diff mbox

[v2,01/30] ldbl-128ibm-compat: Add regular character printing functions

Message ID 20191025153410.15405-2-gabriel@inconstante.net.br
State New
Headers show

Commit Message

Gabriel F. T. Gomes Oct. 25, 2019, 3:33 p.m. UTC
From: "Gabriel F. T. Gomes" <gabrielftg@linux.ibm.com>

No changes since v1.

-- 8< --
The 'mode' argument to __vfprintf_internal allows the selection of the
long double format for all long double arguments requested by the format
string.  Currently, there are two possibilities: long double with the
same format as double or long double as something else.  The 'something
else' format varies between architectures, and on powerpc64le, it means
IBM Extended Precision format.

In preparation for the third option of long double format on
powerpc64le, this patch uses the new mode mask,
PRINTF_LDBL_USES_FLOAT128, which tells __vfprintf_internal to save the
floating-point values into variables of type __float128 and adjusts the
parameters to __printf_fp and __printf_fphex as if it was a call from
strfromf128.

Many files from the stdio-common, wcsmbs, argp, misc, and libio
directories will have IEEE binary128 counterparts.  Setting the correct
compiler options to these files (original and counterparts) would
produce a large amount of repetitive Makefile rules.  To avoid this
repetition, this patch adds a Makefile routine that iterates over the
files adding or removing the appropriate flags.

Tested for powerpc64le.
---
 elf/tst-addr1.c                               |   7 +-
 sysdeps/ieee754/ldbl-128ibm-compat/Makefile   |  47 ++++-
 sysdeps/ieee754/ldbl-128ibm-compat/Versions   |  15 ++
 .../ldbl-128ibm-compat/ieee128-asprintf.c     |  35 ++++
 .../ldbl-128ibm-compat/ieee128-dprintf.c      |  34 ++++
 .../ldbl-128ibm-compat/ieee128-fprintf.c      |  34 ++++
 .../ldbl-128ibm-compat/ieee128-printf.c       |  35 ++++
 .../ldbl-128ibm-compat/ieee128-snprintf.c     |  35 ++++
 .../ldbl-128ibm-compat/ieee128-sprintf.c      |  35 ++++
 .../ldbl-128ibm-compat/ieee128-vasprintf.c    |  27 +++
 .../ldbl-128ibm-compat/ieee128-vdprintf.c     |  26 +++
 .../ldbl-128ibm-compat/ieee128-vfprintf.c     |  26 +++
 .../ldbl-128ibm-compat/ieee128-vprintf.c      |  27 +++
 .../ldbl-128ibm-compat/ieee128-vsnprintf.c    |  28 +++
 .../ldbl-128ibm-compat/ieee128-vsprintf.c     |  27 +++
 .../ldbl-128ibm-compat/test-printf-ibm128.c   |   1 +
 .../ldbl-128ibm-compat/test-printf-ieee128.c  |   1 +
 .../test-printf-ldbl-compat.c                 | 171 ++++++++++++++++++
 .../powerpc64/le/ldbl-128ibm-compat-abi.h     |   8 +
 19 files changed, 617 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-asprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-dprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-printf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vasprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vdprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vfprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsnprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsprintf.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
 create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c
 create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h

Comments

Paul E Murphy Oct. 29, 2019, 3:42 p.m. UTC | #1
On 10/25/19 10:33 AM, Gabriel F. T. Gomes wrote:
> From: "Gabriel F. T. Gomes" <gabrielftg@linux.ibm.com>
> 
> No changes since v1.
> 
> -- 8< --
> The 'mode' argument to __vfprintf_internal allows the selection of the
> long double format for all long double arguments requested by the format
> string.  Currently, there are two possibilities: long double with the
> same format as double or long double as something else.  The 'something
> else' format varies between architectures, and on powerpc64le, it means
> IBM Extended Precision format.
> 
> In preparation for the third option of long double format on
> powerpc64le, this patch uses the new mode mask,
> PRINTF_LDBL_USES_FLOAT128, which tells __vfprintf_internal to save the
> floating-point values into variables of type __float128 and adjusts the
> parameters to __printf_fp and __printf_fphex as if it was a call from
> strfromf128.
> 
> Many files from the stdio-common, wcsmbs, argp, misc, and libio
> directories will have IEEE binary128 counterparts.  Setting the correct
> compiler options to these files (original and counterparts) would
> produce a large amount of repetitive Makefile rules.  To avoid this
> repetition, this patch adds a Makefile routine that iterates over the
> files adding or removing the appropriate flags.
> 
> Tested for powerpc64le.
> ---
>   elf/tst-addr1.c                               |   7 +-
>   sysdeps/ieee754/ldbl-128ibm-compat/Makefile   |  47 ++++-
>   sysdeps/ieee754/ldbl-128ibm-compat/Versions   |  15 ++
>   .../ldbl-128ibm-compat/ieee128-asprintf.c     |  35 ++++
>   .../ldbl-128ibm-compat/ieee128-dprintf.c      |  34 ++++
>   .../ldbl-128ibm-compat/ieee128-fprintf.c      |  34 ++++
>   .../ldbl-128ibm-compat/ieee128-printf.c       |  35 ++++
>   .../ldbl-128ibm-compat/ieee128-snprintf.c     |  35 ++++
>   .../ldbl-128ibm-compat/ieee128-sprintf.c      |  35 ++++
>   .../ldbl-128ibm-compat/ieee128-vasprintf.c    |  27 +++
>   .../ldbl-128ibm-compat/ieee128-vdprintf.c     |  26 +++
>   .../ldbl-128ibm-compat/ieee128-vfprintf.c     |  26 +++
>   .../ldbl-128ibm-compat/ieee128-vprintf.c      |  27 +++
>   .../ldbl-128ibm-compat/ieee128-vsnprintf.c    |  28 +++
>   .../ldbl-128ibm-compat/ieee128-vsprintf.c     |  27 +++
>   .../ldbl-128ibm-compat/test-printf-ibm128.c   |   1 +
>   .../ldbl-128ibm-compat/test-printf-ieee128.c  |   1 +
>   .../test-printf-ldbl-compat.c                 | 171 ++++++++++++++++++
>   .../powerpc64/le/ldbl-128ibm-compat-abi.h     |   8 +
>   19 files changed, 617 insertions(+), 2 deletions(-)
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-asprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-dprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-printf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vasprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vdprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vfprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsnprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsprintf.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
>   create mode 100644 sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c
>   create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h
> 
> diff --git a/elf/tst-addr1.c b/elf/tst-addr1.c
> index 68ff74aabd..ee81acda5b 100644
> --- a/elf/tst-addr1.c
> +++ b/elf/tst-addr1.c
> @@ -19,7 +19,12 @@ do_test (void)
>   		rather than in the binary.  printf and _IO_printf
>   		are aliased and which one comes first in the
>   		hash table is up to the linker.  */
> -	     && strcmp (i.dli_sname, "_IO_printf") != 0);
> +	     && strcmp (i.dli_sname, "_IO_printf") != 0
> +	     /* On architectures where long double with IEEE binary128
> +		format is available as a third option (initially, true
> +		for powerpc64le), printf may be redirected to
> +		__printfieee128.  */
> +	     && strcmp (i.dli_sname, "__printfieee128") != 0);

Should there be a guard against this test for architectures which will 
never support this symbol?

>   }
> 
>   #include <support/test-driver.c>
> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/Makefile b/sysdeps/ieee754/ldbl-128ibm-compat/Makefile
> index 412beb5b5c..89059f37e2 100644
> --- a/sysdeps/ieee754/ldbl-128ibm-compat/Makefile
> +++ b/sysdeps/ieee754/ldbl-128ibm-compat/Makefile
OK, those make rules take a little time to digest.

> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/Versions b/sysdeps/ieee754/ldbl-128ibm-compat/Versions
> index 4aa34dbe59..6a27befed2 100644
> --- a/sysdeps/ieee754/ldbl-128ibm-compat/Versions
> +++ b/sysdeps/ieee754/ldbl-128ibm-compat/Versions

OK. This seems to be the accepted approach to expose the new ieee128 ABI.

> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-asprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-asprintf.c

... the ieee128-*printf.c wrappers all look OK.

> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c
> new file mode 100644
> index 0000000000..5de4ea3e7f
> --- /dev/null
> +++ b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c
> @@ -0,0 +1 @@
> +#include <test-printf-ldbl-compat.c>
> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
> new file mode 100644
> index 0000000000..5de4ea3e7f
> --- /dev/null
> +++ b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
> @@ -0,0 +1 @@
> +#include <test-printf-ldbl-compat.c>
> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c
...
> +  long double ld = -1;

Is this the best value to use for compat tests? Would a value which 
produces unique output for the respective format if the wrong compiler 
flags are used? Or, maybe an extra header in *-ibm128.c and *-ieee128.c 
variants to sanity check __LDBL_MANT_DIG__?


> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h
> new file mode 100644
> index 0000000000..285216b231
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h
> @@ -0,0 +1,8 @@
> +/* ABI version for long double switch to IEEE 128-bit floating point..
> +   This is used by the Versions and math_ldbl_opt.h files in
> +   sysdeps/ieee754/ldbl-128ibm-compat/.  It gives the ABI version where
> +   long double == ibm128 was replaced with long double == _Float128
> +   for libm *l functions and libc functions using long double.  */
> +
> +#define LDBL_IBM128_VERSION		GLIBC_2.31
> +#define LDBL_IBM128_COMPAT_VERSION	GLIBC_2_31
> 

Should this part of the change be held off until all ldbl == ieee128 
changes are in?
Gabriel F. T. Gomes Oct. 30, 2019, 4:10 p.m. UTC | #2
Hi, Paul,

On Tue, 29 Oct 2019, Paul E Murphy wrote:

>On 10/25/19 10:33 AM, Gabriel F. T. Gomes wrote:
>>
>> diff --git a/elf/tst-addr1.c b/elf/tst-addr1.c
>> index 68ff74aabd..ee81acda5b 100644
>> --- a/elf/tst-addr1.c
>> +++ b/elf/tst-addr1.c
>> @@ -19,7 +19,12 @@ do_test (void)
>>   		rather than in the binary.  printf and _IO_printf
>>   		are aliased and which one comes first in the
>>   		hash table is up to the linker.  */
>> -	     && strcmp (i.dli_sname, "_IO_printf") != 0);
>> +	     && strcmp (i.dli_sname, "_IO_printf") != 0
>> +	     /* On architectures where long double with IEEE binary128
>> +		format is available as a third option (initially, true
>> +		for powerpc64le), printf may be redirected to
>> +		__printfieee128.  */
>> +	     && strcmp (i.dli_sname, "__printfieee128") != 0);  
>
>Should there be a guard against this test for architectures which will 
>never support this symbol?

Yeah, sounds good so that we avoid unintended redirections.  On the other
hand, this is also a residue from our initial development effort, when we
added -mabi=ieeelongdouble to a lot more files, than what I have today.
Today, this test case is not built with -mabi=ieeelongdouble, so I think
this hunk should simply go away.

>> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
>> new file mode 100644
>> index 0000000000..5de4ea3e7f
>> --- /dev/null
>> +++ b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
>> @@ -0,0 +1 @@
>> +#include <test-printf-ldbl-compat.c>
>> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c  
>...
>> +  long double ld = -1;  
>
>Is this the best value to use for compat tests? Would a value which 
>produces unique output for the respective format if the wrong compiler 
>flags are used? Or, maybe an extra header in *-ibm128.c and *-ieee128.c 
>variants to sanity check __LDBL_MANT_DIG__?

My rationale for using this value is that it makes it simple to debug when
something goes wrong.  Since the implementation for these functions reuse
the code paths added for _Float128, I didn't think it would be useful to
test for more values again (the _Float128 implementation already checks
for many values).  This test is telling me that the parameters are being
passed and read correctly (on the powerpc64le case, that they are going
through VSX registers, as opposed to two FP registers for IBM long double).

>> +   This is used by the Versions and math_ldbl_opt.h files in
>> +   sysdeps/ieee754/ldbl-128ibm-compat/.  It gives the ABI version where
>> +   long double == ibm128 was replaced with long double == _Float128
>> +   for libm *l functions and libc functions using long double.  */
>> +
>> +#define LDBL_IBM128_VERSION		GLIBC_2.31
>> +#define LDBL_IBM128_COMPAT_VERSION	GLIBC_2_31
>
>Should this part of the change be held off until all ldbl == ieee128 
>changes are in?

I guess you're right. I moved it to the last commit, which actually adds
sysdeps/ieee754/ldbl-128ibm-compat to the Implies file.


Thanks,
Gabriel
diff mbox

Patch

diff --git a/elf/tst-addr1.c b/elf/tst-addr1.c
index 68ff74aabd..ee81acda5b 100644
--- a/elf/tst-addr1.c
+++ b/elf/tst-addr1.c
@@ -19,7 +19,12 @@  do_test (void)
 		rather than in the binary.  printf and _IO_printf
 		are aliased and which one comes first in the
 		hash table is up to the linker.  */
-	     && strcmp (i.dli_sname, "_IO_printf") != 0);
+	     && strcmp (i.dli_sname, "_IO_printf") != 0
+	     /* On architectures where long double with IEEE binary128
+		format is available as a third option (initially, true
+		for powerpc64le), printf may be redirected to
+		__printfieee128.  */
+	     && strcmp (i.dli_sname, "__printfieee128") != 0);
 }
 
 #include <support/test-driver.c>
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/Makefile b/sysdeps/ieee754/ldbl-128ibm-compat/Makefile
index 412beb5b5c..89059f37e2 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/Makefile
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/Makefile
@@ -1,5 +1,30 @@ 
 ifeq ($(subdir),stdio-common)
-routines += ieee128-printf_size
+ldbl-extra-routines += printf_size \
+		       asprintf \
+		       dprintf \
+		       fprintf \
+		       printf \
+		       snprintf \
+		       sprintf \
+		       vasprintf \
+		       vdprintf \
+		       vfprintf \
+		       vprintf \
+		       vsnprintf \
+		       vsprintf
+
+# Printing long double values with IEEE binary128 format reuses part
+# of the internal float128 implementation (__printf_fp, __printf_fphex,
+# and __float128 variables and union members).  Thus, the compilation of
+# the following functions, must have -mfloat128 and -mabi=ibmlongdouble
+# passed to the compiler.
+CFLAGS-vfprintf-internal.c += -mfloat128 -mabi=ibmlongdouble
+
+# Basic tests for the implementation of long double with IEEE binary128
+# format and for the related redirections in installed headers.
+tests-internal += test-printf-ieee128 test-printf-ibm128
+CFLAGS-test-printf-ieee128.c += -mfloat128 -mabi=ieeelongdouble -Wno-psabi
+CFLAGS-test-printf-ibm128.c += -mabi=ibmlongdouble -Wno-psabi
 
 tests-internal += test-printf-size-ieee128 test-printf-size-ibm128
 CFLAGS-test-printf-size-ieee128.c += -mfloat128 -mabi=ieeelongdouble -Wno-psabi
@@ -20,3 +45,23 @@  $(objpfx)test-printf-size-ibm128.out: \
 	$(SHELL) $^ '$(test-program-prefix)' $@; \
 	$(evaluate-test)
 endif
+
+# Add IEEE binary128 files as make targets.
+routines += $(foreach r,$(ldbl-extra-routines),ieee128-$(r))
+
+# On powerpc64le, the routines responsible for converting between long
+# double and string (e.g.: printf, scanf, strtold, strfroml) default to
+# IBM long double mode.  When support for TS 18661-3 was added, several
+# internal functions were modified so that they could also handle
+# floating-point variables with IEEE binary128 format, but as an
+# additional type, _Float128.
+#
+# The following rule ensures that the string conversion routines will
+# always be built in IBM long double mode, with additional support for
+# IEEE binary128, through the use of -mabi=ibmlongdouble and -mfloat128.
+ldbl-ibm128-files := $(objpfx)test-%-ibm128^ \
+		     $(foreach r,$(ldbl-extra-routines),$(objpfx)$(r)^) \
+		     $(foreach r,$(ldbl-extra-routines),$(objpfx)$(r)-internal^)
+obj-suf-foreach = $(foreach suf,$(all-object-suffixes),$(subst ^,$(suf),$(1)))
+$(call obj-suf-foreach,$(ldbl-ibm128-files)): \
+  sysdep-CFLAGS += -mabi=ibmlongdouble
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/Versions b/sysdeps/ieee754/ldbl-128ibm-compat/Versions
index 4aa34dbe59..6a27befed2 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/Versions
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/Versions
@@ -120,4 +120,19 @@  libc {
     __wcstoieee128_l;
 
     __printf_sizeieee128;
+
+    __asprintfieee128;
+    __dprintfieee128;
+    __fprintfieee128;
+    __printfieee128;
+    __snprintfieee128;
+    __sprintfieee128;
+
+    __vasprintfieee128;
+    __vdprintfieee128;
+    __vfprintfieee128;
+    __vprintfieee128;
+    __vsnprintfieee128;
+    __vsprintfieee128;
   }
+}
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-asprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-asprintf.c
new file mode 100644
index 0000000000..35c909b124
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-asprintf.c
@@ -0,0 +1,35 @@ 
+/* Wrapper for asprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdarg.h>
+#include <libio/libioP.h>
+
+extern int
+___ieee128_asprintf (char **string_ptr, const char *format, ...)
+{
+  va_list ap;
+  int done;
+
+  va_start (ap, format);
+  done = __vasprintf_internal (string_ptr, format, ap,
+			       PRINTF_LDBL_USES_FLOAT128);
+  va_end (ap);
+
+  return done;
+}
+strong_alias (___ieee128_asprintf, __asprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-dprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-dprintf.c
new file mode 100644
index 0000000000..0c66c9758b
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-dprintf.c
@@ -0,0 +1,34 @@ 
+/* Wrapper for dprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdarg.h>
+#include <libio/libioP.h>
+
+extern int
+___ieee128_dprintf (int d, const char *format, ...)
+{
+  va_list ap;
+  int done;
+
+  va_start (ap, format);
+  done = __vdprintf_internal (d, format, ap, PRINTF_LDBL_USES_FLOAT128);
+  va_end (ap);
+
+  return done;
+}
+strong_alias (___ieee128_dprintf, __dprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fprintf.c
new file mode 100644
index 0000000000..b4b945092a
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fprintf.c
@@ -0,0 +1,34 @@ 
+/* Wrapper for fprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdarg.h>
+#include <libio/libioP.h>
+
+extern int
+___ieee128_fprintf (FILE *fp, const char *format, ...)
+{
+  va_list ap;
+  int done;
+
+  va_start (ap, format);
+  done = __vfprintf_internal (fp, format, ap, PRINTF_LDBL_USES_FLOAT128);
+  va_end (ap);
+
+  return done;
+}
+strong_alias (___ieee128_fprintf, __fprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-printf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-printf.c
new file mode 100644
index 0000000000..a1c6d7e0cf
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-printf.c
@@ -0,0 +1,35 @@ 
+/* Wrapper for printf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdarg.h>
+#include <libio/libioP.h>
+
+extern int
+___ieee128_printf (const char *format, ...)
+{
+  va_list ap;
+  int done;
+
+  va_start (ap, format);
+  done = __vfprintf_internal (stdout, format, ap,
+			      PRINTF_LDBL_USES_FLOAT128);
+  va_end (ap);
+
+  return done;
+}
+strong_alias (___ieee128_printf, __printfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
new file mode 100644
index 0000000000..2c09a75d59
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
@@ -0,0 +1,35 @@ 
+/* Wrapper for snprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdarg.h>
+#include <libio/libioP.h>
+
+extern int
+___ieee128_snprintf (char *s, size_t maxlen, const char *format, ...)
+{
+  va_list ap;
+  int done;
+
+  va_start (ap, format);
+  done = __vsnprintf_internal (s, maxlen, format, ap,
+			       PRINTF_LDBL_USES_FLOAT128);
+  va_end (ap);
+
+  return done;
+}
+strong_alias (___ieee128_snprintf, __snprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf.c
new file mode 100644
index 0000000000..727a403634
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-sprintf.c
@@ -0,0 +1,35 @@ 
+/* Wrapper for sprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdarg.h>
+#include <libio/libioP.h>
+
+extern int
+___ieee128_sprintf (char *s, const char *format, ...)
+{
+  va_list ap;
+  int done;
+
+  va_start (ap, format);
+  done = __vsprintf_internal (s, -1, format, ap,
+			      PRINTF_LDBL_USES_FLOAT128);
+  va_end (ap);
+
+  return done;
+}
+strong_alias (___ieee128_sprintf, __sprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vasprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vasprintf.c
new file mode 100644
index 0000000000..650e40affb
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vasprintf.c
@@ -0,0 +1,27 @@ 
+/* Wrapper for vasprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libio/libioP.h>
+
+extern int
+___ieee128_vasprintf (char **result_ptr, const char *format, va_list ap)
+{
+  return __vasprintf_internal (result_ptr, format, ap,
+			       PRINTF_LDBL_USES_FLOAT128);
+}
+strong_alias (___ieee128_vasprintf, __vasprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vdprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vdprintf.c
new file mode 100644
index 0000000000..88fbb3743d
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vdprintf.c
@@ -0,0 +1,26 @@ 
+/* Wrapper for vdprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libio/libioP.h>
+
+extern int
+___ieee128_vdprintf (int d, const char *format, va_list ap)
+{
+  return __vdprintf_internal (d, format, ap, PRINTF_LDBL_USES_FLOAT128);
+}
+strong_alias (___ieee128_vdprintf, __vdprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vfprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vfprintf.c
new file mode 100644
index 0000000000..ecc2fd36da
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vfprintf.c
@@ -0,0 +1,26 @@ 
+/* Wrapper for vfprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libio/libioP.h>
+
+extern int
+___ieee128_vfprintf (FILE *fp, const char *format, va_list ap)
+{
+  return __vfprintf_internal (fp, format, ap, PRINTF_LDBL_USES_FLOAT128);
+}
+strong_alias (___ieee128_vfprintf, __vfprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vprintf.c
new file mode 100644
index 0000000000..35347c60be
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vprintf.c
@@ -0,0 +1,27 @@ 
+/* Wrapper for vprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libio/libioP.h>
+
+extern int
+___ieee128_vprintf (const char *format, va_list ap)
+{
+  return __vfprintf_internal (stdout, format, ap,
+			      PRINTF_LDBL_USES_FLOAT128);
+}
+strong_alias (___ieee128_vprintf, __vprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsnprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsnprintf.c
new file mode 100644
index 0000000000..963b0cb228
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsnprintf.c
@@ -0,0 +1,28 @@ 
+/* Wrapper for vsnprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libio/libioP.h>
+
+extern int
+___ieee128_vsnprintf (char *string, size_t maxlen, const char *format,
+		      va_list ap)
+{
+  return __vsnprintf_internal (string, maxlen, format, ap,
+			       PRINTF_LDBL_USES_FLOAT128);
+}
+strong_alias (___ieee128_vsnprintf, __vsnprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsprintf.c
new file mode 100644
index 0000000000..822cc31c16
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-vsprintf.c
@@ -0,0 +1,27 @@ 
+/* Wrapper for vsprintf.  IEEE128 version.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <libio/libioP.h>
+
+extern int
+___ieee128_vsprintf (char *string, const char *format, va_list ap)
+{
+  return __vsprintf_internal (string, -1, format, ap,
+			      PRINTF_LDBL_USES_FLOAT128);
+}
+strong_alias (___ieee128_vsprintf, __vsprintfieee128)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c
new file mode 100644
index 0000000000..5de4ea3e7f
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ibm128.c
@@ -0,0 +1 @@ 
+#include <test-printf-ldbl-compat.c>
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
new file mode 100644
index 0000000000..5de4ea3e7f
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ieee128.c
@@ -0,0 +1 @@ 
+#include <test-printf-ldbl-compat.c>
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c
new file mode 100644
index 0000000000..939a6aad9c
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/test-printf-ldbl-compat.c
@@ -0,0 +1,171 @@ 
+/* Test for the long double variants of *printf functions.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+
+static void
+do_test_call_varg (FILE *stream, const char *format, ...)
+{
+  char *buffer = NULL;
+  char string[128];
+  va_list args;
+
+  printf ("%15s", "vasprintf: ");
+  va_start (args, format);
+  vasprintf (&buffer, format, args);
+  va_end (args);
+  if (buffer == NULL)
+    printf ("Error using vasprintf\n");
+  else
+    {
+      printf ("%s", buffer);
+      free (buffer);
+    }
+  printf ("\n");
+
+  printf ("%15s", "vdprintf: ");
+  va_start (args, format);
+  vdprintf (fileno (stream), format, args);
+  va_end (args);
+  printf ("\n");
+
+  printf ("%15s", "vfprintf: ");
+  va_start (args, format);
+  vfprintf (stream, format, args);
+  va_end (args);
+  printf ("\n");
+
+  printf ("%15s", "vprintf: ");
+  va_start (args, format);
+  vprintf (format, args);
+  va_end (args);
+  printf ("\n");
+
+  printf ("%15s", "vsnprintf: ");
+  va_start (args, format);
+  vsnprintf (string, 127, format, args);
+  va_end (args);
+  printf ("%s", string);
+  printf ("\n");
+
+  printf ("%15s", "vsprintf: ");
+  va_start (args, format);
+  vsprintf (string, format, args);
+  va_end (args);
+  printf ("%s", string);
+  printf ("\n");
+}
+
+static void
+do_test_call_rarg (FILE *stream, const char *format, long double ld)
+{
+  char *buffer = NULL;
+  char string[128];
+
+  printf ("%15s", "asprintf: ");
+  asprintf (&buffer, format, ld);
+  if (buffer == NULL)
+    printf ("Error using asprintf\n");
+  else
+    {
+      printf ("%s", buffer);
+      free (buffer);
+    }
+  printf ("\n");
+
+  printf ("%15s", "dprintf: ");
+  dprintf (fileno (stream), format, ld);
+  printf ("\n");
+
+  printf ("%15s", "fprintf: ");
+  fprintf (stream, format, ld);
+  printf ("\n");
+
+  printf ("%15s", "printf: ");
+  printf (format, ld);
+  printf ("\n");
+
+  printf ("%15s", "snprintf: ");
+  snprintf (string, 127, format, ld);
+  printf ("%s", string);
+  printf ("\n");
+
+  printf ("%15s", "sprintf: ");
+  sprintf (string, format, ld);
+  printf ("%s", string);
+  printf ("\n");
+}
+
+static void
+do_test_call (void)
+{
+  long double ld = -1;
+
+  /* Print in decimal notation.  */
+  do_test_call_rarg (stdout, "%.10Lf", ld);
+  do_test_call_varg (stdout, "%.10Lf", ld);
+
+  /* Print in hexadecimal notation.  */
+  do_test_call_rarg (stdout, "%.10La", ld);
+  do_test_call_varg (stdout, "%.10La", ld);
+}
+
+static int
+do_test (void)
+{
+  struct support_capture_subprocess result;
+  result = support_capture_subprocess ((void *) &do_test_call, NULL);
+
+  /* Compare against the expected output.  */
+  const char *expected =
+    "     asprintf: -1.0000000000\n"
+    "      dprintf: -1.0000000000\n"
+    "      fprintf: -1.0000000000\n"
+    "       printf: -1.0000000000\n"
+    "     snprintf: -1.0000000000\n"
+    "      sprintf: -1.0000000000\n"
+    "    vasprintf: -1.0000000000\n"
+    "     vdprintf: -1.0000000000\n"
+    "     vfprintf: -1.0000000000\n"
+    "      vprintf: -1.0000000000\n"
+    "    vsnprintf: -1.0000000000\n"
+    "     vsprintf: -1.0000000000\n"
+    "     asprintf: -0x1.0000000000p+0\n"
+    "      dprintf: -0x1.0000000000p+0\n"
+    "      fprintf: -0x1.0000000000p+0\n"
+    "       printf: -0x1.0000000000p+0\n"
+    "     snprintf: -0x1.0000000000p+0\n"
+    "      sprintf: -0x1.0000000000p+0\n"
+    "    vasprintf: -0x1.0000000000p+0\n"
+    "     vdprintf: -0x1.0000000000p+0\n"
+    "     vfprintf: -0x1.0000000000p+0\n"
+    "      vprintf: -0x1.0000000000p+0\n"
+    "    vsnprintf: -0x1.0000000000p+0\n"
+    "     vsprintf: -0x1.0000000000p+0\n";
+  TEST_COMPARE_STRING (expected, result.out.buffer);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h
new file mode 100644
index 0000000000..285216b231
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ldbl-128ibm-compat-abi.h
@@ -0,0 +1,8 @@ 
+/* ABI version for long double switch to IEEE 128-bit floating point..
+   This is used by the Versions and math_ldbl_opt.h files in
+   sysdeps/ieee754/ldbl-128ibm-compat/.  It gives the ABI version where
+   long double == ibm128 was replaced with long double == _Float128
+   for libm *l functions and libc functions using long double.  */
+
+#define LDBL_IBM128_VERSION		GLIBC_2.31
+#define LDBL_IBM128_COMPAT_VERSION	GLIBC_2_31