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1da177e4 LT |
1 | /* Optimized version of the standard memset() function. |
2 | ||
3 | Copyright (c) 2002 Hewlett-Packard Co/CERN | |
4 | Sverre Jarp <Sverre.Jarp@cern.ch> | |
5 | ||
6 | Return: dest | |
7 | ||
8 | Inputs: | |
9 | in0: dest | |
10 | in1: value | |
11 | in2: count | |
12 | ||
13 | The algorithm is fairly straightforward: set byte by byte until we | |
14 | we get to a 16B-aligned address, then loop on 128 B chunks using an | |
15 | early store as prefetching, then loop on 32B chucks, then clear remaining | |
16 | words, finally clear remaining bytes. | |
17 | Since a stf.spill f0 can store 16B in one go, we use this instruction | |
18 | to get peak speed when value = 0. */ | |
19 | ||
20 | #include <asm/asmmacro.h> | |
e007c533 | 21 | #include <asm/export.h> |
1da177e4 LT |
22 | #undef ret |
23 | ||
24 | #define dest in0 | |
25 | #define value in1 | |
26 | #define cnt in2 | |
27 | ||
28 | #define tmp r31 | |
29 | #define save_lc r30 | |
30 | #define ptr0 r29 | |
31 | #define ptr1 r28 | |
32 | #define ptr2 r27 | |
33 | #define ptr3 r26 | |
34 | #define ptr9 r24 | |
35 | #define loopcnt r23 | |
36 | #define linecnt r22 | |
37 | #define bytecnt r21 | |
38 | ||
39 | #define fvalue f6 | |
40 | ||
41 | // This routine uses only scratch predicate registers (p6 - p15) | |
42 | #define p_scr p6 // default register for same-cycle branches | |
43 | #define p_nz p7 | |
44 | #define p_zr p8 | |
45 | #define p_unalgn p9 | |
46 | #define p_y p11 | |
47 | #define p_n p12 | |
48 | #define p_yy p13 | |
49 | #define p_nn p14 | |
50 | ||
51 | #define MIN1 15 | |
52 | #define MIN1P1HALF 8 | |
53 | #define LINE_SIZE 128 | |
54 | #define LSIZE_SH 7 // shift amount | |
55 | #define PREF_AHEAD 8 | |
56 | ||
57 | GLOBAL_ENTRY(memset) | |
58 | { .mmi | |
59 | .prologue | |
60 | alloc tmp = ar.pfs, 3, 0, 0, 0 | |
1da177e4 LT |
61 | lfetch.nt1 [dest] // |
62 | .save ar.lc, save_lc | |
63 | mov.i save_lc = ar.lc | |
9df6f705 | 64 | .body |
1da177e4 LT |
65 | } { .mmi |
66 | mov ret0 = dest // return value | |
67 | cmp.ne p_nz, p_zr = value, r0 // use stf.spill if value is zero | |
68 | cmp.eq p_scr, p0 = cnt, r0 | |
69 | ;; } | |
70 | { .mmi | |
71 | and ptr2 = -(MIN1+1), dest // aligned address | |
72 | and tmp = MIN1, dest // prepare to check for correct alignment | |
73 | tbit.nz p_y, p_n = dest, 0 // Do we have an odd address? (M_B_U) | |
74 | } { .mib | |
75 | mov ptr1 = dest | |
76 | mux1 value = value, @brcst // create 8 identical bytes in word | |
77 | (p_scr) br.ret.dpnt.many rp // return immediately if count = 0 | |
78 | ;; } | |
79 | { .mib | |
80 | cmp.ne p_unalgn, p0 = tmp, r0 // | |
81 | } { .mib | |
82 | sub bytecnt = (MIN1+1), tmp // NB: # of bytes to move is 1 higher than loopcnt | |
83 | cmp.gt p_scr, p0 = 16, cnt // is it a minimalistic task? | |
84 | (p_scr) br.cond.dptk.many .move_bytes_unaligned // go move just a few (M_B_U) | |
85 | ;; } | |
86 | { .mmi | |
87 | (p_unalgn) add ptr1 = (MIN1+1), ptr2 // after alignment | |
88 | (p_unalgn) add ptr2 = MIN1P1HALF, ptr2 // after alignment | |
89 | (p_unalgn) tbit.nz.unc p_y, p_n = bytecnt, 3 // should we do a st8 ? | |
90 | ;; } | |
91 | { .mib | |
92 | (p_y) add cnt = -8, cnt // | |
93 | (p_unalgn) tbit.nz.unc p_yy, p_nn = bytecnt, 2 // should we do a st4 ? | |
94 | } { .mib | |
95 | (p_y) st8 [ptr2] = value,-4 // | |
96 | (p_n) add ptr2 = 4, ptr2 // | |
97 | ;; } | |
98 | { .mib | |
99 | (p_yy) add cnt = -4, cnt // | |
100 | (p_unalgn) tbit.nz.unc p_y, p_n = bytecnt, 1 // should we do a st2 ? | |
101 | } { .mib | |
102 | (p_yy) st4 [ptr2] = value,-2 // | |
103 | (p_nn) add ptr2 = 2, ptr2 // | |
104 | ;; } | |
105 | { .mmi | |
106 | mov tmp = LINE_SIZE+1 // for compare | |
107 | (p_y) add cnt = -2, cnt // | |
108 | (p_unalgn) tbit.nz.unc p_yy, p_nn = bytecnt, 0 // should we do a st1 ? | |
109 | } { .mmi | |
110 | setf.sig fvalue=value // transfer value to FLP side | |
111 | (p_y) st2 [ptr2] = value,-1 // | |
112 | (p_n) add ptr2 = 1, ptr2 // | |
113 | ;; } | |
114 | ||
115 | { .mmi | |
116 | (p_yy) st1 [ptr2] = value // | |
117 | cmp.gt p_scr, p0 = tmp, cnt // is it a minimalistic task? | |
118 | } { .mbb | |
119 | (p_yy) add cnt = -1, cnt // | |
120 | (p_scr) br.cond.dpnt.many .fraction_of_line // go move just a few | |
121 | ;; } | |
122 | ||
123 | { .mib | |
124 | nop.m 0 | |
125 | shr.u linecnt = cnt, LSIZE_SH | |
126 | (p_zr) br.cond.dptk.many .l1b // Jump to use stf.spill | |
127 | ;; } | |
128 | ||
129 | TEXT_ALIGN(32) // --------------------- // L1A: store ahead into cache lines; fill later | |
130 | { .mmi | |
131 | and tmp = -(LINE_SIZE), cnt // compute end of range | |
132 | mov ptr9 = ptr1 // used for prefetching | |
133 | and cnt = (LINE_SIZE-1), cnt // remainder | |
134 | } { .mmi | |
135 | mov loopcnt = PREF_AHEAD-1 // default prefetch loop | |
136 | cmp.gt p_scr, p0 = PREF_AHEAD, linecnt // check against actual value | |
137 | ;; } | |
138 | { .mmi | |
139 | (p_scr) add loopcnt = -1, linecnt // | |
140 | add ptr2 = 8, ptr1 // start of stores (beyond prefetch stores) | |
141 | add ptr1 = tmp, ptr1 // first address beyond total range | |
142 | ;; } | |
143 | { .mmi | |
144 | add tmp = -1, linecnt // next loop count | |
145 | mov.i ar.lc = loopcnt // | |
146 | ;; } | |
147 | .pref_l1a: | |
148 | { .mib | |
149 | stf8 [ptr9] = fvalue, 128 // Do stores one cache line apart | |
150 | nop.i 0 | |
151 | br.cloop.dptk.few .pref_l1a | |
152 | ;; } | |
153 | { .mmi | |
154 | add ptr0 = 16, ptr2 // Two stores in parallel | |
155 | mov.i ar.lc = tmp // | |
156 | ;; } | |
157 | .l1ax: | |
158 | { .mmi | |
159 | stf8 [ptr2] = fvalue, 8 | |
160 | stf8 [ptr0] = fvalue, 8 | |
161 | ;; } | |
162 | { .mmi | |
163 | stf8 [ptr2] = fvalue, 24 | |
164 | stf8 [ptr0] = fvalue, 24 | |
165 | ;; } | |
166 | { .mmi | |
167 | stf8 [ptr2] = fvalue, 8 | |
168 | stf8 [ptr0] = fvalue, 8 | |
169 | ;; } | |
170 | { .mmi | |
171 | stf8 [ptr2] = fvalue, 24 | |
172 | stf8 [ptr0] = fvalue, 24 | |
173 | ;; } | |
174 | { .mmi | |
175 | stf8 [ptr2] = fvalue, 8 | |
176 | stf8 [ptr0] = fvalue, 8 | |
177 | ;; } | |
178 | { .mmi | |
179 | stf8 [ptr2] = fvalue, 24 | |
180 | stf8 [ptr0] = fvalue, 24 | |
181 | ;; } | |
182 | { .mmi | |
183 | stf8 [ptr2] = fvalue, 8 | |
184 | stf8 [ptr0] = fvalue, 32 | |
185 | cmp.lt p_scr, p0 = ptr9, ptr1 // do we need more prefetching? | |
186 | ;; } | |
187 | { .mmb | |
188 | stf8 [ptr2] = fvalue, 24 | |
189 | (p_scr) stf8 [ptr9] = fvalue, 128 | |
190 | br.cloop.dptk.few .l1ax | |
191 | ;; } | |
192 | { .mbb | |
193 | cmp.le p_scr, p0 = 8, cnt // just a few bytes left ? | |
194 | (p_scr) br.cond.dpnt.many .fraction_of_line // Branch no. 2 | |
195 | br.cond.dpnt.many .move_bytes_from_alignment // Branch no. 3 | |
196 | ;; } | |
197 | ||
198 | TEXT_ALIGN(32) | |
199 | .l1b: // ------------------------------------ // L1B: store ahead into cache lines; fill later | |
200 | { .mmi | |
201 | and tmp = -(LINE_SIZE), cnt // compute end of range | |
202 | mov ptr9 = ptr1 // used for prefetching | |
203 | and cnt = (LINE_SIZE-1), cnt // remainder | |
204 | } { .mmi | |
205 | mov loopcnt = PREF_AHEAD-1 // default prefetch loop | |
206 | cmp.gt p_scr, p0 = PREF_AHEAD, linecnt // check against actual value | |
207 | ;; } | |
208 | { .mmi | |
209 | (p_scr) add loopcnt = -1, linecnt | |
210 | add ptr2 = 16, ptr1 // start of stores (beyond prefetch stores) | |
211 | add ptr1 = tmp, ptr1 // first address beyond total range | |
212 | ;; } | |
213 | { .mmi | |
214 | add tmp = -1, linecnt // next loop count | |
215 | mov.i ar.lc = loopcnt | |
216 | ;; } | |
217 | .pref_l1b: | |
218 | { .mib | |
219 | stf.spill [ptr9] = f0, 128 // Do stores one cache line apart | |
220 | nop.i 0 | |
221 | br.cloop.dptk.few .pref_l1b | |
222 | ;; } | |
223 | { .mmi | |
224 | add ptr0 = 16, ptr2 // Two stores in parallel | |
225 | mov.i ar.lc = tmp | |
226 | ;; } | |
227 | .l1bx: | |
228 | { .mmi | |
229 | stf.spill [ptr2] = f0, 32 | |
230 | stf.spill [ptr0] = f0, 32 | |
231 | ;; } | |
232 | { .mmi | |
233 | stf.spill [ptr2] = f0, 32 | |
234 | stf.spill [ptr0] = f0, 32 | |
235 | ;; } | |
236 | { .mmi | |
237 | stf.spill [ptr2] = f0, 32 | |
238 | stf.spill [ptr0] = f0, 64 | |
239 | cmp.lt p_scr, p0 = ptr9, ptr1 // do we need more prefetching? | |
240 | ;; } | |
241 | { .mmb | |
242 | stf.spill [ptr2] = f0, 32 | |
243 | (p_scr) stf.spill [ptr9] = f0, 128 | |
244 | br.cloop.dptk.few .l1bx | |
245 | ;; } | |
246 | { .mib | |
247 | cmp.gt p_scr, p0 = 8, cnt // just a few bytes left ? | |
248 | (p_scr) br.cond.dpnt.many .move_bytes_from_alignment // | |
249 | ;; } | |
250 | ||
251 | .fraction_of_line: | |
252 | { .mib | |
253 | add ptr2 = 16, ptr1 | |
254 | shr.u loopcnt = cnt, 5 // loopcnt = cnt / 32 | |
255 | ;; } | |
256 | { .mib | |
257 | cmp.eq p_scr, p0 = loopcnt, r0 | |
258 | add loopcnt = -1, loopcnt | |
259 | (p_scr) br.cond.dpnt.many .store_words | |
260 | ;; } | |
261 | { .mib | |
262 | and cnt = 0x1f, cnt // compute the remaining cnt | |
263 | mov.i ar.lc = loopcnt | |
264 | ;; } | |
265 | TEXT_ALIGN(32) | |
266 | .l2: // ------------------------------------ // L2A: store 32B in 2 cycles | |
267 | { .mmb | |
268 | stf8 [ptr1] = fvalue, 8 | |
269 | stf8 [ptr2] = fvalue, 8 | |
270 | ;; } { .mmb | |
271 | stf8 [ptr1] = fvalue, 24 | |
272 | stf8 [ptr2] = fvalue, 24 | |
273 | br.cloop.dptk.many .l2 | |
274 | ;; } | |
275 | .store_words: | |
276 | { .mib | |
277 | cmp.gt p_scr, p0 = 8, cnt // just a few bytes left ? | |
278 | (p_scr) br.cond.dpnt.many .move_bytes_from_alignment // Branch | |
279 | ;; } | |
280 | ||
281 | { .mmi | |
282 | stf8 [ptr1] = fvalue, 8 // store | |
283 | cmp.le p_y, p_n = 16, cnt | |
284 | add cnt = -8, cnt // subtract | |
285 | ;; } | |
286 | { .mmi | |
287 | (p_y) stf8 [ptr1] = fvalue, 8 // store | |
288 | (p_y) cmp.le.unc p_yy, p_nn = 16, cnt | |
289 | (p_y) add cnt = -8, cnt // subtract | |
290 | ;; } | |
291 | { .mmi // store | |
292 | (p_yy) stf8 [ptr1] = fvalue, 8 | |
293 | (p_yy) add cnt = -8, cnt // subtract | |
294 | ;; } | |
295 | ||
296 | .move_bytes_from_alignment: | |
297 | { .mib | |
298 | cmp.eq p_scr, p0 = cnt, r0 | |
299 | tbit.nz.unc p_y, p0 = cnt, 2 // should we terminate with a st4 ? | |
300 | (p_scr) br.cond.dpnt.few .restore_and_exit | |
301 | ;; } | |
302 | { .mib | |
303 | (p_y) st4 [ptr1] = value,4 | |
304 | tbit.nz.unc p_yy, p0 = cnt, 1 // should we terminate with a st2 ? | |
305 | ;; } | |
306 | { .mib | |
307 | (p_yy) st2 [ptr1] = value,2 | |
308 | tbit.nz.unc p_y, p0 = cnt, 0 // should we terminate with a st1 ? | |
309 | ;; } | |
310 | ||
311 | { .mib | |
312 | (p_y) st1 [ptr1] = value | |
313 | ;; } | |
314 | .restore_and_exit: | |
315 | { .mib | |
316 | nop.m 0 | |
317 | mov.i ar.lc = save_lc | |
318 | br.ret.sptk.many rp | |
319 | ;; } | |
320 | ||
321 | .move_bytes_unaligned: | |
322 | { .mmi | |
323 | .pred.rel "mutex",p_y, p_n | |
324 | .pred.rel "mutex",p_yy, p_nn | |
325 | (p_n) cmp.le p_yy, p_nn = 4, cnt | |
326 | (p_y) cmp.le p_yy, p_nn = 5, cnt | |
327 | (p_n) add ptr2 = 2, ptr1 | |
328 | } { .mmi | |
329 | (p_y) add ptr2 = 3, ptr1 | |
330 | (p_y) st1 [ptr1] = value, 1 // fill 1 (odd-aligned) byte [15, 14 (or less) left] | |
331 | (p_y) add cnt = -1, cnt | |
332 | ;; } | |
333 | { .mmi | |
334 | (p_yy) cmp.le.unc p_y, p0 = 8, cnt | |
335 | add ptr3 = ptr1, cnt // prepare last store | |
336 | mov.i ar.lc = save_lc | |
337 | } { .mmi | |
338 | (p_yy) st2 [ptr1] = value, 4 // fill 2 (aligned) bytes | |
339 | (p_yy) st2 [ptr2] = value, 4 // fill 2 (aligned) bytes [11, 10 (o less) left] | |
340 | (p_yy) add cnt = -4, cnt | |
341 | ;; } | |
342 | { .mmi | |
343 | (p_y) cmp.le.unc p_yy, p0 = 8, cnt | |
344 | add ptr3 = -1, ptr3 // last store | |
345 | tbit.nz p_scr, p0 = cnt, 1 // will there be a st2 at the end ? | |
346 | } { .mmi | |
347 | (p_y) st2 [ptr1] = value, 4 // fill 2 (aligned) bytes | |
348 | (p_y) st2 [ptr2] = value, 4 // fill 2 (aligned) bytes [7, 6 (or less) left] | |
349 | (p_y) add cnt = -4, cnt | |
350 | ;; } | |
351 | { .mmi | |
352 | (p_yy) st2 [ptr1] = value, 4 // fill 2 (aligned) bytes | |
353 | (p_yy) st2 [ptr2] = value, 4 // fill 2 (aligned) bytes [3, 2 (or less) left] | |
354 | tbit.nz p_y, p0 = cnt, 0 // will there be a st1 at the end ? | |
355 | } { .mmi | |
356 | (p_yy) add cnt = -4, cnt | |
357 | ;; } | |
358 | { .mmb | |
359 | (p_scr) st2 [ptr1] = value // fill 2 (aligned) bytes | |
360 | (p_y) st1 [ptr3] = value // fill last byte (using ptr3) | |
361 | br.ret.sptk.many rp | |
362 | } | |
363 | END(memset) | |
e007c533 | 364 | EXPORT_SYMBOL(memset) |