Mercurial > gnulib
view m4/builtin-expect.m4 @ 40214:452ab00796c7
Fix undefined behaviour.
* lib/bitrotate.h (rotl16, rotr16, rotl8, rotr8): Case x to
'unsigned int', to avoid shift operations on 'int'.
* lib/xmemdup0.c (xmemdup0): Don't invoke memcpy with a zero size.
* tests/test-count-leading-zeros.c (main): Use a random number that has
as many bits as TYPE, not only 2*15 or 2*31 bits.
* tests/test-count-trailing-zeros.c (main): Likewise.
* tests/test-count-one-bits.c (main): Likewise.
* tests/test-memmem.c: Don't include "null-ptr.h".
(main): Use zerosize_ptr() instead of null_ptr().
* modules/memmem-tests (Files): Remove tests/null-ptr.h.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Sat, 09 Mar 2019 20:32:25 +0100 |
parents | b06060465f09 |
children |
line wrap: on
line source
dnl Check for __builtin_expect. dnl Copyright 2016-2019 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 Written by Paul Eggert. AC_DEFUN([gl___BUILTIN_EXPECT], [ AC_CACHE_CHECK([for __builtin_expect], [gl_cv___builtin_expect], [AC_LINK_IFELSE( [AC_LANG_SOURCE([[ int main (int argc, char **argv) { argc = __builtin_expect (argc, 100); return argv[argc != 100][0]; }]])], [gl_cv___builtin_expect=yes], [AC_LINK_IFELSE( [AC_LANG_SOURCE([[ #include <builtins.h> int main (int argc, char **argv) { argc = __builtin_expect (argc, 100); return argv[argc != 100][0]; }]])], [gl_cv___builtin_expect="in <builtins.h>"], [gl_cv___builtin_expect=no])])]) if test "$gl_cv___builtin_expect" = yes; then AC_DEFINE([HAVE___BUILTIN_EXPECT], [1]) elif test "$gl_cv___builtin_expect" = "in <builtins.h>"; then AC_DEFINE([HAVE___BUILTIN_EXPECT], [2]) fi AH_VERBATIM([HAVE___BUILTIN_EXPECT], [/* Define to 1 if the compiler supports __builtin_expect, and to 2 if <builtins.h> does. */ #undef HAVE___BUILTIN_EXPECT #ifndef HAVE___BUILTIN_EXPECT # define __builtin_expect(e, c) (e) #elif HAVE___BUILTIN_EXPECT == 2 # include <builtins.h> #endif ]) ])