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| x_unimp.sa 3.3 7/1/91
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| fpsp_unimp --- FPSP handler for unimplemented instruction
| exception.
|
| Invoked when the user program encounters a floating-point
| op-code that hardware does not support. Trap vector# 11
| (See table 8-1 MC68030 User's Manual).
|
|
| Note: An fsave for an unimplemented inst. will create a short
| fsave stack.
|
| Input: 1. Six word stack frame for unimplemented inst, four word
| for illegal
| (See table 8-7 MC68030 User's Manual).
| 2. Unimp (short) fsave state frame created here by fsave
| instruction.
|
|
| Copyright (C) Motorola, Inc. 1990
| All Rights Reserved
|
| For details on the license for this file, please see the
| file, README, in this same directory.
X_UNIMP: |idnt 2,1 | Motorola 040 Floating Point Software Package
|section 8
#include "fpsp.h"
|xref get_op
|xref do_func
|xref sto_res
|xref gen_except
|xref fpsp_fmt_error
.global fpsp_unimp
.global uni_2
fpsp_unimp:
link %a6,#-LOCAL_SIZE
fsave -(%a7)
uni_2:
moveml %d0-%d1/%a0-%a1,USER_DA(%a6)
fmovemx %fp0-%fp3,USER_FP0(%a6)
fmoveml %fpcr/%fpsr/%fpiar,USER_FPCR(%a6)
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
|
| Temporary D25B Fix
| The following lines are used to ensure that the FPSR
| exception byte and condition codes are clear before proceeding
|
movel USER_FPSR(%a6),%d0
andl #0xFF00FF,%d0 |clear all but accrued exceptions
movel %d0,USER_FPSR(%a6)
fmovel #0,%FPSR |clear all user bits
fmovel #0,%FPCR |clear all user exceptions for FPSP
clrb UFLG_TMP(%a6) |clr flag for unsupp data
bsrl get_op |go get operand(s)
clrb STORE_FLG(%a6)
bsrl do_func |do the function
fsave -(%a7) |capture possible exc state
tstb STORE_FLG(%a6)
bnes no_store |if STORE_FLG is set, no store
bsrl sto_res |store the result in user space
no_store:
bral gen_except |post any exceptions and return
|end
|
