[lvm-devel] master - configure: check for __builtin_clz()
Bryn Reeves
bmr at fedoraproject.org
Tue Dec 13 21:04:31 UTC 2016
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=83a9cd5258fbd1acf293734cb4c3aba0f9ffcc9b
Commit: 83a9cd5258fbd1acf293734cb4c3aba0f9ffcc9b
Parent: 930b0b4c9e4ca466d955f8729644ef26a939937c
Author: Bryn M. Reeves <bmr at redhat.com>
AuthorDate: Mon Dec 12 12:03:16 2016 +0000
Committer: Bryn M. Reeves <bmr at redhat.com>
CommitterDate: Tue Dec 13 20:38:40 2016 +0000
configure: check for __builtin_clz()
---
aclocal.m4 | 171 ++++++++++++++++++++++++++++++++++++++++++++++++
configure | 44 ++++++++++++
configure.in | 1 +
include/configure.h.in | 3 +
4 files changed, 219 insertions(+), 0 deletions(-)
diff --git a/aclocal.m4 b/aclocal.m4
index 35107ac..1f02c2b 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -536,4 +536,175 @@ AC_DEFUN([AM_RUN_LOG],
echo "$as_me:$LINENO: \$? = $ac_status" >&AS_MESSAGE_LOG_FD
(exit $ac_status); }])
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_gcc_builtin.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_GCC_BUILTIN(BUILTIN)
+#
+# DESCRIPTION
+#
+# This macro checks if the compiler supports one of GCC's built-in
+# functions; many other compilers also provide those same built-ins.
+#
+# The BUILTIN parameter is the name of the built-in function.
+#
+# If BUILTIN is supported define HAVE_<BUILTIN>. Keep in mind that since
+# builtins usually start with two underscores they will be copied over
+# into the HAVE_<BUILTIN> definition (e.g. HAVE___BUILTIN_EXPECT for
+# __builtin_expect()).
+#
+# The macro caches its result in the ax_cv_have_<BUILTIN> variable (e.g.
+# ax_cv_have___builtin_expect).
+#
+# The macro currently supports the following built-in functions:
+#
+# __builtin_assume_aligned
+# __builtin_bswap16
+# __builtin_bswap32
+# __builtin_bswap64
+# __builtin_choose_expr
+# __builtin___clear_cache
+# __builtin_clrsb
+# __builtin_clrsbl
+# __builtin_clrsbll
+# __builtin_clz
+# __builtin_clzl
+# __builtin_clzll
+# __builtin_complex
+# __builtin_constant_p
+# __builtin_ctz
+# __builtin_ctzl
+# __builtin_ctzll
+# __builtin_expect
+# __builtin_ffs
+# __builtin_ffsl
+# __builtin_ffsll
+# __builtin_fpclassify
+# __builtin_huge_val
+# __builtin_huge_valf
+# __builtin_huge_vall
+# __builtin_inf
+# __builtin_infd128
+# __builtin_infd32
+# __builtin_infd64
+# __builtin_inff
+# __builtin_infl
+# __builtin_isinf_sign
+# __builtin_nan
+# __builtin_nand128
+# __builtin_nand32
+# __builtin_nand64
+# __builtin_nanf
+# __builtin_nanl
+# __builtin_nans
+# __builtin_nansf
+# __builtin_nansl
+# __builtin_object_size
+# __builtin_parity
+# __builtin_parityl
+# __builtin_parityll
+# __builtin_popcount
+# __builtin_popcountl
+# __builtin_popcountll
+# __builtin_powi
+# __builtin_powif
+# __builtin_powil
+# __builtin_prefetch
+# __builtin_trap
+# __builtin_types_compatible_p
+# __builtin_unreachable
+#
+# Unsuppored built-ins will be tested with an empty parameter set and the
+# result of the check might be wrong or meaningless so use with care.
+#
+# LICENSE
+#
+# Copyright (c) 2013 Gabriele Svelto <gabriele.svelto at gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 3
+
+AC_DEFUN([AX_GCC_BUILTIN], [
+ AS_VAR_PUSHDEF([ac_var], [ax_cv_have_$1])
+
+ AC_CACHE_CHECK([for $1], [ac_var], [
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([], [
+ m4_case([$1],
+ [__builtin_assume_aligned], [$1("", 0)],
+ [__builtin_bswap16], [$1(0)],
+ [__builtin_bswap32], [$1(0)],
+ [__builtin_bswap64], [$1(0)],
+ [__builtin_choose_expr], [$1(0, 0, 0)],
+ [__builtin___clear_cache], [$1("", "")],
+ [__builtin_clrsb], [$1(0)],
+ [__builtin_clrsbl], [$1(0)],
+ [__builtin_clrsbll], [$1(0)],
+ [__builtin_clz], [$1(0)],
+ [__builtin_clzl], [$1(0)],
+ [__builtin_clzll], [$1(0)],
+ [__builtin_complex], [$1(0.0, 0.0)],
+ [__builtin_constant_p], [$1(0)],
+ [__builtin_ctz], [$1(0)],
+ [__builtin_ctzl], [$1(0)],
+ [__builtin_ctzll], [$1(0)],
+ [__builtin_expect], [$1(0, 0)],
+ [__builtin_ffs], [$1(0)],
+ [__builtin_ffsl], [$1(0)],
+ [__builtin_ffsll], [$1(0)],
+ [__builtin_fpclassify], [$1(0, 1, 2, 3, 4, 0.0)],
+ [__builtin_huge_val], [$1()],
+ [__builtin_huge_valf], [$1()],
+ [__builtin_huge_vall], [$1()],
+ [__builtin_inf], [$1()],
+ [__builtin_infd128], [$1()],
+ [__builtin_infd32], [$1()],
+ [__builtin_infd64], [$1()],
+ [__builtin_inff], [$1()],
+ [__builtin_infl], [$1()],
+ [__builtin_isinf_sign], [$1(0.0)],
+ [__builtin_nan], [$1("")],
+ [__builtin_nand128], [$1("")],
+ [__builtin_nand32], [$1("")],
+ [__builtin_nand64], [$1("")],
+ [__builtin_nanf], [$1("")],
+ [__builtin_nanl], [$1("")],
+ [__builtin_nans], [$1("")],
+ [__builtin_nansf], [$1("")],
+ [__builtin_nansl], [$1("")],
+ [__builtin_object_size], [$1("", 0)],
+ [__builtin_parity], [$1(0)],
+ [__builtin_parityl], [$1(0)],
+ [__builtin_parityll], [$1(0)],
+ [__builtin_popcount], [$1(0)],
+ [__builtin_popcountl], [$1(0)],
+ [__builtin_popcountll], [$1(0)],
+ [__builtin_powi], [$1(0, 0)],
+ [__builtin_powif], [$1(0, 0)],
+ [__builtin_powil], [$1(0, 0)],
+ [__builtin_prefetch], [$1("")],
+ [__builtin_trap], [$1()],
+ [__builtin_types_compatible_p], [$1(int, int)],
+ [__builtin_unreachable], [$1()],
+ [m4_warn([syntax], [Unsupported built-in $1, the test may fail])
+ $1()]
+ )
+ ])],
+ [AS_VAR_SET([ac_var], [yes])],
+ [AS_VAR_SET([ac_var], [no])])
+ ])
+
+ AS_IF([test yes = AS_VAR_GET([ac_var])],
+ [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_$1), 1,
+ [Define to 1 if the system has the `$1' built-in function])], [])
+
+ AS_VAR_POPDEF([ac_var])
+])
+
m4_include([acinclude.m4])
diff --git a/configure b/configure
index c82a19b..1cb4b54 100755
--- a/configure
+++ b/configure
@@ -6321,6 +6321,50 @@ _ACEOF
esac
+
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __builtin_clz" >&5
+$as_echo_n "checking for __builtin_clz... " >&6; }
+if ${ax_cv_have___builtin_clz+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+
+ __builtin_clz(0)
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+ ax_cv_have___builtin_clz=yes
+else
+ ax_cv_have___builtin_clz=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_have___builtin_clz" >&5
+$as_echo "$ax_cv_have___builtin_clz" >&6; }
+
+ if test yes = $ax_cv_have___builtin_clz; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE___BUILTIN_CLZ 1
+_ACEOF
+
+fi
+
+
+
+
################################################################################
for ac_func in ftruncate gethostname getpagesize gettimeofday localtime_r \
memchr memset mkdir mkfifo munmap nl_langinfo realpath rmdir setenv \
diff --git a/configure.in b/configure.in
index cc77aab..8ec65c8 100644
--- a/configure.in
+++ b/configure.in
@@ -134,6 +134,7 @@ AC_TYPE_UINT8_T
AC_TYPE_UINT16_T
AC_TYPE_UINT32_T
AC_TYPE_UINT64_T
+AX_GCC_BUILTIN([__builtin_clz])
################################################################################
dnl -- Check for functions
diff --git a/include/configure.h.in b/include/configure.h.in
index 3c43bd5..cf8dc94 100644
--- a/include/configure.h.in
+++ b/include/configure.h.in
@@ -341,6 +341,9 @@
/* Define to 1 if the system has the type `ptrdiff_t'. */
#undef HAVE_PTRDIFF_T
+/* Define to 1 if the compiler has the `__builtin_clz` builtin. */
+#undef HAVE___BUILTIN_CLZ
+
/* Define to 1 if you have the <readline/history.h> header file. */
#undef HAVE_READLINE_HISTORY_H
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