1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
//
// $Id$
//
// 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// THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA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
|section 8
#include "fpsp.defs"
|xref real_fline
|xref fpsp_unimp
|xref uni_2
|xref mem_read
|xref fpsp_fmt_error
.global fpsp_fline
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.
//
cmpw #UNIMP_VEC,EXC_VEC-4(%a7)
beql fpsp_unimp
//
// fmovecr with non-zero <ea> handling here
//
subl #4,%a7 //4 accounts for 2-word difference
// ;between six word frame (unimp) and
// ;four word frame
link %a6,#-LOCAL_SIZE
fsave -(%a7)
moveml %d0-%d1/%a0-%a1,USER_DA(%a6)
moveal EXC_PC+4(%a6),%a0 //get address of fline instruction
leal L_SCR1(%a6),%a1 //use L_SCR1 as scratch
movel #4,%d0
addl #4,%a6 //to offset the sub.l #4,a7 above so that
// ;a6 can point correctly to the stack frame
// ;before branching to mem_read
bsrl mem_read
subl #4,%a6
movel L_SCR1(%a6),%d0 //d0 contains the fline and command word
bfextu %d0{#4:#3},%d1 //extract coprocessor id
cmpib #1,%d1 //check if cpid=1
bne not_mvcr //exit if not
bfextu %d0{#16:#6},%d1
cmpib #0x17,%d1 //check if it is an FMOVECR encoding
bne not_mvcr
// ;if an FMOVECR instruction, fix stack
// ;and go to FPSP_UNIMP
fix_stack:
cmpib #VER_40,(%a7) //test for orig unimp frame
bnes ck_rev
subl #UNIMP_40_SIZE-4,%a7 //emulate an orig fsave
moveb #VER_40,(%a7)
moveb #UNIMP_40_SIZE-4,1(%a7)
clrw 2(%a7)
bras fix_con
ck_rev:
cmpib #VER_41,(%a7) //test for rev unimp frame
bnel fpsp_fmt_error //if not $40 or $41, exit with error
subl #UNIMP_41_SIZE-4,%a7 //emulate a rev fsave
moveb #VER_41,(%a7)
moveb #UNIMP_41_SIZE-4,1(%a7)
clrw 2(%a7)
fix_con:
movew EXC_SR+4(%a6),EXC_SR(%a6) //move stacked sr to new position
movel EXC_PC+4(%a6),EXC_PC(%a6) //move stacked pc to new position
fmovel EXC_PC(%a6),%FPIAR //point FPIAR to fline inst
movel #4,%d1
addl %d1,EXC_PC(%a6) //increment stacked pc value to next inst
movew #0x202c,EXC_VEC(%a6) //reformat vector to unimp
clrl EXC_EA(%a6) //clear the EXC_EA field
movew %d0,CMDREG1B(%a6) //move the lower word into CMDREG1B
clrl E_BYTE(%a6)
bsetb #UFLAG,T_BYTE(%a6)
moveml USER_DA(%a6),%d0-%d1/%a0-%a1 //restore data registers
bral uni_2
not_mvcr:
moveml USER_DA(%a6),%d0-%d1/%a0-%a1 //restore data registers
frestore (%a7)+
unlk %a6
addl #4,%a7
bral real_fline
|end
|
