gcc/libgcc/config/rs6000/_kf_to_dd.c
Michael Meissner 781183595a Add conversions between _Float128 and Decimal.
This patch implements conversions between _Float128 and the 3 Decimal floating
types.  It does this by extendending the dfp-bit conversions to add a new
binary floating point type (KF), and doing the conversions in the same manner
as the other binary/decimal conversions.

For conversions from _Float128 to Decimal, this patch uses a function
(__sprintfkf) instead of the sprintf function to convert long double values to
strings.  The __sprintfkf function determines if GLIBC 2.32 or newer is used
and calls the IEEE 128-bit version of sprintf (__sprintfieee128).  If the GLIBC
is earlier than 2.32, the code will convert _Float128 to __ibm128 and then use
the normal sprintf to convert this value.

For conversions from Decimal to _Float128, this patch uses a function
(__strtokf) instead of strtold to convert the strings from the Decimal
conversion to long double.  The __strtokf function determines if GLIBC 2.32 or
newer is used, and if it is, calls the IEEE 128-bit version (__strtoieee128).
If the GLIBC is earlier than 2.32, the code will call strtold and convert the
__ibm128 value to _Float128.

These functions will primarily be used if/when the default PowerPC long double
type is changed to IEEE 128-bit, but they could also be used if the user
explicitly converts _Float128 to/from a Decimal type.

libgcc/
2021-02-22  Michael Meissner  <meissner@linux.ibm.com>

	* config/rs6000/_dd_to_kf.c: New file.
	* config/rs6000/_kf_to_dd.c: New file.
	* config/rs6000/_kf_to_sd.c: New file.
	* config/rs6000/_kf_to_td.c: New file.
	* config/rs6000/_sd_to_kf.c: New file.
	* config/rs6000/_sprintfkf.c: New file.
	* config/rs6000/_sprintfkf.h: New file.
	* config/rs6000/_strtokf.h: New file.
	* config/rs6000/_strtokf.c: New file.
	* config/rs6000/_td_to_kf.c: New file.
	* config/rs6000/quad-float128.h: Add new declarations.
	* config/rs6000/t-float128 (fp128_dec_funcs): New macro.
	(fp128_decstr_funcs): New macro.
	(ibm128_dec_funcs): New macro.
	(fp128_ppc_funcs): Add the new conversions.
	(fp128_dec_objs): Force Decimal <-> __float128 conversions to be
	compiled with -mabi=ieeelongdouble.
	(fp128_decstr_objs): Force __float128 <-> string conversions to be
	compiled with -mabi=ibmlongdouble.
	(ibm128_dec_objs): Force Decimal <-> __float128 conversions to be
	compiled with -mabi=ieeelongdouble.
	(FP128_CFLAGS_DECIMAL): New macro.
	(IBM128_CFLAGS_DECIMAL): New macro.
	* dfp-bit.c (DFP_TO_BFP): Add PowerPC _Float128 support.
	(BFP_TO_DFP): Add PowerPC _Float128 support.
	* dfp-bit.h (BFP_KIND): Add new binary floating point kind for
	IEEE 128-bit floating point.
	(DFP_TO_BFP): Add PowerPC _Float128 support.
	(BFP_TO_DFP): Add PowerPC _Float128 support.
	(BFP_SPRINTF): New macro.
2021-02-22 15:33:29 -05:00

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C

/* Copyright (C) 2021 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* _Float128 -> Decimal64 conversion. */
/* FINE_GRAINED_LIBRARIES is used so we can isolate just to tf_to_dd conversion
function from dp-bits.c. */
#define FINE_GRAINED_LIBRARIES 1
#define L_kf_to_dd 1
#define WIDTH 64
#if !defined(__LONG_DOUBLE_128__) || !defined(__LONG_DOUBLE_IEEE128__)
#error "Long double is not IEEE 128-bit"
#endif
/* Use dfp-bit.c to do the real work. */
#include "dfp-bit.c"