/*-
* SPDX-License-Identifier: BSD-4-Clause
*
* Copyright (c) 2003 Peter Wemm.
* Copyright (c) 1990 Andrew Moore, Talke Studio
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: @(#) ieeefp.h 1.0 (Berkeley) 9/23/93
*/
#ifndef _X86_X86_IEEEFP_H_
#define _X86_X86_IEEEFP_H_
/* Deprecated historical FPU control interface */
/*
* IEEE floating point type, constant and function definitions.
* XXX: {FP,SSE}*FLD and {FP,SSE}*OFF are undocumented pollution.
*/
/*
* Rounding modes.
*/
typedef enum {
FP_RN=0, /* round to nearest */
FP_RM, /* round down towards minus infinity */
FP_RP, /* round up towards plus infinity */
FP_RZ /* truncate */
} fp_rnd_t;
/*
* Precision (i.e., rounding precision) modes.
*/
typedef enum {
FP_PS=0, /* 24 bit (single-precision) */
FP_PRS, /* reserved */
FP_PD, /* 53 bit (double-precision) */
FP_PE /* 64 bit (extended-precision) */
} fp_prec_t;
#define fp_except_t int
/*
* Exception bit masks.
*/
#define FP_X_INV 0x01 /* invalid operation */
#define FP_X_DNML 0x02 /* denormal */
#define FP_X_DZ 0x04 /* zero divide */
#define FP_X_OFL 0x08 /* overflow */
#define FP_X_UFL 0x10 /* underflow */
#define FP_X_IMP 0x20 /* (im)precision */
#define FP_X_STK 0x40 /* stack fault */
/*
* FPU control word bit-field masks.
*/
#define FP_MSKS_FLD 0x3f /* exception masks field */
#define FP_PRC_FLD 0x300 /* precision control field */
#define FP_RND_FLD 0xc00 /* rounding control field */
/*
* FPU status word bit-field masks.
*/
#define FP_STKY_FLD 0x3f /* sticky flags field */
/*
* FPU control word bit-field offsets (shift counts).
*/
#define FP_MSKS_OFF 0 /* exception masks offset */
#define FP_PRC_OFF 8 /* precision control offset */
#define FP_RND_OFF 10 /* rounding control offset */
/*
* FPU status word bit-field offsets (shift counts).
*/
#define FP_STKY_OFF 0 /* sticky flags offset */
#define __fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr)))
#define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr)))
#define __fnclex() __asm __volatile("fnclex")
#define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr)))
#define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr)))
#define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr)))
#define __ldmxcsr(addr) __asm __volatile("ldmxcsr %0" : : "m" (*(addr)))
#define __stmxcsr(addr) __asm __volatile("stmxcsr %0" : "=m" (*(addr)))
/*
* Load the control word. Be careful not to trap if there is a currently
* unmasked exception (ones that will become freshly unmasked are not a
* problem). This case must be handled by a save/restore of the
* environment or even of the full x87 state. Accessing the environment
* is very inefficient, so only do it when necessary.
*/
static __inline void
__fnldcw(unsigned short _cw, unsigned short _newcw)
{
struct {
unsigned _cw;
unsigned _other[6];
} _env;
unsigned short _sw;
if ((_cw & FP_MSKS_FLD) != FP_MSKS_FLD) {
__fnstsw(&_sw);
if (((_sw & ~_cw) & FP_STKY_FLD) != 0) {
__fnstenv(&_env);
_env._cw = _newcw;
__fldenv(&_env);
return;
}
}
__fldcw(&_newcw);
}
#endif/* _X86_X86_IEEEFP_H_ */
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