#define MASK (KMAX-1)
+#define CONCAT2(x,y) x ## y
+#define CONCAT(x,y) CONCAT2(x,y)
static long long scanexp(FILE *f, int pok)
{
}
for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
x = 10*x + c-'0';
- for (y=x; c-'0'<10U && x<LLONG_MAX/100; c = shgetc(f))
+ for (y=x; c-'0'<10U && y<LLONG_MAX/100; c = shgetc(f))
y = 10*y + c-'0';
for (; c-'0'<10U; c = shgetc(f));
shunget(f);
uint32_t x[KMAX];
static const uint32_t th[] = { LD_B1B_MAX };
int i, j, k, a, z;
- long long lrp=-1, dc=0;
+ long long lrp=0, dc=0;
long long e10=0;
- int gotdig = 0;
+ int lnz = 0;
+ int gotdig = 0, gotrad = 0;
int rp;
int e2;
+ int emax = -emin-bits+3;
+ int denormal = 0;
long double y;
long double frac=0;
long double bias=0;
+ static const int p10s[] = { 10, 100, 1000, 10000,
+ 100000, 1000000, 10000000, 100000000 };
j=0;
k=0;
/* Don't let leading zeros consume buffer space */
for (; c=='0'; c = shgetc(f)) gotdig=1;
+ if (c=='.') {
+ gotrad = 1;
+ for (c = shgetc(f); c=='0'; c = shgetc(f)) gotdig=1, lrp--;
+ }
x[0] = 0;
for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
if (c == '.') {
- if (lrp!=-1) break;
+ if (gotrad) break;
+ gotrad = 1;
lrp = dc;
} else if (k < KMAX-2) {
dc++;
+ if (c!='0') lnz = dc;
if (j) x[k] = x[k]*10 + c-'0';
else x[k] = c-'0';
if (++j==9) {
if (c!='0') x[KMAX-3] |= 1;
}
}
- if (lrp==-1) lrp=dc;
+ if (!gotrad) lrp=dc;
if (gotdig && (c|32)=='e') {
e10 = scanexp(f, pok);
return 0;
}
- if (!x[0])
- return sign * 0.0;
- if (lrp==dc && (!k || (k==1 && !j)) && (bits>30 || x[0]>>bits==0))
+ /* Handle zero specially to avoid nasty special cases later */
+ if (!x[0]) return sign * 0.0;
+
+ /* Optimize small integers (w/no exponent) and over/under-flow */
+ if (lrp==dc && dc<10 && (bits>30 || x[0]>>bits==0))
return sign * (long double)x[0];
if (lrp > -emin/2) {
errno = ERANGE;
return sign * LDBL_MIN * LDBL_MIN;
}
+ /* Align incomplete final B1B digit */
if (k<KMAX && j) {
for (; j<9; j++) x[k]*=10;
k++;
e2 = 0;
rp = lrp;
+ /* Optimize small to mid-size integers (even in exp. notation) */
+ if (lnz<9 && lnz<=rp && rp < 18) {
+ if (rp == 9) return sign * (long double)x[0];
+ if (rp < 9) return sign * (long double)x[0] / p10s[8-rp];
+ int bitlim = bits-3*(int)(rp-9);
+ if (bitlim>30 || x[0]>>bitlim==0)
+ return sign * (long double)x[0] * p10s[rp-10];
+ }
+
+ /* Align radix point to B1B digit boundary */
if (rp % 9) {
- static const int p10s[] = {
- 100000000, 10000000, 1000000, 100000,
- 10000, 1000, 100, 10
- };
int rpm9 = rp>=0 ? rp%9 : rp%9+9;
- int p10 = p10s[rpm9-1];
+ int p10 = p10s[8-rpm9];
uint32_t carry = 0;
for (k=a; k!=z; k++) {
uint32_t tmp = x[k] % p10;
rp += 9-rpm9;
}
- while (rp < 9*LD_B1B_DIG || (rp == 9*LD_B1B_DIG && x[0]<th[0])) {
+ /* Upscale until desired number of bits are left of radix point */
+ while (rp < 9*LD_B1B_DIG || (rp == 9*LD_B1B_DIG && x[a]<th[0])) {
uint32_t carry = 0;
e2 -= 29;
for (k=(z-1 & MASK); ; k=(k-1 & MASK)) {
}
}
+ /* Downscale until exactly number of bits are left of radix point */
for (;;) {
uint32_t carry = 0;
int sh = 1;
carry = (1000000000>>sh) * tmp;
if (k==a && !x[k]) {
a = (a+1 & MASK);
+ i--;
rp -= 9;
}
}
}
}
+ /* Assemble desired bits into floating point variable */
for (y=i=0; i<LD_B1B_DIG; i++) {
if ((a+i & MASK)==z) x[z=(z+1 & MASK)] = 0;
y = 1000000000.0L * y + x[a+i & MASK];
y *= sign;
+ /* Limit precision for denormal results */
if (bits > LDBL_MANT_DIG+e2-emin) {
bits = LDBL_MANT_DIG+e2-emin;
if (bits<0) bits=0;
+ denormal = 1;
}
+ /* Calculate bias term to force rounding, move out lower bits */
if (bits < LDBL_MANT_DIG) {
bias = copysignl(scalbn(1, 2*LDBL_MANT_DIG-bits-1), y);
frac = fmodl(y, scalbn(1, LDBL_MANT_DIG-bits));
y += bias;
}
+ /* Process tail of decimal input so it can affect rounding */
if ((a+i & MASK) != z) {
uint32_t t = x[a+i & MASK];
if (t < 500000000 && (t || (a+i+1 & MASK) != z))
y += frac;
y -= bias;
- y = scalbnl(y, e2);
-
- if (!y) errno = ERANGE;
+ if ((e2+LDBL_MANT_DIG & INT_MAX) > emax-5) {
+ if (fabs(y) >= CONCAT(0x1p, LDBL_MANT_DIG)) {
+ if (denormal && bits==LDBL_MANT_DIG+e2-emin)
+ denormal = 0;
+ y *= 0.5;
+ e2++;
+ }
+ if (e2+LDBL_MANT_DIG>emax || (denormal && frac))
+ errno = ERANGE;
+ }
- return y;
+ return scalbnl(y, e2);
}
static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
return scalbnl(y, e2);
}
-long double __floatscan(FILE *f, int c, int prec, int pok)
+long double __floatscan(FILE *f, int prec, int pok)
{
int sign = 1;
int i;
int bits;
int emin;
+ int c;
switch (prec) {
case 0:
- bits = 24;
- emin = -149;
+ bits = FLT_MANT_DIG;
+ emin = FLT_MIN_EXP-bits;
break;
case 1:
- bits = 53;
- emin = -1074;
+ bits = DBL_MANT_DIG;
+ emin = DBL_MIN_EXP-bits;
break;
case 2:
bits = LDBL_MANT_DIG;
- emin = -16445;
+ emin = LDBL_MIN_EXP-bits;
break;
default:
return 0;
}
- if (c<0) c = shgetc(f);
+ while (isspace((c=shgetc(f))));
if (c=='+' || c=='-') {
sign -= 2*(c=='-');
for (i=0; i<8 && (c|32)=="infinity"[i]; i++)
if (i<7) c = shgetc(f);
if (i==3 || i==8 || (i>3 && pok)) {
- if (i==3) shunget(f);
- if (pok) for (; i>3; i--) shunget(f);
- else shlim(f, 0);
+ if (i!=8) {
+ shunget(f);
+ if (pok) for (; i>3; i--) shunget(f);
+ }
return sign * INFINITY;
}
if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
- if (i<3) c = shgetc(f);
+ if (i<2) c = shgetc(f);
if (i==3) {
return NAN;
}
projects / musl / blobdiff