Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

|

|       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

|

|       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