Changes since v1:
- Completely rewrite of the patch to set ENABLE_FLOAT128 at libstdc++
build time and undef _GLIBCXX_USE_FLOAT128 when building user code.
--- 8< ---
In order to use __float128 in C++ it's necessary to check if the
compiler enabled its support too when building user code.
This patch changes the behavior at libstdc++ build by setting
ENABLE_FLOAT128, which is used to set the value of the exported macro
_GLIBCXX_USE_FLOAT128.
2018-03-12 Tulio Magno Quites Machado Filho <tul...@linux.vnet.ibm.com>
PR libstdc++/84654
* acinclude.m4: Set ENABLE_FLOAT128 instead of _GLIBCXX_USE_FLOAT128.
* config.h.in: Remove references to _GLIBCXX_USE_FLOAT128.
* configure: Regenerate.
* include/Makefile.am: Replace the value of _GLIBCXX_USE_FLOAT128
based on ENABLE_FLOAT128.
* include/Makefile.in: Regenerate.
* include/bits/c++config: Define _GLIBCXX_USE_FLOAT128.
[!defined(__FLOAT128__) && !defined(__SIZEOF_FLOAT128__)]: Undefine
_GLIBCXX_USE_FLOAT128.
---
libstdc++-v3/acinclude.m4 | 5 ++---
libstdc++-v3/config.h.in | 3 ---
libstdc++-v3/include/Makefile.am | 13 ++++++++++++-
libstdc++-v3/include/bits/c++config | 6 ++++++
4 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 3bd669a..4f37b6a 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -3062,7 +3062,7 @@ dnl Note: also checks that the types aren't standard
types.
dnl
dnl Defines:
dnl _GLIBCXX_USE_INT128
-dnl _GLIBCXX_USE_FLOAT128
+dnl ENABLE_FLOAT128
dnl
AC_DEFUN([GLIBCXX_ENABLE_INT128_FLOAT128], [
@@ -3117,13 +3117,12 @@ EOF
AC_MSG_CHECKING([for __float128])
if AC_TRY_EVAL(ac_compile); then
- AC_DEFINE(_GLIBCXX_USE_FLOAT128, 1,
- [Define if __float128 is supported on this host.])
enable_float128=yes
else
enable_float128=no
fi
AC_MSG_RESULT($enable_float128)
+ GLIBCXX_CONDITIONAL(ENABLE_FLOAT128, test $enable_float128 = yes)
rm -f conftest*
AC_LANG_RESTORE
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index 5a0f067..765cedc 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -918,9 +918,6 @@
/* Define if fchmodat is available in <sys/stat.h>. */
#undef _GLIBCXX_USE_FCHMODAT
-/* Define if __float128 is supported on this host. */
-#undef _GLIBCXX_USE_FLOAT128
-
/* Defined if gettimeofday is available. */
#undef _GLIBCXX_USE_GETTIMEOFDAY
diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index 70a662f..ba5adda 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -1230,6 +1230,14 @@ stamp-allocator-new:
echo 0 > stamp-allocator-new
endif
+if ENABLE_FLOAT128
+stamp-float128:
+ echo 1 > stamp-float128
+else
+stamp-float128:
+ echo 0 > stamp-float128
+endif
+
# NB: The non-empty default ldbl_compat works around an AIX sed
# oddity, see libstdc++/31957 for details.
${host_builddir}/c++config.h: ${CONFIG_HEADER} \
@@ -1241,7 +1249,8 @@ ${host_builddir}/c++config.h: ${CONFIG_HEADER} \
stamp-extern-template \
stamp-dual-abi \
stamp-cxx11-abi \
- stamp-allocator-new
+ stamp-allocator-new \
+ stamp-float128
@date=`cat ${toplevel_srcdir}/gcc/DATESTAMP` ;\
release=`sed 's/^\([0-9]*\).*$$/\1/' ${toplevel_srcdir}/gcc/BASE-VER` ;\
ns_version=`cat stamp-namespace-version` ;\
@@ -1250,6 +1259,7 @@ ${host_builddir}/c++config.h: ${CONFIG_HEADER} \
dualabi=`cat stamp-dual-abi` ;\
cxx11abi=`cat stamp-cxx11-abi` ;\
allocatornew=`cat stamp-allocator-new` ;\
+ float128=`cat stamp-float128` ;\
ldbl_compat='s,g,g,' ;\
grep "^[ ]*#[ ]*define[ ][
]*_GLIBCXX_LONG_DOUBLE_COMPAT[ ][ ]*1[ ]*$$" \
${CONFIG_HEADER} > /dev/null 2>&1 \
@@ -1262,6 +1272,7 @@ ${host_builddir}/c++config.h: ${CONFIG_HEADER} \
-e "s,define _GLIBCXX_USE_DUAL_ABI, define _GLIBCXX_USE_DUAL_ABI
$$dualabi," \
-e "s,define _GLIBCXX_USE_CXX11_ABI, define _GLIBCXX_USE_CXX11_ABI
$$cxx11abi," \
-e "s,define _GLIBCXX_USE_ALLOCATOR_NEW, define
_GLIBCXX_USE_ALLOCATOR_NEW $$allocatornew," \
+ -e "s,define _GLIBCXX_USE_FLOAT128, define _GLIBCXX_USE_FLOAT128
$$float128," \
-e "$$ldbl_compat" \
< ${glibcxx_srcdir}/include/bits/c++config > $@ ;\
sed -e 's/HAVE_/_GLIBCXX_HAVE_/g' \
diff --git a/libstdc++-v3/include/bits/c++config
b/libstdc++-v3/include/bits/c++config
index 1eb4679..e345241 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -609,4 +609,10 @@ namespace std
# endif
#endif
+/* Define if __float128 is supported on this host. */
+#define _GLIBCXX_USE_FLOAT128
+#if !defined(__FLOAT128__) && !defined(__SIZEOF_FLOAT128__)
+#undef _GLIBCXX_USE_FLOAT128
+#endif
+
// End of prewritten config; the settings discovered at configure time follow.
--
2.9.5
