x_unimp.s

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

//
//      $Id: x_unimp.S,v 1.1 1998/12/14 23:15:33 joel Exp $
//
//	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//	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA 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.defs"

	|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