Commit | Line | Data |
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1394f032 | 1 | /* |
96f1050d | 2 | * Copyright 2004-2009 Analog Devices Inc. |
1394f032 | 3 | * |
de450838 | 4 | * Licensed under the Clear BSD license or the GPL-2 (or later) |
1394f032 BW |
5 | */ |
6 | ||
7 | #include <linux/linkage.h> | |
8 | ||
9 | /* int memcmp(const void *s1, const void *s2, size_t n); | |
10 | * R0 = First Address (s1) | |
11 | * R1 = Second Address (s2) | |
12 | * R2 = count (n) | |
13 | * | |
14 | * Favours word aligned data. | |
15 | */ | |
16 | ||
17 | .text | |
18 | ||
19 | .align 2 | |
20 | ||
21 | ENTRY(_memcmp) | |
22 | I1 = P3; | |
23 | P0 = R0; /* P0 = s1 address */ | |
24 | P3 = R1; /* P3 = s2 Address */ | |
25 | P2 = R2 ; /* P2 = count */ | |
26 | CC = R2 <= 7(IU); | |
27 | IF CC JUMP .Ltoo_small; | |
28 | I0 = R1; /* s2 */ | |
29 | R1 = R1 | R0; /* OR addresses together */ | |
30 | R1 <<= 30; /* check bottom two bits */ | |
31 | CC = AZ; /* AZ set if zero. */ | |
32 | IF !CC JUMP .Lbytes ; /* Jump if addrs not aligned. */ | |
33 | ||
34 | P1 = P2 >> 2; /* count = n/4 */ | |
35 | R3 = 3; | |
36 | R2 = R2 & R3; /* remainder */ | |
37 | P2 = R2; /* set remainder */ | |
38 | ||
39 | LSETUP (.Lquad_loop_s, .Lquad_loop_e) LC0=P1; | |
40 | .Lquad_loop_s: | |
1aafd909 | 41 | #if ANOMALY_05000202 |
4bf3f3cb RG |
42 | R0 = [P0++]; |
43 | R1 = [I0++]; | |
44 | #else | |
1394f032 | 45 | MNOP || R0 = [P0++] || R1 = [I0++]; |
4bf3f3cb | 46 | #endif |
1394f032 BW |
47 | CC = R0 == R1; |
48 | IF !CC JUMP .Lquad_different; | |
49 | .Lquad_loop_e: | |
50 | NOP; | |
51 | ||
52 | P3 = I0; /* s2 */ | |
53 | .Ltoo_small: | |
54 | CC = P2 == 0; /* Check zero count*/ | |
55 | IF CC JUMP .Lfinished; /* very unlikely*/ | |
56 | ||
57 | .Lbytes: | |
58 | LSETUP (.Lbyte_loop_s, .Lbyte_loop_e) LC0=P2; | |
59 | .Lbyte_loop_s: | |
60 | R1 = B[P3++](Z); /* *s2 */ | |
61 | R0 = B[P0++](Z); /* *s1 */ | |
62 | CC = R0 == R1; | |
63 | IF !CC JUMP .Ldifferent; | |
64 | .Lbyte_loop_e: | |
65 | NOP; | |
66 | ||
67 | .Ldifferent: | |
68 | R0 = R0 - R1; | |
69 | P3 = I1; | |
70 | RTS; | |
71 | ||
72 | .Lquad_different: | |
73 | /* We've read two quads which don't match. | |
74 | * Can't just compare them, because we're | |
75 | * a little-endian machine, so the MSBs of | |
76 | * the regs occur at later addresses in the | |
77 | * string. | |
78 | * Arrange to re-read those two quads again, | |
79 | * byte-by-byte. | |
80 | */ | |
81 | P0 += -4; /* back up to the start of the */ | |
82 | P3 = I0; /* quads, and increase the*/ | |
83 | P2 += 4; /* remainder count*/ | |
84 | P3 += -4; | |
85 | JUMP .Lbytes; | |
86 | ||
87 | .Lfinished: | |
88 | R0 = 0; | |
89 | P3 = I1; | |
90 | RTS; | |
91 | ||
51be24c3 | 92 | ENDPROC(_memcmp) |