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-rw-r--r--system/lib/libc/musl/src/internal/floatscan.c496
1 files changed, 496 insertions, 0 deletions
diff --git a/system/lib/libc/musl/src/internal/floatscan.c b/system/lib/libc/musl/src/internal/floatscan.c
new file mode 100644
index 00000000..f6e331d4
--- /dev/null
+++ b/system/lib/libc/musl/src/internal/floatscan.c
@@ -0,0 +1,496 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <math.h>
+#include <float.h>
+#include <limits.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include "shgetc.h"
+#include "floatscan.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+
+#define LD_B1B_DIG 2
+#define LD_B1B_MAX 9007199, 254740991
+#define KMAX 128
+
+#else /* LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 */
+
+#define LD_B1B_DIG 3
+#define LD_B1B_MAX 18, 446744073, 709551615
+#define KMAX 2048
+
+#endif
+
+#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)
+{
+ int c;
+ int x;
+ long long y;
+ int neg = 0;
+
+ c = shgetc(f);
+ if (c=='+' || c=='-') {
+ neg = (c=='-');
+ c = shgetc(f);
+ if (c-'0'>=10U && pok) shunget(f);
+ }
+ if (c-'0'>=10U) {
+ shunget(f);
+ return LLONG_MIN;
+ }
+ for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
+ x = 10*x + c-'0';
+ 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);
+ return neg ? -y : y;
+}
+
+
+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=0, dc=0;
+ long long e10=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 (gotrad) break;
+ gotrad = 1;
+ lrp = dc;
+ } else if (k < KMAX-3) {
+ dc++;
+ if (c!='0') lnz = dc;
+ if (j) x[k] = x[k]*10 + c-'0';
+ else x[k] = c-'0';
+ if (++j==9) {
+ k++;
+ j=0;
+ }
+ gotdig=1;
+ } else {
+ dc++;
+ if (c!='0') x[KMAX-4] |= 1;
+ }
+ }
+ if (!gotrad) lrp=dc;
+
+ if (gotdig && (c|32)=='e') {
+ e10 = scanexp(f, pok);
+ if (e10 == LLONG_MIN) {
+ if (pok) {
+ shunget(f);
+ } else {
+ shlim(f, 0);
+ return 0;
+ }
+ e10 = 0;
+ }
+ lrp += e10;
+ } else if (c>=0) {
+ shunget(f);
+ }
+ if (!gotdig) {
+ errno = EINVAL;
+ shlim(f, 0);
+ return 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_MAX * LDBL_MAX;
+ }
+ if (lrp < emin-2*LDBL_MANT_DIG) {
+ errno = ERANGE;
+ return sign * LDBL_MIN * LDBL_MIN;
+ }
+
+ /* Align incomplete final B1B digit */
+ if (j) {
+ for (; j<9; j++) x[k]*=10;
+ k++;
+ j=0;
+ }
+
+ a = 0;
+ z = 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) {
+ 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)) {
+ uint64_t tmp = ((uint64_t)x[k] << 29) + carry;
+ if (tmp > 1000000000) {
+ carry = tmp / 1000000000;
+ x[k] = tmp % 1000000000;
+ } else {
+ carry = 0;
+ x[k] = tmp;
+ }
+ if (k==(z-1 & MASK) && k!=a && !x[k]) z = k;
+ if (k==a) break;
+ }
+ if (carry) {
+ rp += 9;
+ a = (a-1 & MASK);
+ if (a == z) {
+ z = (z-1 & MASK);
+ x[z-1 & MASK] |= x[z];
+ }
+ x[a] = carry;
+ }
+ }
+
+ /* Downscale until exactly number of bits are left of radix point */
+ for (;;) {
+ uint32_t carry = 0;
+ int sh = 1;
+ for (i=0; i<LD_B1B_DIG; i++) {
+ k = (a+i & MASK);
+ if (k == z || x[k] < th[i]) {
+ i=LD_B1B_DIG;
+ break;
+ }
+ if (x[a+i & MASK] > th[i]) break;
+ }
+ if (i==LD_B1B_DIG && rp==9*LD_B1B_DIG) break;
+ /* FIXME: find a way to compute optimal sh */
+ if (rp > 9+9*LD_B1B_DIG) sh = 9;
+ e2 += sh;
+ for (k=a; k!=z; k=(k+1 & MASK)) {
+ uint32_t tmp = x[k] & (1<<sh)-1;
+ x[k] = (x[k]>>sh) + carry;
+ carry = (1000000000>>sh) * tmp;
+ if (k==a && !x[k]) {
+ a = (a+1 & MASK);
+ i--;
+ rp -= 9;
+ }
+ }
+ if (carry) {
+ if ((z+1 & MASK) != a) {
+ x[z] = carry;
+ z = (z+1 & MASK);
+ } else x[z-1 & MASK] |= 1;
+ }
+ }
+
+ /* 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))-1] = 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 -= frac;
+ 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))
+ frac += 0.25*sign;
+ else if (t > 500000000)
+ frac += 0.75*sign;
+ else if (t == 500000000) {
+ if ((a+i+1 & MASK) == z)
+ frac += 0.5*sign;
+ else
+ frac += 0.75*sign;
+ }
+ if (LDBL_MANT_DIG-bits >= 2 && !fmodl(frac, 1))
+ frac++;
+ }
+
+ y += frac;
+ y -= bias;
+
+ 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 scalbnl(y, e2);
+}
+
+static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
+{
+ uint32_t x = 0;
+ long double y = 0;
+ long double scale = 1;
+ long double bias = 0;
+ int gottail = 0, gotrad = 0, gotdig = 0;
+ long long rp = 0;
+ long long dc = 0;
+ long long e2 = 0;
+ int d;
+ int c;
+
+ c = shgetc(f);
+
+ /* Skip leading zeros */
+ for (; c=='0'; c = shgetc(f)) gotdig = 1;
+
+ if (c=='.') {
+ gotrad = 1;
+ c = shgetc(f);
+ /* Count zeros after the radix point before significand */
+ for (rp=0; c=='0'; c = shgetc(f), rp--) gotdig = 1;
+ }
+
+ for (; c-'0'<10U || (c|32)-'a'<6U || c=='.'; c = shgetc(f)) {
+ if (c=='.') {
+ if (gotrad) break;
+ rp = dc;
+ gotrad = 1;
+ } else {
+ gotdig = 1;
+ if (c > '9') d = (c|32)+10-'a';
+ else d = c-'0';
+ if (dc<8) {
+ x = x*16 + d;
+ } else if (dc < LDBL_MANT_DIG/4+1) {
+ y += d*(scale/=16);
+ } else if (d && !gottail) {
+ y += 0.5*scale;
+ gottail = 1;
+ }
+ dc++;
+ }
+ }
+ if (!gotdig) {
+ shunget(f);
+ if (pok) {
+ shunget(f);
+ if (gotrad) shunget(f);
+ } else {
+ shlim(f, 0);
+ }
+ return sign * 0.0;
+ }
+ if (!gotrad) rp = dc;
+ while (dc<8) x *= 16, dc++;
+ if ((c|32)=='p') {
+ e2 = scanexp(f, pok);
+ if (e2 == LLONG_MIN) {
+ if (pok) {
+ shunget(f);
+ } else {
+ shlim(f, 0);
+ return 0;
+ }
+ e2 = 0;
+ }
+ } else {
+ shunget(f);
+ }
+ e2 += 4*rp - 32;
+
+ if (!x) return sign * 0.0;
+ 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) {
+ x += x + 1;
+ y += y - 1;
+ } else {
+ x += x;
+ y += y;
+ }
+ e2--;
+ }
+
+ if (bits > 32+e2-emin) {
+ bits = 32+e2-emin;
+ if (bits<0) bits=0;
+ }
+
+ if (bits < LDBL_MANT_DIG)
+ bias = copysignl(scalbn(1, 32+LDBL_MANT_DIG-bits-1), sign);
+
+ if (bits<32 && y && !(x&1)) x++, y=0;
+
+ y = bias + sign*(long double)x + sign*y;
+ y -= bias;
+
+ if (!y) errno = ERANGE;
+
+ return scalbnl(y, e2);
+}
+
+long double __floatscan(FILE *f, int prec, int pok)
+{
+ int sign = 1;
+ size_t i;
+ int bits;
+ int emin;
+ int c;
+
+ switch (prec) {
+ case 0:
+ bits = FLT_MANT_DIG;
+ emin = FLT_MIN_EXP-bits;
+ break;
+ case 1:
+ bits = DBL_MANT_DIG;
+ emin = DBL_MIN_EXP-bits;
+ break;
+ case 2:
+ bits = LDBL_MANT_DIG;
+ emin = LDBL_MIN_EXP-bits;
+ break;
+ default:
+ return 0;
+ }
+
+ while (isspace((c=shgetc(f))));
+
+ if (c=='+' || c=='-') {
+ sign -= 2*(c=='-');
+ c = shgetc(f);
+ }
+
+ 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!=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<2) c = shgetc(f);
+ if (i==3) {
+ if (shgetc(f) != '(') {
+ shunget(f);
+ return NAN;
+ }
+ for (i=1; ; i++) {
+ c = shgetc(f);
+ if (c-'0'<10U || c-'A'<26U || c-'a'<26U || c=='_')
+ continue;
+ if (c==')') return NAN;
+ shunget(f);
+ if (!pok) {
+ errno = EINVAL;
+ shlim(f, 0);
+ return 0;
+ }
+ while (i--) shunget(f);
+ return NAN;
+ }
+ return NAN;
+ }
+
+ if (i) {
+ shunget(f);
+ errno = EINVAL;
+ shlim(f, 0);
+ return 0;
+ }
+
+ if (c=='0') {
+ c = shgetc(f);
+ if ((c|32) == 'x')
+ return hexfloat(f, bits, emin, sign, pok);
+ shunget(f);
+ c = '0';
+ }
+
+ return decfloat(f, c, bits, emin, sign, pok);
+}
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