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-rw-r--r--src/internal/floatscan.c439
-rw-r--r--src/internal/floatscan.h8
-rw-r--r--src/internal/shgetc.c24
-rw-r--r--src/internal/shgetc.h25
-rw-r--r--src/internal/stdio_impl.h2
5 files changed, 498 insertions, 0 deletions
diff --git a/src/internal/floatscan.c b/src/internal/floatscan.c
new file mode 100644
index 00000000..b2313293
--- /dev/null
+++ b/src/internal/floatscan.c
@@ -0,0 +1,439 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <math.h>
+#include <float.h>
+#include <limits.h>
+#include <errno.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)
+
+
+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 && x<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=-1, dc=0;
+	long long e10=0;
+	int gotdig = 0;
+	int rp;
+	int e2;
+	long double y;
+	long double frac=0;
+	long double bias=0;
+
+	j=0;
+	k=0;
+
+	/* Don't let leading zeros consume buffer space */
+	for (; c=='0'; c = shgetc(f)) gotdig=1;
+
+	x[0] = 0;
+	for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
+		if (c == '.') {
+			if (lrp!=-1) break;
+			lrp = dc;
+		} else if (k < KMAX-2) {
+			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-3] |= 1;
+		}
+	}
+	if (lrp==-1) 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;
+	}
+
+	if (!x[0])
+		return sign * 0.0;
+	if (lrp==dc && (!k || (k==1 && !j)) && (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;
+	}
+
+	if (k<KMAX && j) {
+		for (; j<9; j++) x[k]*=10;
+		k++;
+		j=0;
+	}
+
+	a = 0;
+	z = k;
+	e2 = 0;
+	rp = lrp;
+
+	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];
+		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;
+	}
+
+	while (rp < 9*LD_B1B_DIG || (rp == 9*LD_B1B_DIG && x[0]<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;
+			if (a == z) {
+				z = (z-1 & MASK);
+				x[z-1 & MASK] |= x[z];
+			}
+			a = (a-1 & MASK);
+			x[a] = carry;
+		}
+	}
+
+	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 (i=0; (k=(a+i & MASK))!=z && i<LD_B1B_DIG+3; i++) {
+			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 && k==z) {
+			if ((z+1 & MASK) != a) {
+				x[z] = carry;
+				z = (z+1 & MASK);
+			} else x[z-1 & MASK] |= 1;
+		}
+	}
+
+	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;
+
+	if (bits > LDBL_MANT_DIG+e2-emin) {
+		bits = LDBL_MANT_DIG+e2-emin;
+		if (bits<0) bits=0;
+	}
+
+	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;
+	}
+
+	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;
+
+	y = scalbnl(y, e2);
+
+	if (!y) errno = ERANGE;
+
+	return y;
+}
+
+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 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 c, int prec, int pok)
+{
+	int sign = 1;
+	int i;
+	int bits;
+	int emin;
+
+	switch (prec) {
+	case 0:
+		bits = 24;
+		emin = -149;
+		break;
+	case 1:
+		bits = 53;
+		emin = -1074;
+		break;
+	case 2:
+		bits = LDBL_MANT_DIG;
+		emin = -16445;
+		break;
+	default:
+		return 0;
+	}
+
+	if (c<0) 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==3) shunget(f);
+		if (pok) for (; i>3; i--) shunget(f);
+		else shlim(f, 0);
+		return sign * INFINITY;
+	}
+	if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
+		if (i<3) c = shgetc(f);
+	if (i==3) {
+		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);
+}
diff --git a/src/internal/floatscan.h b/src/internal/floatscan.h
new file mode 100644
index 00000000..5595b81e
--- /dev/null
+++ b/src/internal/floatscan.h
@@ -0,0 +1,8 @@
+#ifndef FLOATSCAN_H
+#define FLOATSCAN_H
+
+#include <stdio.h>
+
+long double __floatscan(FILE *, int, int, int);
+
+#endif
diff --git a/src/internal/shgetc.c b/src/internal/shgetc.c
new file mode 100644
index 00000000..82e3a4fa
--- /dev/null
+++ b/src/internal/shgetc.c
@@ -0,0 +1,24 @@
+#include "shgetc.h"
+
+void __shlim(FILE *f, off_t lim)
+{
+	f->shlim = lim;
+	f->shcnt = f->rend - f->rpos;
+	if (lim && f->rend - f->rpos > lim)
+		f->shend = f->rpos + lim;
+	else
+		f->shend = f->rend;
+}
+
+int __shgetc(FILE *f)
+{
+	int c;
+	if (f->shcnt >= f->shlim) return EOF;
+	c = __uflow(f);
+	if (f->shlim && f->rend - f->rpos > f->shlim - f->shcnt - 1)
+		f->shend = f->rpos + (f->shlim - f->shcnt - 1);
+	else
+		f->shend = f->rend;
+	if (f->rend) f->shcnt += f->rend - f->buf;
+	return c;
+}
diff --git a/src/internal/shgetc.h b/src/internal/shgetc.h
new file mode 100644
index 00000000..3434cdaa
--- /dev/null
+++ b/src/internal/shgetc.h
@@ -0,0 +1,25 @@
+#include "stdio_impl.h"
+
+void __shlim(FILE *, off_t);
+int __shgetc(FILE *);
+
+static inline off_t shcnt(FILE *f)
+{
+	return f->shcnt + (f->rpos - f->rend);
+}
+
+static inline void shlim(FILE *f, off_t lim)
+{
+	__shlim(f, lim);
+}
+
+static inline int shgetc(FILE *f)
+{
+	if (f->rpos < f->shend) return *f->rpos++;
+	return __shgetc(f);
+}
+
+static inline void shunget(FILE *f)
+{
+	if (f->rend) f->rpos--;
+}
diff --git a/src/internal/stdio_impl.h b/src/internal/stdio_impl.h
index c5f45eb1..5ec296f3 100644
--- a/src/internal/stdio_impl.h
+++ b/src/internal/stdio_impl.h
@@ -59,6 +59,8 @@ struct __FILE_s {
 	off_t off;
 	int (*flush)(FILE *);
 	void *mustbezero_2;
+	unsigned char *shend;
+	off_t shlim, shcnt;
 };
 
 size_t __stdio_read(FILE *, unsigned char *, size_t);
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-11 19:16:49 +0000