freebsd-dev/lib/libc/powerpcspe/gen/fpsetround.c
Brandon Bergren 4f9ed3156c [PowerPC] Fix SPE floating point environment manipulation
Fix multiple problems in the powerpcspe floating point code.

* Endianness handling of the SPEFSCR in fenv.h was completely broken.
* Ensure SPEFSCR synchronization requirements are being met.

The __r.__d -> __r transformations were written by jhibbits.

Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D22526
2019-12-12 17:12:18 +00:00

54 lines
2.0 KiB
C

/* $NetBSD: fpsetround.c,v 1.3 2002/01/13 21:45:48 thorpej Exp $ */
/*
* Copyright (c) 2016 Justin Hibbits
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Dan Winship.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <machine/spr.h>
#include <ieeefp.h>
#ifndef _SOFT_FLOAT
fp_rnd_t
fpsetround(fp_rnd_t rnd_dir)
{
uint32_t fpscr;
fp_rnd_t old;
__asm__ __volatile("mfspr %0, %1" : "=r"(fpscr) : "K"(SPR_SPEFSCR) );
old = (fp_rnd_t)(fpscr & 0x3);
fpscr = (fpscr & 0xfffffffc) | rnd_dir;
__asm__ __volatile("mtspr %1, %0;isync" :: "r"(fpscr), "K"(SPR_SPEFSCR));
return (old);
}
#endif