ldbl-128ibm-compat: Add strfmon_l with IEEE long double format

Similarly to what has been done for printf-like functions, more
specifically to the internal implementation in __vfprintf_internal, this
patch extends __vstrfmon_l_internal to deal with long double values with
binary128 format (as a third format option and reusing the float128
implementation).

Tested for powerpc64le, powerpc64, x86_64, and with build-many-glibcs.

Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>

include/monetary.h

@@ -15,5 +15,6 @@ __vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
    same format as double, in which case the flag should be set to one,
    or as another format, otherwise.  */
 #define STRFMON_LDBL_IS_DBL 0x0001
+#define STRFMON_LDBL_USES_FLOAT128  0x0002
 
 #endif

stdlib/strfmon_l.c

@@ -29,6 +29,7 @@
 #include <stdio.h>
 #include <string.h>
 #include "../locale/localeinfo.h"
+#include <bits/floatn.h>
 
 
 #define out_char(Ch)							      \
@@ -96,6 +97,9 @@ __vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
       {
 	double dbl;
 	long double ldbl;
+#if __HAVE_DISTINCT_FLOAT128
+	_Float128 f128;
+#endif
       }
       fpnum;
       int int_format;
@@ -106,6 +110,7 @@ __vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
       int group;
       char pad;
       int is_long_double;
+      int is_binary128;
       int p_sign_posn;
       int n_sign_posn;
       int sign_posn;
@@ -150,6 +155,7 @@ __vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
       group = 1;			/* Print digits grouped.  */
       pad = ' ';			/* Fill character is <SP>.  */
       is_long_double = 0;		/* Double argument by default.  */
+      is_binary128 = 0;			/* Long double argument by default.  */
       p_sign_posn = -2;			/* This indicates whether the */
       n_sign_posn = -2;			/* '(' flag is given.  */
       width = -1;			/* No width specified so far.  */
@@ -270,6 +276,10 @@ __vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
 	  ++fmt;
 	  if (__glibc_likely ((flags & STRFMON_LDBL_IS_DBL) == 0))
 	    is_long_double = 1;
+#if __HAVE_DISTINCT_FLOAT128
+	  if (__glibc_likely ((flags & STRFMON_LDBL_USES_FLOAT128) != 0))
+	    is_binary128 = is_long_double;
+#endif
 	}
 
       /* Handle format specifier.  */
@@ -324,10 +334,22 @@ __vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
       /* Now it's time to get the value.  */
       if (is_long_double == 1)
 	{
-	  fpnum.ldbl = va_arg (ap, long double);
-	  is_negative = fpnum.ldbl < 0;
-	  if (is_negative)
-	    fpnum.ldbl = -fpnum.ldbl;
+#if __HAVE_DISTINCT_FLOAT128
+	  if (is_binary128 == 1)
+	    {
+	      fpnum.f128 = va_arg (ap, _Float128);
+	      is_negative = fpnum.f128 < 0;
+	      if (is_negative)
+	        fpnum.f128 = -fpnum.f128;
+	    }
+	  else
+#endif
+	  {
+	    fpnum.ldbl = va_arg (ap, long double);
+	    is_negative = fpnum.ldbl < 0;
+	    if (is_negative)
+	      fpnum.ldbl = -fpnum.ldbl;
+	  }
 	}
       else
 	{
@@ -517,6 +539,7 @@ __vstrfmon_l_internal (char *s, size_t maxsize, locale_t loc,
       info.width = left_prec + (right_prec ? (right_prec + 1) : 0);
       info.spec = 'f';
       info.is_long_double = is_long_double;
+      info.is_binary128 = is_binary128;
       info.group = group;
       info.pad = pad;
       info.extra = 1;		/* This means use values from LC_MONETARY.  */

sysdeps/ieee754/ldbl-128ibm-compat/Makefile

@@ -214,6 +214,18 @@ CFLAGS-test-syslog-chk-ieee128.c += -mfloat128 -mabi=ieeelongdouble -Wno-psabi
 CFLAGS-test-syslog-chk-ibm128.c += -mabi=ibmlongdouble -Wno-psabi
 endif
 
+ifeq ($(subdir),stdlib)
+ldbl-extra-routines += strfmon strfmon_l
+
+# 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 files, must have -mfloat128 passed to the compiler.
+# Also, guarantee that they are compiled in IBM long double mode.
+CFLAGS-strfmon.c += -mfloat128 -mabi=ibmlongdouble
+CFLAGS-strfmon_l.c += -mfloat128 -mabi=ibmlongdouble
+endif
+
 # Add IEEE binary128 files as make targets.
 routines += $(foreach r,$(ldbl-extra-routines),ieee128-$(r))
 

sysdeps/ieee754/ldbl-128ibm-compat/Versions

@@ -205,5 +205,8 @@ libc {
 
     __errorieee128;
     __error_at_lineieee128;
+
+    __strfmonieee128;
+    __strfmon_lieee128;
   }
 }

sysdeps/ieee754/ldbl-128ibm-compat/ieee128-strfmon.c

@@ -0,0 +1,35 @@
+/* Wrapper for strfmon.  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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <monetary.h>
+#include <stdarg.h>
+#include <locale/localeinfo.h>
+
+ssize_t
+___ieee128_strfmon (char *s, size_t maxsize, const char *format, ...)
+{
+  va_list ap;
+  ssize_t res;
+
+  va_start (ap, format);
+  res = __vstrfmon_l_internal (s, maxsize, _NL_CURRENT_LOCALE,
+                               format, ap, STRFMON_LDBL_USES_FLOAT128);
+  va_end (ap);
+  return res;
+}
+weak_alias (___ieee128_strfmon, __strfmonieee128)

sysdeps/ieee754/ldbl-128ibm-compat/ieee128-strfmon_l.c

@@ -0,0 +1,35 @@
+/* Wrapper for strfmon_l.  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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <monetary.h>
+#include <stdarg.h>
+#include <locale/localeinfo.h>
+
+ssize_t
+___ieee128_strfmon_l (char *s, size_t maxsize, locale_t loc, const char *format, ...)
+{
+  va_list ap;
+  ssize_t res;
+
+  va_start (ap, format);
+  res = __vstrfmon_l_internal (s, maxsize, loc,
+                               format, ap, STRFMON_LDBL_USES_FLOAT128);
+  va_end (ap);
+  return res;
+}
+weak_alias (___ieee128_strfmon_l, __strfmon_lieee128)