Merge pull request #2094 from ziglang/f128-decimal-literal

float literals now parse using musl's 128 bit float code

1 files changed, 1039 insertions, 0 deletions

diff --git a/src/parse_f128.c b/src/parse_f128.c
new file mode 100644
index 0000000000..bba45e0026
--- /dev/null
+++ b/src/parse_f128.c
@@ -0,0 +1,1039 @@
+// Code ported from musl libc 8f12c4e110acb3bbbdc8abfb3a552c3ced718039
+// and then modified to use softfloat and to assume f128 for everything
+
+#include "parse_f128.h"
+#include "softfloat.h"
+#include <stddef.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <limits.h>
+#include <string.h>
+#include <math.h>
+
+#define shcnt(f) ((f)->shcnt + ((f)->rpos - (f)->buf))
+#define shlim(f, lim) __shlim((f), (lim))
+#define shgetc(f) (((f)->rpos != (f)->shend) ? *(f)->rpos++ : __shgetc(f))
+#define shunget(f) ((f)->shlim>=0 ? (void)(f)->rpos-- : (void)0)
+
+#define sh_fromstring(f, s) \
+	((f)->buf = (f)->rpos = (void *)(s), (f)->rend = (void*)-1)
+
+#define LD_B1B_DIG 4
+#define LD_B1B_MAX 10384593, 717069655, 257060992, 658440191
+#define KMAX 2048
+
+#define MASK (KMAX-1)
+
+#define CONCAT2(x,y) x ## y
+#define CONCAT(x,y) CONCAT2(x,y)
+
+#define F_PERM 1
+#define F_NORD 4
+#define F_NOWR 8
+#define F_EOF 16
+#define F_ERR 32
+#define F_SVB 64
+#define F_APP 128
+
+#define EOF (-1)
+
+#define LDBL_MANT_DIG 113
+#define LDBL_MIN_EXP (-16381)
+#define LDBL_MAX_EXP 16384
+
+#define LDBL_DIG 33
+#define LDBL_MIN_10_EXP (-4931)
+#define LDBL_MAX_10_EXP 4932
+
+#define DECIMAL_DIG 36
+
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+union ldshape {
+	float128_t f;
+	struct {
+		uint64_t lo;
+		uint32_t mid;
+		uint16_t top;
+		uint16_t se;
+	} i;
+	struct {
+		uint64_t lo;
+		uint64_t hi;
+	} i2;
+};
+#elif __BYTE_ORDER == __BIG_ENDIAN
+union ldshape {
+	float128_t f;
+	struct {
+		uint16_t se;
+		uint16_t top;
+		uint32_t mid;
+		uint64_t lo;
+	} i;
+	struct {
+		uint64_t hi;
+		uint64_t lo;
+	} i2;
+};
+#error Unsupported endian
+#endif
+
+struct MuslFILE {
+	unsigned flags;
+	unsigned char *rpos, *rend;
+	int (*close)(struct MuslFILE *);
+	unsigned char *wend, *wpos;
+	unsigned char *mustbezero_1;
+	unsigned char *wbase;
+	size_t (*read)(struct MuslFILE *, unsigned char *, size_t);
+	size_t (*write)(struct MuslFILE *, const unsigned char *, size_t);
+	off_t (*seek)(struct MuslFILE *, off_t, int);
+	unsigned char *buf;
+	size_t buf_size;
+	struct MuslFILE *prev, *next;
+	int fd;
+	int pipe_pid;
+	long lockcount;
+	int mode;
+	volatile int lock;
+	int lbf;
+	void *cookie;
+	off_t off;
+	char *getln_buf;
+	void *mustbezero_2;
+	unsigned char *shend;
+	off_t shlim, shcnt;
+	struct MuslFILE *prev_locked, *next_locked;
+	struct __locale_struct *locale;
+};
+
+static void __shlim(struct MuslFILE *f, off_t lim)
+{
+	f->shlim = lim;
+	f->shcnt = f->buf - f->rpos;
+	/* If lim is nonzero, rend must be a valid pointer. */
+	if (lim && f->rend - f->rpos > lim)
+		f->shend = f->rpos + lim;
+	else
+		f->shend = f->rend;
+}
+
+static int __toread(struct MuslFILE *f)
+{
+	f->mode |= f->mode-1;
+	if (f->wpos != f->wbase) f->write(f, 0, 0);
+	f->wpos = f->wbase = f->wend = 0;
+	if (f->flags & F_NORD) {
+		f->flags |= F_ERR;
+		return EOF;
+	}
+	f->rpos = f->rend = f->buf + f->buf_size;
+	return (f->flags & F_EOF) ? EOF : 0;
+}
+
+static int __uflow(struct MuslFILE *f)
+{
+	unsigned char c;
+	if (!__toread(f) && f->read(f, &c, 1)==1) return c;
+	return EOF;
+}
+
+static int __shgetc(struct MuslFILE *f)
+{
+	int c;
+	off_t cnt = shcnt(f);
+	if (f->shlim && cnt >= f->shlim || (c=__uflow(f)) < 0) {
+		f->shcnt = f->buf - f->rpos + cnt;
+		f->shend = f->rpos;
+		f->shlim = -1;
+		return EOF;
+	}
+	cnt++;
+	if (f->shlim && f->rend - f->rpos > f->shlim - cnt)
+		f->shend = f->rpos + (f->shlim - cnt);
+	else
+		f->shend = f->rend;
+	f->shcnt = f->buf - f->rpos + cnt;
+	if (f->rpos[-1] != c) f->rpos[-1] = c;
+	return c;
+}
+
+static long long scanexp(struct MuslFILE *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 float128_t copysignf128(float128_t x, float128_t y)
+{
+	union ldshape ux = {x}, uy = {y};
+	ux.i.se &= 0x7fff;
+	ux.i.se |= uy.i.se & 0x8000;
+	return ux.f;
+}
+
+static void mul_eq_f128_float(float128_t *x, float op_float) {
+    //x *= 0x1p120f;
+    float32_t op_f32;
+    memcpy(&op_f32, &op_float, sizeof(float));
+    float128_t op_f128;
+    f32_to_f128M(op_f32, &op_f128);
+    float128_t new_value;
+    f128M_mul(x, &op_f128, &new_value);
+    *x = new_value;
+}
+
+static float128_t dbl_to_f128(double x) {
+    float64_t x_f64;
+    memcpy(&x_f64, &x, sizeof(double));
+    float128_t result;
+    f64_to_f128M(x_f64, &result);
+    return result;
+}
+
+static float128_t fmodf128(float128_t x, float128_t y)
+{
+	union ldshape ux = {x}, uy = {y};
+	int ex = ux.i.se & 0x7fff;
+	int ey = uy.i.se & 0x7fff;
+	int sx = ux.i.se & 0x8000;
+
+    float128_t zero;
+    ui32_to_f128M(0, &zero);
+    // if (y == 0 || isnan(y) || ex == 0x7fff)
+	if (f128M_eq(&y, &zero) || f128M_isSignalingNaN(&y) || ex == 0x7fff) {
+		//return (x*y)/(x*y);
+        float128_t x_times_y;
+        f128M_mul(&x, &y, &x_times_y);
+        float128_t result;
+        f128M_div(&x_times_y, &x_times_y, &result);
+        return result;
+    }
+	ux.i.se = ex;
+	uy.i.se = ey;
+	//if (ux.f <= uy.f) {
+    if (f128M_le(&ux.f, &uy.f)) {
+		//if (ux.f == uy.f) {
+		if (f128M_eq(&ux.f, &uy.f)) {
+			//return 0*x;
+            float128_t result;
+            f128M_mul(&zero, &x, &result);
+            return result;
+        }
+		return x;
+	}
+
+	/* normalize x and y */
+	if (!ex) {
+		//ux.f *= 0x1p120f;
+        mul_eq_f128_float(&ux.f, 0x1p120f);
+
+		ex = ux.i.se - 120;
+	}
+	if (!ey) {
+		//uy.f *= 0x1p120f;
+        mul_eq_f128_float(&uy.f, 0x1p120f);
+
+		ey = uy.i.se - 120;
+	}
+
+	/* x mod y */
+	uint64_t hi, lo, xhi, xlo, yhi, ylo;
+	xhi = (ux.i2.hi & -1ULL>>16) | 1ULL<<48;
+	yhi = (uy.i2.hi & -1ULL>>16) | 1ULL<<48;
+	xlo = ux.i2.lo;
+	ylo = uy.i2.lo;
+	for (; ex > ey; ex--) {
+		hi = xhi - yhi;
+		lo = xlo - ylo;
+		if (xlo < ylo)
+			hi -= 1;
+		if (hi >> 63 == 0) {
+			if ((hi|lo) == 0) {
+				//return 0*x;
+                float128_t result;
+                f128M_mul(&zero, &x, &result);
+                return result;
+            }
+			xhi = 2*hi + (lo>>63);
+			xlo = 2*lo;
+		} else {
+			xhi = 2*xhi + (xlo>>63);
+			xlo = 2*xlo;
+		}
+	}
+	hi = xhi - yhi;
+	lo = xlo - ylo;
+	if (xlo < ylo)
+		hi -= 1;
+	if (hi >> 63 == 0) {
+		if ((hi|lo) == 0) {
+			//return 0*x;
+            float128_t result;
+            f128M_mul(&zero, &x, &result);
+            return result;
+        }
+		xhi = hi;
+		xlo = lo;
+	}
+	for (; xhi >> 48 == 0; xhi = 2*xhi + (xlo>>63), xlo = 2*xlo, ex--);
+	ux.i2.hi = xhi;
+	ux.i2.lo = xlo;
+
+	/* scale result */
+	if (ex <= 0) {
+		ux.i.se = (ex+120)|sx;
+		//ux.f *= 0x1p-120f;
+		mul_eq_f128_float(&ux.f, 0x1p-120f);
+	} else
+		ux.i.se = ex|sx;
+	return ux.f;
+}
+
+static float128_t int_mul_f128_cast_u32(int sign, uint32_t x0) {
+    float128_t x0_f128;
+    ui32_to_f128M(x0, &x0_f128);
+    float128_t sign_f128;
+    i32_to_f128M(sign, &sign_f128);
+    float128_t result;
+    f128M_mul(&sign_f128, &x0_f128, &result);
+    return result;
+}
+
+static float128_t triple_divide(int sign, uint32_t x0, int p10s) {
+    float128_t part1 = int_mul_f128_cast_u32(sign, x0);
+    float128_t p10s_f128;
+    i32_to_f128M(p10s, &p10s_f128);
+    float128_t result;
+    f128M_div(&part1, &p10s_f128, &result);
+    return result;
+}
+
+static float128_t triple_multiply(int sign, uint32_t x0, int p10s) {
+    float128_t part1 = int_mul_f128_cast_u32(sign, x0);
+    float128_t p10s_f128;
+    i32_to_f128M(p10s, &p10s_f128);
+    float128_t result;
+    f128M_mul(&part1, &p10s_f128, &result);
+    return result;
+}
+
+static void mul_eq_f128_int(float128_t *y, int sign) {
+    float128_t sign_f128;
+    i32_to_f128M(sign, &sign_f128);
+    float128_t new_value;
+    f128M_mul(y, &sign_f128, &new_value);
+    *y = new_value;
+}
+
+static float128_t make_f128(uint64_t hi, uint64_t lo) {
+	union ldshape ux;
+    ux.i2.hi = hi;
+    ux.i2.lo = lo;
+    return ux.f;
+}
+
+static void mul_eq_f128_f128(float128_t *a, float128_t b) {
+    float128_t new_value;
+    f128M_mul(a, &b, &new_value);
+    *a = new_value;
+}
+
+static void add_eq_f128_dbl(float128_t *a, double b) {
+    float64_t b_f64;
+    memcpy(&b_f64, &b, sizeof(double));
+
+    float128_t b_f128;
+    f64_to_f128M(b_f64, &b_f128);
+
+    float128_t new_value;
+    f128M_add(a, &b_f128, &new_value);
+    *a = new_value;
+}
+
+static float128_t scalbnf128(float128_t x, int n)
+{
+	union ldshape u;
+
+	if (n > 16383) {
+		//x *= 0x1p16383q;
+        mul_eq_f128_f128(&x, make_f128(0x7ffe000000000000, 0x0000000000000000));
+		n -= 16383;
+		if (n > 16383) {
+			//x *= 0x1p16383q;
+            mul_eq_f128_f128(&x, make_f128(0x7ffe000000000000, 0x0000000000000000));
+			n -= 16383;
+			if (n > 16383)
+				n = 16383;
+		}
+	} else if (n < -16382) {
+		//x *= 0x1p-16382q * 0x1p113q;
+        {
+            float128_t mul_result;
+            float128_t a = make_f128(0x0001000000000000, 0x0000000000000000);
+            float128_t b = make_f128(0x4070000000000000, 0x0000000000000000);
+            f128M_mul(&a, &b, &mul_result);
+            mul_eq_f128_f128(&x, mul_result);
+        }
+		n += 16382 - 113;
+		if (n < -16382) {
+			//x *= 0x1p-16382q * 0x1p113q;
+            {
+                float128_t mul_result;
+                float128_t a = make_f128(0x0001000000000000, 0x0000000000000000);
+                float128_t b = make_f128(0x4070000000000000, 0x0000000000000000);
+                f128M_mul(&a, &b, &mul_result);
+                mul_eq_f128_f128(&x, mul_result);
+            }
+			n += 16382 - 113;
+			if (n < -16382)
+				n = -16382;
+		}
+	}
+	//u.f = 1.0;
+    ui32_to_f128M(1, &u.f);
+	u.i.se = 0x3fff + n;
+    mul_eq_f128_f128(&x, u.f);
+    return x;
+}
+
+static float128_t fabsf128(float128_t x)
+{
+	union ldshape u = {x};
+
+	u.i.se &= 0x7fff;
+	return u.f;
+}
+
+static float128_t decfloat(struct MuslFILE *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;
+	float128_t y;
+    float128_t zero;
+    ui32_to_f128M(0, &zero);
+	float128_t frac=zero;
+	float128_t bias=zero;
+	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') {
+				lnz = (KMAX-4)*9;
+				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 zero;
+			}
+			e10 = 0;
+		}
+		lrp += e10;
+	} else if (c>=0) {
+		shunget(f);
+	}
+	if (!gotdig) {
+		errno = EINVAL;
+		shlim(f, 0);
+		return zero;
+	}
+
+	/* Handle zero specially to avoid nasty special cases later */
+	if (!x[0]) {
+        //return sign * 0.0;
+        return dbl_to_f128(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 * (float128_t)x[0];
+        float128_t sign_f128;
+        i32_to_f128M(sign, &sign_f128);
+        float128_t x0_f128;
+        ui32_to_f128M(x[0], &x0_f128);
+        float128_t result;
+        f128M_mul(&sign_f128, &x0_f128, &result);
+        return result;
+    }
+	if (lrp > -emin/2) {
+		errno = ERANGE;
+		//return sign * LDBL_MAX * LDBL_MAX;
+		return zero;
+	}
+	if (lrp < emin-2*LDBL_MANT_DIG) {
+		errno = ERANGE;
+		//return sign * LDBL_MIN * LDBL_MIN;
+		return zero;
+	}
+
+	/* 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 * (float128_t)(x[0]);
+            return int_mul_f128_cast_u32(sign, x[0]);
+        }
+		if (rp < 9) {
+            //return sign * (float128_t)(x[0]) / p10s[8-rp];
+            return triple_divide(sign, x[0], p10s[8-rp]);
+        }
+		int bitlim = bits-3*(int)(rp-9);
+		if (bitlim>30 || x[0]>>bitlim==0)
+			//return sign * (float128_t)(x[0]) * p10s[rp-10];
+			return triple_multiply(sign, x[0], p10s[rp-10]);
+	}
+
+	/* Drop trailing zeros */
+	for (; !x[z-1]; z--);
+
+	/* 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=zero,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];
+        float128_t const_f128;
+        ui64_to_f128M(1000000000, &const_f128);
+        float128_t mul_y;
+        f128M_mul(&const_f128, &y, &mul_y);
+        float128_t x_f128;
+        ui32_to_f128M(x[a+i & MASK], &x_f128);
+        f128M_add(&mul_y, &x_f128, &y);
+	}
+
+	//y *= sign;
+    mul_eq_f128_int(&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 = copysignf128(dbl_to_f128(scalbn(1, 2*LDBL_MANT_DIG-bits-1)), y);
+		frac = fmodf128(y, dbl_to_f128(scalbn(1, LDBL_MANT_DIG-bits)));
+		//y -= frac;
+        {
+            float128_t new_value;
+            f128M_sub(&y, &frac, &new_value);
+            y = new_value;
+        }
+		//y += bias;
+        {
+            float128_t new_value;
+            f128M_add(&y, &frac, &new_value);
+            y = new_value;
+        }
+	}
+
+	/* 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;
+            add_eq_f128_dbl(&frac, 0.25*sign);
+        } else if (t > 500000000) {
+			//frac += 0.75*sign;
+            add_eq_f128_dbl(&frac, 0.75*sign);
+        } else if (t == 500000000) {
+			if ((a+i+1 & MASK) == z) {
+				//frac += 0.5*sign;
+                add_eq_f128_dbl(&frac, 0.5*sign);
+            } else {
+				//frac += 0.75*sign;
+                add_eq_f128_dbl(&frac, 0.75*sign);
+            }
+		}
+		//if (LDBL_MANT_DIG-bits >= 2 && !fmodf128(frac, 1))
+		if (LDBL_MANT_DIG-bits >= 2) {
+            float128_t one;
+            ui32_to_f128M(1, &one);
+            float128_t mod_result = fmodf128(frac, one);
+            if (f128M_eq(&mod_result, &zero)) {
+                //frac++;
+                add_eq_f128_dbl(&frac, 1.0);
+            }
+        }
+	}
+
+	//y += frac;
+    {
+        float128_t new_value;
+        f128M_add(&y, &frac, &new_value);
+        y = new_value;
+    }
+	//y -= bias;
+    {
+        float128_t new_value;
+        f128M_sub(&y, &bias, &new_value);
+        y = new_value;
+    }
+
+	if ((e2+LDBL_MANT_DIG & INT_MAX) > emax-5) {
+		//if (fabsf128(y) >= 0x1p113) 
+        float128_t abs_y = fabsf128(y);
+        float128_t mant_f128 = make_f128(0x4070000000000000, 0x0000000000000000);
+		if (!f128M_lt(&abs_y, &mant_f128)) {
+			if (denormal && bits==LDBL_MANT_DIG+e2-emin)
+				denormal = 0;
+			//y *= 0.5;
+            {
+                float128_t point_5 = dbl_to_f128(0.5);
+                float128_t new_value;
+                f128M_mul(&y, &point_5, &new_value);
+                y = new_value;
+            }
+
+			e2++;
+		}
+		if (e2+LDBL_MANT_DIG>emax || (denormal && !f128M_eq(&frac, &zero)))
+			errno = ERANGE;
+	}
+
+	return scalbnf128(y, e2);
+}
+
+static float128_t hexfloat(struct MuslFILE *f, int bits, int emin, int sign, int pok)
+{
+    float128_t zero;
+    ui32_to_f128M(0, &zero);
+    float128_t one;
+    ui32_to_f128M(1, &one);
+    float128_t sixteen;
+    ui32_to_f128M(16, &sixteen);
+    float128_t point_5 = dbl_to_f128(0.5);
+
+	uint32_t x = 0;
+	float128_t y = zero;
+	float128_t scale = one;
+	float128_t bias = zero;
+	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);
+                {
+                    float128_t divided;
+                    f128M_div(&scale, &sixteen, &divided);
+                    scale = divided;
+                    float128_t d_f128;
+                    i32_to_f128M(d, &d_f128);
+                    float128_t add_op;
+                    f128M_mul(&d_f128, &scale, &add_op);
+                    float128_t new_y;
+                    f128M_add(&y, &add_op, &new_y);
+                    y = new_y;
+                }
+			} else if (d && !gottail) {
+				//y += 0.5*scale;
+                {
+                    float128_t add_op;
+                    f128M_mul(&point_5, &scale, &add_op);
+                    float128_t new_y;
+                    f128M_add(&y, &add_op, &new_y);
+                    y = new_y;
+                }
+				gottail = 1;
+			}
+			dc++;
+		}
+	}
+	if (!gotdig) {
+		shunget(f);
+		if (pok) {
+			shunget(f);
+			if (gotrad) shunget(f);
+		} else {
+			shlim(f, 0);
+		}
+		//return sign * 0.0;
+        return dbl_to_f128(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 zero;
+			}
+			e2 = 0;
+		}
+	} else {
+		shunget(f);
+	}
+	e2 += 4*rp - 32;
+
+	if (!x) {
+        //return sign * 0.0;
+        return dbl_to_f128(sign * 0.0);
+    }
+	if (e2 > -emin) {
+		errno = ERANGE;
+		//return sign * LDBL_MAX * LDBL_MAX;
+		return zero;
+	}
+	if (e2 < emin-2*LDBL_MANT_DIG) {
+		errno = ERANGE;
+		//return sign * LDBL_MIN * LDBL_MIN;
+		return zero;
+	}
+
+	while (x < 0x80000000) {
+		//if (y>=0.5)
+		if (!f128M_lt(&y, &point_5)) {
+			x += x + 1;
+			//y += y - 1;
+            {
+                float128_t minus_one;
+                f128M_sub(&y, &one, &minus_one);
+                float128_t new_y;
+                f128M_add(&y, &minus_one, &new_y);
+                y = new_y;
+            }
+		} else {
+			x += x;
+			//y += y;
+            {
+                float128_t new_y;
+                f128M_add(&y, &y, &new_y);
+                y = new_y;
+            }
+		}
+		e2--;
+	}
+
+	if (bits > 32+e2-emin) {
+		bits = 32+e2-emin;
+		if (bits<0) bits=0;
+	}
+
+	if (bits < LDBL_MANT_DIG) {
+        float128_t sign_f128;
+        i32_to_f128M(sign, &sign_f128);
+		bias = copysignf128(dbl_to_f128(scalbn(1, 32+LDBL_MANT_DIG-bits-1)), sign_f128);
+    }
+
+	//if (bits<32 && y && !(x&1)) x++, y=0;
+	if (bits<32 && !f128M_eq(&y, &zero) && !(x&1)) x++, y=zero;
+
+	//y = bias + sign*(float128_t)x + sign*y;
+    {
+        float128_t x_f128;
+        ui32_to_f128M(x, &x_f128);
+        float128_t sign_f128;
+        i32_to_f128M(sign, &sign_f128);
+        float128_t sign_mul_x;
+        f128M_mul(&sign_f128, &x_f128, &sign_mul_x);
+        float128_t sign_mul_y;
+        f128M_mul(&sign_f128, &y, &sign_mul_y);
+        float128_t bias_op;
+        f128M_add(&bias, &sign_mul_x, &bias_op);
+        float128_t new_y;
+        f128M_add(&bias_op, &sign_mul_y, &new_y);
+        y = new_y;
+    }
+	//y -= bias;
+    {
+        float128_t new_y;
+        f128M_sub(&y, &bias, &new_y);
+        y = new_y;
+    }
+
+	if (f128M_eq(&y, &zero)) errno = ERANGE;
+
+	return scalbnf128(y, e2);
+}
+
+static int isspace(int c)
+{
+	return c == ' ' || (unsigned)c-'\t' < 5;
+}
+
+static inline float128_t makeInf128() {
+	union ldshape ux;
+    ux.i2.hi = 0x7fff000000000000UL;
+    ux.i2.lo = 0x0UL;
+    return ux.f;
+}
+
+static inline float128_t makeNaN128() {
+    uint64_t rand = 0UL;
+	union ldshape ux;
+    ux.i2.hi = 0x7fff000000000000UL | (rand & 0xffffffffffffUL);
+    ux.i2.lo = 0x0UL;
+    return ux.f;
+}
+
+float128_t __floatscan(struct MuslFILE *f, int prec, int pok)
+{
+	int sign = 1;
+	size_t i;
+	int bits = LDBL_MANT_DIG;
+	int emin = LDBL_MIN_EXP-bits;
+	int c;
+
+	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;
+        float128_t sign_f128;
+        i32_to_f128M(sign, &sign_f128);
+        float128_t infinity_f128 = makeInf128();
+        float128_t result;
+        f128M_mul(&sign_f128, &infinity_f128, &result);
+        return result;
+	}
+	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 makeNaN128();
+		}
+		for (i=1; ; i++) {
+			c = shgetc(f);
+			if (c-'0'<10U || c-'A'<26U || c-'a'<26U || c=='_')
+				continue;
+			if (c==')') return makeNaN128();
+			shunget(f);
+			if (!pok) {
+				errno = EINVAL;
+				shlim(f, 0);
+                float128_t zero;
+                ui32_to_f128M(0, &zero);
+				return zero;
+			}
+			while (i--) shunget(f);
+			return makeNaN128();
+		}
+		return makeNaN128();
+	}
+
+	if (i) {
+		shunget(f);
+		errno = EINVAL;
+		shlim(f, 0);
+        float128_t zero;
+        ui32_to_f128M(0, &zero);
+		return zero;
+	}
+
+	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);
+}
+
+float128_t parse_f128(const char *s, char **p) {
+	struct MuslFILE f;
+	sh_fromstring(&f, s);
+	shlim(&f, 0);
+	float128_t y = __floatscan(&f, 2, 1);
+	off_t cnt = shcnt(&f);
+	if (p) *p = cnt ? (char *)s + cnt : (char *)s;
+	return y;
+}