freebsd-skq/lib/libc/riscv/_fpmath.h
Mitchell Horne bbfbc439f2 Fix printf(3) output of long doubles on RISC-V
When the RISC-V port was initially committed to FreeBSD, GCC would
generate 64-bit long doubles, and the definitions in _fpmath.h reflected
that. This was changed to 128-bit in GCC later that year [1], but the
definitions were never updated, despite the documented workaround. This
causes printf(3) and friends to interpret only the low 64-bits of a long
double in ldtoa, thereby printing incorrect values.

Update the definitions now that both clang and GCC generate 128-bit long
doubles.

[1] 54b21fc5ae

PR:		242067
Reported by:	Dennis Clarke <dclarke@blastwave.org>
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D25420
2020-06-29 19:30:35 +00:00

58 lines
2.0 KiB
C

/*-
* Copyright (c) 2002, 2003 David Schultz <das@FreeBSD.ORG>
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
union IEEEl2bits {
long double e;
struct {
unsigned long manl :64;
unsigned long manh :48;
unsigned int exp :15;
unsigned int sign :1;
} bits;
struct {
unsigned long manl :64;
unsigned long manh :48;
unsigned int expsign :16;
} xbits;
};
#define LDBL_NBIT 0
#define LDBL_IMPLICIT_NBIT
#define mask_nbit_l(u) ((void)0)
#define LDBL_MANH_SIZE 48
#define LDBL_MANL_SIZE 64
#define LDBL_TO_ARRAY32(u, a) do { \
(a)[0] = (uint32_t)(u).bits.manl; \
(a)[1] = (uint32_t)((u).bits.manl >> 32); \
(a)[2] = (uint32_t)(u).bits.manh; \
(a)[3] = (uint32_t)((u).bits.manh >> 32); \
} while(0)