1/* Implementation of profiling support. C-SKY ABIV2 version.
2 Copyright (C) 2018-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <sysdep.h>
20
21/* Use an assembly stub with a special ABI. The calling lr has been
22 pushed to the stack (which will be misaligned). We should preserve
23 all registers except ip and pop a word off the stack.
24
25 NOTE: This assumes mcount_internal does not clobber any non-core
26 (coprocessor) registers. Currently this is true, but may require
27 additional attention in the future.
28
29 The calling sequence looks something like:
30func:
31 push lr
32 jbsr _mount
33 <function body>
34*/
35
36/* Don't call mcount when calling mcount... */
37#undef PROF
38
39ENTRY (_mcount)
40 subi sp, 20
41 stw a0, (sp, 0)
42 stw a1, (sp, 4)
43 stw a2, (sp, 8)
44 stw a3, (sp, 12)
45 stw lr, (sp, 16)
46 mov a1, lr
47 ldw a0, (sp, 20)
48#ifdef __PIC__
49 grs t1, .Lgetpc
50.Lgetpc:
51 lrw t0, .Lgetpc@GOTPC
52 addu t1, t0
53 lrw t0, __mcount_internal@PLT
54 ldr.w t0, (t1, t0 << 0)
55 jsr t0
56#else
57 jsri __mcount_internal
58#endif /* !__PIC__ */
59 ldw a0, (sp, 0)
60 ldw a1, (sp, 4)
61 ldw a2, (sp, 8)
62 ldw a3, (sp, 12)
63 ldw t1, (sp, 16)
64 ldw lr, (sp, 20)
65 addi sp, 24
66 jmp t1
67END (_mcount)
68

source code of glibc/sysdeps/csky/abiv2/csky-mcount.S