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#include "floatscan.h"
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#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
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#define LD_B1B_MAX 9007199, 254740991
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#else /* LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 */
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#define LD_B1B_MAX 18, 446744073, 709551615
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#define CONCAT2(x,y) x ## y
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#define CONCAT(x,y) CONCAT2(x,y)
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static long long scanexp(FILE *f, int pok)
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if (c=='+' || c=='-') {
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if (c-'0'>=10U && pok) shunget(f);
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for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
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for (y=x; c-'0'<10U && y<LLONG_MAX/100; c = shgetc(f))
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for (; c-'0'<10U; c = shgetc(f));
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static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int pok)
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static const uint32_t th[] = { LD_B1B_MAX };
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long long lrp=0, dc=0;
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int gotdig = 0, gotrad = 0;
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int emax = -emin-bits+3;
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static const int p10s[] = { 10, 100, 1000, 10000,
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100000, 1000000, 10000000, 100000000 };
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/* Don't let leading zeros consume buffer space */
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for (; c=='0'; c = shgetc(f)) gotdig=1;
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for (c = shgetc(f); c=='0'; c = shgetc(f)) gotdig=1, lrp--;
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for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
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} else if (k < KMAX-3) {
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if (j) x[k] = x[k]*10 + c-'0';
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if (c!='0') x[KMAX-4] |= 1;
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if (gotdig && (c|32)=='e') {
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e10 = scanexp(f, pok);
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if (e10 == LLONG_MIN) {
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/* Handle zero specially to avoid nasty special cases later */
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if (!x[0]) return sign * 0.0;
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/* Optimize small integers (w/no exponent) and over/under-flow */
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if (lrp==dc && dc<10 && (bits>30 || x[0]>>bits==0))
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return sign * (long double)x[0];
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return sign * LDBL_MAX * LDBL_MAX;
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if (lrp < emin-2*LDBL_MANT_DIG) {
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return sign * LDBL_MIN * LDBL_MIN;
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/* Align incomplete final B1B digit */
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for (; j<9; j++) x[k]*=10;
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/* Optimize small to mid-size integers (even in exp. notation) */
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if (lnz<9 && lnz<=rp && rp < 18) {
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if (rp == 9) return sign * (long double)x[0];
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if (rp < 9) return sign * (long double)x[0] / p10s[8-rp];
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int bitlim = bits-3*(int)(rp-9);
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if (bitlim>30 || x[0]>>bitlim==0)
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return sign * (long double)x[0] * p10s[rp-10];
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/* Align radix point to B1B digit boundary */
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int rpm9 = rp>=0 ? rp%9 : rp%9+9;
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int p10 = p10s[8-rpm9];
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for (k=a; k!=z; k++) {
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uint32_t tmp = x[k] % p10;
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x[k] = x[k]/p10 + carry;
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carry = 1000000000/p10 * tmp;
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if (carry) x[z++] = carry;
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/* Upscale until desired number of bits are left of radix point */
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while (rp < 9*LD_B1B_DIG || (rp == 9*LD_B1B_DIG && x[a]<th[0])) {
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for (k=(z-1 & MASK); ; k=(k-1 & MASK)) {
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uint64_t tmp = ((uint64_t)x[k] << 29) + carry;
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if (tmp > 1000000000) {
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carry = tmp / 1000000000;
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x[k] = tmp % 1000000000;
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if (k==(z-1 & MASK) && k!=a && !x[k]) z = k;
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x[z-1 & MASK] |= x[z];
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/* Downscale until exactly number of bits are left of radix point */
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for (i=0; i<LD_B1B_DIG; i++) {
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if (k == z || x[k] < th[i]) {
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if (x[a+i & MASK] > th[i]) break;
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if (i==LD_B1B_DIG && rp==9*LD_B1B_DIG) break;
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/* FIXME: find a way to compute optimal sh */
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if (rp > 9+9*LD_B1B_DIG) sh = 9;
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for (k=a; k!=z; k=(k+1 & MASK)) {
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uint32_t tmp = x[k] & (1<<sh)-1;
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x[k] = (x[k]>>sh) + carry;
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carry = (1000000000>>sh) * tmp;
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if ((z+1 & MASK) != a) {
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} else x[z-1 & MASK] |= 1;
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/* Assemble desired bits into floating point variable */
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for (y=i=0; i<LD_B1B_DIG; i++) {
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if ((a+i & MASK)==z) x[(z=(z+1 & MASK))-1] = 0;
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y = 1000000000.0L * y + x[a+i & MASK];
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/* Limit precision for denormal results */
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if (bits > LDBL_MANT_DIG+e2-emin) {
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bits = LDBL_MANT_DIG+e2-emin;
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/* Calculate bias term to force rounding, move out lower bits */
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if (bits < LDBL_MANT_DIG) {
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bias = copysignl(scalbn(1, 2*LDBL_MANT_DIG-bits-1), y);
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frac = fmodl(y, scalbn(1, LDBL_MANT_DIG-bits));
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/* Process tail of decimal input so it can affect rounding */
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if ((a+i & MASK) != z) {
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uint32_t t = x[a+i & MASK];
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if (t < 500000000 && (t || (a+i+1 & MASK) != z))
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else if (t > 500000000)
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else if (t == 500000000) {
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if ((a+i+1 & MASK) == z)
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if (LDBL_MANT_DIG-bits >= 2 && !fmodl(frac, 1))
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if ((e2+LDBL_MANT_DIG & INT_MAX) > emax-5) {
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if (fabs(y) >= CONCAT(0x1p, LDBL_MANT_DIG)) {
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if (denormal && bits==LDBL_MANT_DIG+e2-emin)
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if (e2+LDBL_MANT_DIG>emax || (denormal && frac))
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return scalbnl(y, e2);
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static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
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long double scale = 1;
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long double bias = 0;
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int gottail = 0, gotrad = 0, gotdig = 0;
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/* Skip leading zeros */
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for (; c=='0'; c = shgetc(f)) gotdig = 1;
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/* Count zeros after the radix point before significand */
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for (rp=0; c=='0'; c = shgetc(f), rp--) gotdig = 1;
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for (; c-'0'<10U || (c|32)-'a'<6U || c=='.'; c = shgetc(f)) {
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if (c > '9') d = (c|32)+10-'a';
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} else if (dc < LDBL_MANT_DIG/4+1) {
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} else if (d && !gottail) {
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if (gotrad) shunget(f);
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if (!gotrad) rp = dc;
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while (dc<8) x *= 16, dc++;
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e2 = scanexp(f, pok);
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if (e2 == LLONG_MIN) {
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if (!x) return sign * 0.0;
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return sign * LDBL_MAX * LDBL_MAX;
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if (e2 < emin-2*LDBL_MANT_DIG) {
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return sign * LDBL_MIN * LDBL_MIN;
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while (x < 0x80000000) {
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if (bits > 32+e2-emin) {
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if (bits < LDBL_MANT_DIG)
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bias = copysignl(scalbn(1, 32+LDBL_MANT_DIG-bits-1), sign);
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if (bits<32 && y && !(x&1)) x++, y=0;
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y = bias + sign*(long double)x + sign*y;
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if (!y) errno = ERANGE;
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return scalbnl(y, e2);
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long double __floatscan(FILE *f, int prec, int pok)
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emin = FLT_MIN_EXP-bits;
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emin = DBL_MIN_EXP-bits;
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bits = LDBL_MANT_DIG;
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emin = LDBL_MIN_EXP-bits;
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while (isspace((c=shgetc(f))));
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if (c=='+' || c=='-') {
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for (i=0; i<8 && (c|32)=="infinity"[i]; i++)
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if (i<7) c = shgetc(f);
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if (i==3 || i==8 || (i>3 && pok)) {
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if (pok) for (; i>3; i--) shunget(f);
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return sign * INFINITY;
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if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
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if (i<2) c = shgetc(f);
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if (shgetc(f) != '(') {
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if (c-'0'<10U || c-'A'<26U || c-'a'<26U || c=='_')
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if (c==')') return NAN;
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while (i--) shunget(f);
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return hexfloat(f, bits, emin, sign, pok);
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return decfloat(f, c, bits, emin, sign, pok);