supermario/base/SuperMarioProj.1994-02-09/OS/FPUEmulation/XFLine.a
2019-06-29 23:17:50 +08:00

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;
; File: XFLine.a
;
; Contains: Routines for handle F-Line traps in general
;
; Originally Written by: Motorola Inc.
; Adapted to Apple/MPW: Jon Okada
;
; Copyright: © 1990, 1991 by Apple Computer, Inc., all rights reserved.
;
; This file is used in these builds: Mac32
;
; Change History (most recent first):
;
; <2+> 6/24/91 BG Folded in Motorola version 2.0 fixes for handling FMOVECR
; instructions with non-zero <ea> fields.
; <2> 3/30/91 BG Rolling in Jon Okada's latest changes.
; <1> 12/14/90 BG First checked into TERROR/BBS.
; xfline.a
; Based upon Motorola file 'x_fline.sa'.
; CHANGE LOG:
; 08 Jan 91 JPO Inserted label "fline" at top of code. Modified code
; for branching to system fline handler. Streamlined
; code for reading fline instruction. Renamed label
; "ck_rev" to "flck_rev".
; 13 Jun 91 JPO Folded in Motorola version 2.0 fixes for handling FMOVECR
; instructions with non-zero <ea> fields.
;
*
* x_fline.sa 3.3 1/10/91
*
* fpsp_fline --- FPSP handler for fline exception
*
* First determine if the exception is one of the unimplemented
* floating point instructions. If so, let fpsp_unimp handle it.
* Next, determine if the instruction is an fmovecr with a non-zero
* <ea> field. If so, handle here and return. Otherwise, it
* must be a real F-line exception.
*
* 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* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA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_FLINE IDNT 2,1 Motorola 040 Floating Point Software Package
fline: ; <1/8/91, JPO>
fpsp_fline:
*
* check for unimplemented vector first. Use EXC_VEC-4 because
* the equate is valid only after a 'link a6' has pushed one more
* long onto the stack.
*
cmp.w #UNIMP_VEC,EXC_VEC-4(a7)
beq fpsp_unimp
*
* fmovecr with non-zero <ea> handling here
*
sub.l #4,a7 ;4 accounts for 2-word difference
* ;between six word frame (unimp) and
* ;four word frame
link a6,#-LOCAL_SIZE
fsave -(a7) ; ADDED <6/13/91, JPO> <T3>
movem.l d0-d1/a0-a1,USER_DA(a6)
movea.l EXC_PC+4(a6),a0 ;get address of fline instruction
; lea.l L_SCR1(a6),a1 ;use L_SCR1 as scratch - deleted <1/8/91, JPO>
; move.l #4,d0 ; deleted <1/8/91, JPO>
; bsr.l mem_read ; deleted <1/8/91, JPO>
; move.l L_SCR1(a6),d0 ;d0 contains the fline and command word - deleted <1/8/91, JPO>
move.l (a0),d0 ; d0 contains the fline and command word <1/8/91, JPO>
bfextu d0{4:3},d1 ;extract coprocessor id
cmpi.b #1,d1 ;check if cpid=1
bne.b not_mvcr ;exit if not
bfextu d0{16:6},d1
cmpi.b #$17,d1 ;check if it is an FMOVECR encoding
bne.b not_mvcr
* ;if an FMOVECR instruction, fix stack
* ;and go to FPSP_UNIMP
;fix_stack: ; label deleted <1/8/91, JPO>
cmpi.b #VER_40,(a7) ;test for orig unimp frame
bne.b flck_rev ; label renamed <1/8/91, JPO>
; sub.l #UNIMP_40_SIZE,a7 ;emulate an orig fsave - DELETED <6/13/91, JPO> <T3>
sub.l #UNIMP_40_SIZE-4,a7 ;emulate an orig fsave - ADDED <6/13/91, JPO> <T3>
move.b #VER_40,(a7)
; clr.b 1(a7) ; DELETED <6/13/91, JPO> <T3>
move.b #UNIMP_40_SIZE-4,1(a7) ; ADDED <6/13/91, JPO> <T3>
clr.w 2(a7)
bra.b fix_con
flck_rev: ; label renamed <1/8/91, JPO>
cmpi.b #VER_41,(a7) ;test for rev unimp frame
bne fpsp_fmt_error ;if not $40 or $41, exit with error
; sub.l #UNIMP_41_SIZE,a7 ;emulate a rev fsave - DELETED <6/13/91, JPO> <T3>
sub.l #UNIMP_41_SIZE-4,a7 ;emulate a rev fsave - ADDED <6/13/91, JPO> <T3>
move.b #VER_41,(a7)
; clr.b 1(a7) ; DELETED <6/13/91, JPO> <T3>
move.b #UNIMP_41_SIZE-4,1(a7) ; ADDED <6/13/91, JPO> <T3>
clr.w 2(a7)
fix_con:
move.w EXC_SR+4(a6),EXC_SR(a6) ;move stacked sr to new position
move.l EXC_PC+4(a6),EXC_PC(a6) ;move stacked pc to new position
fmove.l EXC_PC(a6),FPIAR ;point FPIAR to fline inst
move.l #4,d1
add.l d1,EXC_PC(a6) ;increment stacked pc value to next inst
move.w #$202c,EXC_VEC(a6) ;reformat vector to unimp
clr.l EXC_EA(a6) ;clear the EXC_EA field
move.w d0,CMDREG1B(a6) ;move the lower word into CMDREG1B
clr.l E_BYTE(a6)
bset.b #UFLAG,T_BYTE(a6)
movem.l USER_DA(a6),d0-d1/a0-a1 ;restore data registers
bra uni_2
not_mvcr:
movem.l USER_DA(a6),d0-d1/a0-a1 ;restore data registers
frestore (a7)+ ; ADDED <6/13/91, JPO> <T3>
unlk a6
add.l #4,a7
; bra.l real_fline ; deleted <1/8/91, JPO>
move.l (FLINE_VEC040).W,-(sp) ; push vector to user's handler <1/8/91, JPO>
rts ; execute user's handler <1/8/91, JPO>