1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * arch/alpha/lib/strrchr.S
4 * Contributed by Richard Henderson (rth@tamu.
5 *
6 * Return the address of the last occurrence o
7 * within a null-terminated string, or null if
8 */
9 #include <linux/export.h>
10 #include <asm/regdef.h>
11
12 .set noreorder
13 .set noat
14
15 .align 3
16 .ent strrchr
17 .globl strrchr
18 strrchr:
19 .frame sp, 0, ra
20 .prologue 0
21
22 zapnot a1, 1, a1 # e0 : zero
23 mov zero, t6 # .. e1 : t6 i
24 sll a1, 8, t5 # e0 : repl
25 mov zero, t8 # .. e1 : t8 i
26 or t5, a1, a1 # e0 :
27 ldq_u t0, 0(a0) # .. e1 : load
28 sll a1, 16, t5 # e0 :
29 andnot a0, 7, v0 # .. e1 : alig
30 or t5, a1, a1 # e0 :
31 lda t4, -1 # .. e1 : buil
32 sll a1, 32, t5 # e0 :
33 cmpbge zero, t0, t1 # .. e1 : bits
34 mskqh t4, a0, t4 # e0 :
35 or t5, a1, a1 # .. e1 : char
36 xor t0, a1, t2 # e0 : make
37 cmpbge zero, t4, t4 # .. e1 : bits
38 cmpbge zero, t2, t3 # e0 : bits
39 andnot t1, t4, t1 # .. e1 : clea
40 andnot t3, t4, t3 # e0 : clea
41 bne t1, $eos # .. e1 : did
42
43 /* Character search main loop */
44 $loop:
45 ldq t0, 8(v0) # e0 : load
46 cmovne t3, v0, t6 # .. e1 : save
47 cmovne t3, t3, t8 # e0 :
48 addq v0, 8, v0 # .. e1 :
49 xor t0, a1, t2 # e0 :
50 cmpbge zero, t0, t1 # .. e1 : bits
51 cmpbge zero, t2, t3 # e0 : bits
52 beq t1, $loop # .. e1 : if w
53
54 /* Mask out character matches after te
55 $eos:
56 negq t1, t4 # e0 : isol
57 and t1, t4, t4 # e1 :
58 subq t4, 1, t5 # e0 : buil
59 or t4, t5, t4 # e1 : ...
60
61 and t3, t4, t3 # e0 : mask
62 cmovne t3, t3, t8 # .. e1 : save
63 cmovne t3, v0, t6 # e0 :
64
65 /* Locate the address of the last matc
66
67 /* Retain the early exit for the ev4 -
68 is 5 cycles -- the same as just fal
69 beq t8, $retnull # .. e1 :
70
71 and t8, 0xf0, t2 # e0 : bina
72 cmovne t2, t2, t8 # .. e1 (zdb)
73 cmovne t2, 4, t2 # e0 :
74 and t8, 0xcc, t1 # .. e1 :
75 cmovne t1, t1, t8 # e0 :
76 cmovne t1, 2, t1 # .. e1 :
77 and t8, 0xaa, t0 # e0 :
78 cmovne t0, 1, t0 # .. e1 (zdb)
79 addq t2, t1, t1 # e0 :
80 addq t6, t0, v0 # .. e1 : add
81 addq v0, t1, v0 # e0 :
82 ret # .. e1 :
83
84 $retnull:
85 mov zero, v0 # e0 :
86 ret # .. e1 :
87
88 .end strrchr
89 EXPORT_SYMBOL(strrchr)
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