freebsd-dev/sys/amd64/include/ieeefp.h
2003-11-08 04:39:22 +00:00

293 lines
8.2 KiB
C

/*-
* 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
* $FreeBSD$
*/
/*
* IEEE floating point type and constant definitions.
*/
#ifndef _MACHINE_IEEEFP_H_
#define _MACHINE_IEEEFP_H_
/*
* FP rounding modes
*/
typedef enum {
FP_RN=0, /* round to nearest */
FP_RM, /* round down to minus infinity */
FP_RP, /* round up to plus infinity */
FP_RZ /* truncate */
} fp_rnd_t;
/*
* FP 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
/*
* FP exception 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 */
/*
* FP registers
*/
#define FP_MSKS_REG 0 /* exception masks */
#define FP_PRC_REG 0 /* precision */
#define FP_RND_REG 0 /* direction */
#define FP_STKY_REG 1 /* sticky flags */
/*
* FP register bit field masks
*/
#define FP_MSKS_FLD 0x3f /* exception masks field */
#define FP_PRC_FLD 0x300 /* precision control field */
#define FP_RND_FLD 0xc00 /* round control field */
#define FP_STKY_FLD 0x3f /* sticky flags field */
/*
* SSE mxcsr register bit field masks
*/
#define SSE_STKY_FLD 0x3f /* exception flags */
#define SSE_DAZ_FLD 0x40 /* Denormals are zero */
#define SSE_MSKS_FLD 0x1f80 /* exception masks field */
#define SSE_RND_FLD 0x6000 /* rounding control */
#define SSE_FZ_FLD 0x8000 /* flush to zero on underflow */
/*
* FP register bit field offsets
*/
#define FP_MSKS_OFF 0 /* exception masks offset */
#define FP_PRC_OFF 8 /* precision control offset */
#define FP_RND_OFF 10 /* round control offset */
#define FP_STKY_OFF 0 /* sticky flags offset */
/*
* SSE mxcsr register bit field offsets
*/
#define SSE_STKY_OFF 0 /* exception flags offset */
#define SSE_DAZ_OFF 6 /* DAZ exception mask offset */
#define SSE_MSKS_OFF 7 /* other exception masks offset */
#define SSE_RND_OFF 13 /* rounding control offset */
#define SSE_FZ_OFF 15 /* flush to zero offset */
#if defined(__GNUC__) && !defined(__cplusplus)
#define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr)))
#define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr)))
#define __fldcw(addr) __asm __volatile("fldcw %0" : "=m" (*(addr)))
#define __fnstcw(addr) __asm __volatile("fnstcw %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)))
/*
* General notes about conflicting SSE vs FP status bits.
* This code assumes that software will not fiddle with the control
* bits of the SSE and x87 in such a way to get them out of sync and
* still expect this to work. Break this at your peril.
* Because I based this on the i386 port, the x87 state is used for
* the fpget*() functions, and is shadowed into the SSE state for
* the fpset*() functions. For dual source fpget*() functions, I
* merge the two together. I think.
*/
/* Set rounding control */
static __inline__ fp_rnd_t
__fpgetround(void)
{
unsigned short _cw;
__fnstcw(&_cw);
return ((_cw & FP_RND_FLD) >> FP_RND_OFF);
}
static __inline__ fp_rnd_t
__fpsetround(fp_rnd_t _m)
{
unsigned short _cw;
unsigned int _mxcsr;
fp_rnd_t _p;
__fnstcw(&_cw);
_p = (_cw & FP_RND_FLD) >> FP_RND_OFF;
_cw &= ~FP_RND_FLD;
_cw |= (_m << FP_RND_OFF) & FP_RND_FLD;
__fldcw(&_cw);
__stmxcsr(&_mxcsr);
_mxcsr &= ~SSE_RND_FLD;
_mxcsr |= (_m << SSE_RND_OFF) & SSE_RND_FLD;
__ldmxcsr(&_mxcsr);
return (_p);
}
/*
* Set precision for fadd/fsub/fsqrt etc x87 instructions
* There is no equivalent SSE mode or control.
*/
static __inline__ fp_prec_t
__fpgetprec(void)
{
unsigned short _cw;
__fnstcw(&_cw);
return ((_cw & FP_PRC_FLD) >> FP_PRC_OFF);
}
static __inline__ fp_prec_t
__fpsetprec(fp_rnd_t _m)
{
unsigned short _cw;
fp_prec_t _p;
__fnstcw(&_cw);
_p = (_cw & FP_PRC_FLD) >> FP_PRC_OFF;
_cw &= ~FP_PRC_FLD;
_cw |= (_m << FP_PRC_OFF) & FP_PRC_FLD;
__fldcw(&_cw);
return (_p);
}
/*
* Look at the exception masks
* Note that x87 masks are inverse of the fp*() functions
* API. ie: mask = 1 means disable for x87 and SSE, but
* for the fp*() api, mask = 1 means enabled.
*/
static __inline__ fp_except_t
__fpgetmask(void)
{
unsigned short _cw;
__fnstcw(&_cw);
return ((~_cw) & FP_MSKS_FLD);
}
static __inline__ fp_except_t
__fpsetmask(fp_except_t _m)
{
unsigned short _cw;
unsigned int _mxcsr;
fp_except_t _p;
__fnstcw(&_cw);
_p = (~_cw) & FP_MSKS_FLD;
_cw &= ~FP_MSKS_FLD;
_cw |= (~_m) & FP_MSKS_FLD;
__fldcw(&_cw);
__stmxcsr(&_mxcsr);
/* XXX should we clear non-ieee SSE_DAZ_FLD and SSE_FZ_FLD ? */
_mxcsr &= ~SSE_MSKS_FLD;
_mxcsr |= ((~_m) << SSE_MSKS_OFF) & SSE_MSKS_FLD;
__ldmxcsr(&_mxcsr);
return (_p);
}
/* See which sticky exceptions are pending, and reset them */
static __inline__ fp_except_t
__fpgetsticky(void)
{
unsigned short _sw;
unsigned int _mxcsr;
fp_except_t _ex;
__fnstsw(&_sw);
_ex = _sw & FP_STKY_FLD;
__stmxcsr(&_mxcsr);
_ex |= _mxcsr & SSE_STKY_FLD;
return (_ex);
}
/* Note that this should really be called fpresetsticky() */
static __inline__ fp_except_t
__fpsetsticky(fp_except_t _m)
{
unsigned _env[7];
unsigned int _mxcsr;
fp_except_t _p;
__fnstenv(_env);
_p = _env[FP_STKY_REG] & _m;
__stmxcsr(&_mxcsr);
_p |= _mxcsr & SSE_STKY_FLD;
_env[FP_STKY_REG] &= ~_m;
__fldenv(_env);
_mxcsr &= ~_m;
__ldmxcsr(&_mxcsr);
return (_p);
}
#endif /* __GNUC__ && !__cplusplus */
#if !defined(__IEEEFP_NOINLINES__) && !defined(__cplusplus) && defined(__GNUC__)
#define fpgetround() __fpgetround()
#define fpsetround(_m) __fpsetround(_m)
#define fpgetprec() __fpgetprec()
#define fpsetprec(_m) __fpsetprec(_m)
#define fpgetmask() __fpgetmask()
#define fpsetmask(_m) __fpsetmask(_m)
#define fpgetsticky() __fpgetsticky()
#define fpsetsticky(_m) __fpsetsticky(_m)
/* Suppress prototypes in the MI header. */
#define _IEEEFP_INLINED_ 1
#else /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUC__ */
/* Augment the userland declarations */
__BEGIN_DECLS
extern fp_prec_t fpgetprec(void);
extern fp_prec_t fpsetprec(fp_prec_t);
__END_DECLS
#endif /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUC__ */
#endif /* !_MACHINE_IEEEFP_H_ */