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|       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, then pack source (fpm)

|                       and store in users memory .

|

|  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|       THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA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:

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        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