|
| x_unsupp.sa 3.3 7/1/91
|
| fpsp_unsupp --- FPSP handler for unsupported data type exception
|
| Trap vector #55 (See table 8-1 Mc68030 User's manual).
| Invoked when the user program encounters a data format (packed) that
| hardware does not support or a data type (denormalized numbers or un-
| normalized numbers).
| Normalizes denorms and unnorms, unpacks packed numbers then stores
| them back into the machine to let the 040 finish the operation.
|
| Unsupp calls two routines:
| 1. get_op - gets the operand(s)
| 2. res_func - restore the function back into the 040 or
| if fmove.p fpm,<ea> then pack source (fpm)
| and store in users memory <ea>.
|
| Input: Long fsave stack frame
|
|
| Copyright (C) Motorola, Inc. 1990
| All Rights Reserved
|
| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
| The copyright notice above does not evidence any
| actual or intended publication of such source code.
X_UNSUPP: |idnt 2,1 | Motorola 040 Floating Point Software Package
|section 8
#include "fpsp.h"
|xref get_op
|xref res_func
|xref gen_except
|xref fpsp_fmt_error
.global fpsp_unsupp
fpsp_unsupp:
|
link %a6,#-LOCAL_SIZE
fsave -(%a7)
moveml %d0-%d1/%a0-%a1,USER_DA(%a6)
fmovemx %fp0-%fp3,USER_FP0(%a6)
fmoveml %fpcr/%fpsr/%fpiar,USER_FPCR(%a6)
moveb (%a7),VER_TMP(%a6) |save version number
moveb (%a7),%d0 |test for valid version num
andib #0xf0,%d0 |test for $4x
cmpib #VER_4,%d0 |must be $4x or exit
bnel fpsp_fmt_error
fmovel #0,%FPSR |clear all user status bits
fmovel #0,%FPCR |clear all user control bits
|
| The following lines are used to ensure that the FPSR
| exception byte and condition codes are clear before proceeding,
| except in the case of fmove, which leaves the cc's intact.
|
unsupp_con:
movel USER_FPSR(%a6),%d1
btst #5,CMDREG1B(%a6) |looking for fmove out
bne fmove_con
andl #0xFF00FF,%d1 |clear all but aexcs and qbyte
bras end_fix
fmove_con:
andl #0x0FFF40FF,%d1 |clear all but cc's, snan bit, aexcs, and qbyte
end_fix:
movel %d1,USER_FPSR(%a6)
st UFLG_TMP(%a6) |set flag for unsupp data
bsrl get_op |everything okay, go get operand(s)
bsrl res_func |fix up stack frame so can restore it
clrl -(%a7)
moveb VER_TMP(%a6),(%a7) |move idle fmt word to top of stack
bral gen_except
|
|end
