fpsp.h (11435B)
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|