minix/lib/libc/arch/powerpc/gen/fpsetsticky.c

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/* $NetBSD: fpsetsticky.c,v 1.11 2011/07/10 21:18:47 matt Exp $ */
/*
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* 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>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: fpsetsticky.c,v 1.11 2011/07/10 21:18:47 matt Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <ieeefp.h>
#include <powerpc/fpu.h>
#define STICKYBITS (FPSCR_XX|FPSCR_ZX|FPSCR_UX|FPSCR_OX|FPSCR_VX)
#define INVBITS (FPSCR_VXCVI|FPSCR_VXSQRT|FPSCR_VXSOFT|FPSCR_VXVC|\
FPSCR_VXIMZ|FPSCR_VXZDZ|FPSCR_VXIDI|FPSCR_VXISI|\
FPSCR_VXSNAN)
#define STICKYSHFT 25
#ifdef __weak_alias
__weak_alias(fpsetsticky,_fpsetsticky)
#endif
fp_except
fpsetsticky(fp_except mask)
{
union {
double u_d;
uint64_t u_fpscr;
} ud;
fp_except old;
__asm volatile("mffs %0" : "=f"(ud.u_d));
old = ((uint32_t)ud.u_fpscr & STICKYBITS) >> STICKYSHFT;
/*
* FPSCR_VX (aka FP_X_INV) is not a sticky bit but a summary of the
* all the FPSCR_VX* sticky bits. So when FP_X_INV is cleared then
* clear all of those bits, likewise when it's set, set them all.
*/
if ((mask & FP_X_INV) == 0)
ud.u_fpscr &= ~INVBITS;
else
ud.u_fpscr |= INVBITS;
ud.u_fpscr &= ~STICKYBITS;
ud.u_fpscr |= ((uint32_t)mask << STICKYSHFT) & STICKYBITS;
/*
* Make FPSCR_FX reflect the presence of a set sticky bit (or not).
*/
if (ud.u_fpscr & (STICKYBITS|INVBITS))
ud.u_fpscr |= FPSCR_FX;
else
ud.u_fpscr &= ~FPSCR_FX;
/*
* Write back the fpscr.
*/
__asm volatile("mtfsf 0xff,%0" :: "f"(ud.u_d));
return (old);
}