ldbl-128ibm-compat: Add regular character printing functions

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.

Reviewed-By: Florian Weimer <fweimer@redhat.com>
Reviewed-By: Joseph Myers <joseph@codesourcery.com>
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>

1 files changed, 35 insertions, 0 deletions

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)