mips/math-emu/ieee754.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * MIPS floating point support
0004  * Copyright (C) 1994-2000 Algorithmics Ltd.
0005  *
0006  *  Nov 7, 2000
0007  *  Modification to allow integration with Linux kernel
0008  *
0009  *  Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com
0010  *  Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
0011  */
0012 #ifndef __ARCH_MIPS_MATH_EMU_IEEE754_H
0013 #define __ARCH_MIPS_MATH_EMU_IEEE754_H
0014
0015 #include <linux/compiler.h>
0016 #include <asm/byteorder.h>
0017 #include <linux/kernel.h>
0018 #include <linux/types.h>
0019 #include <linux/sched.h>
0020 #include <asm/bitfield.h>
0021
0022 union ieee754dp {
0023     struct {
0024         __BITFIELD_FIELD(unsigned int sign:1,
0025         __BITFIELD_FIELD(unsigned int bexp:11,
0026         __BITFIELD_FIELD(u64 mant:52,
0027         ;)))
0028     };
0029     u64 bits;
0030 };
0031
0032 union ieee754sp {
0033     struct {
0034         __BITFIELD_FIELD(unsigned sign:1,
0035         __BITFIELD_FIELD(unsigned bexp:8,
0036         __BITFIELD_FIELD(unsigned mant:23,
0037         ;)))
0038     };
0039     u32 bits;
0040 };
0041
0042 /*
0043  * single precision (often aka float)
0044 */
0045 int ieee754sp_class(union ieee754sp x);
0046
0047 union ieee754sp ieee754sp_abs(union ieee754sp x);
0048 union ieee754sp ieee754sp_neg(union ieee754sp x);
0049
0050 union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y);
0051 union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y);
0052 union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y);
0053 union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y);
0054
0055 union ieee754sp ieee754sp_fint(int x);
0056 union ieee754sp ieee754sp_flong(s64 x);
0057 union ieee754sp ieee754sp_fdp(union ieee754dp x);
0058 union ieee754sp ieee754sp_rint(union ieee754sp x);
0059
0060 int ieee754sp_tint(union ieee754sp x);
0061 s64 ieee754sp_tlong(union ieee754sp x);
0062
0063 int ieee754sp_cmp(union ieee754sp x, union ieee754sp y, int cop, int sig);
0064
0065 union ieee754sp ieee754sp_sqrt(union ieee754sp x);
0066
0067 union ieee754sp ieee754sp_maddf(union ieee754sp z, union ieee754sp x,
0068                 union ieee754sp y);
0069 union ieee754sp ieee754sp_msubf(union ieee754sp z, union ieee754sp x,
0070                 union ieee754sp y);
0071 union ieee754sp ieee754sp_madd(union ieee754sp z, union ieee754sp x,
0072                 union ieee754sp y);
0073 union ieee754sp ieee754sp_msub(union ieee754sp z, union ieee754sp x,
0074                 union ieee754sp y);
0075 union ieee754sp ieee754sp_nmadd(union ieee754sp z, union ieee754sp x,
0076                 union ieee754sp y);
0077 union ieee754sp ieee754sp_nmsub(union ieee754sp z, union ieee754sp x,
0078                 union ieee754sp y);
0079 int ieee754sp_2008class(union ieee754sp x);
0080 union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y);
0081 union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y);
0082 union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y);
0083 union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y);
0084
0085 /*
0086  * double precision (often aka double)
0087 */
0088 int ieee754dp_class(union ieee754dp x);
0089
0090 union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y);
0091 union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y);
0092 union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y);
0093 union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y);
0094
0095 union ieee754dp ieee754dp_abs(union ieee754dp x);
0096 union ieee754dp ieee754dp_neg(union ieee754dp x);
0097
0098 union ieee754dp ieee754dp_fint(int x);
0099 union ieee754dp ieee754dp_flong(s64 x);
0100 union ieee754dp ieee754dp_fsp(union ieee754sp x);
0101 union ieee754dp ieee754dp_rint(union ieee754dp x);
0102
0103 int ieee754dp_tint(union ieee754dp x);
0104 s64 ieee754dp_tlong(union ieee754dp x);
0105
0106 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cop, int sig);
0107
0108 union ieee754dp ieee754dp_sqrt(union ieee754dp x);
0109
0110 union ieee754dp ieee754dp_maddf(union ieee754dp z, union ieee754dp x,
0111                 union ieee754dp y);
0112 union ieee754dp ieee754dp_msubf(union ieee754dp z, union ieee754dp x,
0113                 union ieee754dp y);
0114 union ieee754dp ieee754dp_madd(union ieee754dp z, union ieee754dp x,
0115                 union ieee754dp y);
0116 union ieee754dp ieee754dp_msub(union ieee754dp z, union ieee754dp x,
0117                 union ieee754dp y);
0118 union ieee754dp ieee754dp_nmadd(union ieee754dp z, union ieee754dp x,
0119                 union ieee754dp y);
0120 union ieee754dp ieee754dp_nmsub(union ieee754dp z, union ieee754dp x,
0121                 union ieee754dp y);
0122 int ieee754dp_2008class(union ieee754dp x);
0123 union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y);
0124 union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y);
0125 union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y);
0126 union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y);
0127
0128
0129 /* 5 types of floating point number
0130 */
0131 enum {
0132     IEEE754_CLASS_NORM  = 0x00,
0133     IEEE754_CLASS_ZERO  = 0x01,
0134     IEEE754_CLASS_DNORM = 0x02,
0135     IEEE754_CLASS_INF   = 0x03,
0136     IEEE754_CLASS_SNAN  = 0x04,
0137     IEEE754_CLASS_QNAN  = 0x05,
0138 };
0139
0140 /* exception numbers */
0141 #define IEEE754_INEXACT         0x01
0142 #define IEEE754_UNDERFLOW       0x02
0143 #define IEEE754_OVERFLOW        0x04
0144 #define IEEE754_ZERO_DIVIDE     0x08
0145 #define IEEE754_INVALID_OPERATION   0x10
0146
0147 /* cmp operators
0148 */
0149 #define IEEE754_CLT 0x01
0150 #define IEEE754_CEQ 0x02
0151 #define IEEE754_CGT 0x04
0152 #define IEEE754_CUN 0x08
0153
0154 /*
0155  * The control status register
0156  */
0157 struct _ieee754_csr {
0158     __BITFIELD_FIELD(unsigned fcc:7,    /* condition[7:1] */
0159     __BITFIELD_FIELD(unsigned nod:1,    /* set 1 for no denormals */
0160     __BITFIELD_FIELD(unsigned c:1,      /* condition[0] */
0161     __BITFIELD_FIELD(unsigned pad0:3,
0162     __BITFIELD_FIELD(unsigned abs2008:1,    /* IEEE 754-2008 ABS/NEG.fmt */
0163     __BITFIELD_FIELD(unsigned nan2008:1,    /* IEEE 754-2008 NaN mode */
0164     __BITFIELD_FIELD(unsigned cx:6,     /* exceptions this operation */
0165     __BITFIELD_FIELD(unsigned mx:5,     /* exception enable  mask */
0166     __BITFIELD_FIELD(unsigned sx:5,     /* exceptions total */
0167     __BITFIELD_FIELD(unsigned rm:2,     /* current rounding mode */
0168     ;))))))))))
0169 };
0170 #define ieee754_csr (*(struct _ieee754_csr *)(&current->thread.fpu.fcr31))
0171
0172 static inline unsigned int ieee754_getrm(void)
0173 {
0174     return (ieee754_csr.rm);
0175 }
0176
0177 static inline unsigned int ieee754_setrm(unsigned int rm)
0178 {
0179     return (ieee754_csr.rm = rm);
0180 }
0181
0182 /*
0183  * get current exceptions
0184  */
0185 static inline unsigned int ieee754_getcx(void)
0186 {
0187     return (ieee754_csr.cx);
0188 }
0189
0190 /* test for current exception condition
0191  */
0192 static inline int ieee754_cxtest(unsigned int n)
0193 {
0194     return (ieee754_csr.cx & n);
0195 }
0196
0197 /*
0198  * get sticky exceptions
0199  */
0200 static inline unsigned int ieee754_getsx(void)
0201 {
0202     return (ieee754_csr.sx);
0203 }
0204
0205 /* clear sticky conditions
0206 */
0207 static inline unsigned int ieee754_clrsx(void)
0208 {
0209     return (ieee754_csr.sx = 0);
0210 }
0211
0212 /* test for sticky exception condition
0213  */
0214 static inline int ieee754_sxtest(unsigned int n)
0215 {
0216     return (ieee754_csr.sx & n);
0217 }
0218
0219 /* debugging */
0220 union ieee754sp ieee754sp_dump(char *s, union ieee754sp x);
0221 union ieee754dp ieee754dp_dump(char *s, union ieee754dp x);
0222
0223 #define IEEE754_SPCVAL_PZERO        0   /* +0.0 */
0224 #define IEEE754_SPCVAL_NZERO        1   /* -0.0 */
0225 #define IEEE754_SPCVAL_PONE     2   /* +1.0 */
0226 #define IEEE754_SPCVAL_NONE     3   /* -1.0 */
0227 #define IEEE754_SPCVAL_PTEN     4   /* +10.0 */
0228 #define IEEE754_SPCVAL_NTEN     5   /* -10.0 */
0229 #define IEEE754_SPCVAL_PINFINITY    6   /* +inf */
0230 #define IEEE754_SPCVAL_NINFINITY    7   /* -inf */
0231 #define IEEE754_SPCVAL_INDEF_LEG    8   /* legacy quiet NaN */
0232 #define IEEE754_SPCVAL_INDEF_2008   9   /* IEEE 754-2008 quiet NaN */
0233 #define IEEE754_SPCVAL_PMAX     10  /* +max norm */
0234 #define IEEE754_SPCVAL_NMAX     11  /* -max norm */
0235 #define IEEE754_SPCVAL_PMIN     12  /* +min norm */
0236 #define IEEE754_SPCVAL_NMIN     13  /* -min norm */
0237 #define IEEE754_SPCVAL_PMIND        14  /* +min denorm */
0238 #define IEEE754_SPCVAL_NMIND        15  /* -min denorm */
0239 #define IEEE754_SPCVAL_P1E31        16  /* + 1.0e31 */
0240 #define IEEE754_SPCVAL_P1E63        17  /* + 1.0e63 */
0241
0242 extern const union ieee754dp __ieee754dp_spcvals[];
0243 extern const union ieee754sp __ieee754sp_spcvals[];
0244 #define ieee754dp_spcvals ((const union ieee754dp *)__ieee754dp_spcvals)
0245 #define ieee754sp_spcvals ((const union ieee754sp *)__ieee754sp_spcvals)
0246
0247 /*
0248  * Return infinity with given sign
0249  */
0250 #define ieee754dp_inf(sn)     (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
0251 #define ieee754dp_zero(sn)  (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
0252 #define ieee754dp_one(sn)   (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
0253 #define ieee754dp_ten(sn)   (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
0254 #define ieee754dp_indef()   (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
0255                            ieee754_csr.nan2008])
0256 #define ieee754dp_max(sn)   (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
0257 #define ieee754dp_min(sn)   (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
0258 #define ieee754dp_mind(sn)  (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
0259 #define ieee754dp_1e31()    (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31])
0260 #define ieee754dp_1e63()    (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63])
0261
0262 #define ieee754sp_inf(sn)     (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)])
0263 #define ieee754sp_zero(sn)  (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)])
0264 #define ieee754sp_one(sn)   (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)])
0265 #define ieee754sp_ten(sn)   (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)])
0266 #define ieee754sp_indef()   (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF_LEG + \
0267                            ieee754_csr.nan2008])
0268 #define ieee754sp_max(sn)   (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)])
0269 #define ieee754sp_min(sn)   (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)])
0270 #define ieee754sp_mind(sn)  (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)])
0271 #define ieee754sp_1e31()    (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31])
0272 #define ieee754sp_1e63()    (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63])
0273
0274 /*
0275  * Indefinite integer value
0276  */
0277 static inline int ieee754si_indef(void)
0278 {
0279     return ieee754_csr.nan2008 ? 0 : INT_MAX;
0280 }
0281
0282 static inline s64 ieee754di_indef(void)
0283 {
0284     return ieee754_csr.nan2008 ? 0 : S64_MAX;
0285 }
0286
0287 /*
0288  * Overflow integer value
0289  */
0290 static inline int ieee754si_overflow(int xs)
0291 {
0292     return ieee754_csr.nan2008 && xs ? INT_MIN : INT_MAX;
0293 }
0294
0295 static inline s64 ieee754di_overflow(int xs)
0296 {
0297     return ieee754_csr.nan2008 && xs ? S64_MIN : S64_MAX;
0298 }
0299
0300 /* result types for xctx.rt */
0301 #define IEEE754_RT_SP   0
0302 #define IEEE754_RT_DP   1
0303 #define IEEE754_RT_XP   2
0304 #define IEEE754_RT_SI   3
0305 #define IEEE754_RT_DI   4
0306
0307 /* compat */
0308 #define ieee754dp_fix(x)    ieee754dp_tint(x)
0309 #define ieee754sp_fix(x)    ieee754sp_tint(x)
0310
0311 #endif /* __ARCH_MIPS_MATH_EMU_IEEE754_H */