10 #include "floatscan.h"
12 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
15 #define LD_B1B_MAX 9007199, 254740991
18 #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
21 #define LD_B1B_MAX 18, 446744073, 709551615
24 #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
27 #define LD_B1B_MAX 10384593, 717069655, 257060992, 658440191
31 #error Unsupported long double representation
36 #define CONCAT2(x,y) x ## y
37 #define CONCAT(x,y) CONCAT2(x,y)
39 static long long scanexp(FILE *f, int pok)
47 if (c=='+' || c=='-') {
50 if (c-'0'>=10U && pok) shunget(f);
56 for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
58 for (y=x; c-'0'<10U && y<LLONG_MAX/100; c = shgetc(f))
60 for (; c-'0'<10U; c = shgetc(f));
66 static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int pok)
69 static const uint32_t th[] = { LD_B1B_MAX };
71 long long lrp=0, dc=0;
74 int gotdig = 0, gotrad = 0;
77 int emax = -emin-bits+3;
82 static const int p10s[] = { 10, 100, 1000, 10000,
83 100000, 1000000, 10000000, 100000000 };
88 /* Don't let leading zeros consume buffer space */
89 for (; c=='0'; c = shgetc(f)) gotdig=1;
92 for (c = shgetc(f); c=='0'; c = shgetc(f)) gotdig=1, lrp--;
96 for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
101 } else if (k < KMAX-3) {
103 if (c!='0') lnz = dc;
104 if (j) x[k] = x[k]*10 + c-'0';
113 if (c!='0') x[KMAX-4] |= 1;
118 if (gotdig && (c|32)=='e') {
119 e10 = scanexp(f, pok);
120 if (e10 == LLONG_MIN) {
139 /* Handle zero specially to avoid nasty special cases later */
140 if (!x[0]) return sign * 0.0;
142 /* Optimize small integers (w/no exponent) and over/under-flow */
143 if (lrp==dc && dc<10 && (bits>30 || x[0]>>bits==0))
144 return sign * (long double)x[0];
147 return sign * LDBL_MAX * LDBL_MAX;
149 if (lrp < emin-2*LDBL_MANT_DIG) {
151 return sign * LDBL_MIN * LDBL_MIN;
154 /* Align incomplete final B1B digit */
156 for (; j<9; j++) x[k]*=10;
166 /* Optimize small to mid-size integers (even in exp. notation) */
167 if (lnz<9 && lnz<=rp && rp < 18) {
168 if (rp == 9) return sign * (long double)x[0];
169 if (rp < 9) return sign * (long double)x[0] / p10s[8-rp];
170 int bitlim = bits-3*(int)(rp-9);
171 if (bitlim>30 || x[0]>>bitlim==0)
172 return sign * (long double)x[0] * p10s[rp-10];
175 /* Align radix point to B1B digit boundary */
177 int rpm9 = rp>=0 ? rp%9 : rp%9+9;
178 int p10 = p10s[8-rpm9];
180 for (k=a; k!=z; k++) {
181 uint32_t tmp = x[k] % p10;
182 x[k] = x[k]/p10 + carry;
183 carry = 1000000000/p10 * tmp;
189 if (carry) x[z++] = carry;
193 /* Upscale until desired number of bits are left of radix point */
194 while (rp < 9*LD_B1B_DIG || (rp == 9*LD_B1B_DIG && x[a]<th[0])) {
197 for (k=(z-1 & MASK); ; k=(k-1 & MASK)) {
198 uint64_t tmp = ((uint64_t)x[k] << 29) + carry;
199 if (tmp > 1000000000) {
200 carry = tmp / 1000000000;
201 x[k] = tmp % 1000000000;
206 if (k==(z-1 & MASK) && k!=a && !x[k]) z = k;
214 x[z-1 & MASK] |= x[z];
220 /* Downscale until exactly number of bits are left of radix point */
224 for (i=0; i<LD_B1B_DIG; i++) {
226 if (k == z || x[k] < th[i]) {
230 if (x[a+i & MASK] > th[i]) break;
232 if (i==LD_B1B_DIG && rp==9*LD_B1B_DIG) break;
233 /* FIXME: find a way to compute optimal sh */
234 if (rp > 9+9*LD_B1B_DIG) sh = 9;
236 for (k=a; k!=z; k=(k+1 & MASK)) {
237 uint32_t tmp = x[k] & (1<<sh)-1;
238 x[k] = (x[k]>>sh) + carry;
239 carry = (1000000000>>sh) * tmp;
247 if ((z+1 & MASK) != a) {
250 } else x[z-1 & MASK] |= 1;
254 /* Assemble desired bits into floating point variable */
255 for (y=i=0; i<LD_B1B_DIG; i++) {
256 if ((a+i & MASK)==z) x[(z=(z+1 & MASK))-1] = 0;
257 y = 1000000000.0L * y + x[a+i & MASK];
262 /* Limit precision for denormal results */
263 if (bits > LDBL_MANT_DIG+e2-emin) {
264 bits = LDBL_MANT_DIG+e2-emin;
269 /* Calculate bias term to force rounding, move out lower bits */
270 if (bits < LDBL_MANT_DIG) {
271 bias = copysignl(scalbn(1, 2*LDBL_MANT_DIG-bits-1), y);
272 frac = fmodl(y, scalbn(1, LDBL_MANT_DIG-bits));
277 /* Process tail of decimal input so it can affect rounding */
278 if ((a+i & MASK) != z) {
279 uint32_t t = x[a+i & MASK];
280 if (t < 500000000 && (t || (a+i+1 & MASK) != z))
282 else if (t > 500000000)
284 else if (t == 500000000) {
285 if ((a+i+1 & MASK) == z)
290 if (LDBL_MANT_DIG-bits >= 2 && !fmodl(frac, 1))
297 if ((e2+LDBL_MANT_DIG & INT_MAX) > emax-5) {
298 if (fabs(y) >= CONCAT(0x1p, LDBL_MANT_DIG)) {
299 if (denormal && bits==LDBL_MANT_DIG+e2-emin)
304 if (e2+LDBL_MANT_DIG>emax || (denormal && frac))
308 return scalbnl(y, e2);
311 static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
315 long double scale = 1;
316 long double bias = 0;
317 int gottail = 0, gotrad = 0, gotdig = 0;
326 /* Skip leading zeros */
327 for (; c=='0'; c = shgetc(f)) gotdig = 1;
332 /* Count zeros after the radix point before significand */
333 for (rp=0; c=='0'; c = shgetc(f), rp--) gotdig = 1;
336 for (; c-'0'<10U || (c|32)-'a'<6U || c=='.'; c = shgetc(f)) {
343 if (c > '9') d = (c|32)+10-'a';
347 } else if (dc < LDBL_MANT_DIG/4+1) {
349 } else if (d && !gottail) {
360 if (gotrad) shunget(f);
366 if (!gotrad) rp = dc;
367 while (dc<8) x *= 16, dc++;
369 e2 = scanexp(f, pok);
370 if (e2 == LLONG_MIN) {
384 if (!x) return sign * 0.0;
387 return sign * LDBL_MAX * LDBL_MAX;
389 if (e2 < emin-2*LDBL_MANT_DIG) {
391 return sign * LDBL_MIN * LDBL_MIN;
394 while (x < 0x80000000) {
405 if (bits > 32+e2-emin) {
410 if (bits < LDBL_MANT_DIG)
411 bias = copysignl(scalbn(1, 32+LDBL_MANT_DIG-bits-1), sign);
413 if (bits<32 && y && !(x&1)) x++, y=0;
415 y = bias + sign*(long double)x + sign*y;
418 if (!y) errno = ERANGE;
420 return scalbnl(y, e2);
423 long double __floatscan(FILE *f, int prec, int pok)
434 emin = FLT_MIN_EXP-bits;
438 emin = DBL_MIN_EXP-bits;
441 bits = LDBL_MANT_DIG;
442 emin = LDBL_MIN_EXP-bits;
448 while (isspace((c=shgetc(f))));
450 if (c=='+' || c=='-') {
455 for (i=0; i<8 && (c|32)=="infinity"[i]; i++)
456 if (i<7) c = shgetc(f);
457 if (i==3 || i==8 || (i>3 && pok)) {
460 if (pok) for (; i>3; i--) shunget(f);
462 return sign * INFINITY;
464 if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
465 if (i<2) c = shgetc(f);
467 if (shgetc(f) != '(') {
473 if (c-'0'<10U || c-'A'<26U || c-'a'<26U || c=='_')
475 if (c==')') return NAN;
482 while (i--) shunget(f);
498 return hexfloat(f, bits, emin, sign, pok);
503 return decfloat(f, c, bits, emin, sign, pok);