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Diffstat (limited to 'firmware/target/arm/memset16-arm.S')
-rwxr-xr-x | firmware/target/arm/memset16-arm.S | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/firmware/target/arm/memset16-arm.S b/firmware/target/arm/memset16-arm.S new file mode 100755 index 0000000000..13213c57f0 --- /dev/null +++ b/firmware/target/arm/memset16-arm.S | |||
@@ -0,0 +1,80 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2006 by Thom Johansen | ||
11 | * | ||
12 | * All files in this archive are subject to the GNU General Public License. | ||
13 | * See the file COPYING in the source tree root for full license agreement. | ||
14 | * | ||
15 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
16 | * KIND, either express or implied. | ||
17 | * | ||
18 | ****************************************************************************/ | ||
19 | #include "config.h" | ||
20 | |||
21 | .section .icode,"ax",%progbits | ||
22 | |||
23 | .align 2 | ||
24 | |||
25 | /* The following code is based on code from the Linux kernel version 2.6.15.3, | ||
26 | * linux/arch/arm/lib/memset.S | ||
27 | * | ||
28 | * Copyright (C) 1995-2000 Russell King | ||
29 | */ | ||
30 | |||
31 | .global memset16 | ||
32 | .type memset16,%function | ||
33 | memset16: | ||
34 | tst r0, #2 @ unaligned? | ||
35 | cmpne r2, #0 | ||
36 | strneh r1, [r0], #2 @ store one halfword to align | ||
37 | subne r2, r2, #1 | ||
38 | |||
39 | /* | ||
40 | * we know that the pointer in r0 is aligned to a word boundary. | ||
41 | */ | ||
42 | orr r1, r1, r1, lsl #16 | ||
43 | mov r3, r1 | ||
44 | cmp r2, #8 | ||
45 | blt 4f | ||
46 | /* | ||
47 | * We need an extra register for this loop - save the return address and | ||
48 | * use the LR | ||
49 | */ | ||
50 | str lr, [sp, #-4]! | ||
51 | mov ip, r1 | ||
52 | mov lr, r1 | ||
53 | |||
54 | 2: subs r2, r2, #32 | ||
55 | stmgeia r0!, {r1, r3, ip, lr} @ 64 bytes at a time. | ||
56 | stmgeia r0!, {r1, r3, ip, lr} | ||
57 | stmgeia r0!, {r1, r3, ip, lr} | ||
58 | stmgeia r0!, {r1, r3, ip, lr} | ||
59 | bgt 2b | ||
60 | ldmeqfd sp!, {pc} @ Now <64 bytes to go. | ||
61 | /* | ||
62 | * No need to correct the count; we're only testing bits from now on | ||
63 | */ | ||
64 | tst r2, #16 | ||
65 | stmneia r0!, {r1, r3, ip, lr} | ||
66 | stmneia r0!, {r1, r3, ip, lr} | ||
67 | tst r2, #8 | ||
68 | stmneia r0!, {r1, r3, ip, lr} | ||
69 | ldr lr, [sp], #4 | ||
70 | |||
71 | 4: tst r2, #4 | ||
72 | stmneia r0!, {r1, r3} | ||
73 | tst r2, #2 | ||
74 | strne r1, [r0], #4 | ||
75 | |||
76 | tst r2, #1 | ||
77 | strneh r1, [r0], #2 | ||
78 | bx lr | ||
79 | .end: | ||
80 | .size memset16,.end-memset16 | ||