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Diffstat (limited to 'm4/posix_memalign.m4')
| -rw-r--r-- | m4/posix_memalign.m4 | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/m4/posix_memalign.m4 b/m4/posix_memalign.m4 new file mode 100644 index 0000000..072e7cc --- /dev/null +++ b/m4/posix_memalign.m4 @@ -0,0 +1,50 @@ +# posix_memalign.m4 serial 1 +dnl Copyright (C) 2020-2022 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_FUNC_POSIX_MEMALIGN], +[ + AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + + dnl Persuade glibc <stdlib.h> to declare posix_memalign(). + AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) + + AC_CHECK_FUNCS_ONCE([posix_memalign]) + if test $ac_cv_func_posix_memalign = yes; then + dnl On OpenBSD 6.1, posix_memalign (&p, 32, 2406) returns a pointer + dnl that is not a multiple of 32. + AC_CACHE_CHECK([whether posix_memalign works for large alignments], + [gl_cv_func_posix_memalign_works], + [AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[#include <stdlib.h> + ]], + [[void *p; + if (posix_memalign (&p, 32, 2406) == 0) + if (((unsigned long)p % 32) != 0) + return 1; + return 0; + ]]) + ], + [gl_cv_func_posix_memalign_works=yes], + [gl_cv_func_posix_memalign_works=no], + [case "$host_os" in + # Guess no on OpenBSD. + openbsd*) gl_cv_func_posix_memalign_works="guessing no" ;; + # If we don't know, obey --enable-cross-guesses. + *) gl_cv_func_posix_memalign_works="$gl_cross_guess_normal" ;; + esac + ]) + ]) + case "$gl_cv_func_posix_memalign_works" in + *yes) ;; + *) REPLACE_POSIX_MEMALIGN=1 ;; + esac + else + dnl The system does not have posix_memalign. + HAVE_POSIX_MEMALIGN=0 + fi +]) |