diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sparc/lib/urem.S |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/sparc/lib/urem.S')
-rw-r--r-- | arch/sparc/lib/urem.S | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/arch/sparc/lib/urem.S b/arch/sparc/lib/urem.S new file mode 100644 index 000000000000..ec7f0c502c56 --- /dev/null +++ b/arch/sparc/lib/urem.S | |||
@@ -0,0 +1,355 @@ | |||
1 | /* $Id: urem.S,v 1.4 1996/09/30 02:22:42 davem Exp $ | ||
2 | * urem.S: This routine was taken from glibc-1.09 and is covered | ||
3 | * by the GNU Library General Public License Version 2. | ||
4 | */ | ||
5 | |||
6 | /* This file is generated from divrem.m4; DO NOT EDIT! */ | ||
7 | /* | ||
8 | * Division and remainder, from Appendix E of the Sparc Version 8 | ||
9 | * Architecture Manual, with fixes from Gordon Irlam. | ||
10 | */ | ||
11 | |||
12 | /* | ||
13 | * Input: dividend and divisor in %o0 and %o1 respectively. | ||
14 | * | ||
15 | * m4 parameters: | ||
16 | * .urem name of function to generate | ||
17 | * rem rem=div => %o0 / %o1; rem=rem => %o0 % %o1 | ||
18 | * false false=true => signed; false=false => unsigned | ||
19 | * | ||
20 | * Algorithm parameters: | ||
21 | * N how many bits per iteration we try to get (4) | ||
22 | * WORDSIZE total number of bits (32) | ||
23 | * | ||
24 | * Derived constants: | ||
25 | * TOPBITS number of bits in the top decade of a number | ||
26 | * | ||
27 | * Important variables: | ||
28 | * Q the partial quotient under development (initially 0) | ||
29 | * R the remainder so far, initially the dividend | ||
30 | * ITER number of main division loop iterations required; | ||
31 | * equal to ceil(log2(quotient) / N). Note that this | ||
32 | * is the log base (2^N) of the quotient. | ||
33 | * V the current comparand, initially divisor*2^(ITER*N-1) | ||
34 | * | ||
35 | * Cost: | ||
36 | * Current estimate for non-large dividend is | ||
37 | * ceil(log2(quotient) / N) * (10 + 7N/2) + C | ||
38 | * A large dividend is one greater than 2^(31-TOPBITS) and takes a | ||
39 | * different path, as the upper bits of the quotient must be developed | ||
40 | * one bit at a time. | ||
41 | */ | ||
42 | |||
43 | .globl .urem | ||
44 | .urem: | ||
45 | |||
46 | ! Ready to divide. Compute size of quotient; scale comparand. | ||
47 | orcc %o1, %g0, %o5 | ||
48 | bne 1f | ||
49 | mov %o0, %o3 | ||
50 | |||
51 | ! Divide by zero trap. If it returns, return 0 (about as | ||
52 | ! wrong as possible, but that is what SunOS does...). | ||
53 | ta ST_DIV0 | ||
54 | retl | ||
55 | clr %o0 | ||
56 | |||
57 | 1: | ||
58 | cmp %o3, %o5 ! if %o1 exceeds %o0, done | ||
59 | blu Lgot_result ! (and algorithm fails otherwise) | ||
60 | clr %o2 | ||
61 | |||
62 | sethi %hi(1 << (32 - 4 - 1)), %g1 | ||
63 | |||
64 | cmp %o3, %g1 | ||
65 | blu Lnot_really_big | ||
66 | clr %o4 | ||
67 | |||
68 | ! Here the dividend is >= 2**(31-N) or so. We must be careful here, | ||
69 | ! as our usual N-at-a-shot divide step will cause overflow and havoc. | ||
70 | ! The number of bits in the result here is N*ITER+SC, where SC <= N. | ||
71 | ! Compute ITER in an unorthodox manner: know we need to shift V into | ||
72 | ! the top decade: so do not even bother to compare to R. | ||
73 | 1: | ||
74 | cmp %o5, %g1 | ||
75 | bgeu 3f | ||
76 | mov 1, %g7 | ||
77 | |||
78 | sll %o5, 4, %o5 | ||
79 | |||
80 | b 1b | ||
81 | add %o4, 1, %o4 | ||
82 | |||
83 | ! Now compute %g7. | ||
84 | 2: | ||
85 | addcc %o5, %o5, %o5 | ||
86 | bcc Lnot_too_big | ||
87 | add %g7, 1, %g7 | ||
88 | |||
89 | ! We get here if the %o1 overflowed while shifting. | ||
90 | ! This means that %o3 has the high-order bit set. | ||
91 | ! Restore %o5 and subtract from %o3. | ||
92 | sll %g1, 4, %g1 ! high order bit | ||
93 | srl %o5, 1, %o5 ! rest of %o5 | ||
94 | add %o5, %g1, %o5 | ||
95 | |||
96 | b Ldo_single_div | ||
97 | sub %g7, 1, %g7 | ||
98 | |||
99 | Lnot_too_big: | ||
100 | 3: | ||
101 | cmp %o5, %o3 | ||
102 | blu 2b | ||
103 | nop | ||
104 | |||
105 | be Ldo_single_div | ||
106 | nop | ||
107 | /* NB: these are commented out in the V8-Sparc manual as well */ | ||
108 | /* (I do not understand this) */ | ||
109 | ! %o5 > %o3: went too far: back up 1 step | ||
110 | ! srl %o5, 1, %o5 | ||
111 | ! dec %g7 | ||
112 | ! do single-bit divide steps | ||
113 | ! | ||
114 | ! We have to be careful here. We know that %o3 >= %o5, so we can do the | ||
115 | ! first divide step without thinking. BUT, the others are conditional, | ||
116 | ! and are only done if %o3 >= 0. Because both %o3 and %o5 may have the high- | ||
117 | ! order bit set in the first step, just falling into the regular | ||
118 | ! division loop will mess up the first time around. | ||
119 | ! So we unroll slightly... | ||
120 | Ldo_single_div: | ||
121 | subcc %g7, 1, %g7 | ||
122 | bl Lend_regular_divide | ||
123 | nop | ||
124 | |||
125 | sub %o3, %o5, %o3 | ||
126 | mov 1, %o2 | ||
127 | |||
128 | b Lend_single_divloop | ||
129 | nop | ||
130 | Lsingle_divloop: | ||
131 | sll %o2, 1, %o2 | ||
132 | bl 1f | ||
133 | srl %o5, 1, %o5 | ||
134 | ! %o3 >= 0 | ||
135 | sub %o3, %o5, %o3 | ||
136 | b 2f | ||
137 | add %o2, 1, %o2 | ||
138 | 1: ! %o3 < 0 | ||
139 | add %o3, %o5, %o3 | ||
140 | sub %o2, 1, %o2 | ||
141 | 2: | ||
142 | Lend_single_divloop: | ||
143 | subcc %g7, 1, %g7 | ||
144 | bge Lsingle_divloop | ||
145 | tst %o3 | ||
146 | |||
147 | b,a Lend_regular_divide | ||
148 | |||
149 | Lnot_really_big: | ||
150 | 1: | ||
151 | sll %o5, 4, %o5 | ||
152 | |||
153 | cmp %o5, %o3 | ||
154 | bleu 1b | ||
155 | addcc %o4, 1, %o4 | ||
156 | |||
157 | be Lgot_result | ||
158 | sub %o4, 1, %o4 | ||
159 | |||
160 | tst %o3 ! set up for initial iteration | ||
161 | Ldivloop: | ||
162 | sll %o2, 4, %o2 | ||
163 | ! depth 1, accumulated bits 0 | ||
164 | bl L.1.16 | ||
165 | srl %o5,1,%o5 | ||
166 | ! remainder is positive | ||
167 | subcc %o3,%o5,%o3 | ||
168 | ! depth 2, accumulated bits 1 | ||
169 | bl L.2.17 | ||
170 | srl %o5,1,%o5 | ||
171 | ! remainder is positive | ||
172 | subcc %o3,%o5,%o3 | ||
173 | ! depth 3, accumulated bits 3 | ||
174 | bl L.3.19 | ||
175 | srl %o5,1,%o5 | ||
176 | ! remainder is positive | ||
177 | subcc %o3,%o5,%o3 | ||
178 | ! depth 4, accumulated bits 7 | ||
179 | bl L.4.23 | ||
180 | srl %o5,1,%o5 | ||
181 | ! remainder is positive | ||
182 | subcc %o3,%o5,%o3 | ||
183 | b 9f | ||
184 | add %o2, (7*2+1), %o2 | ||
185 | |||
186 | L.4.23: | ||
187 | ! remainder is negative | ||
188 | addcc %o3,%o5,%o3 | ||
189 | b 9f | ||
190 | add %o2, (7*2-1), %o2 | ||
191 | |||
192 | L.3.19: | ||
193 | ! remainder is negative | ||
194 | addcc %o3,%o5,%o3 | ||
195 | ! depth 4, accumulated bits 5 | ||
196 | bl L.4.21 | ||
197 | srl %o5,1,%o5 | ||
198 | ! remainder is positive | ||
199 | subcc %o3,%o5,%o3 | ||
200 | b 9f | ||
201 | add %o2, (5*2+1), %o2 | ||
202 | |||
203 | L.4.21: | ||
204 | ! remainder is negative | ||
205 | addcc %o3,%o5,%o3 | ||
206 | b 9f | ||
207 | add %o2, (5*2-1), %o2 | ||
208 | |||
209 | L.2.17: | ||
210 | ! remainder is negative | ||
211 | addcc %o3,%o5,%o3 | ||
212 | ! depth 3, accumulated bits 1 | ||
213 | bl L.3.17 | ||
214 | srl %o5,1,%o5 | ||
215 | ! remainder is positive | ||
216 | subcc %o3,%o5,%o3 | ||
217 | ! depth 4, accumulated bits 3 | ||
218 | bl L.4.19 | ||
219 | srl %o5,1,%o5 | ||
220 | ! remainder is positive | ||
221 | subcc %o3,%o5,%o3 | ||
222 | b 9f | ||
223 | add %o2, (3*2+1), %o2 | ||
224 | |||
225 | L.4.19: | ||
226 | ! remainder is negative | ||
227 | addcc %o3,%o5,%o3 | ||
228 | b 9f | ||
229 | add %o2, (3*2-1), %o2 | ||
230 | |||
231 | L.3.17: | ||
232 | ! remainder is negative | ||
233 | addcc %o3,%o5,%o3 | ||
234 | ! depth 4, accumulated bits 1 | ||
235 | bl L.4.17 | ||
236 | srl %o5,1,%o5 | ||
237 | ! remainder is positive | ||
238 | subcc %o3,%o5,%o3 | ||
239 | b 9f | ||
240 | add %o2, (1*2+1), %o2 | ||
241 | |||
242 | L.4.17: | ||
243 | ! remainder is negative | ||
244 | addcc %o3,%o5,%o3 | ||
245 | b 9f | ||
246 | add %o2, (1*2-1), %o2 | ||
247 | |||
248 | L.1.16: | ||
249 | ! remainder is negative | ||
250 | addcc %o3,%o5,%o3 | ||
251 | ! depth 2, accumulated bits -1 | ||
252 | bl L.2.15 | ||
253 | srl %o5,1,%o5 | ||
254 | ! remainder is positive | ||
255 | subcc %o3,%o5,%o3 | ||
256 | ! depth 3, accumulated bits -1 | ||
257 | bl L.3.15 | ||
258 | srl %o5,1,%o5 | ||
259 | ! remainder is positive | ||
260 | subcc %o3,%o5,%o3 | ||
261 | ! depth 4, accumulated bits -1 | ||
262 | bl L.4.15 | ||
263 | srl %o5,1,%o5 | ||
264 | ! remainder is positive | ||
265 | subcc %o3,%o5,%o3 | ||
266 | b 9f | ||
267 | add %o2, (-1*2+1), %o2 | ||
268 | |||
269 | L.4.15: | ||
270 | ! remainder is negative | ||
271 | addcc %o3,%o5,%o3 | ||
272 | b 9f | ||
273 | add %o2, (-1*2-1), %o2 | ||
274 | |||
275 | L.3.15: | ||
276 | ! remainder is negative | ||
277 | addcc %o3,%o5,%o3 | ||
278 | ! depth 4, accumulated bits -3 | ||
279 | bl L.4.13 | ||
280 | srl %o5,1,%o5 | ||
281 | ! remainder is positive | ||
282 | subcc %o3,%o5,%o3 | ||
283 | b 9f | ||
284 | add %o2, (-3*2+1), %o2 | ||
285 | |||
286 | L.4.13: | ||
287 | ! remainder is negative | ||
288 | addcc %o3,%o5,%o3 | ||
289 | b 9f | ||
290 | add %o2, (-3*2-1), %o2 | ||
291 | |||
292 | L.2.15: | ||
293 | ! remainder is negative | ||
294 | addcc %o3,%o5,%o3 | ||
295 | ! depth 3, accumulated bits -3 | ||
296 | bl L.3.13 | ||
297 | srl %o5,1,%o5 | ||
298 | ! remainder is positive | ||
299 | subcc %o3,%o5,%o3 | ||
300 | ! depth 4, accumulated bits -5 | ||
301 | bl L.4.11 | ||
302 | srl %o5,1,%o5 | ||
303 | ! remainder is positive | ||
304 | subcc %o3,%o5,%o3 | ||
305 | b 9f | ||
306 | add %o2, (-5*2+1), %o2 | ||
307 | |||
308 | L.4.11: | ||
309 | ! remainder is negative | ||
310 | addcc %o3,%o5,%o3 | ||
311 | b 9f | ||
312 | add %o2, (-5*2-1), %o2 | ||
313 | |||
314 | L.3.13: | ||
315 | ! remainder is negative | ||
316 | addcc %o3,%o5,%o3 | ||
317 | ! depth 4, accumulated bits -7 | ||
318 | bl L.4.9 | ||
319 | srl %o5,1,%o5 | ||
320 | ! remainder is positive | ||
321 | subcc %o3,%o5,%o3 | ||
322 | b 9f | ||
323 | add %o2, (-7*2+1), %o2 | ||
324 | |||
325 | L.4.9: | ||
326 | ! remainder is negative | ||
327 | addcc %o3,%o5,%o3 | ||
328 | b 9f | ||
329 | add %o2, (-7*2-1), %o2 | ||
330 | |||
331 | 9: | ||
332 | Lend_regular_divide: | ||
333 | subcc %o4, 1, %o4 | ||
334 | bge Ldivloop | ||
335 | tst %o3 | ||
336 | |||
337 | bl,a Lgot_result | ||
338 | ! non-restoring fixup here (one instruction only!) | ||
339 | add %o3, %o1, %o3 | ||
340 | |||
341 | Lgot_result: | ||
342 | |||
343 | retl | ||
344 | mov %o3, %o0 | ||
345 | |||
346 | .globl .urem_patch | ||
347 | .urem_patch: | ||
348 | wr %g0, 0x0, %y | ||
349 | nop | ||
350 | nop | ||
351 | nop | ||
352 | udiv %o0, %o1, %o2 | ||
353 | umul %o2, %o1, %o2 | ||
354 | retl | ||
355 | sub %o0, %o2, %o0 | ||