xref: /openbmc/u-boot/arch/nios2/lib/libgcc.c (revision c6af2e7d)
1 /*
2  * This file is part of GNU CC.
3  *
4  * GNU CC is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published
6  * by the Free Software Foundation; either version 2, or (at your
7  * option) any later version.
8  *
9  * GNU CC is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public
15  * License along with GNU CC; see the file COPYING.  If not, write
16  * to the Free Software Foundation, 59 Temple Place - Suite 330,
17  * Boston, MA 02111-1307, USA.
18  */
19 
20 typedef unsigned int UWtype;
21 typedef unsigned int UHWtype;
22 typedef unsigned long long UDWtype;
23 #define W_TYPE_SIZE 32
24 
25 typedef unsigned char UQItype;
26 typedef long SItype;
27 typedef unsigned long USItype;
28 typedef long long DItype;
29 typedef unsigned long long DSItype;
30 
31 #include "longlong.h"
32 
33 
34 typedef int word_type;
35 typedef long Wtype;
36 typedef long long DWtype;
37 
38 struct DWstruct { Wtype low, high;};
39 
40 typedef union
41 {
42   struct DWstruct s;
43   DWtype ll;
44 } DWunion;
45 
46 #define BITS_PER_UNIT 8
47 
48 UDWtype
49 __udivmoddi4 (UDWtype n, UDWtype d, UDWtype *rp);
50 
51 const UQItype __clz_tab[256] =
52 {
53   0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
54   6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
55   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
56   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
57   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
58   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
59   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
60   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
61 };
62 
63 
64 DWtype
65 __ashldi3 (DWtype u, word_type b)
66 {
67   if (b == 0)
68     return u;
69 
70   const DWunion uu = {.ll = u};
71   const word_type bm = (sizeof (Wtype) * BITS_PER_UNIT) - b;
72   DWunion w;
73 
74   if (bm <= 0)
75     {
76       w.s.low = 0;
77       w.s.high = (UWtype) uu.s.low << -bm;
78     }
79   else
80     {
81       const UWtype carries = (UWtype) uu.s.low >> bm;
82 
83       w.s.low = (UWtype) uu.s.low << b;
84       w.s.high = ((UWtype) uu.s.high << b) | carries;
85     }
86 
87   return w.ll;
88 }
89 
90 DWtype
91 __ashrdi3 (DWtype u, word_type b)
92 {
93   if (b == 0)
94     return u;
95 
96   const DWunion uu = {.ll = u};
97   const word_type bm = (sizeof (Wtype) * BITS_PER_UNIT) - b;
98   DWunion w;
99 
100   if (bm <= 0)
101     {
102       /* w.s.high = 1..1 or 0..0 */
103       w.s.high = uu.s.high >> (sizeof (Wtype) * BITS_PER_UNIT - 1);
104       w.s.low = uu.s.high >> -bm;
105     }
106   else
107     {
108       const UWtype carries = (UWtype) uu.s.high << bm;
109 
110       w.s.high = uu.s.high >> b;
111       w.s.low = ((UWtype) uu.s.low >> b) | carries;
112     }
113 
114   return w.ll;
115 }
116 
117 DWtype
118 __lshrdi3 (DWtype u, word_type b)
119 {
120   if (b == 0)
121     return u;
122 
123   const DWunion uu = {.ll = u};
124   const word_type bm = (sizeof (Wtype) * BITS_PER_UNIT) - b;
125   DWunion w;
126 
127   if (bm <= 0)
128     {
129       w.s.high = 0;
130       w.s.low = (UWtype) uu.s.high >> -bm;
131     }
132   else
133     {
134       const UWtype carries = (UWtype) uu.s.high << bm;
135 
136       w.s.high = (UWtype) uu.s.high >> b;
137       w.s.low = ((UWtype) uu.s.low >> b) | carries;
138     }
139 
140   return w.ll;
141 }
142 
143 word_type
144 __cmpdi2 (DWtype a, DWtype b)
145 {
146   const DWunion au = {.ll = a};
147   const DWunion bu = {.ll = b};
148 
149   if (au.s.high < bu.s.high)
150     return 0;
151   else if (au.s.high > bu.s.high)
152     return 2;
153   if ((UWtype) au.s.low < (UWtype) bu.s.low)
154     return 0;
155   else if ((UWtype) au.s.low > (UWtype) bu.s.low)
156     return 2;
157   return 1;
158 }
159 
160 UDWtype
161 __udivmoddi4 (UDWtype n, UDWtype d, UDWtype *rp)
162 {
163   const DWunion nn = {.ll = n};
164   const DWunion dd = {.ll = d};
165   DWunion rr;
166   UWtype d0, d1, n0, n1, n2;
167   UWtype q0, q1;
168   UWtype b, bm;
169 
170   d0 = dd.s.low;
171   d1 = dd.s.high;
172   n0 = nn.s.low;
173   n1 = nn.s.high;
174 
175 #if !UDIV_NEEDS_NORMALIZATION
176   if (d1 == 0)
177     {
178       if (d0 > n1)
179 	{
180 	  /* 0q = nn / 0D */
181 
182 	  udiv_qrnnd (q0, n0, n1, n0, d0);
183 	  q1 = 0;
184 
185 	  /* Remainder in n0.  */
186 	}
187       else
188 	{
189 	  /* qq = NN / 0d */
190 
191 	  if (d0 == 0)
192 	    d0 = 1 / d0;	/* Divide intentionally by zero.  */
193 
194 	  udiv_qrnnd (q1, n1, 0, n1, d0);
195 	  udiv_qrnnd (q0, n0, n1, n0, d0);
196 
197 	  /* Remainder in n0.  */
198 	}
199 
200       if (rp != 0)
201 	{
202 	  rr.s.low = n0;
203 	  rr.s.high = 0;
204 	  *rp = rr.ll;
205 	}
206     }
207 
208 #else /* UDIV_NEEDS_NORMALIZATION */
209 
210   if (d1 == 0)
211     {
212       if (d0 > n1)
213 	{
214 	  /* 0q = nn / 0D */
215 
216 	  count_leading_zeros (bm, d0);
217 
218 	  if (bm != 0)
219 	    {
220 	      /* Normalize, i.e. make the most significant bit of the
221 		 denominator set.  */
222 
223 	      d0 = d0 << bm;
224 	      n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));
225 	      n0 = n0 << bm;
226 	    }
227 
228 	  udiv_qrnnd (q0, n0, n1, n0, d0);
229 	  q1 = 0;
230 
231 	  /* Remainder in n0 >> bm.  */
232 	}
233       else
234 	{
235 	  /* qq = NN / 0d */
236 
237 	  if (d0 == 0)
238 	    d0 = 1 / d0;	/* Divide intentionally by zero.  */
239 
240 	  count_leading_zeros (bm, d0);
241 
242 	  if (bm == 0)
243 	    {
244 	      /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
245 		 conclude (the most significant bit of n1 is set) /\ (the
246 		 leading quotient digit q1 = 1).
247 
248 		 This special case is necessary, not an optimization.
249 		 (Shifts counts of W_TYPE_SIZE are undefined.)  */
250 
251 	      n1 -= d0;
252 	      q1 = 1;
253 	    }
254 	  else
255 	    {
256 	      /* Normalize.  */
257 
258 	      b = W_TYPE_SIZE - bm;
259 
260 	      d0 = d0 << bm;
261 	      n2 = n1 >> b;
262 	      n1 = (n1 << bm) | (n0 >> b);
263 	      n0 = n0 << bm;
264 
265 	      udiv_qrnnd (q1, n1, n2, n1, d0);
266 	    }
267 
268 	  /* n1 != d0...  */
269 
270 	  udiv_qrnnd (q0, n0, n1, n0, d0);
271 
272 	  /* Remainder in n0 >> bm.  */
273 	}
274 
275       if (rp != 0)
276 	{
277 	  rr.s.low = n0 >> bm;
278 	  rr.s.high = 0;
279 	  *rp = rr.ll;
280 	}
281     }
282 #endif /* UDIV_NEEDS_NORMALIZATION */
283 
284   else
285     {
286       if (d1 > n1)
287 	{
288 	  /* 00 = nn / DD */
289 
290 	  q0 = 0;
291 	  q1 = 0;
292 
293 	  /* Remainder in n1n0.  */
294 	  if (rp != 0)
295 	    {
296 	      rr.s.low = n0;
297 	      rr.s.high = n1;
298 	      *rp = rr.ll;
299 	    }
300 	}
301       else
302 	{
303 	  /* 0q = NN / dd */
304 
305 	  count_leading_zeros (bm, d1);
306 	  if (bm == 0)
307 	    {
308 	      /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
309 		 conclude (the most significant bit of n1 is set) /\ (the
310 		 quotient digit q0 = 0 or 1).
311 
312 		 This special case is necessary, not an optimization.  */
313 
314 	      /* The condition on the next line takes advantage of that
315 		 n1 >= d1 (true due to program flow).  */
316 	      if (n1 > d1 || n0 >= d0)
317 		{
318 		  q0 = 1;
319 		  sub_ddmmss (n1, n0, n1, n0, d1, d0);
320 		}
321 	      else
322 		q0 = 0;
323 
324 	      q1 = 0;
325 
326 	      if (rp != 0)
327 		{
328 		  rr.s.low = n0;
329 		  rr.s.high = n1;
330 		  *rp = rr.ll;
331 		}
332 	    }
333 	  else
334 	    {
335 	      UWtype m1, m0;
336 	      /* Normalize.  */
337 
338 	      b = W_TYPE_SIZE - bm;
339 
340 	      d1 = (d1 << bm) | (d0 >> b);
341 	      d0 = d0 << bm;
342 	      n2 = n1 >> b;
343 	      n1 = (n1 << bm) | (n0 >> b);
344 	      n0 = n0 << bm;
345 
346 	      udiv_qrnnd (q0, n1, n2, n1, d1);
347 	      umul_ppmm (m1, m0, q0, d0);
348 
349 	      if (m1 > n1 || (m1 == n1 && m0 > n0))
350 		{
351 		  q0--;
352 		  sub_ddmmss (m1, m0, m1, m0, d1, d0);
353 		}
354 
355 	      q1 = 0;
356 
357 	      /* Remainder in (n1n0 - m1m0) >> bm.  */
358 	      if (rp != 0)
359 		{
360 		  sub_ddmmss (n1, n0, n1, n0, m1, m0);
361 		  rr.s.low = (n1 << b) | (n0 >> bm);
362 		  rr.s.high = n1 >> bm;
363 		  *rp = rr.ll;
364 		}
365 	    }
366 	}
367     }
368 
369   const DWunion ww = {{.low = q0, .high = q1}};
370   return ww.ll;
371 }
372 
373 DWtype
374 __divdi3 (DWtype u, DWtype v)
375 {
376   word_type c = 0;
377   DWunion uu = {.ll = u};
378   DWunion vv = {.ll = v};
379   DWtype w;
380 
381   if (uu.s.high < 0)
382     c = ~c,
383     uu.ll = -uu.ll;
384   if (vv.s.high < 0)
385     c = ~c,
386     vv.ll = -vv.ll;
387 
388   w = __udivmoddi4 (uu.ll, vv.ll, (UDWtype *) 0);
389   if (c)
390     w = -w;
391 
392   return w;
393 }
394 
395 DWtype
396 __negdi2 (DWtype u)
397 {
398   const DWunion uu = {.ll = u};
399   const DWunion w = { {.low = -uu.s.low,
400 		       .high = -uu.s.high - ((UWtype) -uu.s.low > 0) } };
401 
402   return w.ll;
403 }
404 
405 
406 DWtype
407 __muldi3 (DWtype u, DWtype v)
408 {
409   const DWunion uu = {.ll = u};
410   const DWunion vv = {.ll = v};
411   DWunion  w = {.ll = __umulsidi3 (uu.s.low, vv.s.low)};
412 
413   w.s.high += ((UWtype) uu.s.low * (UWtype) vv.s.high
414   + (UWtype) uu.s.high * (UWtype) vv.s.low);
415 
416   return w.ll;
417 }
418 
419 DWtype
420 __moddi3 (DWtype u, DWtype v)
421 {
422   word_type c = 0;
423   DWunion uu = {.ll = u};
424   DWunion vv = {.ll = v};
425   DWtype w;
426 
427   if (uu.s.high < 0)
428     c = ~c,
429     uu.ll = -uu.ll;
430   if (vv.s.high < 0)
431     vv.ll = -vv.ll;
432 
433   (void) __udivmoddi4 (uu.ll, vv.ll, (UDWtype*)&w);
434   if (c)
435     w = -w;
436 
437   return w;
438 }
439 
440 word_type
441 __ucmpdi2 (DWtype a, DWtype b)
442 {
443   const DWunion au = {.ll = a};
444   const DWunion bu = {.ll = b};
445 
446   if ((UWtype) au.s.high < (UWtype) bu.s.high)
447     return 0;
448   else if ((UWtype) au.s.high > (UWtype) bu.s.high)
449     return 2;
450   if ((UWtype) au.s.low < (UWtype) bu.s.low)
451     return 0;
452   else if ((UWtype) au.s.low > (UWtype) bu.s.low)
453     return 2;
454   return 1;
455 }
456 
457 
458 UDWtype
459 __udivdi3 (UDWtype n, UDWtype d)
460 {
461   return __udivmoddi4 (n, d, (UDWtype *) 0);
462 }
463 
464 UDWtype
465 __umoddi3 (UDWtype u, UDWtype v)
466 {
467   UDWtype w;
468   (void) __udivmoddi4 (u, v, &w);
469 
470   return w;
471 }
472 
473 static USItype
474 udivmodsi4(USItype num, USItype den, word_type modwanted)
475 {
476   USItype bit = 1;
477   USItype res = 0;
478 
479   while (den < num && bit && !(den & (1L<<31)))
480     {
481       den <<=1;
482       bit <<=1;
483     }
484   while (bit)
485     {
486       if (num >= den)
487 	{
488 	  num -= den;
489 	  res |= bit;
490 	}
491       bit >>=1;
492       den >>=1;
493     }
494   if (modwanted) return num;
495   return res;
496 }
497 
498 SItype
499 __divsi3 (SItype a, SItype b)
500 {
501   word_type neg = 0;
502   SItype res;
503 
504   if (a < 0)
505     {
506       a = -a;
507       neg = !neg;
508     }
509 
510   if (b < 0)
511     {
512       b = -b;
513       neg = !neg;
514     }
515 
516   res = udivmodsi4 (a, b, 0);
517 
518   if (neg)
519     res = -res;
520 
521   return res;
522 }
523 
524 
525 SItype
526 __udivsi3 (SItype a, SItype b)
527 {
528   return udivmodsi4 (a, b, 0);
529 }
530 
531 
532 SItype
533 __modsi3 (SItype a, SItype b)
534 {
535   word_type neg = 0;
536   SItype res;
537 
538   if (a < 0)
539     {
540       a = -a;
541       neg = 1;
542     }
543 
544   if (b < 0)
545     b = -b;
546 
547   res = udivmodsi4 (a, b, 1);
548 
549   if (neg)
550     res = -res;
551 
552   return res;
553 }
554 
555 SItype
556 __mulsi3 (SItype a, SItype b)
557 {
558   SItype res = 0;
559   USItype cnt = a;
560 
561   while (cnt)
562     {
563       if (cnt & 1)
564         {
565 	  res += b;
566 	}
567       b <<= 1;
568       cnt >>= 1;
569     }
570 
571   return res;
572 }
573 
574 SItype
575 __umodsi3 (SItype a, SItype b)
576 
577 {
578   return udivmodsi4 (a, b, 1);
579 }
580 
581 int
582 __gcc_bcmp (const unsigned char *s1, const unsigned char *s2, unsigned long size)
583 {
584   while (size > 0)
585     {
586       const unsigned char c1 = *s1++, c2 = *s2++;
587       if (c1 != c2)
588 	return c1 - c2;
589       size--;
590     }
591   return 0;
592 }
593