sys/arch/i386/include/npx.h

   1 /*      $NetBSD: npx.h,v 1.25 2010/07/31 21:47:54 joerg Exp $   */
   2
   3 /*-
   4  * Copyright (c) 1990 The Regents of the University of California.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * William Jolitz.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)npx.h       5.3 (Berkeley) 1/18/91
  35  */
  36
  37 /*
  38  * 287/387 NPX Coprocessor Data Structures and Constants
  39  * W. Jolitz 1/90
  40  */
  41
  42 #ifndef _I386_NPX_H_
  43 #define _I386_NPX_H_
  44
  45 #ifndef __minix
  46 /* Environment information of floating point unit */
  47 struct env87 {
  48         long     en_cw;         /* control word (16bits) */
  49         long     en_sw;         /* status word (16bits) */
  50         long     en_tw;         /* tag word (16bits) */
  51         long     en_fip;        /* floating point instruction pointer */
  52         uint16_t en_fcs;        /* floating code segment selector */
  53         uint16_t en_opcode;     /* opcode last executed (11 bits ) */
  54         long     en_foo;        /* floating operand offset */
  55         long     en_fos;        /* floating operand segment selector */
  56 };
  57
  58 /* Contents of each floating point accumulator */
  59 struct fpacc87 {
  60 #ifdef dontdef  /* too unportable */
  61         uint32_t fp_mantlo;     /* mantissa low (31:0) */
  62         uint32_t fp_manthi;     /* mantissa high (63:32) */
  63         int      fp_exp:15;     /* exponent */
  64         int      fp_sgn:1;      /* mantissa sign */
  65 #else
  66         uint8_t  fp_bytes[10];
  67 #endif
  68 };
  69
  70 /* Floating point context */
  71 struct save87 {
  72         struct  env87 sv_env;           /* floating point control/status */
  73         struct  fpacc87 sv_ac[8];       /* accumulator contents, 0-7 */
  74 #ifndef dontdef
  75         uint32_t sv_ex_sw;      /* status word for last exception (was pad) */
  76         uint32_t sv_ex_tw;      /* tag word for last exception (was pad) */
  77         uint8_t  sv_pad[8 * 2 - 2 * 4]; /* bogus historical padding */
  78 #endif
  79 };
  80
  81 /* Environment of FPU/MMX/SSE/SSE2. */
  82 struct envxmm {
  83 /*0*/   uint16_t en_cw;         /* FPU Control Word */
  84         uint16_t en_sw;         /* FPU Status Word */
  85         uint8_t  en_tw;         /* FPU Tag Word (abridged) */
  86         uint8_t  en_rsvd0;
  87         uint16_t en_opcode;     /* FPU Opcode */
  88         uint32_t en_fip;        /* FPU Instruction Pointer */
  89         uint16_t en_fcs;        /* FPU IP selector */
  90         uint16_t en_rsvd1;
  91 /*16*/  uint32_t en_foo;        /* FPU Data pointer */
  92         uint16_t en_fos;        /* FPU Data pointer selector */
  93         uint16_t en_rsvd2;
  94         uint32_t en_mxcsr;      /* MXCSR Register State */
  95         uint32_t en_rsvd3;
  96 };
  97
  98 /* FPU regsters in the extended save format. */
  99 struct fpaccxmm {
 100         uint8_t fp_bytes[10];
 101         uint8_t fp_rsvd[6];
 102 };
 103
 104 /* SSE/SSE2 registers. */
 105 struct xmmreg {
 106         uint8_t sse_bytes[16];
 107 };
 108
 109 /* FPU/MMX/SSE/SSE2 context */
 110 struct savexmm {
 111         struct envxmm sv_env;           /* control/status context */
 112         struct fpaccxmm sv_ac[8];       /* ST/MM regs */
 113         struct xmmreg sv_xmmregs[8];    /* XMM regs */
 114         uint8_t sv_rsvd[16 * 14];
 115         /* 512-bytes --- end of hardware portion of save area */
 116         uint32_t sv_ex_sw;              /* saved SW from last exception */
 117         uint32_t sv_ex_tw;              /* saved TW from last exception */
 118 } __aligned(16);
 119
 120 union savefpu {
 121         struct save87 sv_87;
 122         struct savexmm sv_xmm;
 123 };
 124 #endif /* !__minix */
 125
 126 /*
 127  * The i387 defaults to Intel extended precision mode and round to nearest,
 128  * with all exceptions masked.
 129  */
 130 #define __INITIAL_NPXCW__       0x037f
 131 /* NetBSD uses IEEE double precision. */
 132 #define __NetBSD_NPXCW__        0x127f
 133 /* FreeBSD leaves some exceptions unmasked as well. */
 134 #define __FreeBSD_NPXCW__       0x1272
 135 /* iBCS2 goes a bit further and leaves the underflow exception unmasked. */
 136 #define __iBCS2_NPXCW__         0x0262
 137 /* Linux just uses the default control word. */
 138 #define __Linux_NPXCW__         0x037f
 139 /* SVR4 uses the same control word as iBCS2. */
 140 #define __SVR4_NPXCW__          0x0262
 141
 142 /*
 143  * The default MXCSR value at reset is 0x1f80, IA-32 Instruction
 144  * Set Reference, pg. 3-369.
 145  */
 146 #define __INITIAL_MXCSR__       0x1f80
 147
 148
 149 /*
 150  * 80387 control word bits
 151  */
 152 #define EN_SW_INVOP     0x0001  /* Invalid operation */
 153 #define EN_SW_DENORM    0x0002  /* Denormalized operand */
 154 #define EN_SW_ZERODIV   0x0004  /* Divide by zero */
 155 #define EN_SW_OVERFLOW  0x0008  /* Overflow */
 156 #define EN_SW_UNDERFLOW 0x0010  /* Underflow */
 157 #define EN_SW_PRECLOSS  0x0020  /* Loss of precision */
 158 #define EN_SW_DATACHAIN 0x0080  /* Data chain exception */
 159 #define EN_SW_CTL_PREC  0x0300  /* Precision control */
 160 #define EN_SW_CTL_ROUND 0x0c00  /* Rounding control */
 161 #define EN_SW_CTL_INF   0x1000  /* Infinity control */
 162
 163 /*
 164  * The standard control word from finit is 0x37F, giving:
 165  *      round to nearest
 166  *      64-bit precision
 167  *      all exceptions masked.
 168  *
 169  * Now we want:
 170  *      affine mode (if we decide to support 287's)
 171  *      round to nearest
 172  *      53-bit precision
 173  *      all exceptions masked.
 174  *
 175  * 64-bit precision often gives bad results with high level languages
 176  * because it makes the results of calculations depend on whether
 177  * intermediate values are stored in memory or in FPU registers.
 178  *
 179  * The iBCS control word has underflow, overflow, zero divide, and invalid
 180  * operation exceptions unmasked.  But that causes an unexpected exception
 181  * in the test program 'paranoia' and makes denormals useless (DBL_MIN / 2
 182  * underflows).  It doesn't make a lot of sense to trap underflow without
 183  * trapping denormals.
 184  */
 185
 186 #ifdef _KERNEL
 187
 188 void    probeintr(void);
 189 void    probetrap(void);
 190 int     npx586bug1(int, int);
 191 void    npxinit(struct cpu_info *);
 192 void    process_xmm_to_s87(const struct savexmm *, struct save87 *);
 193 void    process_s87_to_xmm(const struct save87 *, struct savexmm *);
 194 struct lwp;
 195 int     npxtrap(struct lwp *);
 196
 197 #endif
 198
 199 #endif /* !_I386_NPX_H_ */