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/m68k/math-emu/multi_arith.h |
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/m68k/math-emu/multi_arith.h')
-rw-r--r-- | arch/m68k/math-emu/multi_arith.h | 819 |
1 files changed, 819 insertions, 0 deletions
diff --git a/arch/m68k/math-emu/multi_arith.h b/arch/m68k/math-emu/multi_arith.h new file mode 100644 index 000000000000..02251e5afd89 --- /dev/null +++ b/arch/m68k/math-emu/multi_arith.h | |||
@@ -0,0 +1,819 @@ | |||
1 | /* multi_arith.h: multi-precision integer arithmetic functions, needed | ||
2 | to do extended-precision floating point. | ||
3 | |||
4 | (c) 1998 David Huggins-Daines. | ||
5 | |||
6 | Somewhat based on arch/alpha/math-emu/ieee-math.c, which is (c) | ||
7 | David Mosberger-Tang. | ||
8 | |||
9 | You may copy, modify, and redistribute this file under the terms of | ||
10 | the GNU General Public License, version 2, or any later version, at | ||
11 | your convenience. */ | ||
12 | |||
13 | /* Note: | ||
14 | |||
15 | These are not general multi-precision math routines. Rather, they | ||
16 | implement the subset of integer arithmetic that we need in order to | ||
17 | multiply, divide, and normalize 128-bit unsigned mantissae. */ | ||
18 | |||
19 | #ifndef MULTI_ARITH_H | ||
20 | #define MULTI_ARITH_H | ||
21 | |||
22 | #if 0 /* old code... */ | ||
23 | |||
24 | /* Unsigned only, because we don't need signs to multiply and divide. */ | ||
25 | typedef unsigned int int128[4]; | ||
26 | |||
27 | /* Word order */ | ||
28 | enum { | ||
29 | MSW128, | ||
30 | NMSW128, | ||
31 | NLSW128, | ||
32 | LSW128 | ||
33 | }; | ||
34 | |||
35 | /* big-endian */ | ||
36 | #define LO_WORD(ll) (((unsigned int *) &ll)[1]) | ||
37 | #define HI_WORD(ll) (((unsigned int *) &ll)[0]) | ||
38 | |||
39 | /* Convenience functions to stuff various integer values into int128s */ | ||
40 | |||
41 | static inline void zero128(int128 a) | ||
42 | { | ||
43 | a[LSW128] = a[NLSW128] = a[NMSW128] = a[MSW128] = 0; | ||
44 | } | ||
45 | |||
46 | /* Human-readable word order in the arguments */ | ||
47 | static inline void set128(unsigned int i3, unsigned int i2, unsigned int i1, | ||
48 | unsigned int i0, int128 a) | ||
49 | { | ||
50 | a[LSW128] = i0; | ||
51 | a[NLSW128] = i1; | ||
52 | a[NMSW128] = i2; | ||
53 | a[MSW128] = i3; | ||
54 | } | ||
55 | |||
56 | /* Convenience functions (for testing as well) */ | ||
57 | static inline void int64_to_128(unsigned long long src, int128 dest) | ||
58 | { | ||
59 | dest[LSW128] = (unsigned int) src; | ||
60 | dest[NLSW128] = src >> 32; | ||
61 | dest[NMSW128] = dest[MSW128] = 0; | ||
62 | } | ||
63 | |||
64 | static inline void int128_to_64(const int128 src, unsigned long long *dest) | ||
65 | { | ||
66 | *dest = src[LSW128] | (long long) src[NLSW128] << 32; | ||
67 | } | ||
68 | |||
69 | static inline void put_i128(const int128 a) | ||
70 | { | ||
71 | printk("%08x %08x %08x %08x\n", a[MSW128], a[NMSW128], | ||
72 | a[NLSW128], a[LSW128]); | ||
73 | } | ||
74 | |||
75 | /* Internal shifters: | ||
76 | |||
77 | Note that these are only good for 0 < count < 32. | ||
78 | */ | ||
79 | |||
80 | static inline void _lsl128(unsigned int count, int128 a) | ||
81 | { | ||
82 | a[MSW128] = (a[MSW128] << count) | (a[NMSW128] >> (32 - count)); | ||
83 | a[NMSW128] = (a[NMSW128] << count) | (a[NLSW128] >> (32 - count)); | ||
84 | a[NLSW128] = (a[NLSW128] << count) | (a[LSW128] >> (32 - count)); | ||
85 | a[LSW128] <<= count; | ||
86 | } | ||
87 | |||
88 | static inline void _lsr128(unsigned int count, int128 a) | ||
89 | { | ||
90 | a[LSW128] = (a[LSW128] >> count) | (a[NLSW128] << (32 - count)); | ||
91 | a[NLSW128] = (a[NLSW128] >> count) | (a[NMSW128] << (32 - count)); | ||
92 | a[NMSW128] = (a[NMSW128] >> count) | (a[MSW128] << (32 - count)); | ||
93 | a[MSW128] >>= count; | ||
94 | } | ||
95 | |||
96 | /* Should be faster, one would hope */ | ||
97 | |||
98 | static inline void lslone128(int128 a) | ||
99 | { | ||
100 | asm volatile ("lsl.l #1,%0\n" | ||
101 | "roxl.l #1,%1\n" | ||
102 | "roxl.l #1,%2\n" | ||
103 | "roxl.l #1,%3\n" | ||
104 | : | ||
105 | "=d" (a[LSW128]), | ||
106 | "=d"(a[NLSW128]), | ||
107 | "=d"(a[NMSW128]), | ||
108 | "=d"(a[MSW128]) | ||
109 | : | ||
110 | "0"(a[LSW128]), | ||
111 | "1"(a[NLSW128]), | ||
112 | "2"(a[NMSW128]), | ||
113 | "3"(a[MSW128])); | ||
114 | } | ||
115 | |||
116 | static inline void lsrone128(int128 a) | ||
117 | { | ||
118 | asm volatile ("lsr.l #1,%0\n" | ||
119 | "roxr.l #1,%1\n" | ||
120 | "roxr.l #1,%2\n" | ||
121 | "roxr.l #1,%3\n" | ||
122 | : | ||
123 | "=d" (a[MSW128]), | ||
124 | "=d"(a[NMSW128]), | ||
125 | "=d"(a[NLSW128]), | ||
126 | "=d"(a[LSW128]) | ||
127 | : | ||
128 | "0"(a[MSW128]), | ||
129 | "1"(a[NMSW128]), | ||
130 | "2"(a[NLSW128]), | ||
131 | "3"(a[LSW128])); | ||
132 | } | ||
133 | |||
134 | /* Generalized 128-bit shifters: | ||
135 | |||
136 | These bit-shift to a multiple of 32, then move whole longwords. */ | ||
137 | |||
138 | static inline void lsl128(unsigned int count, int128 a) | ||
139 | { | ||
140 | int wordcount, i; | ||
141 | |||
142 | if (count % 32) | ||
143 | _lsl128(count % 32, a); | ||
144 | |||
145 | if (0 == (wordcount = count / 32)) | ||
146 | return; | ||
147 | |||
148 | /* argh, gak, endian-sensitive */ | ||
149 | for (i = 0; i < 4 - wordcount; i++) { | ||
150 | a[i] = a[i + wordcount]; | ||
151 | } | ||
152 | for (i = 3; i >= 4 - wordcount; --i) { | ||
153 | a[i] = 0; | ||
154 | } | ||
155 | } | ||
156 | |||
157 | static inline void lsr128(unsigned int count, int128 a) | ||
158 | { | ||
159 | int wordcount, i; | ||
160 | |||
161 | if (count % 32) | ||
162 | _lsr128(count % 32, a); | ||
163 | |||
164 | if (0 == (wordcount = count / 32)) | ||
165 | return; | ||
166 | |||
167 | for (i = 3; i >= wordcount; --i) { | ||
168 | a[i] = a[i - wordcount]; | ||
169 | } | ||
170 | for (i = 0; i < wordcount; i++) { | ||
171 | a[i] = 0; | ||
172 | } | ||
173 | } | ||
174 | |||
175 | static inline int orl128(int a, int128 b) | ||
176 | { | ||
177 | b[LSW128] |= a; | ||
178 | } | ||
179 | |||
180 | static inline int btsthi128(const int128 a) | ||
181 | { | ||
182 | return a[MSW128] & 0x80000000; | ||
183 | } | ||
184 | |||
185 | /* test bits (numbered from 0 = LSB) up to and including "top" */ | ||
186 | static inline int bftestlo128(int top, const int128 a) | ||
187 | { | ||
188 | int r = 0; | ||
189 | |||
190 | if (top > 31) | ||
191 | r |= a[LSW128]; | ||
192 | if (top > 63) | ||
193 | r |= a[NLSW128]; | ||
194 | if (top > 95) | ||
195 | r |= a[NMSW128]; | ||
196 | |||
197 | r |= a[3 - (top / 32)] & ((1 << (top % 32 + 1)) - 1); | ||
198 | |||
199 | return (r != 0); | ||
200 | } | ||
201 | |||
202 | /* Aargh. We need these because GCC is broken */ | ||
203 | /* FIXME: do them in assembly, for goodness' sake! */ | ||
204 | static inline void mask64(int pos, unsigned long long *mask) | ||
205 | { | ||
206 | *mask = 0; | ||
207 | |||
208 | if (pos < 32) { | ||
209 | LO_WORD(*mask) = (1 << pos) - 1; | ||
210 | return; | ||
211 | } | ||
212 | LO_WORD(*mask) = -1; | ||
213 | HI_WORD(*mask) = (1 << (pos - 32)) - 1; | ||
214 | } | ||
215 | |||
216 | static inline void bset64(int pos, unsigned long long *dest) | ||
217 | { | ||
218 | /* This conditional will be optimized away. Thanks, GCC! */ | ||
219 | if (pos < 32) | ||
220 | asm volatile ("bset %1,%0":"=m" | ||
221 | (LO_WORD(*dest)):"id"(pos)); | ||
222 | else | ||
223 | asm volatile ("bset %1,%0":"=m" | ||
224 | (HI_WORD(*dest)):"id"(pos - 32)); | ||
225 | } | ||
226 | |||
227 | static inline int btst64(int pos, unsigned long long dest) | ||
228 | { | ||
229 | if (pos < 32) | ||
230 | return (0 != (LO_WORD(dest) & (1 << pos))); | ||
231 | else | ||
232 | return (0 != (HI_WORD(dest) & (1 << (pos - 32)))); | ||
233 | } | ||
234 | |||
235 | static inline void lsl64(int count, unsigned long long *dest) | ||
236 | { | ||
237 | if (count < 32) { | ||
238 | HI_WORD(*dest) = (HI_WORD(*dest) << count) | ||
239 | | (LO_WORD(*dest) >> count); | ||
240 | LO_WORD(*dest) <<= count; | ||
241 | return; | ||
242 | } | ||
243 | count -= 32; | ||
244 | HI_WORD(*dest) = LO_WORD(*dest) << count; | ||
245 | LO_WORD(*dest) = 0; | ||
246 | } | ||
247 | |||
248 | static inline void lsr64(int count, unsigned long long *dest) | ||
249 | { | ||
250 | if (count < 32) { | ||
251 | LO_WORD(*dest) = (LO_WORD(*dest) >> count) | ||
252 | | (HI_WORD(*dest) << (32 - count)); | ||
253 | HI_WORD(*dest) >>= count; | ||
254 | return; | ||
255 | } | ||
256 | count -= 32; | ||
257 | LO_WORD(*dest) = HI_WORD(*dest) >> count; | ||
258 | HI_WORD(*dest) = 0; | ||
259 | } | ||
260 | #endif | ||
261 | |||
262 | static inline void fp_denormalize(struct fp_ext *reg, unsigned int cnt) | ||
263 | { | ||
264 | reg->exp += cnt; | ||
265 | |||
266 | switch (cnt) { | ||
267 | case 0 ... 8: | ||
268 | reg->lowmant = reg->mant.m32[1] << (8 - cnt); | ||
269 | reg->mant.m32[1] = (reg->mant.m32[1] >> cnt) | | ||
270 | (reg->mant.m32[0] << (32 - cnt)); | ||
271 | reg->mant.m32[0] = reg->mant.m32[0] >> cnt; | ||
272 | break; | ||
273 | case 9 ... 32: | ||
274 | reg->lowmant = reg->mant.m32[1] >> (cnt - 8); | ||
275 | if (reg->mant.m32[1] << (40 - cnt)) | ||
276 | reg->lowmant |= 1; | ||
277 | reg->mant.m32[1] = (reg->mant.m32[1] >> cnt) | | ||
278 | (reg->mant.m32[0] << (32 - cnt)); | ||
279 | reg->mant.m32[0] = reg->mant.m32[0] >> cnt; | ||
280 | break; | ||
281 | case 33 ... 39: | ||
282 | asm volatile ("bfextu %1{%2,#8},%0" : "=d" (reg->lowmant) | ||
283 | : "m" (reg->mant.m32[0]), "d" (64 - cnt)); | ||
284 | if (reg->mant.m32[1] << (40 - cnt)) | ||
285 | reg->lowmant |= 1; | ||
286 | reg->mant.m32[1] = reg->mant.m32[0] >> (cnt - 32); | ||
287 | reg->mant.m32[0] = 0; | ||
288 | break; | ||
289 | case 40 ... 71: | ||
290 | reg->lowmant = reg->mant.m32[0] >> (cnt - 40); | ||
291 | if ((reg->mant.m32[0] << (72 - cnt)) || reg->mant.m32[1]) | ||
292 | reg->lowmant |= 1; | ||
293 | reg->mant.m32[1] = reg->mant.m32[0] >> (cnt - 32); | ||
294 | reg->mant.m32[0] = 0; | ||
295 | break; | ||
296 | default: | ||
297 | reg->lowmant = reg->mant.m32[0] || reg->mant.m32[1]; | ||
298 | reg->mant.m32[0] = 0; | ||
299 | reg->mant.m32[1] = 0; | ||
300 | break; | ||
301 | } | ||
302 | } | ||
303 | |||
304 | static inline int fp_overnormalize(struct fp_ext *reg) | ||
305 | { | ||
306 | int shift; | ||
307 | |||
308 | if (reg->mant.m32[0]) { | ||
309 | asm ("bfffo %1{#0,#32},%0" : "=d" (shift) : "dm" (reg->mant.m32[0])); | ||
310 | reg->mant.m32[0] = (reg->mant.m32[0] << shift) | (reg->mant.m32[1] >> (32 - shift)); | ||
311 | reg->mant.m32[1] = (reg->mant.m32[1] << shift); | ||
312 | } else { | ||
313 | asm ("bfffo %1{#0,#32},%0" : "=d" (shift) : "dm" (reg->mant.m32[1])); | ||
314 | reg->mant.m32[0] = (reg->mant.m32[1] << shift); | ||
315 | reg->mant.m32[1] = 0; | ||
316 | shift += 32; | ||
317 | } | ||
318 | |||
319 | return shift; | ||
320 | } | ||
321 | |||
322 | static inline int fp_addmant(struct fp_ext *dest, struct fp_ext *src) | ||
323 | { | ||
324 | int carry; | ||
325 | |||
326 | /* we assume here, gcc only insert move and a clr instr */ | ||
327 | asm volatile ("add.b %1,%0" : "=d,g" (dest->lowmant) | ||
328 | : "g,d" (src->lowmant), "0,0" (dest->lowmant)); | ||
329 | asm volatile ("addx.l %1,%0" : "=d" (dest->mant.m32[1]) | ||
330 | : "d" (src->mant.m32[1]), "0" (dest->mant.m32[1])); | ||
331 | asm volatile ("addx.l %1,%0" : "=d" (dest->mant.m32[0]) | ||
332 | : "d" (src->mant.m32[0]), "0" (dest->mant.m32[0])); | ||
333 | asm volatile ("addx.l %0,%0" : "=d" (carry) : "0" (0)); | ||
334 | |||
335 | return carry; | ||
336 | } | ||
337 | |||
338 | static inline int fp_addcarry(struct fp_ext *reg) | ||
339 | { | ||
340 | if (++reg->exp == 0x7fff) { | ||
341 | if (reg->mant.m64) | ||
342 | fp_set_sr(FPSR_EXC_INEX2); | ||
343 | reg->mant.m64 = 0; | ||
344 | fp_set_sr(FPSR_EXC_OVFL); | ||
345 | return 0; | ||
346 | } | ||
347 | reg->lowmant = (reg->mant.m32[1] << 7) | (reg->lowmant ? 1 : 0); | ||
348 | reg->mant.m32[1] = (reg->mant.m32[1] >> 1) | | ||
349 | (reg->mant.m32[0] << 31); | ||
350 | reg->mant.m32[0] = (reg->mant.m32[0] >> 1) | 0x80000000; | ||
351 | |||
352 | return 1; | ||
353 | } | ||
354 | |||
355 | static inline void fp_submant(struct fp_ext *dest, struct fp_ext *src1, | ||
356 | struct fp_ext *src2) | ||
357 | { | ||
358 | /* we assume here, gcc only insert move and a clr instr */ | ||
359 | asm volatile ("sub.b %1,%0" : "=d,g" (dest->lowmant) | ||
360 | : "g,d" (src2->lowmant), "0,0" (src1->lowmant)); | ||
361 | asm volatile ("subx.l %1,%0" : "=d" (dest->mant.m32[1]) | ||
362 | : "d" (src2->mant.m32[1]), "0" (src1->mant.m32[1])); | ||
363 | asm volatile ("subx.l %1,%0" : "=d" (dest->mant.m32[0]) | ||
364 | : "d" (src2->mant.m32[0]), "0" (src1->mant.m32[0])); | ||
365 | } | ||
366 | |||
367 | #define fp_mul64(desth, destl, src1, src2) ({ \ | ||
368 | asm ("mulu.l %2,%1:%0" : "=d" (destl), "=d" (desth) \ | ||
369 | : "g" (src1), "0" (src2)); \ | ||
370 | }) | ||
371 | #define fp_div64(quot, rem, srch, srcl, div) \ | ||
372 | asm ("divu.l %2,%1:%0" : "=d" (quot), "=d" (rem) \ | ||
373 | : "dm" (div), "1" (srch), "0" (srcl)) | ||
374 | #define fp_add64(dest1, dest2, src1, src2) ({ \ | ||
375 | asm ("add.l %1,%0" : "=d,dm" (dest2) \ | ||
376 | : "dm,d" (src2), "0,0" (dest2)); \ | ||
377 | asm ("addx.l %1,%0" : "=d" (dest1) \ | ||
378 | : "d" (src1), "0" (dest1)); \ | ||
379 | }) | ||
380 | #define fp_addx96(dest, src) ({ \ | ||
381 | /* we assume here, gcc only insert move and a clr instr */ \ | ||
382 | asm volatile ("add.l %1,%0" : "=d,g" (dest->m32[2]) \ | ||
383 | : "g,d" (temp.m32[1]), "0,0" (dest->m32[2])); \ | ||
384 | asm volatile ("addx.l %1,%0" : "=d" (dest->m32[1]) \ | ||
385 | : "d" (temp.m32[0]), "0" (dest->m32[1])); \ | ||
386 | asm volatile ("addx.l %1,%0" : "=d" (dest->m32[0]) \ | ||
387 | : "d" (0), "0" (dest->m32[0])); \ | ||
388 | }) | ||
389 | #define fp_sub64(dest, src) ({ \ | ||
390 | asm ("sub.l %1,%0" : "=d,dm" (dest.m32[1]) \ | ||
391 | : "dm,d" (src.m32[1]), "0,0" (dest.m32[1])); \ | ||
392 | asm ("subx.l %1,%0" : "=d" (dest.m32[0]) \ | ||
393 | : "d" (src.m32[0]), "0" (dest.m32[0])); \ | ||
394 | }) | ||
395 | #define fp_sub96c(dest, srch, srcm, srcl) ({ \ | ||
396 | char carry; \ | ||
397 | asm ("sub.l %1,%0" : "=d,dm" (dest.m32[2]) \ | ||
398 | : "dm,d" (srcl), "0,0" (dest.m32[2])); \ | ||
399 | asm ("subx.l %1,%0" : "=d" (dest.m32[1]) \ | ||
400 | : "d" (srcm), "0" (dest.m32[1])); \ | ||
401 | asm ("subx.l %2,%1; scs %0" : "=d" (carry), "=d" (dest.m32[0]) \ | ||
402 | : "d" (srch), "1" (dest.m32[0])); \ | ||
403 | carry; \ | ||
404 | }) | ||
405 | |||
406 | static inline void fp_multiplymant(union fp_mant128 *dest, struct fp_ext *src1, | ||
407 | struct fp_ext *src2) | ||
408 | { | ||
409 | union fp_mant64 temp; | ||
410 | |||
411 | fp_mul64(dest->m32[0], dest->m32[1], src1->mant.m32[0], src2->mant.m32[0]); | ||
412 | fp_mul64(dest->m32[2], dest->m32[3], src1->mant.m32[1], src2->mant.m32[1]); | ||
413 | |||
414 | fp_mul64(temp.m32[0], temp.m32[1], src1->mant.m32[0], src2->mant.m32[1]); | ||
415 | fp_addx96(dest, temp); | ||
416 | |||
417 | fp_mul64(temp.m32[0], temp.m32[1], src1->mant.m32[1], src2->mant.m32[0]); | ||
418 | fp_addx96(dest, temp); | ||
419 | } | ||
420 | |||
421 | static inline void fp_dividemant(union fp_mant128 *dest, struct fp_ext *src, | ||
422 | struct fp_ext *div) | ||
423 | { | ||
424 | union fp_mant128 tmp; | ||
425 | union fp_mant64 tmp64; | ||
426 | unsigned long *mantp = dest->m32; | ||
427 | unsigned long fix, rem, first, dummy; | ||
428 | int i; | ||
429 | |||
430 | /* the algorithm below requires dest to be smaller than div, | ||
431 | but both have the high bit set */ | ||
432 | if (src->mant.m64 >= div->mant.m64) { | ||
433 | fp_sub64(src->mant, div->mant); | ||
434 | *mantp = 1; | ||
435 | } else | ||
436 | *mantp = 0; | ||
437 | mantp++; | ||
438 | |||
439 | /* basic idea behind this algorithm: we can't divide two 64bit numbers | ||
440 | (AB/CD) directly, but we can calculate AB/C0, but this means this | ||
441 | quotient is off by C0/CD, so we have to multiply the first result | ||
442 | to fix the result, after that we have nearly the correct result | ||
443 | and only a few corrections are needed. */ | ||
444 | |||
445 | /* C0/CD can be precalculated, but it's an 64bit division again, but | ||
446 | we can make it a bit easier, by dividing first through C so we get | ||
447 | 10/1D and now only a single shift and the value fits into 32bit. */ | ||
448 | fix = 0x80000000; | ||
449 | dummy = div->mant.m32[1] / div->mant.m32[0] + 1; | ||
450 | dummy = (dummy >> 1) | fix; | ||
451 | fp_div64(fix, dummy, fix, 0, dummy); | ||
452 | fix--; | ||
453 | |||
454 | for (i = 0; i < 3; i++, mantp++) { | ||
455 | if (src->mant.m32[0] == div->mant.m32[0]) { | ||
456 | fp_div64(first, rem, 0, src->mant.m32[1], div->mant.m32[0]); | ||
457 | |||
458 | fp_mul64(*mantp, dummy, first, fix); | ||
459 | *mantp += fix; | ||
460 | } else { | ||
461 | fp_div64(first, rem, src->mant.m32[0], src->mant.m32[1], div->mant.m32[0]); | ||
462 | |||
463 | fp_mul64(*mantp, dummy, first, fix); | ||
464 | } | ||
465 | |||
466 | fp_mul64(tmp.m32[0], tmp.m32[1], div->mant.m32[0], first - *mantp); | ||
467 | fp_add64(tmp.m32[0], tmp.m32[1], 0, rem); | ||
468 | tmp.m32[2] = 0; | ||
469 | |||
470 | fp_mul64(tmp64.m32[0], tmp64.m32[1], *mantp, div->mant.m32[1]); | ||
471 | fp_sub96c(tmp, 0, tmp64.m32[0], tmp64.m32[1]); | ||
472 | |||
473 | src->mant.m32[0] = tmp.m32[1]; | ||
474 | src->mant.m32[1] = tmp.m32[2]; | ||
475 | |||
476 | while (!fp_sub96c(tmp, 0, div->mant.m32[0], div->mant.m32[1])) { | ||
477 | src->mant.m32[0] = tmp.m32[1]; | ||
478 | src->mant.m32[1] = tmp.m32[2]; | ||
479 | *mantp += 1; | ||
480 | } | ||
481 | } | ||
482 | } | ||
483 | |||
484 | #if 0 | ||
485 | static inline unsigned int fp_fls128(union fp_mant128 *src) | ||
486 | { | ||
487 | unsigned long data; | ||
488 | unsigned int res, off; | ||
489 | |||
490 | if ((data = src->m32[0])) | ||
491 | off = 0; | ||
492 | else if ((data = src->m32[1])) | ||
493 | off = 32; | ||
494 | else if ((data = src->m32[2])) | ||
495 | off = 64; | ||
496 | else if ((data = src->m32[3])) | ||
497 | off = 96; | ||
498 | else | ||
499 | return 128; | ||
500 | |||
501 | asm ("bfffo %1{#0,#32},%0" : "=d" (res) : "dm" (data)); | ||
502 | return res + off; | ||
503 | } | ||
504 | |||
505 | static inline void fp_shiftmant128(union fp_mant128 *src, int shift) | ||
506 | { | ||
507 | unsigned long sticky; | ||
508 | |||
509 | switch (shift) { | ||
510 | case 0: | ||
511 | return; | ||
512 | case 1: | ||
513 | asm volatile ("lsl.l #1,%0" | ||
514 | : "=d" (src->m32[3]) : "0" (src->m32[3])); | ||
515 | asm volatile ("roxl.l #1,%0" | ||
516 | : "=d" (src->m32[2]) : "0" (src->m32[2])); | ||
517 | asm volatile ("roxl.l #1,%0" | ||
518 | : "=d" (src->m32[1]) : "0" (src->m32[1])); | ||
519 | asm volatile ("roxl.l #1,%0" | ||
520 | : "=d" (src->m32[0]) : "0" (src->m32[0])); | ||
521 | return; | ||
522 | case 2 ... 31: | ||
523 | src->m32[0] = (src->m32[0] << shift) | (src->m32[1] >> (32 - shift)); | ||
524 | src->m32[1] = (src->m32[1] << shift) | (src->m32[2] >> (32 - shift)); | ||
525 | src->m32[2] = (src->m32[2] << shift) | (src->m32[3] >> (32 - shift)); | ||
526 | src->m32[3] = (src->m32[3] << shift); | ||
527 | return; | ||
528 | case 32 ... 63: | ||
529 | shift -= 32; | ||
530 | src->m32[0] = (src->m32[1] << shift) | (src->m32[2] >> (32 - shift)); | ||
531 | src->m32[1] = (src->m32[2] << shift) | (src->m32[3] >> (32 - shift)); | ||
532 | src->m32[2] = (src->m32[3] << shift); | ||
533 | src->m32[3] = 0; | ||
534 | return; | ||
535 | case 64 ... 95: | ||
536 | shift -= 64; | ||
537 | src->m32[0] = (src->m32[2] << shift) | (src->m32[3] >> (32 - shift)); | ||
538 | src->m32[1] = (src->m32[3] << shift); | ||
539 | src->m32[2] = src->m32[3] = 0; | ||
540 | return; | ||
541 | case 96 ... 127: | ||
542 | shift -= 96; | ||
543 | src->m32[0] = (src->m32[3] << shift); | ||
544 | src->m32[1] = src->m32[2] = src->m32[3] = 0; | ||
545 | return; | ||
546 | case -31 ... -1: | ||
547 | shift = -shift; | ||
548 | sticky = 0; | ||
549 | if (src->m32[3] << (32 - shift)) | ||
550 | sticky = 1; | ||
551 | src->m32[3] = (src->m32[3] >> shift) | (src->m32[2] << (32 - shift)) | sticky; | ||
552 | src->m32[2] = (src->m32[2] >> shift) | (src->m32[1] << (32 - shift)); | ||
553 | src->m32[1] = (src->m32[1] >> shift) | (src->m32[0] << (32 - shift)); | ||
554 | src->m32[0] = (src->m32[0] >> shift); | ||
555 | return; | ||
556 | case -63 ... -32: | ||
557 | shift = -shift - 32; | ||
558 | sticky = 0; | ||
559 | if ((src->m32[2] << (32 - shift)) || src->m32[3]) | ||
560 | sticky = 1; | ||
561 | src->m32[3] = (src->m32[2] >> shift) | (src->m32[1] << (32 - shift)) | sticky; | ||
562 | src->m32[2] = (src->m32[1] >> shift) | (src->m32[0] << (32 - shift)); | ||
563 | src->m32[1] = (src->m32[0] >> shift); | ||
564 | src->m32[0] = 0; | ||
565 | return; | ||
566 | case -95 ... -64: | ||
567 | shift = -shift - 64; | ||
568 | sticky = 0; | ||
569 | if ((src->m32[1] << (32 - shift)) || src->m32[2] || src->m32[3]) | ||
570 | sticky = 1; | ||
571 | src->m32[3] = (src->m32[1] >> shift) | (src->m32[0] << (32 - shift)) | sticky; | ||
572 | src->m32[2] = (src->m32[0] >> shift); | ||
573 | src->m32[1] = src->m32[0] = 0; | ||
574 | return; | ||
575 | case -127 ... -96: | ||
576 | shift = -shift - 96; | ||
577 | sticky = 0; | ||
578 | if ((src->m32[0] << (32 - shift)) || src->m32[1] || src->m32[2] || src->m32[3]) | ||
579 | sticky = 1; | ||
580 | src->m32[3] = (src->m32[0] >> shift) | sticky; | ||
581 | src->m32[2] = src->m32[1] = src->m32[0] = 0; | ||
582 | return; | ||
583 | } | ||
584 | |||
585 | if (shift < 0 && (src->m32[0] || src->m32[1] || src->m32[2] || src->m32[3])) | ||
586 | src->m32[3] = 1; | ||
587 | else | ||
588 | src->m32[3] = 0; | ||
589 | src->m32[2] = 0; | ||
590 | src->m32[1] = 0; | ||
591 | src->m32[0] = 0; | ||
592 | } | ||
593 | #endif | ||
594 | |||
595 | static inline void fp_putmant128(struct fp_ext *dest, union fp_mant128 *src, | ||
596 | int shift) | ||
597 | { | ||
598 | unsigned long tmp; | ||
599 | |||
600 | switch (shift) { | ||
601 | case 0: | ||
602 | dest->mant.m64 = src->m64[0]; | ||
603 | dest->lowmant = src->m32[2] >> 24; | ||
604 | if (src->m32[3] || (src->m32[2] << 8)) | ||
605 | dest->lowmant |= 1; | ||
606 | break; | ||
607 | case 1: | ||
608 | asm volatile ("lsl.l #1,%0" | ||
609 | : "=d" (tmp) : "0" (src->m32[2])); | ||
610 | asm volatile ("roxl.l #1,%0" | ||
611 | : "=d" (dest->mant.m32[1]) : "0" (src->m32[1])); | ||
612 | asm volatile ("roxl.l #1,%0" | ||
613 | : "=d" (dest->mant.m32[0]) : "0" (src->m32[0])); | ||
614 | dest->lowmant = tmp >> 24; | ||
615 | if (src->m32[3] || (tmp << 8)) | ||
616 | dest->lowmant |= 1; | ||
617 | break; | ||
618 | case 31: | ||
619 | asm volatile ("lsr.l #1,%1; roxr.l #1,%0" | ||
620 | : "=d" (dest->mant.m32[0]) | ||
621 | : "d" (src->m32[0]), "0" (src->m32[1])); | ||
622 | asm volatile ("roxr.l #1,%0" | ||
623 | : "=d" (dest->mant.m32[1]) : "0" (src->m32[2])); | ||
624 | asm volatile ("roxr.l #1,%0" | ||
625 | : "=d" (tmp) : "0" (src->m32[3])); | ||
626 | dest->lowmant = tmp >> 24; | ||
627 | if (src->m32[3] << 7) | ||
628 | dest->lowmant |= 1; | ||
629 | break; | ||
630 | case 32: | ||
631 | dest->mant.m32[0] = src->m32[1]; | ||
632 | dest->mant.m32[1] = src->m32[2]; | ||
633 | dest->lowmant = src->m32[3] >> 24; | ||
634 | if (src->m32[3] << 8) | ||
635 | dest->lowmant |= 1; | ||
636 | break; | ||
637 | } | ||
638 | } | ||
639 | |||
640 | #if 0 /* old code... */ | ||
641 | static inline int fls(unsigned int a) | ||
642 | { | ||
643 | int r; | ||
644 | |||
645 | asm volatile ("bfffo %1{#0,#32},%0" | ||
646 | : "=d" (r) : "md" (a)); | ||
647 | return r; | ||
648 | } | ||
649 | |||
650 | /* fls = "find last set" (cf. ffs(3)) */ | ||
651 | static inline int fls128(const int128 a) | ||
652 | { | ||
653 | if (a[MSW128]) | ||
654 | return fls(a[MSW128]); | ||
655 | if (a[NMSW128]) | ||
656 | return fls(a[NMSW128]) + 32; | ||
657 | /* XXX: it probably never gets beyond this point in actual | ||
658 | use, but that's indicative of a more general problem in the | ||
659 | algorithm (i.e. as per the actual 68881 implementation, we | ||
660 | really only need at most 67 bits of precision [plus | ||
661 | overflow]) so I'm not going to fix it. */ | ||
662 | if (a[NLSW128]) | ||
663 | return fls(a[NLSW128]) + 64; | ||
664 | if (a[LSW128]) | ||
665 | return fls(a[LSW128]) + 96; | ||
666 | else | ||
667 | return -1; | ||
668 | } | ||
669 | |||
670 | static inline int zerop128(const int128 a) | ||
671 | { | ||
672 | return !(a[LSW128] | a[NLSW128] | a[NMSW128] | a[MSW128]); | ||
673 | } | ||
674 | |||
675 | static inline int nonzerop128(const int128 a) | ||
676 | { | ||
677 | return (a[LSW128] | a[NLSW128] | a[NMSW128] | a[MSW128]); | ||
678 | } | ||
679 | |||
680 | /* Addition and subtraction */ | ||
681 | /* Do these in "pure" assembly, because "extended" asm is unmanageable | ||
682 | here */ | ||
683 | static inline void add128(const int128 a, int128 b) | ||
684 | { | ||
685 | /* rotating carry flags */ | ||
686 | unsigned int carry[2]; | ||
687 | |||
688 | carry[0] = a[LSW128] > (0xffffffff - b[LSW128]); | ||
689 | b[LSW128] += a[LSW128]; | ||
690 | |||
691 | carry[1] = a[NLSW128] > (0xffffffff - b[NLSW128] - carry[0]); | ||
692 | b[NLSW128] = a[NLSW128] + b[NLSW128] + carry[0]; | ||
693 | |||
694 | carry[0] = a[NMSW128] > (0xffffffff - b[NMSW128] - carry[1]); | ||
695 | b[NMSW128] = a[NMSW128] + b[NMSW128] + carry[1]; | ||
696 | |||
697 | b[MSW128] = a[MSW128] + b[MSW128] + carry[0]; | ||
698 | } | ||
699 | |||
700 | /* Note: assembler semantics: "b -= a" */ | ||
701 | static inline void sub128(const int128 a, int128 b) | ||
702 | { | ||
703 | /* rotating borrow flags */ | ||
704 | unsigned int borrow[2]; | ||
705 | |||
706 | borrow[0] = b[LSW128] < a[LSW128]; | ||
707 | b[LSW128] -= a[LSW128]; | ||
708 | |||
709 | borrow[1] = b[NLSW128] < a[NLSW128] + borrow[0]; | ||
710 | b[NLSW128] = b[NLSW128] - a[NLSW128] - borrow[0]; | ||
711 | |||
712 | borrow[0] = b[NMSW128] < a[NMSW128] + borrow[1]; | ||
713 | b[NMSW128] = b[NMSW128] - a[NMSW128] - borrow[1]; | ||
714 | |||
715 | b[MSW128] = b[MSW128] - a[MSW128] - borrow[0]; | ||
716 | } | ||
717 | |||
718 | /* Poor man's 64-bit expanding multiply */ | ||
719 | static inline void mul64(unsigned long long a, unsigned long long b, int128 c) | ||
720 | { | ||
721 | unsigned long long acc; | ||
722 | int128 acc128; | ||
723 | |||
724 | zero128(acc128); | ||
725 | zero128(c); | ||
726 | |||
727 | /* first the low words */ | ||
728 | if (LO_WORD(a) && LO_WORD(b)) { | ||
729 | acc = (long long) LO_WORD(a) * LO_WORD(b); | ||
730 | c[NLSW128] = HI_WORD(acc); | ||
731 | c[LSW128] = LO_WORD(acc); | ||
732 | } | ||
733 | /* Next the high words */ | ||
734 | if (HI_WORD(a) && HI_WORD(b)) { | ||
735 | acc = (long long) HI_WORD(a) * HI_WORD(b); | ||
736 | c[MSW128] = HI_WORD(acc); | ||
737 | c[NMSW128] = LO_WORD(acc); | ||
738 | } | ||
739 | /* The middle words */ | ||
740 | if (LO_WORD(a) && HI_WORD(b)) { | ||
741 | acc = (long long) LO_WORD(a) * HI_WORD(b); | ||
742 | acc128[NMSW128] = HI_WORD(acc); | ||
743 | acc128[NLSW128] = LO_WORD(acc); | ||
744 | add128(acc128, c); | ||
745 | } | ||
746 | /* The first and last words */ | ||
747 | if (HI_WORD(a) && LO_WORD(b)) { | ||
748 | acc = (long long) HI_WORD(a) * LO_WORD(b); | ||
749 | acc128[NMSW128] = HI_WORD(acc); | ||
750 | acc128[NLSW128] = LO_WORD(acc); | ||
751 | add128(acc128, c); | ||
752 | } | ||
753 | } | ||
754 | |||
755 | /* Note: unsigned */ | ||
756 | static inline int cmp128(int128 a, int128 b) | ||
757 | { | ||
758 | if (a[MSW128] < b[MSW128]) | ||
759 | return -1; | ||
760 | if (a[MSW128] > b[MSW128]) | ||
761 | return 1; | ||
762 | if (a[NMSW128] < b[NMSW128]) | ||
763 | return -1; | ||
764 | if (a[NMSW128] > b[NMSW128]) | ||
765 | return 1; | ||
766 | if (a[NLSW128] < b[NLSW128]) | ||
767 | return -1; | ||
768 | if (a[NLSW128] > b[NLSW128]) | ||
769 | return 1; | ||
770 | |||
771 | return (signed) a[LSW128] - b[LSW128]; | ||
772 | } | ||
773 | |||
774 | inline void div128(int128 a, int128 b, int128 c) | ||
775 | { | ||
776 | int128 mask; | ||
777 | |||
778 | /* Algorithm: | ||
779 | |||
780 | Shift the divisor until it's at least as big as the | ||
781 | dividend, keeping track of the position to which we've | ||
782 | shifted it, i.e. the power of 2 which we've multiplied it | ||
783 | by. | ||
784 | |||
785 | Then, for this power of 2 (the mask), and every one smaller | ||
786 | than it, subtract the mask from the dividend and add it to | ||
787 | the quotient until the dividend is smaller than the raised | ||
788 | divisor. At this point, divide the dividend and the mask | ||
789 | by 2 (i.e. shift one place to the right). Lather, rinse, | ||
790 | and repeat, until there are no more powers of 2 left. */ | ||
791 | |||
792 | /* FIXME: needless to say, there's room for improvement here too. */ | ||
793 | |||
794 | /* Shift up */ | ||
795 | /* XXX: since it just has to be "at least as big", we can | ||
796 | probably eliminate this horribly wasteful loop. I will | ||
797 | have to prove this first, though */ | ||
798 | set128(0, 0, 0, 1, mask); | ||
799 | while (cmp128(b, a) < 0 && !btsthi128(b)) { | ||
800 | lslone128(b); | ||
801 | lslone128(mask); | ||
802 | } | ||
803 | |||
804 | /* Shift down */ | ||
805 | zero128(c); | ||
806 | do { | ||
807 | if (cmp128(a, b) >= 0) { | ||
808 | sub128(b, a); | ||
809 | add128(mask, c); | ||
810 | } | ||
811 | lsrone128(mask); | ||
812 | lsrone128(b); | ||
813 | } while (nonzerop128(mask)); | ||
814 | |||
815 | /* The remainder is in a... */ | ||
816 | } | ||
817 | #endif | ||
818 | |||
819 | #endif /* MULTI_ARITH_H */ | ||