__float128 typeinfo
Marc Glisse
marc.glisse@inria.fr
Fri Jun 6 17:21:00 GMT 2014
On Fri, 6 Jun 2014, Jason Merrill wrote:
> On 06/06/2014 11:58 AM, Marc Glisse wrote:
>> On Fri, 6 Jun 2014, Jason Merrill wrote:
>>
>>> What's your rationale for keeping this in a separate version block
>>> rather than in 1.3.9 (like __int128)?
>>
>> Powerpc already has those symbols in CXXABI_LDBL_1.3 (for a type that
>> isn't __float128 but (de)mangles that way). That doesn't prevent from
>> using CXXABI_1.3.9 in the x86/ia64-specific file though, so I can do
>> that if you prefer. If a new target implements __float128 in 4.11 or
>> 4.12, they will have to refine the configure test and provide a
>> different .ver file to avoid adding symbols to an old version.
>
> Fair enough. Let's stick with your approach then, but drop the 1.3.9 from
> the name.
Ok. To help with the review, I am appending the updated patch (untested).
(if we add numeric_limits<__float128> later, I think it should go into
GLIBCXX_FLOAT128_1)
> Why is __float128 handled as a target type, anyway? I'd think it ought to be
> a standard type that just isn't supported on all targets, like __int128.
I don't know. Since it is implemented in software on all platforms as far
as I know, it shouldn't be that specific to a target. But it isn't just
__float128, on some targets my patch may start generating extra symbols
for half-floats (ARM) or __float80.
DJ Delorie's work on __intN may be a good direction for __floatN as well,
IIUC we will have a global list of 4 __intN types, and the target decides
the value of N for each of them, so we can refer to those type nodes in
common code but they are still target-specific. Or maybe there isn't
enough variety in float types to deserve this.
--
Marc Glisse
-------------- next part --------------
Index: gcc/cp/rtti.c
===================================================================
--- gcc/cp/rtti.c (revision 211311)
+++ gcc/cp/rtti.c (working copy)
@@ -1540,20 +1540,31 @@ emit_support_tinfos (void)
/*tag_scope=*/ts_current, false);
pop_abi_namespace ();
if (!COMPLETE_TYPE_P (bltn_type))
return;
dtor = CLASSTYPE_DESTRUCTORS (bltn_type);
if (!dtor || DECL_EXTERNAL (dtor))
return;
doing_runtime = 1;
for (ix = 0; fundamentals[ix]; ix++)
emit_support_tinfo_1 (*fundamentals[ix]);
+
+ /* Search for an extra floating point type like __float128. */
+ for (enum machine_mode mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
+ mode != VOIDmode;
+ mode = GET_MODE_WIDER_MODE (mode))
+ {
+ tree type = c_common_type_for_mode (mode, false);
+ if (type && type != float_type_node && type != double_type_node
+ && type != long_double_type_node)
+ emit_support_tinfo_1 (type);
+ }
}
/* Finish a type info decl. DECL_PTR is a pointer to an unemitted
tinfo decl. Determine whether it needs emitting, and if so
generate the initializer. */
bool
emit_tinfo_decl (tree decl)
{
tree type = TREE_TYPE (DECL_NAME (decl));
Index: libstdc++-v3/config/abi/pre/float128.ver
===================================================================
--- libstdc++-v3/config/abi/pre/float128.ver (revision 0)
+++ libstdc++-v3/config/abi/pre/float128.ver (working copy)
@@ -0,0 +1,10 @@
+# Appended to version file.
+
+CXXABI_FLOAT128 {
+
+ # typeinfo and typeinfo name for __float128
+ _ZT[IS]g;
+ _ZT[IS]Pg;
+ _ZT[IS]PKg;
+
+};
Index: libstdc++-v3/configure
===================================================================
--- libstdc++-v3/configure (revision 211311)
+++ libstdc++-v3/configure (working copy)
@@ -15698,20 +15698,23 @@ $as_echo "#define _GLIBCXX_USE_FLOAT128
$as_echo "$enable_float128" >&6; }
rm -f conftest*
ac_ext=c
ac_cpp='$CPP $CPPFLAGS'
ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
ac_compiler_gnu=$ac_cv_c_compiler_gnu
+if test "$enable_float128" = yes; then
+ port_specific_symbol_files="$port_specific_symbol_files \$(top_srcdir)/config/abi/pre/float128.ver"
+fi
# Checks for compiler support that doesn't require linking.
# All these tests are for C++; save the language and the compiler flags.
# The CXXFLAGS thing is suspicious, but based on similar bits previously
# found in GLIBCXX_CONFIGURE.
ac_ext=cpp
ac_cpp='$CXXCPP $CPPFLAGS'
ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
Index: libstdc++-v3/configure.ac
===================================================================
--- libstdc++-v3/configure.ac (revision 211311)
+++ libstdc++-v3/configure.ac (working copy)
@@ -146,20 +146,23 @@ GLIBCXX_ENABLE_HOSTED
# Enable descriptive messages to standard output on termination.
GLIBCXX_ENABLE_VERBOSE
# Enable compiler support that doesn't require linking.
GLIBCXX_ENABLE_SJLJ_EXCEPTIONS
GLIBCXX_ENABLE_PCH($is_hosted)
GLIBCXX_ENABLE_THREADS
GLIBCXX_ENABLE_ATOMIC_BUILTINS
GLIBCXX_ENABLE_DECIMAL_FLOAT
GLIBCXX_ENABLE_INT128_FLOAT128
+if test "$enable_float128" = yes; then
+ port_specific_symbol_files="$port_specific_symbol_files \$(top_srcdir)/config/abi/pre/float128.ver"
+fi
# Checks for compiler support that doesn't require linking.
GLIBCXX_CHECK_COMPILER_FEATURES
# Enable all the variable C++ runtime options that don't require linking.
GLIBCXX_ENABLE_CSTDIO
GLIBCXX_ENABLE_CLOCALE
GLIBCXX_ENABLE_ALLOCATOR
GLIBCXX_ENABLE_CHEADERS($c_model) dnl c_model from configure.host
GLIBCXX_ENABLE_LONG_LONG([yes])
Index: libstdc++-v3/testsuite/util/testsuite_abi.cc
===================================================================
--- libstdc++-v3/testsuite/util/testsuite_abi.cc (revision 211311)
+++ libstdc++-v3/testsuite/util/testsuite_abi.cc (working copy)
@@ -206,47 +206,50 @@ check_version(symbol& test, bool added)
known_versions.push_back("CXXABI_1.3.1");
known_versions.push_back("CXXABI_1.3.2");
known_versions.push_back("CXXABI_1.3.3");
known_versions.push_back("CXXABI_1.3.4");
known_versions.push_back("CXXABI_1.3.5");
known_versions.push_back("CXXABI_1.3.6");
known_versions.push_back("CXXABI_1.3.7");
known_versions.push_back("CXXABI_1.3.8");
known_versions.push_back("CXXABI_1.3.9");
known_versions.push_back("CXXABI_TM_1");
+ known_versions.push_back("CXXABI_FLOAT128");
}
compat_list::iterator begin = known_versions.begin();
compat_list::iterator end = known_versions.end();
// Check for compatible version.
if (test.version_name.size())
{
compat_list::iterator it1 = find(begin, end, test.version_name);
compat_list::iterator it2 = find(begin, end, test.name);
if (it1 != end)
test.version_status = symbol::compatible;
else
test.version_status = symbol::incompatible;
// Check that added symbols are added in the latest pre-release version.
bool latestp = (test.version_name == "GLIBCXX_3.4.21"
|| test.version_name == "CXXABI_1.3.9"
+ || test.version_name == "CXXABI_FLOAT128"
|| test.version_name == "CXXABI_TM_1");
if (added && !latestp)
test.version_status = symbol::incompatible;
// Check that long double compatibility symbols demangled as
- // __float128 are put into some _LDBL_ version name.
+ // __float128 and regular __float128 symbols are put into some _LDBL_
+ // or _FLOAT128 version name.
if (added && test.demangled_name.find("__float128") != std::string::npos)
{
- // Has to be in _LDBL_ version name.
- if (test.version_name.find("_LDBL_") == std::string::npos)
+ if (test.version_name.find("_LDBL_") == std::string::npos
+ && test.version_name.find("_FLOAT128") == std::string::npos)
test.version_status = symbol::incompatible;
}
// Check for weak label.
if (it1 == end && it2 == end)
test.version_status = symbol::incompatible;
// Check that
// GLIBCXX_3.4
// GLIBCXX_3.4.5
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