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- /*
- (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
- See the copyright notice in the ACK home directory, in the file "Copyright".
- */
- /* $Id$ */
- #include <ctype.h>
- #include "flt_misc.h"
- /* The following tables can be computed with the following bc(1)
- program:
- obase=16
- scale=0
- define t(x){
- auto a, b, c
- a=2;b=1;c=2^32;n=1
- while(a<x) {
- b=a;n+=n;a*=a
- }
- n/=2
- a=b
- while(b<x) {
- a=b;b*=c;n+=32
- }
- n-=32
- b=a
- while(a<x) {
- b=a;a+=a;n+=1
- }
- n-=1
- x*=16^16
- b=x%a
- x/=a
- if(a<=(2*b)) x+=1
- obase=10
- n
- obase=16
- return(x)
- }
- for (i=1;i<28;i++) {
- t(10^i)
- }
- 0
- for (i=1;i<20;i++) {
- t(10^(28*i))
- }
- 0
- define r(x){
- auto a, b, c
- a=2;b=1;c=2^32;n=1
- while(a<x) {
- b=a;n+=n;a*=a
- }
- n/=2
- a=b
- while(b<x) {
- a=b;b*=c;n+=32
- }
- n-=32
- b=a
- while(a<x) {
- b=a;a+=a;n+=1
- }
- a=b
- a*=16^16
- b=a%x
- a/=x
- if(x<=(2*b)) a+=1
- obase=10
- -n
- obase=16
- return(a)
- }
- for (i=1;i<28;i++) {
- r(10^i)
- }
- 0
- for (i=1;i<20;i++) {
- r(10^(28*i))
- }
- 0
- */
- static flt_arith s10pow[] = { /* representation of 10 ** i */
- { 0, 0, 0x80000000, 0 },
- { 0, 3, 0xA0000000, 0 },
- { 0, 6, 0xC8000000, 0 },
- { 0, 9, 0xFA000000, 0 },
- { 0, 13, 0x9C400000, 0 },
- { 0, 16, 0xC3500000, 0 },
- { 0, 19, 0xF4240000, 0 },
- { 0, 23, 0x98968000, 0 },
- { 0, 26, 0xBEBC2000, 0 },
- { 0, 29, 0xEE6B2800, 0 },
- { 0, 33, 0x9502F900, 0 },
- { 0, 36, 0xBA43B740, 0 },
- { 0, 39, 0xE8D4A510, 0 },
- { 0, 43, 0x9184E72A, 0 },
- { 0, 46, 0xB5E620F4, 0x80000000 },
- { 0, 49, 0xE35FA931, 0xA0000000 },
- { 0, 53, 0x8E1BC9BF, 0x04000000 },
- { 0, 56, 0xB1A2BC2E, 0xC5000000 },
- { 0, 59, 0xDE0B6B3A, 0x76400000 },
- { 0, 63, 0x8AC72304, 0x89E80000 },
- { 0, 66, 0xAD78EBC5, 0xAC620000 },
- { 0, 69, 0xD8D726B7, 0x177A8000 },
- { 0, 73, 0x87867832, 0x6EAC9000 },
- { 0, 76, 0xA968163F, 0x0A57B400 },
- { 0, 79, 0xD3C21BCE, 0xCCEDA100 },
- { 0, 83, 0x84595161, 0x401484A0 },
- { 0, 86, 0xA56FA5B9, 0x9019A5C8 },
- { 0, 89, 0xCECB8F27, 0xF4200F3A }
- };
- static flt_arith big_10pow[] = { /* representation of 10 ** (28*i) */
- { 0, 0, 0x80000000, 0 },
- { 0, 93, 0x813F3978, 0xF8940984 },
- { 0, 186, 0x82818F12, 0x81ED44A0 },
- { 0, 279, 0x83C7088E, 0x1AAB65DB },
- { 0, 372, 0x850FADC0, 0x9923329E },
- { 0, 465, 0x865B8692, 0x5B9BC5C2 },
- { 0, 558, 0x87AA9AFF, 0x79042287 },
- { 0, 651, 0x88FCF317, 0xF22241E2 },
- { 0, 744, 0x8A5296FF, 0xE33CC930 },
- { 0, 837, 0x8BAB8EEF, 0xB6409C1A },
- { 0, 930, 0x8D07E334, 0x55637EB3 },
- { 0, 1023, 0x8E679C2F, 0x5E44FF8F },
- { 0, 1116, 0x8FCAC257, 0x558EE4E6 },
- { 0, 1209, 0x91315E37, 0xDB165AA9 },
- { 0, 1302, 0x929B7871, 0xDE7F22B9 },
- { 0, 1395, 0x940919BB, 0xD4620B6D },
- { 0, 1488, 0x957A4AE1, 0xEBF7F3D4 },
- { 0, 1581, 0x96EF14C6, 0x454AA840 },
- { 0, 1674, 0x98678061, 0x27ECE4F5 },
- { 0, 1767, 0x99E396C1, 0x3A3ACFF2 }
- };
- static flt_arith r_10pow[] = { /* representation of 10 ** -i */
- { 0, 0, 0x80000000, 0 },
- { 0, -4, 0xCCCCCCCC, 0xCCCCCCCD },
- { 0, -7, 0xA3D70A3D, 0x70A3D70A },
- { 0, -10, 0x83126E97, 0x8D4FDF3B },
- { 0, -14, 0xD1B71758, 0xE219652C },
- { 0, -17, 0xA7C5AC47, 0x1B478423 },
- { 0, -20, 0x8637BD05, 0xAF6C69B6 },
- { 0, -24, 0xD6BF94D5, 0xE57A42BC },
- { 0, -27, 0xABCC7711, 0x8461CEFD },
- { 0, -30, 0x89705F41, 0x36B4A597 },
- { 0, -34, 0xDBE6FECE, 0xBDEDD5BF },
- { 0, -37, 0xAFEBFF0B, 0xCB24AAFF },
- { 0, -40, 0x8CBCCC09, 0x6F5088CC },
- { 0, -44, 0xE12E1342, 0x4BB40E13 },
- { 0, -47, 0xB424DC35, 0x095CD80F },
- { 0, -50, 0x901D7CF7, 0x3AB0ACD9 },
- { 0, -54, 0xE69594BE, 0xC44DE15B },
- { 0, -57, 0xB877AA32, 0x36A4B449 },
- { 0, -60, 0x9392EE8E, 0x921D5D07 },
- { 0, -64, 0xEC1E4A7D, 0xB69561A5 },
- { 0, -67, 0xBCE50864, 0x92111AEB },
- { 0, -70, 0x971DA050, 0x74DA7BEF },
- { 0, -74, 0xF1C90080, 0xBAF72CB1 },
- { 0, -77, 0xC16D9A00, 0x95928A27 },
- { 0, -80, 0x9ABE14CD, 0x44753B53 },
- { 0, -84, 0xF79687AE, 0xD3EEC551 },
- { 0, -87, 0xC6120625, 0x76589DDB },
- { 0, -90, 0x9E74D1B7, 0x91E07E48 }
- };
- static flt_arith r_big_10pow[] = { /* representation of 10 ** -(28*i) */
- { 0, 0, 0x80000000, 0 },
- { 0, -94, 0xFD87B5F2, 0x8300CA0E },
- { 0, -187, 0xFB158592, 0xBE068D2F },
- { 0, -280, 0xF8A95FCF, 0x88747D94 },
- { 0, -373, 0xF64335BC, 0xF065D37D },
- { 0, -466, 0xF3E2F893, 0xDEC3F126 },
- { 0, -559, 0xF18899B1, 0xBC3F8CA2 },
- { 0, -652, 0xEF340A98, 0x172AACE5 },
- { 0, -745, 0xECE53CEC, 0x4A314EBE },
- { 0, -838, 0xEA9C2277, 0x23EE8BCB },
- { 0, -931, 0xE858AD24, 0x8F5C22CA },
- { 0, -1024, 0xE61ACF03, 0x3D1A45DF },
- { 0, -1117, 0xE3E27A44, 0x4D8D98B8 },
- { 0, -1210, 0xE1AFA13A, 0xFBD14D6E },
- { 0, -1303, 0xDF82365C, 0x497B5454 },
- { 0, -1396, 0xDD5A2C3E, 0xAB3097CC },
- { 0, -1489, 0xDB377599, 0xB6074245 },
- { 0, -1582, 0xD91A0545, 0xCDB51186 },
- { 0, -1675, 0xD701CE3B, 0xD387BF48 },
- { 0, -1768, 0xD4EEC394, 0xD6258BF8 }
- };
- #define BIGSZ (sizeof(big_10pow)/sizeof(big_10pow[0]))
- #define SMALLSZ (sizeof(s10pow)/sizeof(s10pow[0]))
- static void add_exponent(flt_arith *e, int exp)
- {
- int neg = exp < 0;
- int divsz, modsz;
- flt_arith x;
- register int status = 0;
- if (neg) exp = -exp;
- divsz = exp / SMALLSZ;
- modsz = exp % SMALLSZ;
- if (!status) status = flt_status;
- flt_mul(e, (neg ? r_10pow : s10pow) + modsz, &x);
- if (!status) status = flt_status;
- while (divsz >= BIGSZ) {
- flt_mul(&x, neg ? &r_big_10pow[BIGSZ-1] : &big_10pow[BIGSZ-1],&x);
- if (!status) status = flt_status;
- divsz -= BIGSZ-1;
- }
- flt_mul(&x, (neg ? r_big_10pow : big_10pow) + divsz, e);
- if (!status) status = flt_status;
- flt_status = status;
- }
- void flt_str2flt(char *s, flt_arith *e)
- {
- register int c;
- int dotseen = 0;
- int digitseen = 0;
- int exp = 0;
- while (isspace(*s)) s++;
- flt_status = 0;
- e->flt_sign = 0;
- e->flt_exp = 0;
- e->m1 = e->m2 = 0;
- c = *s;
- switch(c) {
- case '-':
- e->flt_sign = 1;
- case '+':
- s++;
- }
- while (c = *s++, isdigit(c) || (c == '.' && ! dotseen++)) {
- if (c == '.') continue;
- digitseen = 1;
- if (e->m1 >= 0 && e->m1 <= 0x7FFFFFFF/5) {
- struct flt_mantissa a1;
- a1 = e->flt_mantissa;
- flt_b64_sft(&(e->flt_mantissa), -3);
- flt_b64_sft(&a1, -1);
- flt_b64_add(&(e->flt_mantissa), &a1);
- a1.flt_h_32 = 0;
- a1.flt_l_32 = c - '0';
- flt_b64_add(&(e->flt_mantissa), &a1);
- }
- else exp++;
- if (dotseen) exp--;
- }
- if (! digitseen) {
- flt_status = FLT_NOFLT;
- return;
- }
- if (c == 'E' || c == 'e') {
- int exp1 = 0;
- int sign = 1;
- switch(*s) {
- case '-':
- sign = -1;
- case '+':
- s++;
- }
- if (c = *s, isdigit(c)) {
- do {
- exp1 = 10 * exp1 + (c - '0');
- } while (c = *++s, isdigit(c));
- }
- exp += sign * exp1;
- }
- if (e->m1 == 0 && e->m2 == 0) return;
- e->flt_exp = 63;
- flt_nrm(e);
- add_exponent(e, exp);
- flt_chk(e);
- }
- #define NDIG 18
- static char *flt_ecvt(flt_arith *e, int *decpt, int *sign)
- {
- /* Like ecvt(), but for extended precision */
- static char buf[NDIG+1];
- register char *p = buf;
- register char *pe;
- register int findex = 0;
- pe = &buf[NDIG];
- buf[0] = '\0';
- *sign = 0;
- if (e->flt_sign) {
- *sign = 1;
- e->flt_sign = 0;
- }
- *decpt = 0;
- if (e->m1 != 0) {
- register flt_arith *pp = &big_10pow[1];
- findex = 1;
- while (flt_cmp(e, &big_10pow[BIGSZ-1]) >= 0) {
- flt_mul(e,&r_big_10pow[BIGSZ-1],e);
- *decpt += (BIGSZ-1)*SMALLSZ;
- }
- while (flt_cmp(e,pp) >= 0) {
- pp++;
- findex++;
- }
- findex--;
- flt_mul(e,&r_big_10pow[findex],e);
- *decpt += findex*SMALLSZ;
- pp = &s10pow[1];
- findex = 1;
- while (pp < &s10pow[SMALLSZ] && flt_cmp(e, pp) >= 0) {
- pp++;
- findex++;
- }
- findex--;
- *decpt += findex;
- if (flt_cmp(e, &s10pow[0]) < 0) {
- while (flt_cmp(e, &r_big_10pow[BIGSZ-1]) < 0) {
- flt_mul(e,&big_10pow[BIGSZ-1],e);
- *decpt -= (BIGSZ-1)*SMALLSZ;
- }
- pp = &r_big_10pow[1];
- findex = 1;
- while(flt_cmp(e,pp) < 0) {
- pp++;
- findex++;
- }
- findex--;
- flt_mul(e,&big_10pow[findex],e);
- *decpt -= findex*SMALLSZ;
- /* here, value >= 10 ** -28 */
- flt_mul(e, &s10pow[1], e);
- (*decpt)--;
- pp = &r_10pow[0];
- findex = 0;
- while(flt_cmp(e, pp) < 0) {
- pp++;
- findex++;
- }
- flt_mul(e, &s10pow[findex], e);
- *decpt -= findex;
- findex = 0;
- }
- (*decpt)++; /* because now value in [1.0, 10.0) */
- }
- while (p <= pe) {
- if (findex) {
- flt_arith tc, oldtc;
- int count = 0;
- oldtc.flt_exp = 0;
- oldtc.flt_sign = 0;
- oldtc.m1 = 0;
- oldtc.m2 = 0;
- tc = s10pow[findex];
- while (flt_cmp(e, &tc) >= 0) {
- oldtc = tc;
- flt_add(&tc, &s10pow[findex], &tc);
- count++;
- }
- *p++ = count + '0';
- oldtc.flt_sign = 1;
- flt_add(e, &oldtc, e);
- findex--;
- continue;
- }
- if (e->flt_exp >= 0 && e->m1 != 0) {
- flt_arith x;
- x.m2 = 0; x.flt_exp = e->flt_exp;
- x.flt_sign = 1;
- x.m1 = (e->m1 >> 1) & 0x7FFFFFFF;
- x.m1 = x.m1>>(30-e->flt_exp);
- *p++ = (x.m1) + '0';
- if (x.m1) {
- x.m1 = x.m1 << (31-e->flt_exp);
- flt_add(e, &x, e);
- }
- }
- else *p++ = '0';
- if (e->m1) flt_mul(e, &s10pow[1], e);
- }
- if (pe >= buf) {
- p = pe;
- *p += 5; /* round of at the end */
- while (*p > '9') {
- *p = '0';
- if (p > buf) ++*--p;
- else {
- *p = '1';
- ++*decpt;
- }
- }
- *pe = '\0';
- while (--pe > buf && *pe == '0') *pe = '\0';
- }
- return buf;
- }
- void flt_flt2str(flt_arith *e, char *buf, int bufsize)
- {
- int sign, dp;
- register int i;
- register char *s1;
- char Xbuf[NDIG+12];
- register char *s = Xbuf;
- flt_arith e1;
- e1 = *e;
- flt_status = 0;
- s1 = flt_ecvt(&e1,&dp,&sign);
- if (sign)
- *s++ = '-';
- *s++ = *s1++;
- *s++ = '.';
- for (i = NDIG-1; i > 0; i--) {
- if (*s1) *s++ = *s1++;
- else {
- if (i == NDIG-1) *s++ = '0';
- break;
- }
- }
- if (e->m1 | e->m2) {
- --dp ;
- }
- if (dp != 0) {
- *s++ = 'e';
- if ( dp<0 ) {
- *s++ = '-' ; dp= -dp ;
- } else {
- *s++ = '+' ;
- }
- s1 = &Xbuf[NDIG+12];
- *--s1 = '\0';
- do {
- *--s1 = dp % 10 + '0';
- dp /= 10;
- } while (dp != 0);
- while (*s1) *s++ = *s1++;
- }
- *s++ = '\0';
- if (s - Xbuf > bufsize) {
- flt_status = FLT_BTSM;
- return;
- }
- s = Xbuf;
- s1 = buf;
- do {
- *s1++ = *s;
- } while (*s++);
- }
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