double'],
     [gl_cv_cc_long_double_expbit0],
     [
@@ -21,14 +22,14 @@ typedef union { long double value; unsigned int word[NWORDS]; }
         memory_long_double;
 static unsigned int ored_words[NWORDS];
 static unsigned int anded_words[NWORDS];
-static void add_to_ored_words (long double x)
+static void add_to_ored_words (long double *x)
 {
   memory_long_double m;
   size_t i;
   /* Clear it first, in case
      sizeof (long double) < sizeof (memory_long_double).  */
   memset (&m, 0, sizeof (memory_long_double));
-  m.value = x;
+  m.value = *x;
   for (i = 0; i < NWORDS; i++)
     {
       ored_words[i] |= m.word[i];
@@ -37,17 +38,15 @@ static void add_to_ored_words (long double x)
 }
 int main ()
 {
+  static long double samples[5] = { 0.25L, 0.5L, 1.0L, 2.0L, 4.0L };
   size_t j;
   FILE *fp = fopen ("conftest.out", "w");
   if (fp == NULL)
     return 1;
   for (j = 0; j < NWORDS; j++)
     anded_words[j] = ~ (unsigned int) 0;
-  add_to_ored_words (0.25L);
-  add_to_ored_words (0.5L);
-  add_to_ored_words (1.0L);
-  add_to_ored_words (2.0L);
-  add_to_ored_words (4.0L);
+  for (j = 0; j < 5; j++)
+    add_to_ored_words (&samples[j]);
   /* Remove bits that are common (e.g. if representation of the first mantissa
      bit is explicit).  */
   for (j = 0; j < NWORDS; j++)
@@ -79,9 +78,24 @@ int main ()
         [gl_cv_cc_long_double_expbit0=`cat conftest.out`],
         [gl_cv_cc_long_double_expbit0="unknown"],
         [
-          dnl When cross-compiling, we don't know. It depends on the
+          dnl When cross-compiling, in general we don't know. It depends on the
           dnl ABI and compiler version. There are too many cases.
           gl_cv_cc_long_double_expbit0="unknown"
+          case "$host_os" in
+            mingw*) # On native Windows (little-endian), we know the result
+                    # in two cases: mingw, MSVC.
+              AC_EGREP_CPP([Known], [
+#ifdef __MINGW32__
+ Known
+#endif
+                ], [gl_cv_cc_long_double_expbit0="word 2 bit 0"])
+              AC_EGREP_CPP([Known], [
+#ifdef _MSC_VER
+ Known
+#endif
+                ], [gl_cv_cc_long_double_expbit0="word 1 bit 20"])
+              ;;
+          esac
         ])
       rm -f conftest.out
     ])