| 1 |
1623 |
jcastillo |
|
|
| 2 |
|
|
| x_operr.sa 3.5 7/1/91
|
| 3 |
|
|
|
|
| 4 |
|
|
| fpsp_operr --- FPSP handler for operand error exception
|
| 5 |
|
|
|
|
| 6 |
|
|
| See 68040 User's Manual pp. 9-44f
|
| 7 |
|
|
|
|
| 8 |
|
|
| Note 1: For trap disabled 040 does the following:
|
| 9 |
|
|
| If the dest is a fp reg, then an extended precision non_signaling
|
| 10 |
|
|
| NAN is stored in the dest reg. If the dest format is b, w, or l and
|
| 11 |
|
|
| the source op is a NAN, then garbage is stored as the result (actually
|
| 12 |
|
|
| the upper 32 bits of the mantissa are sent to the integer unit). If
|
| 13 |
|
|
| the dest format is integer (b, w, l) and the operr is caused by
|
| 14 |
|
|
| integer overflow, or the source op is inf, then the result stored is
|
| 15 |
|
|
| garbage.
|
| 16 |
|
|
| There are three cases in which operr is incorrectly signaled on the
|
| 17 |
|
|
| 040. This occurs for move_out of format b, w, or l for the largest
|
| 18 |
|
|
| negative integer (-2^7 for b, -2^15 for w, -2^31 for l).
|
| 19 |
|
|
|
|
| 20 |
|
|
| On opclass = 011 fmove.(b,w,l) that causes a conversion
|
| 21 |
|
|
| overflow -> OPERR, the exponent in wbte (and fpte) is:
|
| 22 |
|
|
| byte 56 - (62 - exp)
|
| 23 |
|
|
| word 48 - (62 - exp)
|
| 24 |
|
|
| long 32 - (62 - exp)
|
| 25 |
|
|
|
|
| 26 |
|
|
| where exp = (true exp) - 1
|
| 27 |
|
|
|
|
| 28 |
|
|
| So, wbtemp and fptemp will contain the following on erroneously
|
| 29 |
|
|
| signalled operr:
|
| 30 |
|
|
| fpts = 1
|
| 31 |
|
|
| fpte = $4000 (15 bit externally)
|
| 32 |
|
|
| byte fptm = $ffffffff ffffff80
|
| 33 |
|
|
| word fptm = $ffffffff ffff8000
|
| 34 |
|
|
| long fptm = $ffffffff 80000000
|
| 35 |
|
|
|
|
| 36 |
|
|
| Note 2: For trap enabled 040 does the following:
|
| 37 |
|
|
| If the inst is move_out, then same as Note 1.
|
| 38 |
|
|
| If the inst is not move_out, the dest is not modified.
|
| 39 |
|
|
| The exceptional operand is not defined for integer overflow
|
| 40 |
|
|
| during a move_out.
|
| 41 |
|
|
|
|
| 42 |
|
|
|
| 43 |
|
|
| Copyright (C) Motorola, Inc. 1990
|
| 44 |
|
|
| All Rights Reserved
|
| 45 |
|
|
|
|
| 46 |
|
|
| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
|
| 47 |
|
|
| The copyright notice above does not evidence any
|
| 48 |
|
|
| actual or intended publication of such source code.
|
| 49 |
|
|
|
| 50 |
|
|
X_OPERR: |idnt 2,1 | Motorola 040 Floating Point Software Package
|
| 51 |
|
|
|
| 52 |
|
|
|section 8
|
| 53 |
|
|
|
| 54 |
|
|
.include "fpsp.h"
|
| 55 |
|
|
|
| 56 |
|
|
|xref mem_write
|
| 57 |
|
|
|xref real_operr
|
| 58 |
|
|
|xref real_inex
|
| 59 |
|
|
|xref get_fline
|
| 60 |
|
|
|xref fpsp_done
|
| 61 |
|
|
|xref reg_dest
|
| 62 |
|
|
|
| 63 |
|
|
.global fpsp_operr
|
| 64 |
|
|
fpsp_operr:
|
| 65 |
|
|
|
|
| 66 |
|
|
link %a6,#-LOCAL_SIZE
|
| 67 |
|
|
fsave -(%a7)
|
| 68 |
|
|
moveml %d0-%d1/%a0-%a1,USER_DA(%a6)
|
| 69 |
|
|
fmovemx %fp0-%fp3,USER_FP0(%a6)
|
| 70 |
|
|
fmoveml %fpcr/%fpsr/%fpiar,USER_FPCR(%a6)
|
| 71 |
|
|
|
| 72 |
|
|
|
|
| 73 |
|
|
| Check if this is an opclass 3 instruction.
|
| 74 |
|
|
| If so, fall through, else branch to operr_end
|
| 75 |
|
|
|
|
| 76 |
|
|
btstb #TFLAG,T_BYTE(%a6)
|
| 77 |
|
|
beqs operr_end
|
| 78 |
|
|
|
| 79 |
|
|
|
|
| 80 |
|
|
| If the destination size is B,W,or L, the operr must be
|
| 81 |
|
|
| handled here.
|
| 82 |
|
|
|
|
| 83 |
|
|
movel CMDREG1B(%a6),%d0
|
| 84 |
|
|
bfextu %d0{#3:#3},%d0 |0=long, 4=word, 6=byte
|
| 85 |
|
|
cmpib #0,%d0 |determine size; check long
|
| 86 |
|
|
beq operr_long
|
| 87 |
|
|
cmpib #4,%d0 |check word
|
| 88 |
|
|
beq operr_word
|
| 89 |
|
|
cmpib #6,%d0 |check byte
|
| 90 |
|
|
beq operr_byte
|
| 91 |
|
|
|
| 92 |
|
|
|
|
| 93 |
|
|
| The size is not B,W,or L, so the operr is handled by the
|
| 94 |
|
|
| kernel handler. Set the operr bits and clean up, leaving
|
| 95 |
|
|
| only the integer exception frame on the stack, and the
|
| 96 |
|
|
| fpu in the original exceptional state.
|
| 97 |
|
|
|
|
| 98 |
|
|
operr_end:
|
| 99 |
|
|
bsetb #operr_bit,FPSR_EXCEPT(%a6)
|
| 100 |
|
|
bsetb #aiop_bit,FPSR_AEXCEPT(%a6)
|
| 101 |
|
|
|
| 102 |
|
|
moveml USER_DA(%a6),%d0-%d1/%a0-%a1
|
| 103 |
|
|
fmovemx USER_FP0(%a6),%fp0-%fp3
|
| 104 |
|
|
fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar
|
| 105 |
|
|
frestore (%a7)+
|
| 106 |
|
|
unlk %a6
|
| 107 |
|
|
bral real_operr
|
| 108 |
|
|
|
| 109 |
|
|
operr_long:
|
| 110 |
|
|
moveql #4,%d1 |write size to d1
|
| 111 |
|
|
moveb STAG(%a6),%d0 |test stag for nan
|
| 112 |
|
|
andib #0xe0,%d0 |clr all but tag
|
| 113 |
|
|
cmpib #0x60,%d0 |check for nan
|
| 114 |
|
|
beq operr_nan
|
| 115 |
|
|
cmpil #0x80000000,FPTEMP_LO(%a6) |test if ls lword is special
|
| 116 |
|
|
bnes chklerr |if not equal, check for incorrect operr
|
| 117 |
|
|
bsr check_upper |check if exp and ms mant are special
|
| 118 |
|
|
tstl %d0
|
| 119 |
|
|
bnes chklerr |if d0 is true, check for incorrect operr
|
| 120 |
|
|
movel #0x80000000,%d0 |store special case result
|
| 121 |
|
|
bsr operr_store
|
| 122 |
|
|
bra not_enabled |clean and exit
|
| 123 |
|
|
|
|
| 124 |
|
|
| CHECK FOR INCORRECTLY GENERATED OPERR EXCEPTION HERE
|
| 125 |
|
|
|
|
| 126 |
|
|
chklerr:
|
| 127 |
|
|
movew FPTEMP_EX(%a6),%d0
|
| 128 |
|
|
andw #0x7FFF,%d0 |ignore sign bit
|
| 129 |
|
|
cmpw #0x3FFE,%d0 |this is the only possible exponent value
|
| 130 |
|
|
bnes chklerr2
|
| 131 |
|
|
fixlong:
|
| 132 |
|
|
movel FPTEMP_LO(%a6),%d0
|
| 133 |
|
|
bsr operr_store
|
| 134 |
|
|
bra not_enabled
|
| 135 |
|
|
chklerr2:
|
| 136 |
|
|
movew FPTEMP_EX(%a6),%d0
|
| 137 |
|
|
andw #0x7FFF,%d0 |ignore sign bit
|
| 138 |
|
|
cmpw #0x4000,%d0
|
| 139 |
|
|
bcc store_max |exponent out of range
|
| 140 |
|
|
|
| 141 |
|
|
movel FPTEMP_LO(%a6),%d0
|
| 142 |
|
|
andl #0x7FFF0000,%d0 |look for all 1's on bits 30-16
|
| 143 |
|
|
cmpl #0x7FFF0000,%d0
|
| 144 |
|
|
beqs fixlong
|
| 145 |
|
|
|
| 146 |
|
|
tstl FPTEMP_LO(%a6)
|
| 147 |
|
|
bpls chklepos
|
| 148 |
|
|
cmpl #0xFFFFFFFF,FPTEMP_HI(%a6)
|
| 149 |
|
|
beqs fixlong
|
| 150 |
|
|
bra store_max
|
| 151 |
|
|
chklepos:
|
| 152 |
|
|
tstl FPTEMP_HI(%a6)
|
| 153 |
|
|
beqs fixlong
|
| 154 |
|
|
bra store_max
|
| 155 |
|
|
|
| 156 |
|
|
operr_word:
|
| 157 |
|
|
moveql #2,%d1 |write size to d1
|
| 158 |
|
|
moveb STAG(%a6),%d0 |test stag for nan
|
| 159 |
|
|
andib #0xe0,%d0 |clr all but tag
|
| 160 |
|
|
cmpib #0x60,%d0 |check for nan
|
| 161 |
|
|
beq operr_nan
|
| 162 |
|
|
cmpil #0xffff8000,FPTEMP_LO(%a6) |test if ls lword is special
|
| 163 |
|
|
bnes chkwerr |if not equal, check for incorrect operr
|
| 164 |
|
|
bsr check_upper |check if exp and ms mant are special
|
| 165 |
|
|
tstl %d0
|
| 166 |
|
|
bnes chkwerr |if d0 is true, check for incorrect operr
|
| 167 |
|
|
movel #0x80000000,%d0 |store special case result
|
| 168 |
|
|
bsr operr_store
|
| 169 |
|
|
bra not_enabled |clean and exit
|
| 170 |
|
|
|
|
| 171 |
|
|
| CHECK FOR INCORRECTLY GENERATED OPERR EXCEPTION HERE
|
| 172 |
|
|
|
|
| 173 |
|
|
chkwerr:
|
| 174 |
|
|
movew FPTEMP_EX(%a6),%d0
|
| 175 |
|
|
andw #0x7FFF,%d0 |ignore sign bit
|
| 176 |
|
|
cmpw #0x3FFE,%d0 |this is the only possible exponent value
|
| 177 |
|
|
bnes store_max
|
| 178 |
|
|
movel FPTEMP_LO(%a6),%d0
|
| 179 |
|
|
swap %d0
|
| 180 |
|
|
bsr operr_store
|
| 181 |
|
|
bra not_enabled
|
| 182 |
|
|
|
| 183 |
|
|
operr_byte:
|
| 184 |
|
|
moveql #1,%d1 |write size to d1
|
| 185 |
|
|
moveb STAG(%a6),%d0 |test stag for nan
|
| 186 |
|
|
andib #0xe0,%d0 |clr all but tag
|
| 187 |
|
|
cmpib #0x60,%d0 |check for nan
|
| 188 |
|
|
beqs operr_nan
|
| 189 |
|
|
cmpil #0xffffff80,FPTEMP_LO(%a6) |test if ls lword is special
|
| 190 |
|
|
bnes chkberr |if not equal, check for incorrect operr
|
| 191 |
|
|
bsr check_upper |check if exp and ms mant are special
|
| 192 |
|
|
tstl %d0
|
| 193 |
|
|
bnes chkberr |if d0 is true, check for incorrect operr
|
| 194 |
|
|
movel #0x80000000,%d0 |store special case result
|
| 195 |
|
|
bsr operr_store
|
| 196 |
|
|
bra not_enabled |clean and exit
|
| 197 |
|
|
|
|
| 198 |
|
|
| CHECK FOR INCORRECTLY GENERATED OPERR EXCEPTION HERE
|
| 199 |
|
|
|
|
| 200 |
|
|
chkberr:
|
| 201 |
|
|
movew FPTEMP_EX(%a6),%d0
|
| 202 |
|
|
andw #0x7FFF,%d0 |ignore sign bit
|
| 203 |
|
|
cmpw #0x3FFE,%d0 |this is the only possible exponent value
|
| 204 |
|
|
bnes store_max
|
| 205 |
|
|
movel FPTEMP_LO(%a6),%d0
|
| 206 |
|
|
asll #8,%d0
|
| 207 |
|
|
swap %d0
|
| 208 |
|
|
bsr operr_store
|
| 209 |
|
|
bra not_enabled
|
| 210 |
|
|
|
| 211 |
|
|
|
|
| 212 |
|
|
| This operr condition is not of the special case. Set operr
|
| 213 |
|
|
| and aiop and write the portion of the nan to memory for the
|
| 214 |
|
|
| given size.
|
| 215 |
|
|
|
|
| 216 |
|
|
operr_nan:
|
| 217 |
|
|
orl #opaop_mask,USER_FPSR(%a6) |set operr & aiop
|
| 218 |
|
|
|
| 219 |
|
|
movel ETEMP_HI(%a6),%d0 |output will be from upper 32 bits
|
| 220 |
|
|
bsr operr_store
|
| 221 |
|
|
bra end_operr
|
| 222 |
|
|
|
|
| 223 |
|
|
| Store_max loads the max pos or negative for the size, sets
|
| 224 |
|
|
| the operr and aiop bits, and clears inex and ainex, incorrectly
|
| 225 |
|
|
| set by the 040.
|
| 226 |
|
|
|
|
| 227 |
|
|
store_max:
|
| 228 |
|
|
orl #opaop_mask,USER_FPSR(%a6) |set operr & aiop
|
| 229 |
|
|
bclrb #inex2_bit,FPSR_EXCEPT(%a6)
|
| 230 |
|
|
bclrb #ainex_bit,FPSR_AEXCEPT(%a6)
|
| 231 |
|
|
fmovel #0,%FPSR
|
| 232 |
|
|
|
| 233 |
|
|
tstw FPTEMP_EX(%a6) |check sign
|
| 234 |
|
|
blts load_neg
|
| 235 |
|
|
movel #0x7fffffff,%d0
|
| 236 |
|
|
bsr operr_store
|
| 237 |
|
|
bra end_operr
|
| 238 |
|
|
load_neg:
|
| 239 |
|
|
movel #0x80000000,%d0
|
| 240 |
|
|
bsr operr_store
|
| 241 |
|
|
bra end_operr
|
| 242 |
|
|
|
| 243 |
|
|
|
|
| 244 |
|
|
| This routine stores the data in d0, for the given size in d1,
|
| 245 |
|
|
| to memory or data register as required. A read of the fline
|
| 246 |
|
|
| is required to determine the destination.
|
| 247 |
|
|
|
|
| 248 |
|
|
operr_store:
|
| 249 |
|
|
movel %d0,L_SCR1(%a6) |move write data to L_SCR1
|
| 250 |
|
|
movel %d1,-(%a7) |save register size
|
| 251 |
|
|
bsrl get_fline |fline returned in d0
|
| 252 |
|
|
movel (%a7)+,%d1
|
| 253 |
|
|
bftst %d0{#26:#3} |if mode is zero, dest is Dn
|
| 254 |
|
|
bnes dest_mem
|
| 255 |
|
|
|
|
| 256 |
|
|
| Destination is Dn. Get register number from d0. Data is on
|
| 257 |
|
|
| the stack at (a7). D1 has size: 1=byte,2=word,4=long/single
|
| 258 |
|
|
|
|
| 259 |
|
|
andil #7,%d0 |isolate register number
|
| 260 |
|
|
cmpil #4,%d1
|
| 261 |
|
|
beqs op_long |the most frequent case
|
| 262 |
|
|
cmpil #2,%d1
|
| 263 |
|
|
bnes op_con
|
| 264 |
|
|
orl #8,%d0
|
| 265 |
|
|
bras op_con
|
| 266 |
|
|
op_long:
|
| 267 |
|
|
orl #0x10,%d0
|
| 268 |
|
|
op_con:
|
| 269 |
|
|
movel %d0,%d1 |format size:reg for reg_dest
|
| 270 |
|
|
bral reg_dest |call to reg_dest returns to caller
|
| 271 |
|
|
| ;of operr_store
|
| 272 |
|
|
|
|
| 273 |
|
|
| Destination is memory. Get from integer exception frame
|
| 274 |
|
|
| and call mem_write.
|
| 275 |
|
|
|
|
| 276 |
|
|
dest_mem:
|
| 277 |
|
|
leal L_SCR1(%a6),%a0 |put ptr to write data in a0
|
| 278 |
|
|
movel EXC_EA(%a6),%a1 |put user destination address in a1
|
| 279 |
|
|
movel %d1,%d0 |put size in d0
|
| 280 |
|
|
bsrl mem_write
|
| 281 |
|
|
rts
|
| 282 |
|
|
|
|
| 283 |
|
|
| Check the exponent for $c000 and the upper 32 bits of the
|
| 284 |
|
|
| mantissa for $ffffffff. If both are true, return d0 clr
|
| 285 |
|
|
| and store the lower n bits of the least lword of FPTEMP
|
| 286 |
|
|
| to d0 for write out. If not, it is a real operr, and set d0.
|
| 287 |
|
|
|
|
| 288 |
|
|
check_upper:
|
| 289 |
|
|
cmpil #0xffffffff,FPTEMP_HI(%a6) |check if first byte is all 1's
|
| 290 |
|
|
bnes true_operr |if not all 1's then was true operr
|
| 291 |
|
|
cmpiw #0xc000,FPTEMP_EX(%a6) |check if incorrectly signalled
|
| 292 |
|
|
beqs not_true_operr |branch if not true operr
|
| 293 |
|
|
cmpiw #0xbfff,FPTEMP_EX(%a6) |check if incorrectly signalled
|
| 294 |
|
|
beqs not_true_operr |branch if not true operr
|
| 295 |
|
|
true_operr:
|
| 296 |
|
|
movel #1,%d0 |signal real operr
|
| 297 |
|
|
rts
|
| 298 |
|
|
not_true_operr:
|
| 299 |
|
|
clrl %d0 |signal no real operr
|
| 300 |
|
|
rts
|
| 301 |
|
|
|
| 302 |
|
|
|
|
| 303 |
|
|
| End_operr tests for operr enabled. If not, it cleans up the stack
|
| 304 |
|
|
| and does an rte. If enabled, it cleans up the stack and branches
|
| 305 |
|
|
| to the kernel operr handler with only the integer exception
|
| 306 |
|
|
| frame on the stack and the fpu in the original exceptional state
|
| 307 |
|
|
| with correct data written to the destination.
|
| 308 |
|
|
|
|
| 309 |
|
|
end_operr:
|
| 310 |
|
|
btstb #operr_bit,FPCR_ENABLE(%a6)
|
| 311 |
|
|
beqs not_enabled
|
| 312 |
|
|
enabled:
|
| 313 |
|
|
moveml USER_DA(%a6),%d0-%d1/%a0-%a1
|
| 314 |
|
|
fmovemx USER_FP0(%a6),%fp0-%fp3
|
| 315 |
|
|
fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar
|
| 316 |
|
|
frestore (%a7)+
|
| 317 |
|
|
unlk %a6
|
| 318 |
|
|
bral real_operr
|
| 319 |
|
|
|
| 320 |
|
|
not_enabled:
|
| 321 |
|
|
|
|
| 322 |
|
|
| It is possible to have either inex2 or inex1 exceptions with the
|
| 323 |
|
|
| operr. If the inex enable bit is set in the FPCR, and either
|
| 324 |
|
|
| inex2 or inex1 occurred, we must clean up and branch to the
|
| 325 |
|
|
| real inex handler.
|
| 326 |
|
|
|
|
| 327 |
|
|
ck_inex:
|
| 328 |
|
|
moveb FPCR_ENABLE(%a6),%d0
|
| 329 |
|
|
andb FPSR_EXCEPT(%a6),%d0
|
| 330 |
|
|
andib #0x3,%d0
|
| 331 |
|
|
beq operr_exit
|
| 332 |
|
|
|
|
| 333 |
|
|
| Inexact enabled and reported, and we must take an inexact exception.
|
| 334 |
|
|
|
|
| 335 |
|
|
take_inex:
|
| 336 |
|
|
moveb #INEX_VEC,EXC_VEC+1(%a6)
|
| 337 |
|
|
movel USER_FPSR(%a6),FPSR_SHADOW(%a6)
|
| 338 |
|
|
orl #sx_mask,E_BYTE(%a6)
|
| 339 |
|
|
moveml USER_DA(%a6),%d0-%d1/%a0-%a1
|
| 340 |
|
|
fmovemx USER_FP0(%a6),%fp0-%fp3
|
| 341 |
|
|
fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar
|
| 342 |
|
|
frestore (%a7)+
|
| 343 |
|
|
unlk %a6
|
| 344 |
|
|
bral real_inex
|
| 345 |
|
|
|
|
| 346 |
|
|
| Since operr is only an E1 exception, there is no need to frestore
|
| 347 |
|
|
| any state back to the fpu.
|
| 348 |
|
|
|
|
| 349 |
|
|
operr_exit:
|
| 350 |
|
|
moveml USER_DA(%a6),%d0-%d1/%a0-%a1
|
| 351 |
|
|
fmovemx USER_FP0(%a6),%fp0-%fp3
|
| 352 |
|
|
fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar
|
| 353 |
|
|
unlk %a6
|
| 354 |
|
|
bral fpsp_done
|
| 355 |
|
|
|
| 356 |
|
|
|end
|
