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comparison dyncall/dyncall_call_arm32_thumb_apple.s @ 0:3e629dc19168

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initial from svn dyncall-1745
author Daniel Adler
date Thu, 19 Mar 2015 22:24:28 +0100
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children 351bb41d3bb1
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-1:000000000000 0:3e629dc19168
1 /*
2
3 Package: dyncall
4 Library: dyncall
5 File: dyncall/dyncall_call_arm32_thumb_apple.s
6 Description: ARM Thumb call kernel implementation for apple assembler.
7 License:
8
9 Copyright (c) 2007-2011 Daniel Adler <dadler@uni-goettingen.de>,
10 Tassilo Philipp <tphilipp@potion-studios.com>
11
12 Permission to use, copy, modify, and distribute this software for any
13 purpose with or without fee is hereby granted, provided that the above
14 copyright notice and this permission notice appear in all copies.
15
16 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
17 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
18 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
19 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
20 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
21 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
22 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23
24 */
25
26
27 .text
28 .thumb
29 .code 16
30 .globl _dcCall_arm32_thumb
31
32 /* Main dyncall call. */
33 .thumb_func
34 _dcCall_arm32_thumb:
35
36 /* Prolog. This function never needs to spill inside its prolog, so just store the permanent registers. */
37 push {r4-r7, r14} /* Frame ptr, permanent registers, link register -> save area on stack. */
38 mov r7, r13 /* Set frame ptr. */
39
40 /* Call. */
41 mov r4, r0 /* Move 'fptr' to r4 (1st argument is passed in r0). */
42
43 /* Disable 'thumb' address forcing... */
44
45 /* mov r0, #1 */ /* Assure that LSB is set to 1 (THUMB call). - Not Required and not useful for interworking calls */
46 /* orr r4, r0 */
47
48 mov r5, r1 /* Move 'args' to r5 (2nd argument is passed in r1). */
49 mov r6, r2 /* Move 'size' to r6 (3rd argument is passed in r2). */
50
51 cmp r6, #16 /* Jump to call if no more than 4 arguments. */
52 ble call
53
54 sub r6, #16 /* Size of remaining arguments. */
55 mov r0, r13 /* Set stack pointer to top of stack. */
56 sub r0, r0, r6
57 lsr r0, #3 /* Align stack on 8 byte boundaries. */
58 lsl r0, #3
59 mov r13, r0
60
61 add r1, #16 /* Let r1 point to remaining arguments. */
62 mov r2, #0 /* Init byte counter to 0. */
63 .thumb_func
64 pushArgs:
65 ldrb r3, [r1, r2] /* Load a byte into r3. */
66 strb r3, [r0, r2] /* Push byte onto stack. */
67 add r2, r2, #1 /* Increment byte counter. */
68 cmp r2, r6
69 bne pushArgs
70 .thumb_func
71 call:
72 ldmia r5!, {r0-r3} /* Load first 4 arguments for new call into r0-r3. */
73
74 /* 'blx %r4' workaround for ARMv4t in THUMB: */
75 blx r4 /* Branch and force THUMB-mode return (LR bit 0 set). */
76
77 /* Epilog. */
78 mov r13, r7 /* Reset stack ptr. */
79 pop {r4-r7, r15} /* Restore permanent registers and program counter. (Force a stay in THUMB in ARMv4, whether ARMv5 can return in ARM or THUMB depending on the bit 0. */
80