#include <math.h>
#include <float.h>
#include <limits.h>
+#include <errno.h>
#include "shgetc.h"
#include "floatscan.h"
}
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/10; c = shgetc(f))
+ for (y=x; c-'0'<10U && x<LLONG_MAX/100; c = shgetc(f))
y = 10*y + c-'0';
for (; c-'0'<10U; c = shgetc(f));
shunget(f);
}
-static long double decfloat(FILE *f, int bits, int emin, int sign, int pok)
+static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int pok)
{
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 e10=0;
+ int lnz = 0;
int gotdig = 0;
int rp;
int e2;
long double y;
long double frac=0;
long double bias=0;
- int c;
+ static const int p10s[] = { 10, 100, 1000, 10000,
+ 100000, 1000000, 10000000, 100000000 };
j=0;
k=0;
- c = shgetc(f);
-
/* Don't let leading zeros consume buffer space */
for (; c=='0'; c = shgetc(f)) gotdig=1;
if (c == '.') {
if (lrp!=-1) break;
lrp = dc;
- } else if (k < KMAX) {
+ } else if (k < KMAX-2) {
+ if (c!='0') lnz = dc;
dc++;
if (j) x[k] = x[k]*10 + c-'0';
else x[k] = c-'0';
gotdig=1;
} else {
dc++;
- x[KMAX-1] |= c-'0';
+ if (c!='0') x[KMAX-3] |= 1;
}
}
if (lrp==-1) lrp=dc;
shunget(f);
}
if (!gotdig) {
+ errno = EINVAL;
shlim(f, 0);
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)
+ if (lrp > -emin/2) {
+ errno = ERANGE;
return sign * LDBL_MAX * LDBL_MAX;
- if (lrp < emin-2*LDBL_MANT_DIG)
+ }
+ if (lrp < emin-2*LDBL_MANT_DIG) {
+ 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;
- while (rp < 18+9*LD_B1B_DIG) {
+ /* 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) {
+ int rpm9 = rp>=0 ? rp%9 : rp%9+9;
+ int p10 = p10s[8-rpm9];
+ uint32_t carry = 0;
+ for (k=a; k!=z; k++) {
+ uint32_t tmp = x[k] % p10;
+ x[k] = x[k]/p10 + carry;
+ carry = 1000000000/p10 * tmp;
+ if (k==a && !x[k]) {
+ a = (a+1 & MASK);
+ rp -= 9;
+ }
+ }
+ if (carry) x[z++] = carry;
+ rp += 9-rpm9;
+ }
+
+ /* 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)) {
}
}
- if (rp % 9) {
- static const int p10s[] = {
- 100000000, 10000000, 1000000, 100000,
- 10000, 1000, 100, 10
- };
- int rpm9 = rp % 9;
- int p10 = p10s[rpm9-1];
- uint32_t carry = 0;
- for (k=a; k!=z; k=(k+1 & MASK)) {
- uint32_t tmp = x[k] % p10;
- x[k] = x[k]/p10 + carry;
- carry = 1000000000/p10 * tmp;
- if (k==a && !x[k]) {
- a = (a+1 & MASK);
- rp -= 9;
- }
- }
- if (carry) {
- if ((z+1 & MASK) != a) {
- x[z] = carry;
- z = (z+1 & MASK);
- } else x[z-1 & MASK] |= 1;
- }
- rp += 9-rpm9;
- }
-
+ /* 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;
}
}
}
}
- for (y=i=0; i<LD_B1B_DIG && (a+i & MASK)!=z; i++)
+ /* 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;
}
+ /* 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 = scalbnl(y, e2);
+ if (!y) errno = ERANGE;
+
return y;
}
}
e2 = 0;
}
+ } else {
+ shunget(f);
}
e2 += 4*rp - 32;
if (!x) return sign * 0.0;
- if (e2 > -emin) return sign * LDBL_MAX * LDBL_MAX;
- if (e2 < emin-2*LDBL_MANT_DIG) return sign * LDBL_MIN * LDBL_MIN;
+ if (e2 > -emin) {
+ errno = ERANGE;
+ return sign * LDBL_MAX * LDBL_MAX;
+ }
+ if (e2 < emin-2*LDBL_MANT_DIG) {
+ errno = ERANGE;
+ return sign * LDBL_MIN * LDBL_MIN;
+ }
while (x < 0x80000000) {
if (y>=0.5) {
y = bias + sign*(long double)x + sign*y;
y -= bias;
+ if (!y) errno = ERANGE;
+
return scalbnl(y, e2);
}
if (i) {
shunget(f);
+ errno = EINVAL;
shlim(f, 0);
return 0;
}
c = shgetc(f);
if ((c|32) == 'x')
return hexfloat(f, bits, emin, sign, pok);
+ shunget(f);
c = '0';
}
- shunget(f);
- return decfloat(f, bits, emin, sign, pok);
+ return decfloat(f, c, bits, emin, sign, pok);
}
projects / musl / blobdiff