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1 | /* Optimized version of the standard strcpy() function. |
2 | This file is part of the GNU C Library. | |
f7a9f785 | 3 | Copyright (C) 2000-2016 Free Software Foundation, Inc. |
d5efd131 MF |
4 | Contributed by Dan Pop <Dan.Pop@cern.ch>. |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
75efb018 MF |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
d5efd131 MF |
19 | |
20 | /* Return: dest | |
21 | ||
22 | Inputs: | |
23 | in0: dest | |
24 | in1: src | |
25 | ||
26 | In this form, it assumes little endian mode. For big endian mode, | |
27 | the two shifts in .l2 must be inverted: | |
28 | ||
29 | shl value = r[1], sh1 // value = w0 << sh1 | |
30 | shr.u tmp = r[0], sh2 // tmp = w1 >> sh2 | |
31 | */ | |
32 | ||
33 | #include <sysdep.h> | |
34 | #undef ret | |
35 | ||
36 | #define saved_lc r15 | |
37 | #define saved_pr r16 | |
38 | #define thresh r17 | |
39 | #define dest r19 | |
40 | #define src r20 | |
41 | #define len r21 | |
42 | #define asrc r22 | |
43 | #define tmp r23 | |
44 | #define pos r24 | |
45 | #define w0 r25 | |
46 | #define w1 r26 | |
47 | #define c r27 | |
48 | #define sh2 r28 | |
49 | #define sh1 r29 | |
50 | #define loopcnt r30 | |
51 | #define value r31 | |
52 | ||
53 | ENTRY(strcpy) | |
54 | .prologue | |
55 | alloc r2 = ar.pfs, 2, 0, 30, 32 | |
56 | ||
57 | #define MEMLAT 2 | |
58 | .rotr r[MEMLAT + 2] | |
59 | .rotp p[MEMLAT + 1] | |
60 | ||
61 | mov ret0 = in0 // return value = dest | |
62 | .save pr, saved_pr | |
63 | mov saved_pr = pr // save the predicate registers | |
64 | .save ar.lc, saved_lc | |
65 | mov saved_lc = ar.lc // save the loop counter | |
66 | .body | |
67 | sub tmp = r0, in0 ;; // tmp = -dest | |
68 | mov dest = in0 // dest | |
69 | mov src = in1 // src | |
70 | and loopcnt = 7, tmp ;; // loopcnt = -dest % 8 | |
71 | cmp.eq p6, p0 = loopcnt, r0 | |
72 | adds loopcnt = -1, loopcnt // --loopcnt | |
73 | (p6) br.cond.sptk .dest_aligned ;; | |
74 | mov ar.lc = loopcnt | |
75 | .l1: // copy -dest % 8 bytes | |
76 | ld1 c = [src], 1 // c = *src++ | |
77 | ;; | |
78 | st1 [dest] = c, 1 // *dest++ = c | |
79 | cmp.eq p6, p0 = c, r0 | |
80 | (p6) br.cond.dpnt .restore_and_exit | |
81 | br.cloop.dptk .l1 ;; | |
82 | .dest_aligned: | |
83 | and sh1 = 7, src // sh1 = src % 8 | |
84 | mov ar.lc = -1 // "infinite" loop | |
85 | and asrc = -8, src ;; // asrc = src & -OPSIZ -- align src | |
86 | sub thresh = 8, sh1 | |
87 | mov pr.rot = 1 << 16 // set rotating predicates | |
88 | cmp.ne p7, p0 = r0, r0 // clear p7 | |
89 | shl sh1 = sh1, 3 ;; // sh1 = 8 * (src % 8) | |
90 | sub sh2 = 64, sh1 // sh2 = 64 - sh1 | |
91 | cmp.eq p6, p0 = sh1, r0 // is the src aligned? | |
92 | (p6) br.cond.sptk .src_aligned ;; | |
93 | ld8 r[1] = [asrc],8 ;; | |
94 | ||
95 | .align 32 | |
96 | .l2: | |
97 | ld8.s r[0] = [asrc], 8 | |
98 | shr.u value = r[1], sh1 ;; // value = w0 >> sh1 | |
99 | czx1.r pos = value ;; // do we have an "early" zero | |
100 | cmp.lt p7, p0 = pos, thresh // in w0 >> sh1? | |
101 | (p7) br.cond.dpnt .found0 | |
102 | chk.s r[0], .recovery2 // it is safe to do that only | |
103 | .back2: // after the previous test | |
104 | shl tmp = r[0], sh2 // tmp = w1 << sh2 | |
105 | ;; | |
106 | or value = value, tmp ;; // value |= tmp | |
107 | czx1.r pos = value ;; | |
108 | cmp.ne p7, p0 = 8, pos | |
109 | (p7) br.cond.dpnt .found0 | |
110 | st8 [dest] = value, 8 // store val to dest | |
111 | br.ctop.dptk .l2 ;; | |
112 | .src_aligned: | |
113 | .l3: | |
114 | (p[0]) ld8.s r[0] = [src], 8 | |
115 | (p[MEMLAT]) chk.s r[MEMLAT], .recovery3 | |
116 | .back3: | |
117 | (p[MEMLAT]) mov value = r[MEMLAT] | |
118 | (p[MEMLAT]) czx1.r pos = r[MEMLAT] ;; | |
119 | (p[MEMLAT]) cmp.ne p7, p0 = 8, pos | |
120 | (p7) br.cond.dpnt .found0 | |
121 | (p[MEMLAT]) st8 [dest] = r[MEMLAT], 8 | |
122 | br.ctop.dptk .l3 ;; | |
123 | .found0: | |
124 | mov ar.lc = pos | |
125 | .l4: | |
126 | extr.u c = value, 0, 8 // c = value & 0xff | |
127 | shr.u value = value, 8 | |
128 | ;; | |
129 | st1 [dest] = c, 1 | |
130 | br.cloop.dptk .l4 ;; | |
131 | .restore_and_exit: | |
132 | mov ar.lc = saved_lc // restore the loop counter | |
133 | mov pr = saved_pr, -1 // restore the predicate registers | |
134 | br.ret.sptk.many b0 | |
135 | .recovery2: | |
136 | add tmp = -8, asrc ;; | |
137 | ld8 r[0] = [tmp] | |
138 | br.cond.sptk .back2 | |
139 | .recovery3: | |
140 | add tmp = -(MEMLAT + 1) * 8, src ;; | |
141 | ld8 r[MEMLAT] = [tmp] | |
142 | br.cond.sptk .back3 | |
143 | END(strcpy) | |
144 | libc_hidden_builtin_def (strcpy) |