linux/arch/mips/math-emu/ieee754.h
Ralf Baechle 56a6473339 MIPS: math-emu: Switch to using the MIPS rounding modes.
Previously math-emu was using the IEEE-754 constants internally.  These
were differing by having the constants for rounding to +/- infinity
switched, so a conversion was necessary.  This would be entirely
avoidable if the MIPS constants were used throughout, so get rid of
the bloat.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:12:38 +02:00

333 lines
9.3 KiB
C

/*
* MIPS floating point support
* Copyright (C) 1994-2000 Algorithmics Ltd.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Nov 7, 2000
* Modification to allow integration with Linux kernel
*
* Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
* Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
*/
#ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
#define __ARCH_MIPS_MATH_EMU_IEEE754_H
#include <linux/compiler.h>
#include <asm/byteorder.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <asm/bitfield.h>
union ieee754dp {
struct {
__BITFIELD_FIELD(unsigned int sign:1,
__BITFIELD_FIELD(unsigned int bexp:11,
__BITFIELD_FIELD(u64 mant:52,
;)))
};
u64 bits;
};
union ieee754sp {
struct {
__BITFIELD_FIELD(unsigned sign:1,
__BITFIELD_FIELD(unsigned bexp:8,
__BITFIELD_FIELD(unsigned mant:23,
;)))
};
u32 bits;
};
/*
* single precision (often aka float)
*/
int ieee754sp_class(union ieee754sp x);
union ieee754sp ieee754sp_abs(union ieee754sp x);
union ieee754sp ieee754sp_neg(union ieee754sp x);
union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y);
union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y);
union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y);
union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y);
union ieee754sp ieee754sp_fint(int x);
union ieee754sp ieee754sp_flong(s64 x);
union ieee754sp ieee754sp_fdp(union ieee754dp x);
int ieee754sp_tint(union ieee754sp x);
s64 ieee754sp_tlong(union ieee754sp x);
int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
union ieee754sp ieee754sp_sqrt(union ieee754sp x);
/*
* double precision (often aka double)
*/
int ieee754dp_class(union ieee754dp x);
union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
union ieee754dp ieee754dp_abs(union ieee754dp x);
union ieee754dp ieee754dp_neg(union ieee754dp x);
union ieee754dp ieee754dp_fint(int x);
union ieee754dp ieee754dp_flong(s64 x);
union ieee754dp ieee754dp_fsp(union ieee754sp x);
int ieee754dp_tint(union ieee754dp x);
s64 ieee754dp_tlong(union ieee754dp x);
int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
union ieee754dp ieee754dp_sqrt(union ieee754dp x);
/* 5 types of floating point number
*/
enum {
IEEE754_CLASS_NORM = 0x00,
IEEE754_CLASS_ZERO = 0x01,
IEEE754_CLASS_DNORM = 0x02,
IEEE754_CLASS_INF = 0x03,
IEEE754_CLASS_SNAN = 0x04,
IEEE754_CLASS_QNAN = 0x05,
};
/* exception numbers */
#define IEEE754_INEXACT 0x01
#define IEEE754_UNDERFLOW 0x02
#define IEEE754_OVERFLOW 0x04
#define IEEE754_ZERO_DIVIDE 0x08
#define IEEE754_INVALID_OPERATION 0x10
/* cmp operators
*/
#define IEEE754_CLT 0x01
#define IEEE754_CEQ 0x02
#define IEEE754_CGT 0x04
#define IEEE754_CUN 0x08
/* "normal" comparisons
*/
static inline int ieee754sp_eq(union ieee754sp x, union ieee754sp y)
{
return ieee754sp_cmp(x, y, IEEE754_CEQ, 0);
}
static inline int ieee754sp_ne(union ieee754sp x, union ieee754sp y)
{
return ieee754sp_cmp(x, y,
IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
}
static inline int ieee754sp_lt(union ieee754sp x, union ieee754sp y)
{
return ieee754sp_cmp(x, y, IEEE754_CLT, 0);
}
static inline int ieee754sp_le(union ieee754sp x, union ieee754sp y)
{
return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
}
static inline int ieee754sp_gt(union ieee754sp x, union ieee754sp y)
{
return ieee754sp_cmp(x, y, IEEE754_CGT, 0);
}
static inline int ieee754sp_ge(union ieee754sp x, union ieee754sp y)
{
return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
}
static inline int ieee754dp_eq(union ieee754dp x, union ieee754dp y)
{
return ieee754dp_cmp(x, y, IEEE754_CEQ, 0);
}
static inline int ieee754dp_ne(union ieee754dp x, union ieee754dp y)
{
return ieee754dp_cmp(x, y,
IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0);
}
static inline int ieee754dp_lt(union ieee754dp x, union ieee754dp y)
{
return ieee754dp_cmp(x, y, IEEE754_CLT, 0);
}
static inline int ieee754dp_le(union ieee754dp x, union ieee754dp y)
{
return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0);
}
static inline int ieee754dp_gt(union ieee754dp x, union ieee754dp y)
{
return ieee754dp_cmp(x, y, IEEE754_CGT, 0);
}
static inline int ieee754dp_ge(union ieee754dp x, union ieee754dp y)
{
return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0);
}
/*
* The control status register
*/
struct _ieee754_csr {
__BITFIELD_FIELD(unsigned pad0:7,
__BITFIELD_FIELD(unsigned nod:1, /* set 1 for no denormalised numbers */
__BITFIELD_FIELD(unsigned c:1, /* condition */
__BITFIELD_FIELD(unsigned pad1:5,
__BITFIELD_FIELD(unsigned cx:6, /* exceptions this operation */
__BITFIELD_FIELD(unsigned mx:5, /* exception enable mask */
__BITFIELD_FIELD(unsigned sx:5, /* exceptions total */
__BITFIELD_FIELD(unsigned rm:2, /* current rounding mode */
;))))))))
};
#define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
static inline unsigned ieee754_getrm(void)
{
return (ieee754_csr.rm);
}
static inline unsigned ieee754_setrm(unsigned rm)
{
return (ieee754_csr.rm = rm);
}
/*
* get current exceptions
*/
static inline unsigned ieee754_getcx(void)
{
return (ieee754_csr.cx);
}
/* test for current exception condition
*/
static inline int ieee754_cxtest(unsigned n)
{
return (ieee754_csr.cx & n);
}
/*
* get sticky exceptions
*/
static inline unsigned ieee754_getsx(void)
{
return (ieee754_csr.sx);
}
/* clear sticky conditions
*/
static inline unsigned ieee754_clrsx(void)
{
return (ieee754_csr.sx = 0);
}
/* test for sticky exception condition
*/
static inline int ieee754_sxtest(unsigned n)
{
return (ieee754_csr.sx & n);
}
/* debugging */
union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
#define IEEE754_SPCVAL_PZERO 0
#define IEEE754_SPCVAL_NZERO 1
#define IEEE754_SPCVAL_PONE 2
#define IEEE754_SPCVAL_NONE 3
#define IEEE754_SPCVAL_PTEN 4
#define IEEE754_SPCVAL_NTEN 5
#define IEEE754_SPCVAL_PINFINITY 6
#define IEEE754_SPCVAL_NINFINITY 7
#define IEEE754_SPCVAL_INDEF 8
#define IEEE754_SPCVAL_PMAX 9 /* +max norm */
#define IEEE754_SPCVAL_NMAX 10 /* -max norm */
#define IEEE754_SPCVAL_PMIN 11 /* +min norm */
#define IEEE754_SPCVAL_NMIN 12 /* +min norm */
#define IEEE754_SPCVAL_PMIND 13 /* +min denorm */
#define IEEE754_SPCVAL_NMIND 14 /* +min denorm */
#define IEEE754_SPCVAL_P1E31 15 /* + 1.0e31 */
#define IEEE754_SPCVAL_P1E63 16 /* + 1.0e63 */
extern const union ieee754dp __ieee754dp_spcvals[];
extern const union ieee754sp __ieee754sp_spcvals[];
#define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
#define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
/*
* Return infinity with given sign
*/
#define ieee754dp_inf(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
#define ieee754dp_zero(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
#define ieee754dp_one(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
#define ieee754dp_ten(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
#define ieee754dp_indef() (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF])
#define ieee754dp_max(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
#define ieee754dp_min(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
#define ieee754dp_mind(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
#define ieee754dp_1e31() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
#define ieee754dp_1e63() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
#define ieee754sp_inf(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
#define ieee754sp_zero(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
#define ieee754sp_one(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
#define ieee754sp_ten(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
#define ieee754sp_indef() (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF])
#define ieee754sp_max(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
#define ieee754sp_min(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
#define ieee754sp_mind(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
#define ieee754sp_1e31() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
#define ieee754sp_1e63() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
/*
* Indefinite integer value
*/
static inline int ieee754si_indef(void)
{
return INT_MAX;
}
static inline s64 ieee754di_indef(void)
{
return S64_MAX;
}
/* result types for xctx.rt */
#define IEEE754_RT_SP 0
#define IEEE754_RT_DP 1
#define IEEE754_RT_XP 2
#define IEEE754_RT_SI 3
#define IEEE754_RT_DI 4
/* compat */
#define ieee754dp_fix(x) ieee754dp_tint(x)
#define ieee754sp_fix(x) ieee754sp_tint(x)
#endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */