Update from Gnulib

This incorporates:
2020-07-30 work around some Oracle Studio attribute bugs
2020-07-29 fsusage, regex, stat-size: remove Cray support
2020-07-26 inttypes: remove support for AIX 4
2020-07-26 gettimeofday: remove workaround for Mac OS X 10.0
2020-07-26 don't require gl_LOCALTIME_BUFFER_DEFAULTS
2020-07-26 alloca: remove Cray-2 and Cray Y-MP support
2020-07-26 libgmp: remove dependency on havelib
2020-07-26 libgmp: remove HAVE_GMP, LIB_GMP
2020-07-25 multiarch: prepare for x86_64+arm64 universal in macOS 11
2020-07-25 sigprocmask: small autoconf macro improvement
2020-07-25 small autoconf macro improvements
2020-07-24 timespec: remove dependence on ‘verify’
2020-07-24 optimize a few more three-valued comparisons
2020-07-24 fix _GL_CMP parenthesization typo
2020-07-23 optimize three-valued comparison between integers
2020-07-24 doc: update for Mac OS X 10.13
2020-07-23 fchmodat, lchmod: use /proc on Cygwin
2020-07-21 inttypes: fix PRI*PTR and SCN*PTR on 64-bit native Windows
2020-07-12 libgmp: avoid warning when --without-libgmp is used
2020-07-12 libgmp: link to the correct shared library
* lib/mini-gmp-gnulib.c: Ignore -Wsuggest-attribute=malloc only for
* build-aux/config.guess, build-aux/config.sub:
* build-aux/install-sh, doc/misc/texinfo.tex, lib/c-strcasecmp.c:
* lib/c-strncasecmp.c, lib/fchmodat.c, lib/fsusage.c:
* lib/gettimeofday.c, lib/inttypes.in.h, lib/lchmod.c:
* lib/mini-gmp-gnulib.c, lib/nstrftime.c, lib/regex.h, lib/timespec.h:
* m4/alloca.m4, m4/getgroups.m4, m4/gettimeofday.m4:
* m4/gnulib-common.m4, m4/inttypes.m4, m4/libgmp.m4, m4/mktime.m4:
* m4/multiarch.m4:
Copy from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* src/Makefile.in, test/Makefile.in (LIBGMP):
Rename from LIB_GMP for compatibility with Gnulib.
All uses changed.

9 files changed, 150 insertions, 187 deletions

diff --git a/m4/alloca.m4 b/m4/alloca.m4
index 59225245b91..d3e98c51bf4 100644
--- a/m4/alloca.m4
+++ b/m4/alloca.m4
@@ -1,4 +1,4 @@
-# alloca.m4 serial 15
+# alloca.m4 serial 16
 dnl Copyright (C) 2002-2004, 2006-2007, 2009-2020 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
@@ -51,12 +51,9 @@ AC_DEFUN([gl_FUNC_ALLOCA],
 AC_DEFUN([gl_PREREQ_ALLOCA], [:])
 
 # This works around a bug in autoconf <= 2.68.
-# See <https://lists.gnu.org/r/bug-gnulib/2011-06/msg00277.html>.
-
-m4_version_prereq([2.69], [] ,[
-
-# This is taken from the following Autoconf patch:
-# https://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=6cd9f12520b0d6f76d3230d7565feba1ecf29497
+# See <https://lists.gnu.org/r/bug-gnulib/2011-06/msg00277.html> and
+# <https://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=6cd9f12520b0d6f76d3230d7565feba1ecf29497>.
+# Also it has a simplification that is not yet in Autoconf.
 
 # _AC_LIBOBJ_ALLOCA
 # -----------------
@@ -72,26 +69,6 @@ AC_LIBSOURCES(alloca.c)
 AC_SUBST([ALLOCA], [\${LIBOBJDIR}alloca.$ac_objext])dnl
 AC_DEFINE(C_ALLOCA, 1, [Define to 1 if using 'alloca.c'.])
 
-AC_CACHE_CHECK(whether 'alloca.c' needs Cray hooks, ac_cv_os_cray,
-[AC_EGREP_CPP(webecray,
-[#if defined CRAY && ! defined CRAY2
-webecray
-#else
-wenotbecray
-#endif
-], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
-if test $ac_cv_os_cray = yes; then
-  for ac_func in _getb67 GETB67 getb67; do
-    AC_CHECK_FUNC($ac_func,
-                  [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func,
-                                      [Define to one of '_getb67', 'GETB67',
-                                       'getb67' for Cray-2 and Cray-YMP
-                                       systems. This function is required for
-                                       'alloca.c' support on those systems.])
-    break])
-  done
-fi
-
 AC_CACHE_CHECK([stack direction for C alloca],
                [ac_cv_c_stack_direction],
 [AC_RUN_IFELSE([AC_LANG_SOURCE(
@@ -124,5 +101,4 @@ AH_VERBATIM([STACK_DIRECTION],
         STACK_DIRECTION = 0 => direction of growth unknown */
 @%:@undef STACK_DIRECTION])dnl
 AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction)
-])# _AC_LIBOBJ_ALLOCA
 ])
diff --git a/m4/getgroups.m4 b/m4/getgroups.m4
index 3e7e46f8672..e3441621b25 100644
--- a/m4/getgroups.m4
+++ b/m4/getgroups.m4
@@ -1,4 +1,4 @@
-# serial 23
+# serial 24
 
 dnl From Jim Meyering.
 dnl A wrapper around AC_FUNC_GETGROUPS.
@@ -79,7 +79,8 @@ AC_DEFUN([gl_FUNC_GETGROUPS],
       AC_DEFINE([GETGROUPS_ZERO_BUG], [1], [Define this to 1 if
         getgroups(0,NULL) does not return the number of groups.])
     else
-      dnl Detect FreeBSD bug; POSIX requires getgroups(-1,ptr) to fail.
+      dnl Detect Mac OS X and FreeBSD bug; POSIX requires getgroups(-1,ptr)
+      dnl to fail.
       AC_CACHE_CHECK([whether getgroups handles negative values],
         [gl_cv_func_getgroups_works],
         [AC_RUN_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
diff --git a/m4/gettimeofday.m4 b/m4/gettimeofday.m4
index c72b3eacc63..578ed49b077 100644
--- a/m4/gettimeofday.m4
+++ b/m4/gettimeofday.m4
@@ -1,4 +1,4 @@
-# serial 27
+# serial 28
 
 # Copyright (C) 2001-2003, 2005, 2007, 2009-2020 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
@@ -19,7 +19,6 @@ AC_DEFUN([gl_FUNC_GETTIMEOFDAY],
   if test $ac_cv_func_gettimeofday != yes; then
     HAVE_GETTIMEOFDAY=0
   else
-    gl_FUNC_GETTIMEOFDAY_CLOBBER
     AC_CACHE_CHECK([for gettimeofday with POSIX signature],
       [gl_cv_func_gettimeofday_posix_signature],
       [AC_COMPILE_IFELSE(
@@ -66,63 +65,5 @@ int gettimeofday (struct timeval *restrict, struct timezone *restrict);
      declaration of the second argument to gettimeofday.])
 ])
 
-
-dnl See if gettimeofday clobbers the static buffer that localtime uses
-dnl for its return value.  The gettimeofday function from Mac OS X 10.0.4
-dnl (i.e., Darwin 1.3.7) has this problem.
-dnl
-dnl If it does, then arrange to use gettimeofday and localtime only via
-dnl the wrapper functions that work around the problem.
-
-AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
-[
- AC_REQUIRE([gl_HEADER_SYS_TIME_H])
- AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
- AC_REQUIRE([gl_LOCALTIME_BUFFER_DEFAULTS])
-
- AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer],
-  [gl_cv_func_gettimeofday_clobber],
-  [AC_RUN_IFELSE(
-     [AC_LANG_PROGRAM(
-        [[#include <string.h>
-          #include <sys/time.h>
-          #include <time.h>
-          #include <stdlib.h>
-        ]],
-        [[
-          time_t t = 0;
-          struct tm *lt;
-          struct tm saved_lt;
-          struct timeval tv;
-          lt = localtime (&t);
-          saved_lt = *lt;
-          gettimeofday (&tv, NULL);
-          return memcmp (lt, &saved_lt, sizeof (struct tm)) != 0;
-        ]])],
-     [gl_cv_func_gettimeofday_clobber=no],
-     [gl_cv_func_gettimeofday_clobber=yes],
-     [# When cross-compiling:
-      case "$host_os" in
-                       # Guess all is fine on glibc systems.
-        *-gnu* | gnu*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
-                       # Guess all is fine on musl systems.
-        *-musl*)       gl_cv_func_gettimeofday_clobber="guessing no" ;;
-                       # Guess no on native Windows.
-        mingw*)        gl_cv_func_gettimeofday_clobber="guessing no" ;;
-                       # If we don't know, obey --enable-cross-guesses.
-        *)             gl_cv_func_gettimeofday_clobber="$gl_cross_guess_inverted" ;;
-      esac
-     ])])
-
- case "$gl_cv_func_gettimeofday_clobber" in
-   *yes)
-     REPLACE_GETTIMEOFDAY=1
-     AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1],
-       [Define if gettimeofday clobbers the localtime buffer.])
-     gl_LOCALTIME_BUFFER_NEEDED
-     ;;
- esac
-])
-
 # Prerequisites of lib/gettimeofday.c.
 AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [:])
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index f4ba5e3a00d..57f3a780118 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,4 +1,4 @@
-# gnulib-common.m4 serial 50
+# gnulib-common.m4 serial 52
 dnl Copyright (C) 2007-2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -120,9 +120,14 @@ AC_DEFUN([gl_COMMON_BODY], [
 #endif
 
 /* Avoid __attribute__ ((cold)) on MinGW; see thread starting at
-   <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>. */
+   <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>.
+   Also, Oracle Studio 12.6 requires 'cold' not '__cold__'.  */
 #if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__
-# define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__))
+# ifndef __SUNPRO_C
+#  define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__))
+# else
+#  define _GL_ATTRIBUTE_COLD __attribute__ ((cold))
+# endif
 #else
 # define _GL_ATTRIBUTE_COLD
 #endif
@@ -176,7 +181,8 @@ AC_DEFUN([gl_COMMON_BODY], [
 # define _GL_ATTRIBUTE_LEAF
 #endif
 
-#if _GL_HAS_ATTRIBUTE (may_alias)
+/* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK.  */
+#if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C
 # define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__))
 #else
 # define _GL_ATTRIBUTE_MAY_ALIAS
@@ -293,6 +299,20 @@ AC_DEFUN([gl_COMMON_BODY], [
        errno.  */
 #define _GL_ASYNC_SAFE
 ])
+  AH_VERBATIM([micro_optimizations],
+[/* _GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2.
+   It returns
+     1  if n1 > n2
+     0  if n1 == n2
+     -1 if n1 < n2
+   The naïve code   (n1 > n2 ? 1 : n1 < n2 ? -1 : 0)  produces a conditional
+   jump with nearly all GCC versions up to GCC 10.
+   This variant     (n1 < n2 ? -1 : n1 > n2)  produces a conditional with many
+   GCC versions up to GCC 9.
+   The better code  (n1 > n2) - (n1 < n2)  from Hacker's Delight § 2-9
+   avoids conditional jumps in all GCC versions >= 3.4.  */
+#define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2)))
+])
   dnl Hint which direction to take regarding cross-compilation guesses:
   dnl When a user installs a program on a platform they are not intimately
   dnl familiar with, --enable-cross-guesses=conservative is the appropriate
@@ -612,6 +632,15 @@ AC_DEFUN([gl_BIGENDIAN],
   AC_C_BIGENDIAN
 ])
 
+# gl_SILENT(command)
+# executes command, but without the normal configure output.
+AC_DEFUN([gl_SILENT],
+[
+  {
+    $1
+  } AS_MESSAGE_FD>/dev/null
+])
+
 # gl_CACHE_VAL_SILENT(cache-id, command-to-set-it)
 # is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not
 # output a spurious "(cached)" mark in the midst of other configure output.
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index f577a6fa741..4472af81b70 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -120,7 +120,6 @@ AC_DEFUN([gl_EARLY],
   # Code from module libc-config:
   # Code from module libgmp:
   # Code from module limits-h:
-  # Code from module localtime-buffer:
   # Code from module lstat:
   # Code from module malloca:
   # Code from module manywarnings:
@@ -508,7 +507,6 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36=false
   gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1=false
   gl_gnulib_enabled_lchmod=false
-  gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9=false
   gl_gnulib_enabled_malloca=false
   gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31=false
   gl_gnulib_enabled_open=false
@@ -624,14 +622,6 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_lchmod=true
     fi
   }
-  func_gl_gnulib_m4code_2049e887c7e5308faad27b3f894bb8c9 ()
-  {
-    if ! $gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9; then
-      AC_REQUIRE([gl_LOCALTIME_BUFFER_DEFAULTS])
-      AC_LIBOBJ([localtime-buffer])
-      gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9=true
-    fi
-  }
   func_gl_gnulib_m4code_malloca ()
   {
     if ! $gl_gnulib_enabled_malloca; then
@@ -751,9 +741,6 @@ AC_DEFUN([gl_INIT],
   if case $host_os in mingw*) false;; *) test $HAVE_GETRANDOM = 0 || test $REPLACE_GETRANDOM = 1;; esac; then
     func_gl_gnulib_m4code_open
   fi
-  if test $NEED_LOCALTIME_BUFFER = 1; then
-    func_gl_gnulib_m4code_2049e887c7e5308faad27b3f894bb8c9
-  fi
   if test $HAVE_READLINKAT = 0; then
     func_gl_gnulib_m4code_260941c0e5dc67ec9e87d1fb321c300b
   fi
@@ -785,7 +772,6 @@ AC_DEFUN([gl_INIT],
   AM_CONDITIONAL([gl_GNULIB_ENABLED_be453cec5eecf5731a274f2de7f2db36], [$gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1], [$gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_lchmod], [$gl_gnulib_enabled_lchmod])
-  AM_CONDITIONAL([gl_GNULIB_ENABLED_2049e887c7e5308faad27b3f894bb8c9], [$gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_malloca], [$gl_gnulib_enabled_malloca])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31], [$gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_open], [$gl_gnulib_enabled_open])
@@ -1030,8 +1016,6 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/lchmod.c
   lib/libc-config.h
   lib/limits.in.h
-  lib/localtime-buffer.c
-  lib/localtime-buffer.h
   lib/lstat.c
   lib/malloca.c
   lib/malloca.h
@@ -1176,7 +1160,6 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/lchmod.m4
   m4/libgmp.m4
   m4/limits-h.m4
-  m4/localtime-buffer.m4
   m4/lstat.m4
   m4/malloca.m4
   m4/manywarnings-c++.m4
diff --git a/m4/inttypes.m4 b/m4/inttypes.m4
index 224d0cdd8e2..28bac816b69 100644
--- a/m4/inttypes.m4
+++ b/m4/inttypes.m4
@@ -1,4 +1,4 @@
-# inttypes.m4 serial 29
+# inttypes.m4 serial 31
 dnl Copyright (C) 2006-2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -35,12 +35,19 @@ AC_DEFUN_ONCE([gl_INTTYPES_INCOMPLETE],
 # Ensure that the PRI* and SCN* macros are defined appropriately.
 AC_DEFUN([gl_INTTYPES_PRI_SCN],
 [
-  AC_REQUIRE([gt_INTTYPES_PRI])
-
   PRIPTR_PREFIX=
   if test -n "$STDINT_H"; then
-    dnl Using the gnulib <stdint.h>. It always defines intptr_t to 'long'.
-    PRIPTR_PREFIX='"l"'
+    dnl Using the gnulib <stdint.h>. It defines intptr_t to 'long' or
+    dnl 'long long', depending on _WIN64.
+    AC_COMPILE_IFELSE(
+      [AC_LANG_PROGRAM([[
+         #ifdef _WIN64
+         LLP64
+         #endif
+         ]]),
+      ],
+      [PRIPTR_PREFIX='"l"'],
+      [PRIPTR_PREFIX='"ll"'])
   else
     dnl Using the system's <stdint.h>.
     for glpfx in '' l ll I64; do
@@ -152,7 +159,6 @@ AC_DEFUN([gl_INTTYPES_H_DEFAULTS],
   REPLACE_STRTOUMAX=0;   AC_SUBST([REPLACE_STRTOUMAX])
   INT32_MAX_LT_INTMAX_MAX=1;  AC_SUBST([INT32_MAX_LT_INTMAX_MAX])
   INT64_MAX_EQ_LONG_MAX='defined _LP64';  AC_SUBST([INT64_MAX_EQ_LONG_MAX])
-  PRI_MACROS_BROKEN=0;   AC_SUBST([PRI_MACROS_BROKEN])
   PRIPTR_PREFIX=__PRIPTR_PREFIX;  AC_SUBST([PRIPTR_PREFIX])
   UINT32_MAX_LT_UINTMAX_MAX=1;  AC_SUBST([UINT32_MAX_LT_UINTMAX_MAX])
   UINT64_MAX_EQ_ULONG_MAX='defined _LP64';  AC_SUBST([UINT64_MAX_EQ_ULONG_MAX])
diff --git a/m4/libgmp.m4 b/m4/libgmp.m4
index b569bb73462..82c065e2c2c 100644
--- a/m4/libgmp.m4
+++ b/m4/libgmp.m4
@@ -1,44 +1,67 @@
+# libgmp.m4 serial 4
 # Configure the GMP library or a replacement.
-
 dnl Copyright 2020 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.
 
+dnl gl_LIBGMP
+dnl Search for an installed libgmp.
+dnl If found, set and AC_SUBST HAVE_LIBGMP=yes and the LIBGMP and LTLIBGMP
+dnl variables, and augment the CPPFLAGS variable, and #define HAVE_LIBGMP to 1.
+dnl Otherwise, set and AC_SUBST HAVE_LIBGMP=no and LIBGMP and LTLIBGMP to
+dnl empty.
+
 AC_DEFUN([gl_LIBGMP],
 [
   AC_ARG_WITH([libgmp],
     [AS_HELP_STRING([--without-libgmp],
        [do not use the GNU Multiple Precision (GMP) library;
         this is the default on systems lacking libgmp.])])
-
-  AC_CHECK_HEADERS_ONCE([gmp.h])
-  GMP_H=gmp.h
-  LIB_GMP=
-
-  case $with_libgmp in
-    no) ;;
-    yes) GMP_H= LIB_GMP=-lgmp;;
-    *) if test "$ac_cv_header_gmp_h" = yes; then
-         gl_saved_LIBS=$LIBS
+  case "$with_libgmp" in
+    no)
+      HAVE_LIBGMP=no
+      LIBGMP=
+      LTLIBGMP=
+      ;;
+    *)
+      dnl Prefer AC_LIB_HAVE_LINKFLAGS if the havelib module is also in use.
+      m4_ifdef([gl_HAVE_MODULE_HAVELIB],
+        [AC_LIB_HAVE_LINKFLAGS([gmp], [],
+           [#include <gmp.h>],
+           [static const mp_limb_t x[2] = { 0x73, 0x55 };
+            mpz_t tmp;
+            mpz_roinit_n (tmp, x, 2);
+           ],
+           [no])],
+        [gl_saved_LIBS=$LIBS
          AC_SEARCH_LIBS([__gmpz_roinit_n], [gmp])
          LIBS=$gl_saved_LIBS
          case $ac_cv_search___gmpz_roinit_n in
            'none needed')
-             GMP_H=;;
+             HAVE_LIBGMP=yes LIBGMP=;;
            -*)
-             GMP_H= LIB_GMP=$ac_cv_search___gmpz_roinit_n;;
+             HAVE_LIBGMP=yes LIBGMP=$ac_cv_search___gmpz_roinit_n;;
+           *)
+             HAVE_LIBGMP=no LIBGMP=;;
          esac
-       fi;;
+         LTLIBGMP=$LIBGMP
+         AC_SUBST([HAVE_LIBGMP])
+         AC_SUBST([LIBGMP])
+         AC_SUBST([LTLIBGMP])])
+      if test "$with_libgmp,$HAVE_LIBGMP" = yes,no; then
+        AC_MSG_ERROR(
+          [GMP not found, although --with-libgmp was specified.m4_ifdef(
+             [AC_LIB_HAVE_LINKFLAGS],
+             [ Try specifying --with-libgmp-prefix=DIR.])])
+      fi
+      ;;
   esac
-
-  if test -z "$GMP_H"; then
-    AC_DEFINE([HAVE_GMP], 1,
-      [Define to 1 if you have the GMP library instead of just the
-       mini-gmp replacement.])
+  if test $HAVE_LIBGMP = yes; then
+    GMP_H=
+  else
+    GMP_H=gmp.h
   fi
-
-  AC_SUBST([LIB_GMP])
   AC_SUBST([GMP_H])
   AM_CONDITIONAL([GL_GENERATE_GMP_H], [test -n "$GMP_H"])
 ])
diff --git a/m4/mktime.m4 b/m4/mktime.m4
index c00843f0f40..8d9b827fe21 100644
--- a/m4/mktime.m4
+++ b/m4/mktime.m4
@@ -1,4 +1,4 @@
-# serial 31
+# serial 32
 dnl Copyright (C) 2002-2003, 2005-2007, 2009-2020 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
@@ -33,15 +33,15 @@ AC_DEFUN([gl_FUNC_MKTIME_WORKS],
   AC_CHECK_DECLS_ONCE([alarm])
   AC_CHECK_FUNCS_ONCE([tzset])
   AC_REQUIRE([gl_MULTIARCH])
-  if test $APPLE_UNIVERSAL_BUILD = 1; then
-    # A universal build on Apple Mac OS X platforms.
-    # The test result would be 'yes' in 32-bit mode and 'no' in 64-bit mode.
-    # But we need a configuration result that is valid in both modes.
-    gl_cv_func_working_mktime=no
-  fi
   AC_CACHE_CHECK([for working mktime], [gl_cv_func_working_mktime],
-    [AC_RUN_IFELSE(
-       [AC_LANG_SOURCE(
+    [if test $APPLE_UNIVERSAL_BUILD = 1; then
+       # A universal build on Apple Mac OS X platforms.
+       # The test result would be 'yes' in 32-bit mode and 'no' in 64-bit mode.
+       # But we need a configuration result that is valid in both modes.
+       gl_cv_func_working_mktime="guessing no"
+     else
+       AC_RUN_IFELSE(
+         [AC_LANG_SOURCE(
 [[/* Test program from Paul Eggert and Tony Leneis.  */
 #include <limits.h>
 #include <stdlib.h>
@@ -242,14 +242,15 @@ main ()
     result |= 64;
   return result;
 }]])],
-       [gl_cv_func_working_mktime=yes],
-       [gl_cv_func_working_mktime=no],
-       [case "$host_os" in
-                  # Guess no on native Windows.
-          mingw*) gl_cv_func_working_mktime="guessing no" ;;
-          *)      gl_cv_func_working_mktime="$gl_cross_guess_normal" ;;
-        esac
-       ])
+         [gl_cv_func_working_mktime=yes],
+         [gl_cv_func_working_mktime=no],
+         [case "$host_os" in
+                    # Guess no on native Windows.
+            mingw*) gl_cv_func_working_mktime="guessing no" ;;
+            *)      gl_cv_func_working_mktime="$gl_cross_guess_normal" ;;
+          esac
+         ])
+     fi
     ])
 ])
 
diff --git a/m4/multiarch.m4 b/m4/multiarch.m4
index 3c2034c5e00..2c61afbd76e 100644
--- a/m4/multiarch.m4
+++ b/m4/multiarch.m4
@@ -1,4 +1,4 @@
-# multiarch.m4 serial 7
+# multiarch.m4 serial 9
 dnl Copyright (C) 2008-2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -21,37 +21,40 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN_ONCE([gl_MULTIARCH],
 [
   dnl Code similar to autoconf-2.63 AC_C_BIGENDIAN.
-  gl_cv_c_multiarch=no
-  AC_COMPILE_IFELSE(
-    [AC_LANG_SOURCE(
-      [[#ifndef __APPLE_CC__
-         not a universal capable compiler
-        #endif
-        typedef int dummy;
-      ]])],
-    [
-     dnl Check for potential -arch flags.  It is not universal unless
-     dnl there are at least two -arch flags with different values.
-     arch=
-     prev=
-     for word in ${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}; do
-       if test -n "$prev"; then
-         case $word in
-           i?86 | x86_64 | ppc | ppc64)
-             if test -z "$arch" || test "$arch" = "$word"; then
-               arch="$word"
-             else
-               gl_cv_c_multiarch=yes
-             fi
-             ;;
-         esac
-         prev=
-       else
-         if test "x$word" = "x-arch"; then
-           prev=arch
-         fi
-       fi
-     done
+  AC_CACHE_CHECK([whether the compiler produces multi-arch binaries],
+    [gl_cv_c_multiarch],
+    [gl_cv_c_multiarch=no
+     AC_COMPILE_IFELSE(
+       [AC_LANG_SOURCE(
+         [[#ifndef __APPLE_CC__
+            not a universal capable compiler
+           #endif
+           typedef int dummy;
+         ]])],
+       [
+        dnl Check for potential -arch flags.  It is not universal unless
+        dnl there are at least two -arch flags with different values.
+        arch=
+        prev=
+        for word in ${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}; do
+          if test -n "$prev"; then
+            case $word in
+              i?86 | x86_64 | ppc | ppc64 | arm | arm64)
+                if test -z "$arch" || test "$arch" = "$word"; then
+                  arch="$word"
+                else
+                  gl_cv_c_multiarch=yes
+                fi
+                ;;
+            esac
+            prev=
+          else
+            if test "x$word" = "x-arch"; then
+              prev=arch
+            fi
+          fi
+        done
+       ])
     ])
   if test $gl_cv_c_multiarch = yes; then
     APPLE_UNIVERSAL_BUILD=1