arch/m68k/fpsp040/fpsp.h

   1 |
   2 |       fpsp.h 3.3 3.3
   3 |
   4
   5 |               Copyright (C) Motorola, Inc. 1990
   6 |                       All Rights Reserved
   7 |
   8 |       For details on the license for this file, please see the
   9 |       file, README, in this same directory.
  10
  11 |       fpsp.h --- stack frame offsets during FPSP exception handling
  12 |
  13 |       These equates are used to access the exception frame, the fsave
  14 |       frame and any local variables needed by the FPSP package.
  15 |
  16 |       All FPSP handlers begin by executing:
  17 |
  18 |               link    a6,#-LOCAL_SIZE
  19 |               fsave   -(a7)
  20 |               movem.l d0-d1/a0-a1,USER_DA(a6)
  21 |               fmovem.x fp0-fp3,USER_FP0(a6)
  22 |               fmove.l fpsr/fpcr/fpiar,USER_FPSR(a6)
  23 |
  24 |       After initialization, the stack looks like this:
  25 |
  26 |       A7 ---> +-------------------------------+
  27 |               |                               |
  28 |               |       FPU fsave area          |
  29 |               |                               |
  30 |               +-------------------------------+
  31 |               |                               |
  32 |               |       FPSP Local Variables    |
  33 |               |            including          |
  34 |               |         saved registers       |
  35 |               |                               |
  36 |               +-------------------------------+
  37 |       A6 ---> |       Saved A6                |
  38 |               +-------------------------------+
  39 |               |                               |
  40 |               |       Exception Frame         |
  41 |               |                               |
  42 |               |                               |
  43 |
  44 |       Positive offsets from A6 refer to the exception frame.  Negative
  45 |       offsets refer to the Local Variable area and the fsave area.
  46 |       The fsave frame is also accessible from the top via A7.
  47 |
  48 |       On exit, the handlers execute:
  49 |
  50 |               movem.l USER_DA(a6),d0-d1/a0-a1
  51 |               fmovem.x USER_FP0(a6),fp0-fp3
  52 |               fmove.l USER_FPSR(a6),fpsr/fpcr/fpiar
  53 |               frestore (a7)+
  54 |               unlk    a6
  55 |
  56 |       and then either "bra fpsp_done" if the exception was completely
  57 |       handled by the package, or "bra real_xxxx" which is an external
  58 |       label to a routine that will process a real exception of the
  59 |       type that was generated.  Some handlers may omit the "frestore"
  60 |       if the FPU state after the exception is idle.
  61 |
  62 |       Sometimes the exception handler will transform the fsave area
  63 |       because it needs to report an exception back to the user.  This
  64 |       can happen if the package is entered for an unimplemented float
  65 |       instruction that generates (say) an underflow.  Alternatively,
  66 |       a second fsave frame can be pushed onto the stack and the
  67 |       handler exit code will reload the new frame and discard the old.
  68 |
  69 |       The registers d0, d1, a0, a1 and fp0-fp3 are always saved and
  70 |       restored from the "local variable" area and can be used as
  71 |       temporaries.  If a routine needs to change any
  72 |       of these registers, it should modify the saved copy and let
  73 |       the handler exit code restore the value.
  74 |
  75 |----------------------------------------------------------------------
  76 |
  77 |       Local Variables on the stack
  78 |
  79         .set    LOCAL_SIZE,192          | bytes needed for local variables
  80         .set    LV,-LOCAL_SIZE  | convenient base value
  81 |
  82         .set    USER_DA,LV+0            | save space for D0-D1,A0-A1
  83         .set    USER_D0,LV+0            | saved user D0
  84         .set    USER_D1,LV+4            | saved user D1
  85         .set    USER_A0,LV+8            | saved user A0
  86         .set    USER_A1,LV+12           | saved user A1
  87         .set    USER_FP0,LV+16          | saved user FP0
  88         .set    USER_FP1,LV+28          | saved user FP1
  89         .set    USER_FP2,LV+40          | saved user FP2
  90         .set    USER_FP3,LV+52          | saved user FP3
  91         .set    USER_FPCR,LV+64         | saved user FPCR
  92         .set    FPCR_ENABLE,USER_FPCR+2 |       FPCR exception enable
  93         .set    FPCR_MODE,USER_FPCR+3   |       FPCR rounding mode control
  94         .set    USER_FPSR,LV+68         | saved user FPSR
  95         .set    FPSR_CC,USER_FPSR+0     |       FPSR condition code
  96         .set    FPSR_QBYTE,USER_FPSR+1  |       FPSR quotient
  97         .set    FPSR_EXCEPT,USER_FPSR+2 |       FPSR exception
  98         .set    FPSR_AEXCEPT,USER_FPSR+3        |       FPSR accrued exception
  99         .set    USER_FPIAR,LV+72                | saved user FPIAR
 100         .set    FP_SCR1,LV+76           | room for a temporary float value
 101         .set    FP_SCR2,LV+92           | room for a temporary float value
 102         .set    L_SCR1,LV+108           | room for a temporary long value
 103         .set    L_SCR2,LV+112           | room for a temporary long value
 104         .set    STORE_FLG,LV+116
 105         .set    BINDEC_FLG,LV+117               | used in bindec
 106         .set    DNRM_FLG,LV+118         | used in res_func
 107         .set    RES_FLG,LV+119          | used in res_func
 108         .set    DY_MO_FLG,LV+120                | dyadic/monadic flag
 109         .set    UFLG_TMP,LV+121         | temporary for uflag errata
 110         .set    CU_ONLY,LV+122          | cu-only flag
 111         .set    VER_TMP,LV+123          | temp holding for version number
 112         .set    L_SCR3,LV+124           | room for a temporary long value
 113         .set    FP_SCR3,LV+128          | room for a temporary float value
 114         .set    FP_SCR4,LV+144          | room for a temporary float value
 115         .set    FP_SCR5,LV+160          | room for a temporary float value
 116         .set    FP_SCR6,LV+176
 117 |
 118 |NEXT           equ     LV+192          ;need to increase LOCAL_SIZE
 119 |
 120 |--------------------------------------------------------------------------
 121 |
 122 |       fsave offsets and bit definitions
 123 |
 124 |       Offsets are defined from the end of an fsave because the last 10
 125 |       words of a busy frame are the same as the unimplemented frame.
 126 |
 127         .set    CU_SAVEPC,LV-92         | micro-pc for CU (1 byte)
 128         .set    FPR_DIRTY_BITS,LV-91            | fpr dirty bits
 129 |
 130         .set    WBTEMP,LV-76            | write back temp (12 bytes)
 131         .set    WBTEMP_EX,WBTEMP                | wbtemp sign and exponent (2 bytes)
 132         .set    WBTEMP_HI,WBTEMP+4      | wbtemp mantissa [63:32] (4 bytes)
 133         .set    WBTEMP_LO,WBTEMP+8      | wbtemp mantissa [31:00] (4 bytes)
 134 |
 135         .set    WBTEMP_SGN,WBTEMP+2     | used to store sign
 136 |
 137         .set    FPSR_SHADOW,LV-64               | fpsr shadow reg
 138 |
 139         .set    FPIARCU,LV-60           | Instr. addr. reg. for CU (4 bytes)
 140 |
 141         .set    CMDREG2B,LV-52          | cmd reg for machine 2
 142         .set    CMDREG3B,LV-48          | cmd reg for E3 exceptions (2 bytes)
 143 |
 144         .set    NMNEXC,LV-44            | NMNEXC (unsup,snan bits only)
 145         .set    nmn_unsup_bit,1 |
 146         .set    nmn_snan_bit,0  |
 147 |
 148         .set    NMCEXC,LV-43            | NMNEXC & NMCEXC
 149         .set    nmn_operr_bit,7
 150         .set    nmn_ovfl_bit,6
 151         .set    nmn_unfl_bit,5
 152         .set    nmc_unsup_bit,4
 153         .set    nmc_snan_bit,3
 154         .set    nmc_operr_bit,2
 155         .set    nmc_ovfl_bit,1
 156         .set    nmc_unfl_bit,0
 157 |
 158         .set    STAG,LV-40              | source tag (1 byte)
 159         .set    WBTEMP_GRS,LV-40                | alias wbtemp guard, round, sticky
 160         .set    guard_bit,1             | guard bit is bit number 1
 161         .set    round_bit,0             | round bit is bit number 0
 162         .set    stag_mask,0xE0          | upper 3 bits are source tag type
 163         .set    denorm_bit,7            | bit determines if denorm or unnorm
 164         .set    etemp15_bit,4           | etemp exponent bit #15
 165         .set    wbtemp66_bit,2          | wbtemp mantissa bit #66
 166         .set    wbtemp1_bit,1           | wbtemp mantissa bit #1
 167         .set    wbtemp0_bit,0           | wbtemp mantissa bit #0
 168 |
 169         .set    STICKY,LV-39            | holds sticky bit
 170         .set    sticky_bit,7
 171 |
 172         .set    CMDREG1B,LV-36          | cmd reg for E1 exceptions (2 bytes)
 173         .set    kfact_bit,12            | distinguishes static/dynamic k-factor
 174 |                                       ;on packed move outs.  NOTE: this
 175 |                                       ;equate only works when CMDREG1B is in
 176 |                                       ;a register.
 177 |
 178         .set    CMDWORD,LV-35           | command word in cmd1b
 179         .set    direction_bit,5         | bit 0 in opclass
 180         .set    size_bit2,12            | bit 2 in size field
 181 |
 182         .set    DTAG,LV-32              | dest tag (1 byte)
 183         .set    dtag_mask,0xE0          | upper 3 bits are dest type tag
 184         .set    fptemp15_bit,4          | fptemp exponent bit #15
 185 |
 186         .set    WB_BYTE,LV-31           | holds WBTE15 bit (1 byte)
 187         .set    wbtemp15_bit,4          | wbtemp exponent bit #15
 188 |
 189         .set    E_BYTE,LV-28            | holds E1 and E3 bits (1 byte)
 190         .set    E1,2            | which bit is E1 flag
 191         .set    E3,1            | which bit is E3 flag
 192         .set    SFLAG,0         | which bit is S flag
 193 |
 194         .set    T_BYTE,LV-27            | holds T and U bits (1 byte)
 195         .set    XFLAG,7         | which bit is X flag
 196         .set    UFLAG,5         | which bit is U flag
 197         .set    TFLAG,4         | which bit is T flag
 198 |
 199         .set    FPTEMP,LV-24            | fptemp (12 bytes)
 200         .set    FPTEMP_EX,FPTEMP                | fptemp sign and exponent (2 bytes)
 201         .set    FPTEMP_HI,FPTEMP+4      | fptemp mantissa [63:32] (4 bytes)
 202         .set    FPTEMP_LO,FPTEMP+8      | fptemp mantissa [31:00] (4 bytes)
 203 |
 204         .set    FPTEMP_SGN,FPTEMP+2     | used to store sign
 205 |
 206         .set    ETEMP,LV-12             | etemp (12 bytes)
 207         .set    ETEMP_EX,ETEMP          | etemp sign and exponent (2 bytes)
 208         .set    ETEMP_HI,ETEMP+4                | etemp mantissa [63:32] (4 bytes)
 209         .set    ETEMP_LO,ETEMP+8                | etemp mantissa [31:00] (4 bytes)
 210 |
 211         .set    ETEMP_SGN,ETEMP+2               | used to store sign
 212 |
 213         .set    EXC_SR,4                | exception frame status register
 214         .set    EXC_PC,6                | exception frame program counter
 215         .set    EXC_VEC,10              | exception frame vector (format+vector#)
 216         .set    EXC_EA,12               | exception frame effective address
 217 |
 218 |--------------------------------------------------------------------------
 219 |
 220 |       FPSR/FPCR bits
 221 |
 222         .set    neg_bit,3       |  negative result
 223         .set    z_bit,2 |  zero result
 224         .set    inf_bit,1       |  infinity result
 225         .set    nan_bit,0       |  not-a-number result
 226 |
 227         .set    q_sn_bit,7      |  sign bit of quotient byte
 228 |
 229         .set    bsun_bit,7      |  branch on unordered
 230         .set    snan_bit,6      |  signalling nan
 231         .set    operr_bit,5     |  operand error
 232         .set    ovfl_bit,4      |  overflow
 233         .set    unfl_bit,3      |  underflow
 234         .set    dz_bit,2        |  divide by zero
 235         .set    inex2_bit,1     |  inexact result 2
 236         .set    inex1_bit,0     |  inexact result 1
 237 |
 238         .set    aiop_bit,7      |  accrued illegal operation
 239         .set    aovfl_bit,6     |  accrued overflow
 240         .set    aunfl_bit,5     |  accrued underflow
 241         .set    adz_bit,4       |  accrued divide by zero
 242         .set    ainex_bit,3     |  accrued inexact
 243 |
 244 |       FPSR individual bit masks
 245 |
 246         .set    neg_mask,0x08000000
 247         .set    z_mask,0x04000000
 248         .set    inf_mask,0x02000000
 249         .set    nan_mask,0x01000000
 250 |
 251         .set    bsun_mask,0x00008000    |
 252         .set    snan_mask,0x00004000
 253         .set    operr_mask,0x00002000
 254         .set    ovfl_mask,0x00001000
 255         .set    unfl_mask,0x00000800
 256         .set    dz_mask,0x00000400
 257         .set    inex2_mask,0x00000200
 258         .set    inex1_mask,0x00000100
 259 |
 260         .set    aiop_mask,0x00000080    |  accrued illegal operation
 261         .set    aovfl_mask,0x00000040   |  accrued overflow
 262         .set    aunfl_mask,0x00000020   |  accrued underflow
 263         .set    adz_mask,0x00000010     |  accrued divide by zero
 264         .set    ainex_mask,0x00000008   |  accrued inexact
 265 |
 266 |       FPSR combinations used in the FPSP
 267 |
 268         .set    dzinf_mask,inf_mask+dz_mask+adz_mask
 269         .set    opnan_mask,nan_mask+operr_mask+aiop_mask
 270         .set    nzi_mask,0x01ffffff     |  clears N, Z, and I
 271         .set    unfinx_mask,unfl_mask+inex2_mask+aunfl_mask+ainex_mask
 272         .set    unf2inx_mask,unfl_mask+inex2_mask+ainex_mask
 273         .set    ovfinx_mask,ovfl_mask+inex2_mask+aovfl_mask+ainex_mask
 274         .set    inx1a_mask,inex1_mask+ainex_mask
 275         .set    inx2a_mask,inex2_mask+ainex_mask
 276         .set    snaniop_mask,nan_mask+snan_mask+aiop_mask
 277         .set    naniop_mask,nan_mask+aiop_mask
 278         .set    neginf_mask,neg_mask+inf_mask
 279         .set    infaiop_mask,inf_mask+aiop_mask
 280         .set    negz_mask,neg_mask+z_mask
 281         .set    opaop_mask,operr_mask+aiop_mask
 282         .set    unfl_inx_mask,unfl_mask+aunfl_mask+ainex_mask
 283         .set    ovfl_inx_mask,ovfl_mask+aovfl_mask+ainex_mask
 284 |
 285 |--------------------------------------------------------------------------
 286 |
 287 |       FPCR rounding modes
 288 |
 289         .set    x_mode,0x00     |  round to extended
 290         .set    s_mode,0x40     |  round to single
 291         .set    d_mode,0x80     |  round to double
 292 |
 293         .set    rn_mode,0x00    |  round nearest
 294         .set    rz_mode,0x10    |  round to zero
 295         .set    rm_mode,0x20    |  round to minus infinity
 296         .set    rp_mode,0x30    |  round to plus infinity
 297 |
 298 |--------------------------------------------------------------------------
 299 |
 300 |       Miscellaneous equates
 301 |
 302         .set    signan_bit,6    |  signalling nan bit in mantissa
 303         .set    sign_bit,7
 304 |
 305         .set    rnd_stky_bit,29 |  round/sticky bit of mantissa
 306 |                               this can only be used if in a data register
 307         .set    sx_mask,0x01800000 |  set s and x bits in word $48
 308 |
 309         .set    LOCAL_EX,0
 310         .set    LOCAL_SGN,2
 311         .set    LOCAL_HI,4
 312         .set    LOCAL_LO,8
 313         .set    LOCAL_GRS,12    |  valid ONLY for FP_SCR1, FP_SCR2
 314 |
 315 |
 316         .set    norm_tag,0x00   |  tag bits in {7:5} position
 317         .set    zero_tag,0x20
 318         .set    inf_tag,0x40
 319         .set    nan_tag,0x60
 320         .set    dnrm_tag,0x80
 321 |
 322 |       fsave sizes and formats
 323 |
 324         .set    VER_4,0x40              |  fpsp compatible version numbers
 325 |                                       are in the $40s {$40-$4f}
 326         .set    VER_40,0x40             |  original version number
 327         .set    VER_41,0x41             |  revision version number
 328 |
 329         .set    BUSY_SIZE,100           |  size of busy frame
 330         .set    BUSY_FRAME,LV-BUSY_SIZE |  start of busy frame
 331 |
 332         .set    UNIMP_40_SIZE,44                |  size of orig unimp frame
 333         .set    UNIMP_41_SIZE,52                |  size of rev unimp frame
 334 |
 335         .set    IDLE_SIZE,4             |  size of idle frame
 336         .set    IDLE_FRAME,LV-IDLE_SIZE |  start of idle frame
 337 |
 338 |       exception vectors
 339 |
 340         .set    TRACE_VEC,0x2024                |  trace trap
 341         .set    FLINE_VEC,0x002C                |  real F-line
 342         .set    UNIMP_VEC,0x202C                |  unimplemented
 343         .set    INEX_VEC,0x00C4
 344 |
 345         .set    dbl_thresh,0x3C01
 346         .set    sgl_thresh,0x3F81
 347 |