blob: c47ccf8353ad839be86e8e7e57ed15583b016210 [file] [log] [blame]
sewardj69fe0712005-02-12 19:01:03 +00001/*
2** emfloat.c
3** Source for emulated floating-point routines.
4** BYTEmark (tm)
5** BYTE's Native Mode Benchmarks
6** Rick Grehan, BYTE Magazine.
7**
8** Created:
9** Last update: 3/95
10**
11** DISCLAIMER
12** The source, executable, and documentation files that comprise
13** the BYTEmark benchmarks are made available on an "as is" basis.
14** This means that we at BYTE Magazine have made every reasonable
15** effort to verify that the there are no errors in the source and
16** executable code. We cannot, however, guarantee that the programs
17** are error-free. Consequently, McGraw-HIll and BYTE Magazine make
18** no claims in regard to the fitness of the source code, executable
19** code, and documentation of the BYTEmark.
20** Furthermore, BYTE Magazine, McGraw-Hill, and all employees
21** of McGraw-Hill cannot be held responsible for any damages resulting
22** from the use of this code or the results obtained from using
23** this code.
24*/
25
26#include "../pub/libvex_basictypes.h"
27
28static HWord (*serviceFn)(HWord,HWord) = 0;
29
30
31/////////////////////////////////////////////////////////////////////
32/////////////////////////////////////////////////////////////////////
33
34static char* my_strcpy ( char* dest, const char* src )
35{
36 char* dest_orig = dest;
37 while (*src) *dest++ = *src++;
38 *dest = 0;
39 return dest_orig;
40}
41
42static void* my_memcpy ( void *dest, const void *src, int sz )
43{
44 const char *s = (const char *)src;
45 char *d = (char *)dest;
46
47 while (sz--)
48 *d++ = *s++;
49
50 return dest;
51}
52
53static void* my_memmove( void *dst, const void *src, unsigned int len )
54{
55 register char *d;
56 register char *s;
57 if ( dst > src ) {
58 d = (char *)dst + len - 1;
59 s = (char *)src + len - 1;
60 while ( len >= 4 ) {
61 *d-- = *s--;
62 *d-- = *s--;
63 *d-- = *s--;
64 *d-- = *s--;
65 len -= 4;
66 }
67 while ( len-- ) {
68 *d-- = *s--;
69 }
70 } else if ( dst < src ) {
71 d = (char *)dst;
72 s = (char *)src;
73 while ( len >= 4 ) {
74 *d++ = *s++;
75 *d++ = *s++;
76 *d++ = *s++;
77 *d++ = *s++;
78 len -= 4;
79 }
80 while ( len-- ) {
81 *d++ = *s++;
82 }
83 }
84 return dst;
85}
86
87/////////////////////////////////////////////////////////////////////
88
cerion6ded3892005-12-13 21:30:48 +000089static void vexxx_log_bytes ( char* p, int n )
sewardj69fe0712005-02-12 19:01:03 +000090{
91 int i;
92 for (i = 0; i < n; i++)
93 (*serviceFn)( 1, (int)p[i] );
94}
95
96/*---------------------------------------------------------*/
cerion6ded3892005-12-13 21:30:48 +000097/*--- vexxx_printf ---*/
sewardj69fe0712005-02-12 19:01:03 +000098/*---------------------------------------------------------*/
99
cerion6ded3892005-12-13 21:30:48 +0000100/* This should be the only <...> include in the entire VEXXX library.
101 New code for vexxx_util.c should go above this point. */
sewardj69fe0712005-02-12 19:01:03 +0000102#include <stdarg.h>
103
cerion6ded3892005-12-13 21:30:48 +0000104static HChar vexxx_toupper ( HChar c )
sewardj69fe0712005-02-12 19:01:03 +0000105{
106 if (c >= 'a' && c <= 'z')
107 return toHChar(c + ('A' - 'a'));
108 else
109 return c;
110}
111
cerion6ded3892005-12-13 21:30:48 +0000112static Int vexxx_strlen ( const HChar* str )
sewardj69fe0712005-02-12 19:01:03 +0000113{
114 Int i = 0;
115 while (str[i] != 0) i++;
116 return i;
117}
118
cerion6ded3892005-12-13 21:30:48 +0000119Bool vexxx_streq ( const HChar* s1, const HChar* s2 )
sewardj69fe0712005-02-12 19:01:03 +0000120{
121 while (True) {
122 if (*s1 == 0 && *s2 == 0)
123 return True;
124 if (*s1 != *s2)
125 return False;
126 s1++;
127 s2++;
128 }
129}
130
131/* Some flags. */
132#define VG_MSG_SIGNED 1 /* The value is signed. */
133#define VG_MSG_ZJUSTIFY 2 /* Must justify with '0'. */
134#define VG_MSG_LJUSTIFY 4 /* Must justify on the left. */
135#define VG_MSG_PAREN 8 /* Parenthesize if present (for %y) */
136#define VG_MSG_COMMA 16 /* Add commas to numbers (for %d, %u) */
137
138/* Copy a string into the buffer. */
139static UInt
140myvprintf_str ( void(*send)(HChar), Int flags, Int width, HChar* str,
141 Bool capitalise )
142{
cerion6ded3892005-12-13 21:30:48 +0000143# define MAYBE_TOUPPER(ch) toHChar(capitalise ? vexxx_toupper(ch) : (ch))
sewardj69fe0712005-02-12 19:01:03 +0000144 UInt ret = 0;
145 Int i, extra;
cerion6ded3892005-12-13 21:30:48 +0000146 Int len = vexxx_strlen(str);
sewardj69fe0712005-02-12 19:01:03 +0000147
148 if (width == 0) {
149 ret += len;
150 for (i = 0; i < len; i++)
151 send(MAYBE_TOUPPER(str[i]));
152 return ret;
153 }
154
155 if (len > width) {
156 ret += width;
157 for (i = 0; i < width; i++)
158 send(MAYBE_TOUPPER(str[i]));
159 return ret;
160 }
161
162 extra = width - len;
163 if (flags & VG_MSG_LJUSTIFY) {
164 ret += extra;
165 for (i = 0; i < extra; i++)
166 send(' ');
167 }
168 ret += len;
169 for (i = 0; i < len; i++)
170 send(MAYBE_TOUPPER(str[i]));
171 if (!(flags & VG_MSG_LJUSTIFY)) {
172 ret += extra;
173 for (i = 0; i < extra; i++)
174 send(' ');
175 }
176
177# undef MAYBE_TOUPPER
178
179 return ret;
180}
181
182/* Write P into the buffer according to these args:
183 * If SIGN is true, p is a signed.
184 * BASE is the base.
185 * If WITH_ZERO is true, '0' must be added.
186 * WIDTH is the width of the field.
187 */
188static UInt
189myvprintf_int64 ( void(*send)(HChar), Int flags, Int base, Int width, ULong pL)
190{
191 HChar buf[40];
192 Int ind = 0;
193 Int i, nc = 0;
194 Bool neg = False;
195 HChar *digits = "0123456789ABCDEF";
196 UInt ret = 0;
197 UInt p = (UInt)pL;
198
199 if (base < 2 || base > 16)
200 return ret;
201
202 if ((flags & VG_MSG_SIGNED) && (Int)p < 0) {
203 p = - (Int)p;
204 neg = True;
205 }
206
207 if (p == 0)
208 buf[ind++] = '0';
209 else {
210 while (p > 0) {
211 if ((flags & VG_MSG_COMMA) && 10 == base &&
212 0 == (ind-nc) % 3 && 0 != ind)
213 {
214 buf[ind++] = ',';
215 nc++;
216 }
217 buf[ind++] = digits[p % base];
218 p /= base;
219 }
220 }
221
222 if (neg)
223 buf[ind++] = '-';
224
225 if (width > 0 && !(flags & VG_MSG_LJUSTIFY)) {
226 for(; ind < width; ind++) {
227 //vassert(ind < 39);
228 buf[ind] = toHChar((flags & VG_MSG_ZJUSTIFY) ? '0': ' ');
229 }
230 }
231
232 /* Reverse copy to buffer. */
233 ret += ind;
234 for (i = ind -1; i >= 0; i--) {
235 send(buf[i]);
236 }
237 if (width > 0 && (flags & VG_MSG_LJUSTIFY)) {
238 for(; ind < width; ind++) {
239 ret++;
240 send(' '); // Never pad with zeroes on RHS -- changes the value!
241 }
242 }
243 return ret;
244}
245
246
247/* A simple vprintf(). */
248static
249UInt vprintf_wrk ( void(*send)(HChar), const HChar *format, va_list vargs )
250{
251 UInt ret = 0;
252 int i;
253 int flags;
254 int width;
255 Bool is_long;
256
257 /* We assume that vargs has already been initialised by the
258 caller, using va_start, and that the caller will similarly
259 clean up with va_end.
260 */
261
262 for (i = 0; format[i] != 0; i++) {
263 if (format[i] != '%') {
264 send(format[i]);
265 ret++;
266 continue;
267 }
268 i++;
269 /* A '%' has been found. Ignore a trailing %. */
270 if (format[i] == 0)
271 break;
272 if (format[i] == '%') {
273 /* `%%' is replaced by `%'. */
274 send('%');
275 ret++;
276 continue;
277 }
278 flags = 0;
279 is_long = False;
280 width = 0; /* length of the field. */
281 if (format[i] == '(') {
282 flags |= VG_MSG_PAREN;
283 i++;
284 }
285 /* If ',' follows '%', commas will be inserted. */
286 if (format[i] == ',') {
287 flags |= VG_MSG_COMMA;
288 i++;
289 }
290 /* If '-' follows '%', justify on the left. */
291 if (format[i] == '-') {
292 flags |= VG_MSG_LJUSTIFY;
293 i++;
294 }
295 /* If '0' follows '%', pads will be inserted. */
296 if (format[i] == '0') {
297 flags |= VG_MSG_ZJUSTIFY;
298 i++;
299 }
300 /* Compute the field length. */
301 while (format[i] >= '0' && format[i] <= '9') {
302 width *= 10;
303 width += format[i++] - '0';
304 }
305 while (format[i] == 'l') {
306 i++;
307 is_long = True;
308 }
309
310 switch (format[i]) {
311 case 'd': /* %d */
312 flags |= VG_MSG_SIGNED;
313 if (is_long)
314 ret += myvprintf_int64(send, flags, 10, width,
315 (ULong)(va_arg (vargs, Long)));
316 else
317 ret += myvprintf_int64(send, flags, 10, width,
318 (ULong)(va_arg (vargs, Int)));
319 break;
320 case 'u': /* %u */
321 if (is_long)
322 ret += myvprintf_int64(send, flags, 10, width,
323 (ULong)(va_arg (vargs, ULong)));
324 else
325 ret += myvprintf_int64(send, flags, 10, width,
326 (ULong)(va_arg (vargs, UInt)));
327 break;
328 case 'p': /* %p */
329 ret += 2;
330 send('0');
331 send('x');
332 ret += myvprintf_int64(send, flags, 16, width,
333 (ULong)((HWord)va_arg (vargs, void *)));
334 break;
335 case 'x': /* %x */
336 if (is_long)
337 ret += myvprintf_int64(send, flags, 16, width,
338 (ULong)(va_arg (vargs, ULong)));
339 else
340 ret += myvprintf_int64(send, flags, 16, width,
341 (ULong)(va_arg (vargs, UInt)));
342 break;
343 case 'c': /* %c */
344 ret++;
345 send(toHChar(va_arg (vargs, int)));
346 break;
347 case 's': case 'S': { /* %s */
348 char *str = va_arg (vargs, char *);
349 if (str == (char*) 0) str = "(null)";
350 ret += myvprintf_str(send, flags, width, str,
351 toBool(format[i]=='S'));
352 break;
353 }
354# if 0
355 case 'y': { /* %y - print symbol */
sewardj69fe0712005-02-12 19:01:03 +0000356 Addr a = va_arg(vargs, Addr);
357
florian75d774c2014-10-25 20:10:30 +0000358 HChar *name;
359 if (VG_(get_fnname_w_offset)(a, &name)) {
360 HChar buf[1 + VG_strlen(name) + 1 + 1];
sewardj69fe0712005-02-12 19:01:03 +0000361 if (flags & VG_MSG_PAREN) {
florian75d774c2014-10-25 20:10:30 +0000362 VG_(sprintf)(str, "(%s)", name):
363 } else {
364 VG_(sprintf)(str, "%s", name):
365 }
sewardj69fe0712005-02-12 19:01:03 +0000366 ret += myvprintf_str(send, flags, width, buf, 0);
367 }
368 break;
369 }
370# endif
371 default:
372 break;
373 }
374 }
375 return ret;
376}
377
378
379/* A general replacement for printf(). Note that only low-level
380 debugging info should be sent via here. The official route is to
381 to use vg_message(). This interface is deprecated.
382*/
383static HChar myprintf_buf[1000];
384static Int n_myprintf_buf;
385
386static void add_to_myprintf_buf ( HChar c )
387{
388 if (c == '\n' || n_myprintf_buf >= 1000-10 /*paranoia*/ ) {
cerion6ded3892005-12-13 21:30:48 +0000389 (*vexxx_log_bytes)( myprintf_buf, vexxx_strlen(myprintf_buf) );
sewardj69fe0712005-02-12 19:01:03 +0000390 n_myprintf_buf = 0;
391 myprintf_buf[n_myprintf_buf] = 0;
392 }
393 myprintf_buf[n_myprintf_buf++] = c;
394 myprintf_buf[n_myprintf_buf] = 0;
395}
396
cerion6ded3892005-12-13 21:30:48 +0000397static UInt vexxx_printf ( const char *format, ... )
sewardj69fe0712005-02-12 19:01:03 +0000398{
399 UInt ret;
400 va_list vargs;
401 va_start(vargs,format);
402
403 n_myprintf_buf = 0;
404 myprintf_buf[n_myprintf_buf] = 0;
405 ret = vprintf_wrk ( add_to_myprintf_buf, format, vargs );
406
407 if (n_myprintf_buf > 0) {
cerion6ded3892005-12-13 21:30:48 +0000408 (*vexxx_log_bytes)( myprintf_buf, n_myprintf_buf );
sewardj69fe0712005-02-12 19:01:03 +0000409 }
410
411 va_end(vargs);
412
413 return ret;
414}
415
416/*---------------------------------------------------------------*/
cerion6ded3892005-12-13 21:30:48 +0000417/*--- end vexxx_util.c ---*/
sewardj69fe0712005-02-12 19:01:03 +0000418/*---------------------------------------------------------------*/
419
420
421/////////////////////////////////////////////////////////////////////
422/////////////////////////////////////////////////////////////////////
423
424//#include <stdio.h>
425//#include <string.h>
426//#include <malloc.h>
427
428typedef unsigned char uchar;
429typedef unsigned int uint;
430typedef unsigned short ushort;
431typedef unsigned long ulong;
432typedef int int32; /* Signed 32 bit integer */
433
434#define INTERNAL_FPF_PRECISION 4
435#define CPUEMFLOATLOOPMAX 500000L
436#define EMFARRAYSIZE 3000L
437
438typedef struct {
439 int adjust; /* Set adjust code */
440 ulong request_secs; /* # of seconds requested */
441 ulong arraysize; /* Size of array */
442 ulong loops; /* Loops per iterations */
443 double emflops; /* Results */
444} EmFloatStruct;
445
446
447
448/* Is this a 64 bit architecture? If so, this will define LONG64 */
449/* Uwe F. Mayer 15 November 1997 */
450// #include "pointer.h"
451
452#define u8 unsigned char
453#define u16 unsigned short
454#ifdef LONG64
455#define u32 unsigned int
456#else
457#define u32 unsigned long
458#endif
459#define uchar unsigned char
460#define ulong unsigned long
461
462#define MAX_EXP 32767L
463#define MIN_EXP (-32767L)
464
465#define IFPF_IS_ZERO 0
466#define IFPF_IS_SUBNORMAL 1
467#define IFPF_IS_NORMAL 2
468#define IFPF_IS_INFINITY 3
469#define IFPF_IS_NAN 4
470#define IFPF_TYPE_COUNT 5
471
472#define ZERO_ZERO 0
473#define ZERO_SUBNORMAL 1
474#define ZERO_NORMAL 2
475#define ZERO_INFINITY 3
476#define ZERO_NAN 4
477
478#define SUBNORMAL_ZERO 5
479#define SUBNORMAL_SUBNORMAL 6
480#define SUBNORMAL_NORMAL 7
481#define SUBNORMAL_INFINITY 8
482#define SUBNORMAL_NAN 9
483
484#define NORMAL_ZERO 10
485#define NORMAL_SUBNORMAL 11
486#define NORMAL_NORMAL 12
487#define NORMAL_INFINITY 13
488#define NORMAL_NAN 14
489
490#define INFINITY_ZERO 15
491#define INFINITY_SUBNORMAL 16
492#define INFINITY_NORMAL 17
493#define INFINITY_INFINITY 18
494#define INFINITY_NAN 19
495
496#define NAN_ZERO 20
497#define NAN_SUBNORMAL 21
498#define NAN_NORMAL 22
499#define NAN_INFINITY 23
500#define NAN_NAN 24
501#define OPERAND_ZERO 0
502#define OPERAND_SUBNORMAL 1
503#define OPERAND_NORMAL 2
504#define OPERAND_INFINITY 3
505#define OPERAND_NAN 4
506
507typedef struct
508{
509 u8 type; /* Indicates, NORMAL, SUBNORMAL, etc. */
510 u8 sign; /* Mantissa sign */
511 short exp; /* Signed exponent...no bias */
512 u16 mantissa[INTERNAL_FPF_PRECISION];
513} InternalFPF;
514
515static
516void SetupCPUEmFloatArrays(InternalFPF *abase,
517 InternalFPF *bbase, InternalFPF *cbase, ulong arraysize);
518static
519ulong DoEmFloatIteration(InternalFPF *abase,
520 InternalFPF *bbase, InternalFPF *cbase,
521 ulong arraysize, ulong loops);
522
523static void SetInternalFPFZero(InternalFPF *dest,
524 uchar sign);
525static void SetInternalFPFInfinity(InternalFPF *dest,
526 uchar sign);
527static void SetInternalFPFNaN(InternalFPF *dest);
528static int IsMantissaZero(u16 *mant);
529static void Add16Bits(u16 *carry,u16 *a,u16 b,u16 c);
530static void Sub16Bits(u16 *borrow,u16 *a,u16 b,u16 c);
531static void ShiftMantLeft1(u16 *carry,u16 *mantissa);
532static void ShiftMantRight1(u16 *carry,u16 *mantissa);
533static void StickyShiftRightMant(InternalFPF *ptr,int amount);
534static void normalize(InternalFPF *ptr);
535static void denormalize(InternalFPF *ptr,int minimum_exponent);
536static void RoundInternalFPF(InternalFPF *ptr);
537static void choose_nan(InternalFPF *x,InternalFPF *y,InternalFPF *z,
538 int intel_flag);
539static void AddSubInternalFPF(uchar operation,InternalFPF *x,
540 InternalFPF *y,InternalFPF *z);
541static void MultiplyInternalFPF(InternalFPF *x,InternalFPF *y,
542 InternalFPF *z);
543static void DivideInternalFPF(InternalFPF *x,InternalFPF *y,
544 InternalFPF *z);
545
546static void Int32ToInternalFPF(int32 mylong,
547 InternalFPF *dest);
548static int InternalFPFToString(char *dest,
549 InternalFPF *src);
550
551static int32 randnum(int32 lngval);
552
553static int32 randwc(int32 num)
554{
555 return(randnum((int32)0)%num);
556}
557
558static int32 randw[2] = { (int32)13 , (int32)117 };
559static int32 randnum(int32 lngval)
560{
561 register int32 interm;
562
563 if (lngval!=(int32)0)
564 { randw[0]=(int32)13; randw[1]=(int32)117; }
565
566 interm=(randw[0]*(int32)254754+randw[1]*(int32)529562)%(int32)999563;
567 randw[1]=randw[0];
568 randw[0]=interm;
569 return(interm);
570}
571
572
573static
574void SetupCPUEmFloatArrays(InternalFPF *abase,
575 InternalFPF *bbase,
576 InternalFPF *cbase,
577 ulong arraysize)
578{
579ulong i;
580InternalFPF locFPF1,locFPF2;
581
582randnum((int32)13);
583
584for(i=0;i<arraysize;i++)
585{/* LongToInternalFPF(randwc(50000L),&locFPF1); */
586 Int32ToInternalFPF(randwc((int32)50000),&locFPF1);
587 /* LongToInternalFPF(randwc(50000L)+1L,&locFPF2); */
588 Int32ToInternalFPF(randwc((int32)50000)+(int32)1,&locFPF2);
589 DivideInternalFPF(&locFPF1,&locFPF2,abase+i);
590 /* LongToInternalFPF(randwc(50000L)+1L,&locFPF2); */
591 Int32ToInternalFPF(randwc((int32)50000)+(int32)1,&locFPF2);
592 DivideInternalFPF(&locFPF1,&locFPF2,bbase+i);
593}
594return;
595}
596
597
598static char* str1 = "loops %d\n";
599static
600ulong DoEmFloatIteration(InternalFPF *abase,
601 InternalFPF *bbase,
602 InternalFPF *cbase,
603 ulong arraysize, ulong loops)
604{
605static uchar jtable[16] = {0,0,0,0,1,1,1,1,2,2,2,2,2,3,3,3};
606ulong i;
607int number_of_loops;
608 loops = 100;
609number_of_loops=loops-1; /* the index of the first loop we run */
610
cerion6ded3892005-12-13 21:30:48 +0000611vexxx_printf(str1, (int)loops);
sewardj69fe0712005-02-12 19:01:03 +0000612
613/*
614** Each pass through the array performs operations in
615** the followingratios:
616** 4 adds, 4 subtracts, 5 multiplies, 3 divides
617** (adds and subtracts being nearly the same operation)
618*/
619
620{
621 for(i=0;i<arraysize;i++)
622 switch(jtable[i % 16])
623 {
624 case 0: /* Add */
625 AddSubInternalFPF(0,abase+i,
626 bbase+i,
627 cbase+i);
628 break;
629 case 1: /* Subtract */
630 AddSubInternalFPF(1,abase+i,
631 bbase+i,
632 cbase+i);
633 break;
634 case 2: /* Multiply */
635 MultiplyInternalFPF(abase+i,
636 bbase+i,
637 cbase+i);
638 break;
639 case 3: /* Divide */
640 DivideInternalFPF(abase+i,
641 bbase+i,
642 cbase+i);
643 break;
644 }
645{
646 ulong j[8]; /* we test 8 entries */
647 int k;
648 ulong i;
649 char buffer[1024];
650 if (100==loops) /* the first loop */
651 {
652 j[0]=(ulong)2;
653 j[1]=(ulong)6;
654 j[2]=(ulong)10;
655 j[3]=(ulong)14;
656 j[4]=(ulong)(arraysize-14);
657 j[5]=(ulong)(arraysize-10);
658 j[6]=(ulong)(arraysize-6);
659 j[7]=(ulong)(arraysize-2);
660 for(k=0;k<8;k++){
661 i=j[k];
662 InternalFPFToString(buffer,abase+i);
cerion6ded3892005-12-13 21:30:48 +0000663 vexxx_printf("%6d: (%s) ",i,buffer);
sewardj69fe0712005-02-12 19:01:03 +0000664 switch(jtable[i % 16])
665 {
666 case 0: my_strcpy(buffer,"+"); break;
667 case 1: my_strcpy(buffer,"-"); break;
668 case 2: my_strcpy(buffer,"*"); break;
669 case 3: my_strcpy(buffer,"/"); break;
670 }
cerion6ded3892005-12-13 21:30:48 +0000671 vexxx_printf("%s ",buffer);
sewardj69fe0712005-02-12 19:01:03 +0000672 InternalFPFToString(buffer,bbase+i);
cerion6ded3892005-12-13 21:30:48 +0000673 vexxx_printf("(%s) = ",buffer);
sewardj69fe0712005-02-12 19:01:03 +0000674 InternalFPFToString(buffer,cbase+i);
cerion6ded3892005-12-13 21:30:48 +0000675 vexxx_printf("%s\n",buffer);
sewardj69fe0712005-02-12 19:01:03 +0000676 }
677return 0;
678 }
679}
680}
681return 0;
682}
683
684/***********************
685** SetInternalFPFZero **
686************************
687** Set an internal floating-point-format number to zero.
688** sign determines the sign of the zero.
689*/
690static void SetInternalFPFZero(InternalFPF *dest,
691 uchar sign)
692{
693int i; /* Index */
694
695dest->type=IFPF_IS_ZERO;
696dest->sign=sign;
697dest->exp=MIN_EXP;
698for(i=0;i<INTERNAL_FPF_PRECISION;i++)
699 dest->mantissa[i]=0;
700return;
701}
702
703/***************************
704** SetInternalFPFInfinity **
705****************************
706** Set an internal floating-point-format number to infinity.
707** This can happen if the exponent exceeds MAX_EXP.
708** As above, sign picks the sign of infinity.
709*/
710static void SetInternalFPFInfinity(InternalFPF *dest,
711 uchar sign)
712{
713int i; /* Index */
714
715dest->type=IFPF_IS_INFINITY;
716dest->sign=sign;
717dest->exp=MIN_EXP;
718for(i=0;i<INTERNAL_FPF_PRECISION;i++)
719 dest->mantissa[i]=0;
720return;
721}
722
723/**********************
724** SetInternalFPFNaN **
725***********************
726** Set an internal floating-point-format number to Nan
727** (not a number). Note that we "emulate" an 80x87 as far
728** as the mantissa bits go.
729*/
730static void SetInternalFPFNaN(InternalFPF *dest)
731{
732int i; /* Index */
733
734dest->type=IFPF_IS_NAN;
735dest->exp=MAX_EXP;
736dest->sign=1;
737dest->mantissa[0]=0x4000;
738for(i=1;i<INTERNAL_FPF_PRECISION;i++)
739 dest->mantissa[i]=0;
740
741return;
742}
743
744/*******************
745** IsMantissaZero **
746********************
747** Pass this routine a pointer to an internal floating point format
748** number's mantissa. It checks for an all-zero mantissa.
749** Returns 0 if it is NOT all zeros, !=0 otherwise.
750*/
751static int IsMantissaZero(u16 *mant)
752{
753int i; /* Index */
754int n; /* Return value */
755
756n=0;
757for(i=0;i<INTERNAL_FPF_PRECISION;i++)
758 n|=mant[i];
759
760return(!n);
761}
762
763/**************
764** Add16Bits **
765***************
766** Add b, c, and carry. Retult in a. New carry in carry.
767*/
768static void Add16Bits(u16 *carry,
769 u16 *a,
770 u16 b,
771 u16 c)
772{
773u32 accum; /* Accumulator */
774
775/*
776** Do the work in the 32-bit accumulator so we can return
777** the carry.
778*/
779accum=(u32)b;
780accum+=(u32)c;
781accum+=(u32)*carry;
782*carry=(u16)((accum & 0x00010000) ? 1 : 0); /* New carry */
783*a=(u16)(accum & 0xFFFF); /* Result is lo 16 bits */
784return;
785}
786
787/**************
788** Sub16Bits **
789***************
790** Additive inverse of above.
791*/
792static void Sub16Bits(u16 *borrow,
793 u16 *a,
794 u16 b,
795 u16 c)
796{
797u32 accum; /* Accumulator */
798
799accum=(u32)b;
800accum-=(u32)c;
801accum-=(u32)*borrow;
802*borrow=(u32)((accum & 0x00010000) ? 1 : 0); /* New borrow */
803*a=(u16)(accum & 0xFFFF);
804return;
805}
806
807/*******************
808** ShiftMantLeft1 **
809********************
810** Shift a vector of 16-bit numbers left 1 bit. Also provides
811** a carry bit, which is shifted in at the beginning, and
812** shifted out at the end.
813*/
814static void ShiftMantLeft1(u16 *carry,
815 u16 *mantissa)
816{
817int i; /* Index */
818int new_carry;
819u16 accum; /* Temporary holding placed */
820
821for(i=INTERNAL_FPF_PRECISION-1;i>=0;i--)
822{ accum=mantissa[i];
823 new_carry=accum & 0x8000; /* Get new carry */
824 accum=accum<<1; /* Do the shift */
825 if(*carry)
826 accum|=1; /* Insert previous carry */
827 *carry=new_carry;
828 mantissa[i]=accum; /* Return shifted value */
829}
830return;
831}
832
833/********************
834** ShiftMantRight1 **
835*********************
836** Shift a mantissa right by 1 bit. Provides carry, as
837** above
838*/
839static void ShiftMantRight1(u16 *carry,
840 u16 *mantissa)
841{
842int i; /* Index */
843int new_carry;
844u16 accum;
845
846for(i=0;i<INTERNAL_FPF_PRECISION;i++)
847{ accum=mantissa[i];
848 new_carry=accum & 1; /* Get new carry */
849 accum=accum>>1;
850 if(*carry)
851 accum|=0x8000;
852 *carry=new_carry;
853 mantissa[i]=accum;
854}
855return;
856}
857
858
859/*****************************
860** StickyShiftMantRight **
861******************************
862** This is a shift right of the mantissa with a "sticky bit".
863** I.E., if a carry of 1 is shifted out of the least significant
864** bit, the least significant bit is set to 1.
865*/
866static void StickyShiftRightMant(InternalFPF *ptr,
867 int amount)
868{
869int i; /* Index */
870u16 carry; /* Self-explanatory */
871u16 *mantissa;
872
873mantissa=ptr->mantissa;
874
875if(ptr->type!=IFPF_IS_ZERO) /* Don't bother shifting a zero */
876{
877 /*
878 ** If the amount of shifting will shift everyting
879 ** out of existence, then just clear the whole mantissa
880 ** and set the lowmost bit to 1.
881 */
882 if(amount>=INTERNAL_FPF_PRECISION * 16)
883 {
884 for(i=0;i<INTERNAL_FPF_PRECISION-1;i++)
885 mantissa[i]=0;
886 mantissa[INTERNAL_FPF_PRECISION-1]=1;
887 }
888 else
889 for(i=0;i<amount;i++)
890 {
891 carry=0;
892 ShiftMantRight1(&carry,mantissa);
893 if(carry)
894 mantissa[INTERNAL_FPF_PRECISION-1] |= 1;
895 }
896}
897return;
898}
899
900
901/**************************************************
902** POST ARITHMETIC PROCESSING **
903** (NORMALIZE, ROUND, OVERFLOW, AND UNDERFLOW) **
904**************************************************/
905
906/**************
907** normalize **
908***************
909** Normalize an internal-representation number. Normalization
910** discards empty most-significant bits.
911*/
912static void normalize(InternalFPF *ptr)
913{
914u16 carry;
915
916/*
917** As long as there's a highmost 0 bit, shift the significand
918** left 1 bit. Each time you do this, though, you've
919** gotta decrement the exponent.
920*/
921while ((ptr->mantissa[0] & 0x8000) == 0)
922{
923 carry = 0;
924 ShiftMantLeft1(&carry, ptr->mantissa);
925 ptr->exp--;
926}
927return;
928}
929
930/****************
931** denormalize **
932*****************
933** Denormalize an internal-representation number. This means
934** shifting it right until its exponent is equivalent to
935** minimum_exponent. (You have to do this often in order
936** to perform additions and subtractions).
937*/
938static void denormalize(InternalFPF *ptr,
939 int minimum_exponent)
940{
941long exponent_difference;
942
943if (IsMantissaZero(ptr->mantissa))
944{
cerion6ded3892005-12-13 21:30:48 +0000945 vexxx_printf("Error: zero significand in denormalize\n");
sewardj69fe0712005-02-12 19:01:03 +0000946}
947
948exponent_difference = ptr->exp-minimum_exponent;
949if (exponent_difference < 0)
950{
951 /*
952 ** The number is subnormal
953 */
954 exponent_difference = -exponent_difference;
955 if (exponent_difference >= (INTERNAL_FPF_PRECISION * 16))
956 {
957 /* Underflow */
958 SetInternalFPFZero(ptr, ptr->sign);
959 }
960 else
961 {
962 ptr->exp+=exponent_difference;
963 StickyShiftRightMant(ptr, exponent_difference);
964 }
965}
966return;
967}
968
969
970/*********************
971** RoundInternalFPF **
972**********************
973** Round an internal-representation number.
974** The kind of rounding we do here is simplest...referred to as
975** "chop". "Extraneous" rightmost bits are simply hacked off.
976*/
977void RoundInternalFPF(InternalFPF *ptr)
978{
979/* int i; */
980
981if (ptr->type == IFPF_IS_NORMAL ||
982 ptr->type == IFPF_IS_SUBNORMAL)
983{
984 denormalize(ptr, MIN_EXP);
985 if (ptr->type != IFPF_IS_ZERO)
986 {
987
988 /* clear the extraneous bits */
989 ptr->mantissa[3] &= 0xfff8;
990/* for (i=4; i<INTERNAL_FPF_PRECISION; i++)
991 {
992 ptr->mantissa[i] = 0;
993 }
994*/
995 /*
996 ** Check for overflow
997 */
998/* Does not do anything as ptr->exp is a short and MAX_EXP=37268
999 if (ptr->exp > MAX_EXP)
1000 {
1001 SetInternalFPFInfinity(ptr, ptr->sign);
1002 }
1003*/
1004 }
1005}
1006return;
1007}
1008
1009/*******************************************************
1010** ARITHMETIC OPERATIONS ON INTERNAL REPRESENTATION **
1011*******************************************************/
1012
1013/***************
1014** choose_nan **
1015****************
1016** Called by routines that are forced to perform math on
1017** a pair of NaN's. This routine "selects" which NaN is
1018** to be returned.
1019*/
1020static void choose_nan(InternalFPF *x,
1021 InternalFPF *y,
1022 InternalFPF *z,
1023 int intel_flag)
1024{
1025int i;
1026
1027/*
1028** Compare the two mantissas,
1029** return the larger. Note that we will be emulating
1030** an 80387 in this operation.
1031*/
1032for (i=0; i<INTERNAL_FPF_PRECISION; i++)
1033{
1034 if (x->mantissa[i] > y->mantissa[i])
1035 {
1036 my_memmove((void *)x,(void *)z,sizeof(InternalFPF));
1037 return;
1038 }
1039 if (x->mantissa[i] < y->mantissa[i])
1040 {
1041 my_memmove((void *)y,(void *)z,sizeof(InternalFPF));
1042 return;
1043 }
1044}
1045
1046/*
1047** They are equal
1048*/
1049if (!intel_flag)
1050 /* if the operation is addition */
1051 my_memmove((void *)x,(void *)z,sizeof(InternalFPF));
1052else
1053 /* if the operation is multiplication */
1054 my_memmove((void *)y,(void *)z,sizeof(InternalFPF));
1055return;
1056}
1057
1058
1059/**********************
1060** AddSubInternalFPF **
1061***********************
1062** Adding or subtracting internal-representation numbers.
1063** Internal-representation numbers pointed to by x and y are
1064** added/subtracted and the result returned in z.
1065*/
1066static void AddSubInternalFPF(uchar operation,
1067 InternalFPF *x,
1068 InternalFPF *y,
1069 InternalFPF *z)
1070{
1071int exponent_difference;
1072u16 borrow;
1073u16 carry;
1074int i;
1075InternalFPF locx,locy; /* Needed since we alter them */
1076
1077/*
1078** Following big switch statement handles the
1079** various combinations of operand types.
1080*/
1081switch ((x->type * IFPF_TYPE_COUNT) + y->type)
1082{
1083case ZERO_ZERO:
1084 my_memmove((void *)x,(void *)z,sizeof(InternalFPF));
1085 if (x->sign ^ y->sign ^ operation)
1086 {
1087 z->sign = 0; /* positive */
1088 }
1089 break;
1090
1091case NAN_ZERO:
1092case NAN_SUBNORMAL:
1093case NAN_NORMAL:
1094case NAN_INFINITY:
1095case SUBNORMAL_ZERO:
1096case NORMAL_ZERO:
1097case INFINITY_ZERO:
1098case INFINITY_SUBNORMAL:
1099case INFINITY_NORMAL:
1100 my_memmove((void *)x,(void *)z,sizeof(InternalFPF));
1101 break;
1102
1103
1104case ZERO_NAN:
1105case SUBNORMAL_NAN:
1106case NORMAL_NAN:
1107case INFINITY_NAN:
1108 my_memmove((void *)y,(void *)z,sizeof(InternalFPF));
1109 break;
1110
1111case ZERO_SUBNORMAL:
1112case ZERO_NORMAL:
1113case ZERO_INFINITY:
1114case SUBNORMAL_INFINITY:
1115case NORMAL_INFINITY:
1116 my_memmove((void *)y,(void *)z,sizeof(InternalFPF));
1117 z->sign ^= operation;
1118 break;
1119
1120case SUBNORMAL_SUBNORMAL:
1121case SUBNORMAL_NORMAL:
1122case NORMAL_SUBNORMAL:
1123case NORMAL_NORMAL:
1124 /*
1125 ** Copy x and y to locals, since we may have
1126 ** to alter them.
1127 */
1128 my_memmove((void *)&locx,(void *)x,sizeof(InternalFPF));
1129 my_memmove((void *)&locy,(void *)y,sizeof(InternalFPF));
1130
1131 /* compute sum/difference */
1132 exponent_difference = locx.exp-locy.exp;
1133 if (exponent_difference == 0)
1134 {
1135 /*
1136 ** locx.exp == locy.exp
1137 ** so, no shifting required
1138 */
1139 if (locx.type == IFPF_IS_SUBNORMAL ||
1140 locy.type == IFPF_IS_SUBNORMAL)
1141 z->type = IFPF_IS_SUBNORMAL;
1142 else
1143 z->type = IFPF_IS_NORMAL;
1144
1145 /*
1146 ** Assume that locx.mantissa > locy.mantissa
1147 */
1148 z->sign = locx.sign;
1149 z->exp= locx.exp;
1150 }
1151 else
1152 if (exponent_difference > 0)
1153 {
1154 /*
1155 ** locx.exp > locy.exp
1156 */
1157 StickyShiftRightMant(&locy,
1158 exponent_difference);
1159 z->type = locx.type;
1160 z->sign = locx.sign;
1161 z->exp = locx.exp;
1162 }
1163 else /* if (exponent_difference < 0) */
1164 {
1165 /*
1166 ** locx.exp < locy.exp
1167 */
1168 StickyShiftRightMant(&locx,
1169 -exponent_difference);
1170 z->type = locy.type;
1171 z->sign = locy.sign ^ operation;
1172 z->exp = locy.exp;
1173 }
1174
1175 if (locx.sign ^ locy.sign ^ operation)
1176 {
1177 /*
1178 ** Signs are different, subtract mantissas
1179 */
1180 borrow = 0;
1181 for (i=(INTERNAL_FPF_PRECISION-1); i>=0; i--)
1182 Sub16Bits(&borrow,
1183 &z->mantissa[i],
1184 locx.mantissa[i],
1185 locy.mantissa[i]);
1186
1187 if (borrow)
1188 {
1189 /* The y->mantissa was larger than the
1190 ** x->mantissa leaving a negative
1191 ** result. Change the result back to
1192 ** an unsigned number and flip the
1193 ** sign flag.
1194 */
1195 z->sign = locy.sign ^ operation;
1196 borrow = 0;
1197 for (i=(INTERNAL_FPF_PRECISION-1); i>=0; i--)
1198 {
1199 Sub16Bits(&borrow,
1200 &z->mantissa[i],
1201 0,
1202 z->mantissa[i]);
1203 }
1204 }
1205 else
1206 {
1207 /* The assumption made above
1208 ** (i.e. x->mantissa >= y->mantissa)
1209 ** was correct. Therefore, do nothing.
1210 ** z->sign = x->sign;
1211 */
1212 }
1213
1214 if (IsMantissaZero(z->mantissa))
1215 {
1216 z->type = IFPF_IS_ZERO;
1217 z->sign = 0; /* positive */
1218 }
1219 else
1220 if (locx.type == IFPF_IS_NORMAL ||
1221 locy.type == IFPF_IS_NORMAL)
1222 {
1223 normalize(z);
1224 }
1225 }
1226 else
1227 {
1228 /* signs are the same, add mantissas */
1229 carry = 0;
1230 for (i=(INTERNAL_FPF_PRECISION-1); i>=0; i--)
1231 {
1232 Add16Bits(&carry,
1233 &z->mantissa[i],
1234 locx.mantissa[i],
1235 locy.mantissa[i]);
1236 }
1237
1238 if (carry)
1239 {
1240 z->exp++;
1241 carry=0;
1242 ShiftMantRight1(&carry,z->mantissa);
1243 z->mantissa[0] |= 0x8000;
1244 z->type = IFPF_IS_NORMAL;
1245 }
1246 else
1247 if (z->mantissa[0] & 0x8000)
1248 z->type = IFPF_IS_NORMAL;
1249 }
1250 break;
1251
1252case INFINITY_INFINITY:
1253 SetInternalFPFNaN(z);
1254 break;
1255
1256case NAN_NAN:
1257 choose_nan(x, y, z, 1);
1258 break;
1259}
1260
1261/*
1262** All the math is done; time to round.
1263*/
1264RoundInternalFPF(z);
1265return;
1266}
1267
1268
1269/************************
1270** MultiplyInternalFPF **
1271*************************
1272** Two internal-representation numbers x and y are multiplied; the
1273** result is returned in z.
1274*/
1275static void MultiplyInternalFPF(InternalFPF *x,
1276 InternalFPF *y,
1277 InternalFPF *z)
1278{
1279int i;
1280int j;
1281u16 carry;
1282u16 extra_bits[INTERNAL_FPF_PRECISION];
1283InternalFPF locy; /* Needed since this will be altered */
1284/*
1285** As in the preceding function, this large switch
1286** statement selects among the many combinations
1287** of operands.
1288*/
1289switch ((x->type * IFPF_TYPE_COUNT) + y->type)
1290{
1291case INFINITY_SUBNORMAL:
1292case INFINITY_NORMAL:
1293case INFINITY_INFINITY:
1294case ZERO_ZERO:
1295case ZERO_SUBNORMAL:
1296case ZERO_NORMAL:
1297 my_memmove((void *)x,(void *)z,sizeof(InternalFPF));
1298 z->sign ^= y->sign;
1299 break;
1300
1301case SUBNORMAL_INFINITY:
1302case NORMAL_INFINITY:
1303case SUBNORMAL_ZERO:
1304case NORMAL_ZERO:
1305 my_memmove((void *)y,(void *)z,sizeof(InternalFPF));
1306 z->sign ^= x->sign;
1307 break;
1308
1309case ZERO_INFINITY:
1310case INFINITY_ZERO:
1311 SetInternalFPFNaN(z);
1312 break;
1313
1314case NAN_ZERO:
1315case NAN_SUBNORMAL:
1316case NAN_NORMAL:
1317case NAN_INFINITY:
1318 my_memmove((void *)x,(void *)z,sizeof(InternalFPF));
1319 break;
1320
1321case ZERO_NAN:
1322case SUBNORMAL_NAN:
1323case NORMAL_NAN:
1324case INFINITY_NAN:
1325 my_memmove((void *)y,(void *)z,sizeof(InternalFPF));
1326 break;
1327
1328
1329case SUBNORMAL_SUBNORMAL:
1330case SUBNORMAL_NORMAL:
1331case NORMAL_SUBNORMAL:
1332case NORMAL_NORMAL:
1333 /*
1334 ** Make a local copy of the y number, since we will be
1335 ** altering it in the process of multiplying.
1336 */
1337 my_memmove((void *)&locy,(void *)y,sizeof(InternalFPF));
1338
1339 /*
1340 ** Check for unnormal zero arguments
1341 */
1342 if (IsMantissaZero(x->mantissa) || IsMantissaZero(y->mantissa))
1343 SetInternalFPFInfinity(z, 0);
1344
1345 /*
1346 ** Initialize the result
1347 */
1348 if (x->type == IFPF_IS_SUBNORMAL ||
1349 y->type == IFPF_IS_SUBNORMAL)
1350 z->type = IFPF_IS_SUBNORMAL;
1351 else
1352 z->type = IFPF_IS_NORMAL;
1353
1354 z->sign = x->sign ^ y->sign;
1355 z->exp = x->exp + y->exp ;
1356 for (i=0; i<INTERNAL_FPF_PRECISION; i++)
1357 {
1358 z->mantissa[i] = 0;
1359 extra_bits[i] = 0;
1360 }
1361
1362 for (i=0; i<(INTERNAL_FPF_PRECISION*16); i++)
1363 {
1364 /*
1365 ** Get rightmost bit of the multiplier
1366 */
1367 carry = 0;
1368 ShiftMantRight1(&carry, locy.mantissa);
1369 if (carry)
1370 {
1371 /*
1372 ** Add the multiplicand to the product
1373 */
1374 carry = 0;
1375 for (j=(INTERNAL_FPF_PRECISION-1); j>=0; j--)
1376 Add16Bits(&carry,
1377 &z->mantissa[j],
1378 z->mantissa[j],
1379 x->mantissa[j]);
1380 }
1381 else
1382 {
1383 carry = 0;
1384 }
1385
1386 /*
1387 ** Shift the product right. Overflow bits get
1388 ** shifted into extra_bits. We'll use it later
1389 ** to help with the "sticky" bit.
1390 */
1391 ShiftMantRight1(&carry, z->mantissa);
1392 ShiftMantRight1(&carry, extra_bits);
1393 }
1394
1395 /*
1396 ** Normalize
1397 ** Note that we use a "special" normalization routine
1398 ** because we need to use the extra bits. (These are
1399 ** bits that may have been shifted off the bottom that
1400 ** we want to reclaim...if we can.
1401 */
1402 while ((z->mantissa[0] & 0x8000) == 0)
1403 {
1404 carry = 0;
1405 ShiftMantLeft1(&carry, extra_bits);
1406 ShiftMantLeft1(&carry, z->mantissa);
1407 z->exp--;
1408 }
1409
1410 /*
1411 ** Set the sticky bit if any bits set in extra bits.
1412 */
1413 if (IsMantissaZero(extra_bits))
1414 {
1415 z->mantissa[INTERNAL_FPF_PRECISION-1] |= 1;
1416 }
1417 break;
1418
1419case NAN_NAN:
1420 choose_nan(x, y, z, 0);
1421 break;
1422}
1423
1424/*
1425** All math done...do rounding.
1426*/
1427RoundInternalFPF(z);
1428return;
1429}
1430
1431
1432/**********************
1433** DivideInternalFPF **
1434***********************
1435** Divide internal FPF number x by y. Return result in z.
1436*/
1437static void DivideInternalFPF(InternalFPF *x,
1438 InternalFPF *y,
1439 InternalFPF *z)
1440{
1441int i;
1442int j;
1443u16 carry;
1444u16 extra_bits[INTERNAL_FPF_PRECISION];
1445InternalFPF locx; /* Local for x number */
1446
1447/*
1448** As with preceding function, the following switch
1449** statement selects among the various possible
1450** operands.
1451*/
1452switch ((x->type * IFPF_TYPE_COUNT) + y->type)
1453{
1454case ZERO_ZERO:
1455case INFINITY_INFINITY:
1456 SetInternalFPFNaN(z);
1457 break;
1458
1459case ZERO_SUBNORMAL:
1460case ZERO_NORMAL:
1461 if (IsMantissaZero(y->mantissa))
1462 {
1463 SetInternalFPFNaN(z);
1464 break;
1465 }
1466
1467case ZERO_INFINITY:
1468case SUBNORMAL_INFINITY:
1469case NORMAL_INFINITY:
1470 SetInternalFPFZero(z, x->sign ^ y->sign);
1471 break;
1472
1473case SUBNORMAL_ZERO:
1474case NORMAL_ZERO:
1475 if (IsMantissaZero(x->mantissa))
1476 {
1477 SetInternalFPFNaN(z);
1478 break;
1479 }
1480
1481case INFINITY_ZERO:
1482case INFINITY_SUBNORMAL:
1483case INFINITY_NORMAL:
1484 SetInternalFPFInfinity(z, 0);
1485 z->sign = x->sign ^ y->sign;
1486 break;
1487
1488case NAN_ZERO:
1489case NAN_SUBNORMAL:
1490case NAN_NORMAL:
1491case NAN_INFINITY:
1492 my_memmove((void *)x,(void *)z,sizeof(InternalFPF));
1493 break;
1494
1495case ZERO_NAN:
1496case SUBNORMAL_NAN:
1497case NORMAL_NAN:
1498case INFINITY_NAN:
1499 my_memmove((void *)y,(void *)z,sizeof(InternalFPF));
1500 break;
1501
1502case SUBNORMAL_SUBNORMAL:
1503case NORMAL_SUBNORMAL:
1504case SUBNORMAL_NORMAL:
1505case NORMAL_NORMAL:
1506 /*
1507 ** Make local copy of x number, since we'll be
1508 ** altering it in the process of dividing.
1509 */
1510 my_memmove((void *)&locx,(void *)x,sizeof(InternalFPF));
1511
1512 /*
1513 ** Check for unnormal zero arguments
1514 */
1515 if (IsMantissaZero(locx.mantissa))
1516 {
1517 if (IsMantissaZero(y->mantissa))
1518 SetInternalFPFNaN(z);
1519 else
1520 SetInternalFPFZero(z, 0);
1521 break;
1522 }
1523 if (IsMantissaZero(y->mantissa))
1524 {
1525 SetInternalFPFInfinity(z, 0);
1526 break;
1527 }
1528
1529 /*
1530 ** Initialize the result
1531 */
1532 z->type = x->type;
1533 z->sign = x->sign ^ y->sign;
1534 z->exp = x->exp - y->exp +
1535 ((INTERNAL_FPF_PRECISION * 16 * 2));
1536 for (i=0; i<INTERNAL_FPF_PRECISION; i++)
1537 {
1538 z->mantissa[i] = 0;
1539 extra_bits[i] = 0;
1540 }
1541
1542 while ((z->mantissa[0] & 0x8000) == 0)
1543 {
1544 carry = 0;
1545 ShiftMantLeft1(&carry, locx.mantissa);
1546 ShiftMantLeft1(&carry, extra_bits);
1547
1548 /*
1549 ** Time to subtract yet?
1550 */
1551 if (carry == 0)
1552 for (j=0; j<INTERNAL_FPF_PRECISION; j++)
1553 {
1554 if (y->mantissa[j] > extra_bits[j])
1555 {
1556 carry = 0;
1557 goto no_subtract;
1558 }
1559 if (y->mantissa[j] < extra_bits[j])
1560 break;
1561 }
1562 /*
1563 ** Divisor (y) <= dividend (x), subtract
1564 */
1565 carry = 0;
1566 for (j=(INTERNAL_FPF_PRECISION-1); j>=0; j--)
1567 Sub16Bits(&carry,
1568 &extra_bits[j],
1569 extra_bits[j],
1570 y->mantissa[j]);
1571 carry = 1; /* 1 shifted into quotient */
1572 no_subtract:
1573 ShiftMantLeft1(&carry, z->mantissa);
1574 z->exp--;
1575 }
1576 break;
1577
1578case NAN_NAN:
1579 choose_nan(x, y, z, 0);
1580 break;
1581}
1582
1583/*
1584** Math complete...do rounding
1585*/
1586RoundInternalFPF(z);
1587}
1588
1589/**********************
1590** LongToInternalFPF **
1591** Int32ToInternalFPF **
1592***********************
1593** Convert a signed (long) 32-bit integer into an internal FPF number.
1594*/
1595/* static void LongToInternalFPF(long mylong, */
1596static void Int32ToInternalFPF(int32 mylong,
1597 InternalFPF *dest)
1598{
1599int i; /* Index */
1600u16 myword; /* Used to hold converted stuff */
1601/*
1602** Save the sign and get the absolute value. This will help us
1603** with 64-bit machines, since we use only the lower 32
1604** bits just in case. (No longer necessary after we use int32.)
1605*/
1606/* if(mylong<0L) */
1607if(mylong<(int32)0)
1608{ dest->sign=1;
1609 mylong=(int32)0-mylong;
1610}
1611else
1612 dest->sign=0;
1613/*
1614** Prepare the destination floating point number
1615*/
1616dest->type=IFPF_IS_NORMAL;
1617for(i=0;i<INTERNAL_FPF_PRECISION;i++)
1618 dest->mantissa[i]=0;
1619
1620/*
1621** See if we've got a zero. If so, make the resultant FP
1622** number a true zero and go home.
1623*/
1624if(mylong==0)
1625{ dest->type=IFPF_IS_ZERO;
1626 dest->exp=0;
1627 return;
1628}
1629
1630/*
1631** Not a true zero. Set the exponent to 32 (internal FPFs have
1632** no bias) and load the low and high words into their proper
1633** locations in the mantissa. Then normalize. The action of
1634** normalizing slides the mantissa bits into place and sets
1635** up the exponent properly.
1636*/
1637dest->exp=32;
1638myword=(u16)((mylong >> 16) & 0xFFFFL);
1639dest->mantissa[0]=myword;
1640myword=(u16)(mylong & 0xFFFFL);
1641dest->mantissa[1]=myword;
1642normalize(dest);
1643return;
1644}
1645
1646#if 1
1647/************************
1648** InternalFPFToString **
1649*************************
1650** FOR DEBUG PURPOSES
1651** This routine converts an internal floating point representation
1652** number to a string. Used in debugging the package.
1653** Returns length of converted number.
1654** NOTE: dest must point to a buffer big enough to hold the
1655** result. Also, this routine does append a null (an effect
1656** of using the sprintf() function). It also returns
1657** a length count.
1658** NOTE: This routine returns 5 significant digits. Thats
1659** about all I feel safe with, given the method of
1660** conversion. It should be more than enough for programmers
1661** to determine whether the package is properly ported.
1662*/
1663static int InternalFPFToString(char *dest,
1664 InternalFPF *src)
1665{
1666InternalFPF locFPFNum; /* Local for src (will be altered) */
1667InternalFPF IFPF10; /* Floating-point 10 */
1668InternalFPF IFPFComp; /* For doing comparisons */
1669int msign; /* Holding for mantissa sign */
1670int expcount; /* Exponent counter */
1671int ccount; /* Character counter */
1672int i,j,k; /* Index */
1673u16 carryaccum; /* Carry accumulator */
1674u16 mycarry; /* Local for carry */
1675
1676/*
1677** Check first for the simple things...Nan, Infinity, Zero.
1678** If found, copy the proper string in and go home.
1679*/
1680switch(src->type)
1681{
1682 case IFPF_IS_NAN:
1683 my_memcpy(dest,"NaN",3);
1684 return(3);
1685
1686 case IFPF_IS_INFINITY:
1687 if(src->sign==0)
1688 my_memcpy(dest,"+Inf",4);
1689 else
1690 my_memcpy(dest,"-Inf",4);
1691 return(4);
1692
1693 case IFPF_IS_ZERO:
1694 if(src->sign==0)
1695 my_memcpy(dest,"+0",2);
1696 else
1697 my_memcpy(dest,"-0",2);
1698 return(2);
1699}
1700
1701/*
1702** Move the internal number into our local holding area, since
1703** we'll be altering it to print it out.
1704*/
1705my_memcpy((void *)&locFPFNum,(void *)src,sizeof(InternalFPF));
1706
1707/*
1708** Set up a floating-point 10...which we'll use a lot in a minute.
1709*/
1710/* LongToInternalFPF(10L,&IFPF10); */
1711Int32ToInternalFPF((int32)10,&IFPF10);
1712
1713/*
1714** Save the mantissa sign and make it positive.
1715*/
1716msign=src->sign;
1717
1718/* src->sign=0 */ /* bug, fixed Nov. 13, 1997 */
1719(&locFPFNum)->sign=0;
1720
1721expcount=0; /* Init exponent counter */
1722
1723/*
1724** See if the number is less than 10. If so, multiply
1725** the number repeatedly by 10 until it's not. For each
1726** multiplication, decrement a counter so we can keep track
1727** of the exponent.
1728*/
1729
1730while(1)
1731{ AddSubInternalFPF(1,&locFPFNum,&IFPF10,&IFPFComp);
1732 if(IFPFComp.sign==0) break;
1733 MultiplyInternalFPF(&locFPFNum,&IFPF10,&IFPFComp);
1734 expcount--;
1735 my_memcpy((void *)&locFPFNum,(void *)&IFPFComp,sizeof(InternalFPF));
1736}
1737/*
1738** Do the reverse of the above. As long as the number is
1739** greater than or equal to 10, divide it by 10. Increment the
1740** exponent counter for each multiplication.
1741*/
1742
1743while(1)
1744{
1745 AddSubInternalFPF(1,&locFPFNum,&IFPF10,&IFPFComp);
1746 if(IFPFComp.sign!=0) break;
1747 DivideInternalFPF(&locFPFNum,&IFPF10,&IFPFComp);
1748 expcount++;
1749 my_memcpy((void *)&locFPFNum,(void *)&IFPFComp,sizeof(InternalFPF));
1750}
1751
1752/*
1753** About time to start storing things. First, store the
1754** mantissa sign.
1755*/
1756ccount=1; /* Init character counter */
1757if(msign==0)
1758 *dest++='+';
1759else
1760 *dest++='-';
1761
1762/*
1763** At this point we know that the number is in the range
1764** 10 > n >=1. We need to "strip digits" out of the
1765** mantissa. We do this by treating the mantissa as
1766** an integer and multiplying by 10. (Not a floating-point
1767** 10, but an integer 10. Since this is debug code and we
1768** could care less about speed, we'll do it the stupid
1769** way and simply add the number to itself 10 times.
1770** Anything that makes it to the left of the implied binary point
1771** gets stripped off and emitted. We'll do this for
1772** 5 significant digits (which should be enough to
1773** verify things).
1774*/
1775/*
1776** Re-position radix point
1777*/
1778carryaccum=0;
1779while(locFPFNum.exp>0)
1780{
1781 mycarry=0;
1782 ShiftMantLeft1(&mycarry,locFPFNum.mantissa);
1783 carryaccum=(carryaccum<<1);
1784 if(mycarry) carryaccum++;
1785 locFPFNum.exp--;
1786}
1787
1788while(locFPFNum.exp<0)
1789{
1790 mycarry=0;
1791 ShiftMantRight1(&mycarry,locFPFNum.mantissa);
1792 locFPFNum.exp++;
1793}
1794
1795for(i=0;i<6;i++)
1796 if(i==1)
1797 { /* Emit decimal point */
1798 *dest++='.';
1799 ccount++;
1800 }
1801 else
1802 { /* Emit a digit */
1803 *dest++=('0'+carryaccum);
1804 ccount++;
1805
1806 carryaccum=0;
1807 my_memcpy((void *)&IFPF10,
1808 (void *)&locFPFNum,
1809 sizeof(InternalFPF));
1810
1811 /* Do multiply via repeated adds */
1812 for(j=0;j<9;j++)
1813 {
1814 mycarry=0;
1815 for(k=(INTERNAL_FPF_PRECISION-1);k>=0;k--)
1816 Add16Bits(&mycarry,&(IFPFComp.mantissa[k]),
1817 locFPFNum.mantissa[k],
1818 IFPF10.mantissa[k]);
1819 carryaccum+=mycarry ? 1 : 0;
1820 my_memcpy((void *)&locFPFNum,
1821 (void *)&IFPFComp,
1822 sizeof(InternalFPF));
1823 }
1824 }
1825
1826/*
1827** Now move the 'E', the exponent sign, and the exponent
1828** into the string.
1829*/
1830*dest++='E';
1831
1832/* sprint is supposed to return an integer, but it caused problems on SunOS
1833 * with the native cc. Hence we force it.
1834 * Uwe F. Mayer
1835 */
1836if (expcount < 0) {
1837 *dest++ = '-';
1838 expcount =- expcount;
1839}
1840else *dest++ = ' ';
1841
1842*dest++ = (char)(expcount + '0');
1843*dest++ = 0;
1844
1845ccount += 3;
1846/*
1847** All done, go home.
1848*/
1849return(ccount);
1850
1851}
1852
1853#endif
1854
1855
1856
1857////////////////////////////////////////////////////////////////////////
1858static
1859void* AllocateMemory ( unsigned long n, int* p )
1860{
1861 *p = 0;
1862 void* r = (void*) (*serviceFn)(2,n);
1863 return r;
1864}
1865static
1866void FreeMemory ( void* p, int* zz )
1867{
1868 *zz = 0;
1869 // free(p);
1870}
1871
1872
1873
1874/**************
1875** DoEmFloat **
1876***************
1877** Perform the floating-point emulation routines portion of the
1878** CPU benchmark. Returns the operations per second.
1879*/
1880static
1881void DoEmFloat(void)
1882{
1883EmFloatStruct *locemfloatstruct; /* Local structure */
1884InternalFPF *abase; /* Base of A array */
1885InternalFPF *bbase; /* Base of B array */
1886InternalFPF *cbase; /* Base of C array */
1887ulong tickcount; /* # of ticks */
1888char *errorcontext; /* Error context string pointer */
1889int systemerror; /* For holding error code */
1890ulong loops; /* # of loops */
1891
1892/*
1893** Link to global structure
1894*/
1895EmFloatStruct global_emfloatstruct;
1896 global_emfloatstruct.adjust = 0;
1897 global_emfloatstruct.request_secs = 0;
1898 global_emfloatstruct.arraysize = 100;
1899 global_emfloatstruct.loops = 1;
1900 global_emfloatstruct.emflops = 0.0;
1901locemfloatstruct=&global_emfloatstruct;
1902
1903/*
1904** Set the error context
1905*/
1906errorcontext="CPU:Floating Emulation";
1907
1908
1909abase=(InternalFPF *)AllocateMemory(locemfloatstruct->arraysize*sizeof(InternalFPF),
1910 &systemerror);
1911
1912bbase=(InternalFPF *)AllocateMemory(locemfloatstruct->arraysize*sizeof(InternalFPF),
1913 &systemerror);
1914
1915cbase=(InternalFPF *)AllocateMemory(locemfloatstruct->arraysize*sizeof(InternalFPF),
1916 &systemerror);
1917
1918/*
1919** Set up the arrays
1920*/
1921SetupCPUEmFloatArrays(abase,bbase,cbase,locemfloatstruct->arraysize);
1922
1923 loops=100;
1924 tickcount=DoEmFloatIteration(abase,bbase,cbase,
1925 locemfloatstruct->arraysize,
1926 loops);
1927
1928FreeMemory((void *)abase,&systemerror);
1929FreeMemory((void *)bbase,&systemerror);
1930FreeMemory((void *)cbase,&systemerror);
1931
1932return;
1933}
1934
1935//////////////////
1936void entry ( HWord(*f)(HWord,HWord) )
1937{
1938 serviceFn = f;
cerion6ded3892005-12-13 21:30:48 +00001939 vexxx_printf("starting\n");
sewardj69fe0712005-02-12 19:01:03 +00001940 DoEmFloat();
1941 (*serviceFn)(0,0);
1942}