]>
Commit | Line | Data |
---|---|---|
04067002 | 1 | /* Optimized memset implementation for PowerPC64. |
d614a753 | 2 | Copyright (C) 1997-2020 Free Software Foundation, Inc. |
04067002 UD |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 | 16 | License along with the GNU C Library; if not, see |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
04067002 UD |
18 | |
19 | #include <sysdep.h> | |
04067002 | 20 | |
f17a4233 | 21 | /* void * [r3] memset (void *s [r3], int c [r4], size_t n [r5])); |
04067002 UD |
22 | Returns 's'. |
23 | ||
24 | The memset is done in three sizes: byte (8 bits), word (32 bits), | |
25 | cache line (256 bits). There is a special case for setting cache lines | |
26 | to 0, to take advantage of the dcbz instruction. */ | |
27 | ||
18e0054b WSM |
28 | #ifndef MEMSET |
29 | # define MEMSET memset | |
30 | #endif | |
a88f47a7 | 31 | .machine power4 |
d5b41185 | 32 | ENTRY_TOCLESS (MEMSET, 5) |
04067002 UD |
33 | CALL_MCOUNT 3 |
34 | ||
35 | #define rTMP r0 | |
36 | #define rRTN r3 /* Initial value of 1st argument. */ | |
2d67d91a JM |
37 | #define rMEMP0 r3 /* Original value of 1st arg. */ |
38 | #define rCHR r4 /* Char to set in each byte. */ | |
39 | #define rLEN r5 /* Length of region to set. */ | |
40 | #define rMEMP r6 /* Address at which we are storing. */ | |
04067002 UD |
41 | #define rALIGN r7 /* Number of bytes we are setting now (when aligning). */ |
42 | #define rMEMP2 r8 | |
43 | ||
44 | #define rNEG64 r8 /* Constant -64 for clearing with dcbz. */ | |
45 | #define rCLS r8 /* Cache line size obtained from static. */ | |
46 | #define rCLM r9 /* Cache line size mask to check for cache alignment. */ | |
47 | L(_memset): | |
04067002 UD |
48 | /* Take care of case for size <= 4. */ |
49 | cmpldi cr1, rLEN, 8 | |
50 | andi. rALIGN, rMEMP0, 7 | |
51 | mr rMEMP, rMEMP0 | |
52 | ble- cr1, L(small) | |
53 | ||
54 | /* Align to doubleword boundary. */ | |
55 | cmpldi cr5, rLEN, 31 | |
3be87c77 | 56 | insrdi rCHR, rCHR, 8, 48 /* Replicate byte to halfword. */ |
04067002 UD |
57 | beq+ L(aligned2) |
58 | mtcrf 0x01, rMEMP0 | |
59 | subfic rALIGN, rALIGN, 8 | |
60 | cror 28,30,31 /* Detect odd word aligned. */ | |
61 | add rMEMP, rMEMP, rALIGN | |
62 | sub rLEN, rLEN, rALIGN | |
3be87c77 | 63 | insrdi rCHR, rCHR, 16, 32 /* Replicate halfword to word. */ |
04067002 UD |
64 | bt 29, L(g4) |
65 | /* Process the even word of doubleword. */ | |
66 | bf+ 31, L(g2) | |
67 | stb rCHR, 0(rMEMP0) | |
68 | bt 30, L(g4x) | |
69 | L(g2): | |
70 | sth rCHR, -6(rMEMP) | |
71 | L(g4x): | |
72 | stw rCHR, -4(rMEMP) | |
73 | b L(aligned) | |
74 | /* Process the odd word of doubleword. */ | |
75 | L(g4): | |
76 | bf 28, L(g4x) /* If false, word aligned on odd word. */ | |
77 | bf+ 31, L(g0) | |
78 | stb rCHR, 0(rMEMP0) | |
79 | bt 30, L(aligned) | |
80 | L(g0): | |
81 | sth rCHR, -2(rMEMP) | |
82 | ||
83 | /* Handle the case of size < 31. */ | |
84 | L(aligned2): | |
3be87c77 | 85 | insrdi rCHR, rCHR, 16, 32 /* Replicate halfword to word. */ |
04067002 UD |
86 | L(aligned): |
87 | mtcrf 0x01, rLEN | |
88 | ble cr5, L(medium) | |
89 | /* Align to 32-byte boundary. */ | |
90 | andi. rALIGN, rMEMP, 0x18 | |
91 | subfic rALIGN, rALIGN, 0x20 | |
3be87c77 | 92 | insrdi rCHR, rCHR, 32, 0 /* Replicate word to double word. */ |
04067002 UD |
93 | beq L(caligned) |
94 | mtcrf 0x01, rALIGN | |
95 | add rMEMP, rMEMP, rALIGN | |
96 | sub rLEN, rLEN, rALIGN | |
97 | cmplwi cr1, rALIGN, 0x10 | |
98 | mr rMEMP2, rMEMP | |
99 | bf 28, L(a1) | |
100 | stdu rCHR, -8(rMEMP2) | |
101 | L(a1): blt cr1, L(a2) | |
102 | std rCHR, -8(rMEMP2) | |
103 | stdu rCHR, -16(rMEMP2) | |
104 | L(a2): | |
105 | ||
106 | /* Now aligned to a 32 byte boundary. */ | |
107 | L(caligned): | |
108 | cmpldi cr1, rCHR, 0 | |
109 | clrrdi. rALIGN, rLEN, 5 | |
110 | mtcrf 0x01, rLEN | |
111 | beq cr1, L(zloopstart) /* Special case for clearing memory using dcbz. */ | |
112 | L(nondcbz): | |
113 | srdi rTMP, rALIGN, 5 | |
114 | mtctr rTMP | |
115 | beq L(medium) /* We may not actually get to do a full line. */ | |
116 | clrldi. rLEN, rLEN, 59 | |
117 | add rMEMP, rMEMP, rALIGN | |
118 | li rNEG64, -0x40 | |
119 | bdz L(cloopdone) | |
120 | ||
121 | L(c3): dcbtst rNEG64, rMEMP | |
122 | std rCHR, -8(rMEMP) | |
123 | std rCHR, -16(rMEMP) | |
124 | std rCHR, -24(rMEMP) | |
125 | stdu rCHR, -32(rMEMP) | |
126 | bdnz L(c3) | |
127 | L(cloopdone): | |
128 | std rCHR, -8(rMEMP) | |
129 | std rCHR, -16(rMEMP) | |
130 | cmpldi cr1, rLEN, 16 | |
131 | std rCHR, -24(rMEMP) | |
132 | stdu rCHR, -32(rMEMP) | |
133 | beqlr | |
134 | add rMEMP, rMEMP, rALIGN | |
135 | b L(medium_tail2) | |
136 | ||
137 | .align 5 | |
138 | /* Clear lines of memory in 128-byte chunks. */ | |
139 | L(zloopstart): | |
140 | /* If the remaining length is less the 32 bytes, don't bother getting | |
141 | the cache line size. */ | |
142 | beq L(medium) | |
143 | li rCLS,128 /* cache line size is 128 */ | |
144 | ||
145 | /* Now we know the cache line size, and it is not 32-bytes, but | |
146 | we may not yet be aligned to the cache line. May have a partial | |
147 | line to fill, so touch it 1st. */ | |
148 | dcbt 0,rMEMP | |
149 | L(getCacheAligned): | |
150 | cmpldi cr1,rLEN,32 | |
151 | andi. rTMP,rMEMP,127 | |
3be87c77 AM |
152 | blt cr1,L(handletail32) |
153 | beq L(cacheAligned) | |
04067002 UD |
154 | addi rMEMP,rMEMP,32 |
155 | addi rLEN,rLEN,-32 | |
3be87c77 AM |
156 | std rCHR,-32(rMEMP) |
157 | std rCHR,-24(rMEMP) | |
158 | std rCHR,-16(rMEMP) | |
159 | std rCHR,-8(rMEMP) | |
160 | b L(getCacheAligned) | |
04067002 UD |
161 | |
162 | /* Now we are aligned to the cache line and can use dcbz. */ | |
163 | L(cacheAligned): | |
164 | cmpld cr1,rLEN,rCLS | |
3be87c77 | 165 | blt cr1,L(handletail32) |
04067002 UD |
166 | dcbz 0,rMEMP |
167 | subf rLEN,rCLS,rLEN | |
3be87c77 AM |
168 | add rMEMP,rMEMP,rCLS |
169 | b L(cacheAligned) | |
04067002 UD |
170 | |
171 | /* We are here because the cache line size was set and was not 32-bytes | |
172 | and the remainder (rLEN) is less than the actual cache line size. | |
173 | So set up the preconditions for L(nondcbz) and go there. */ | |
174 | L(handletail32): | |
175 | clrrwi. rALIGN, rLEN, 5 | |
176 | b L(nondcbz) | |
177 | ||
178 | .align 5 | |
179 | L(small): | |
180 | /* Memset of 8 bytes or less. */ | |
181 | cmpldi cr6, rLEN, 4 | |
182 | cmpldi cr5, rLEN, 1 | |
183 | ble cr6,L(le4) | |
184 | subi rLEN, rLEN, 4 | |
185 | stb rCHR,0(rMEMP) | |
186 | stb rCHR,1(rMEMP) | |
187 | stb rCHR,2(rMEMP) | |
188 | stb rCHR,3(rMEMP) | |
189 | addi rMEMP,rMEMP, 4 | |
190 | cmpldi cr5, rLEN, 1 | |
191 | L(le4): | |
192 | cmpldi cr1, rLEN, 3 | |
193 | bltlr cr5 | |
194 | stb rCHR, 0(rMEMP) | |
195 | beqlr cr5 | |
196 | stb rCHR, 1(rMEMP) | |
197 | bltlr cr1 | |
198 | stb rCHR, 2(rMEMP) | |
199 | beqlr cr1 | |
200 | stb rCHR, 3(rMEMP) | |
201 | blr | |
202 | ||
203 | /* Memset of 0-31 bytes. */ | |
204 | .align 5 | |
205 | L(medium): | |
3be87c77 | 206 | insrdi rCHR, rCHR, 32, 0 /* Replicate word to double word. */ |
04067002 UD |
207 | cmpldi cr1, rLEN, 16 |
208 | L(medium_tail2): | |
209 | add rMEMP, rMEMP, rLEN | |
210 | L(medium_tail): | |
211 | bt- 31, L(medium_31t) | |
212 | bt- 30, L(medium_30t) | |
213 | L(medium_30f): | |
214 | bt- 29, L(medium_29t) | |
215 | L(medium_29f): | |
216 | bge- cr1, L(medium_27t) | |
217 | bflr- 28 | |
218 | std rCHR, -8(rMEMP) | |
219 | blr | |
220 | ||
221 | L(medium_31t): | |
222 | stbu rCHR, -1(rMEMP) | |
223 | bf- 30, L(medium_30f) | |
224 | L(medium_30t): | |
225 | sthu rCHR, -2(rMEMP) | |
226 | bf- 29, L(medium_29f) | |
227 | L(medium_29t): | |
228 | stwu rCHR, -4(rMEMP) | |
229 | blt- cr1, L(medium_27f) | |
230 | L(medium_27t): | |
231 | std rCHR, -8(rMEMP) | |
232 | stdu rCHR, -16(rMEMP) | |
233 | L(medium_27f): | |
234 | bflr- 28 | |
235 | L(medium_28t): | |
236 | std rCHR, -8(rMEMP) | |
237 | blr | |
18e0054b | 238 | END_GEN_TB (MEMSET,TB_TOCLESS) |
04067002 UD |
239 | libc_hidden_builtin_def (memset) |
240 | ||
241 | /* Copied from bzero.S to prevent the linker from inserting a stub | |
242 | between bzero and memset. */ | |
d5b41185 | 243 | ENTRY_TOCLESS (__bzero) |
04067002 | 244 | CALL_MCOUNT 3 |
04067002 UD |
245 | mr r5,r4 |
246 | li r4,0 | |
247 | b L(_memset) | |
3b473fec AZ |
248 | END (__bzero) |
249 | #ifndef __bzero | |
2d67d91a | 250 | weak_alias (__bzero, bzero) |
8a29a3d0 | 251 | #endif |