diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/alpha/lib/strncpy.S |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/alpha/lib/strncpy.S')
-rw-r--r-- | arch/alpha/lib/strncpy.S | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/alpha/lib/strncpy.S b/arch/alpha/lib/strncpy.S new file mode 100644 index 000000000000..338551c7113c --- /dev/null +++ b/arch/alpha/lib/strncpy.S | |||
@@ -0,0 +1,81 @@ | |||
1 | /* | ||
2 | * arch/alpha/lib/strncpy.S | ||
3 | * Contributed by Richard Henderson (rth@tamu.edu) | ||
4 | * | ||
5 | * Copy no more than COUNT bytes of the null-terminated string from | ||
6 | * SRC to DST. If SRC does not cover all of COUNT, the balance is | ||
7 | * zeroed. | ||
8 | * | ||
9 | * Or, rather, if the kernel cared about that weird ANSI quirk. This | ||
10 | * version has cropped that bit o' nastiness as well as assuming that | ||
11 | * __stxncpy is in range of a branch. | ||
12 | */ | ||
13 | |||
14 | .set noat | ||
15 | .set noreorder | ||
16 | |||
17 | .text | ||
18 | |||
19 | .align 4 | ||
20 | .globl strncpy | ||
21 | .ent strncpy | ||
22 | strncpy: | ||
23 | .frame $30, 0, $26 | ||
24 | .prologue 0 | ||
25 | |||
26 | mov $16, $0 # set return value now | ||
27 | beq $18, $zerolen | ||
28 | unop | ||
29 | bsr $23, __stxncpy # do the work of the copy | ||
30 | |||
31 | unop | ||
32 | bne $18, $multiword # do we have full words left? | ||
33 | subq $24, 1, $3 # nope | ||
34 | subq $27, 1, $4 | ||
35 | |||
36 | or $3, $24, $3 # clear the bits between the last | ||
37 | or $4, $27, $4 # written byte and the last byte in COUNT | ||
38 | andnot $4, $3, $4 | ||
39 | zap $1, $4, $1 | ||
40 | |||
41 | stq_u $1, 0($16) | ||
42 | ret | ||
43 | |||
44 | .align 4 | ||
45 | $multiword: | ||
46 | subq $24, 1, $2 # clear the final bits in the prev word | ||
47 | or $2, $24, $2 | ||
48 | zapnot $1, $2, $1 | ||
49 | subq $18, 1, $18 | ||
50 | |||
51 | stq_u $1, 0($16) | ||
52 | addq $16, 8, $16 | ||
53 | unop | ||
54 | beq $18, 1f | ||
55 | |||
56 | nop | ||
57 | unop | ||
58 | nop | ||
59 | blbc $18, 0f | ||
60 | |||
61 | stq_u $31, 0($16) # zero one word | ||
62 | subq $18, 1, $18 | ||
63 | addq $16, 8, $16 | ||
64 | beq $18, 1f | ||
65 | |||
66 | 0: stq_u $31, 0($16) # zero two words | ||
67 | subq $18, 2, $18 | ||
68 | stq_u $31, 8($16) | ||
69 | addq $16, 16, $16 | ||
70 | bne $18, 0b | ||
71 | |||
72 | 1: ldq_u $1, 0($16) # clear the leading bits in the final word | ||
73 | subq $27, 1, $2 | ||
74 | or $2, $27, $2 | ||
75 | |||
76 | zap $1, $2, $1 | ||
77 | stq_u $1, 0($16) | ||
78 | $zerolen: | ||
79 | ret | ||
80 | |||
81 | .end strncpy | ||