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|
|       x_unimp.sa 3.3 7/1/91
|
|       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
|
|       THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA 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_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