source: trunk/libs/newlib/src/newlib/libc/machine/m32c/setjmp.S @ 444

Last change on this file since 444 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 3.8 KB
Line 
1/*
2
3Copyright (c) 2005 Red Hat Incorporated.
4All rights reserved.
5
6Redistribution and use in source and binary forms, with or without
7modification, are permitted provided that the following conditions are met:
8
9    Redistributions of source code must retain the above copyright
10    notice, this list of conditions and the following disclaimer.
11
12    Redistributions in binary form must reproduce the above copyright
13    notice, this list of conditions and the following disclaimer in the
14    documentation and/or other materials provided with the distribution.
15
16    The name of Red Hat Incorporated may not be used to endorse
17    or promote products derived from this software without specific
18    prior written permission.
19
20THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
23DISCLAIMED.  IN NO EVENT SHALL RED HAT INCORPORATED BE LIABLE FOR ANY
24DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
25(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
27ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31*/
32
33#if defined(__r8c_cpu__) || defined(__m16c_cpu__)
34#define A16 1
35#endif
36
37/* We implement setjmp/longjmp much like the way gcc implements
38   exceptions - we create new stack frames, then switch to them and
39   return.  Thus, the two setjmp's below each push all the relevent
40   registers, then copy the whole frame into the buffer (first $sp is
41   moved, then smovf copies the frame itself), and the two longjmps
42   restore $sp, copy the frame back into place, and issue the same
43   return as the setjmp would have used.
44
45   Since the sizes of registers differs between the 16 and 24 bit
46   models, we provide separate implementations for each rather than
47   trying to parameterize them.
48
49   Jump buffer sizes: 21 bytes for 16 bit, 34 bytes for 24 bit.
50*/
51
52        .text
53
54#ifdef A16      /* 16 bit versions */
55
56        .global _setjmp
57_setjmp:
58        enter   #0
59        pushm   r1,r2,r3,a0,a1,sb,fb
60
61; At this point, the stack looks like this:
62; ... [pc:3] [oldfb:2] <fb> [r1:2] [r2:2] [r3:2] [a0:2] [a1:2] [sb:2] [fb:2] <sp> */
63
64        mov.w   r1,a1           ;  a1 is the destination of smovf
65        mov.b   #0,r1h
66        stc     sp,a0           ;  r1h:a0 is the source of smovf
67        mov.w   a0,[a1]
68        add.w   #2,a1
69        mov.w   #19,r3          ;  plus two for sp later
70        smovf.b
71
72        ; Return 0 to caller.
73        mov.w   #0,r0
74        popm    r1,r2,r3,a0,a1,sb,fb
75        exitd
76
77        .global _longjmp
78_longjmp:
79        enter   #0
80        mov.w   r1,a0           ;  pointer to jump buf
81        mov.w   r2,r0           ;  setjmp's "new" return value
82
83        mov.b   #0,r1h          ;  r1h: a0 is the source, now jmpbuf
84        mov.w   [a0],a1         ;  dest is new stack
85        ldc     a1,sp
86        add.w   #2,a0
87        mov.w   #19,r3
88        smovf.b
89
90        ;; now return to our caller with this newly restored frame
91        popm    r1,r2,r3,a0,a1,sb,fb
92        exitd
93
94#else   /* 24 bit versions */
95
96        .global _setjmp
97_setjmp:
98        enter   #0
99        pushm   r1,r2,r3,a0,a1,sb,fb
100
101; At this point, the stack looks like this:
102; ... [jbuf:4] [pc:4] [oldfb:4] <fb> [r1:2] [r2:2] [r3:2] [a0:4] [a1:4] [sb:4] [fb:4] <sp> */
103
104        mov.l   8[fb],a1        ;  a1 is the destination of smovf
105        stc     sp,a0           ;  r1h:a0 is the source of smovf
106        mov.l   a0,[a1]
107        add.l   #4,a1
108        mov.w   #30,r3          ;  plus two for sp later
109        smovf.b
110
111        ; Return 0 to caller.
112        mov.w   #0,r0
113        popm    r1,r2,r3,a0,a1,sb,fb
114        exitd
115
116        .global _longjmp
117_longjmp:
118        enter   #0
119; ... [rv:2] [jbuf:4] [pc:4] [oldfb:4] <fb>
120        mov.l   8[fb],a0        ;  pointer to jump buf
121        mov.w   12[fb],r0       ;  setjmp's "new" return value
122
123        mov.l   [a0],a1         ;  dest is new stack
124        ldc     a1,sp
125        add.l   #4,a0
126        mov.w   #30,r3
127        smovf.b
128
129        ;; now return to our caller with this newly restored frame
130        popm    r1,r2,r3,a0,a1,sb,fb
131        exitd
132#endif
133
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