| 1 | #include "libm.h" |
| 2 | |
| 3 | #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 |
| 4 | long double remquol(long double x, long double y, int *quo) |
| 5 | { |
| 6 | 	return remquo(x, y, quo); |
| 7 | } |
| 8 | #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 |
| 9 | long double remquol(long double x, long double y, int *quo) |
| 10 | { |
| 11 | 	union ldshape ux = {x}, uy = {y}; |
| 12 | 	int ex = ux.i.se & 0x7fff; |
| 13 | 	int ey = uy.i.se & 0x7fff; |
| 14 | 	int sx = ux.i.se >> 15; |
| 15 | 	int sy = uy.i.se >> 15; |
| 16 | 	uint32_t q; |
| 17 | |
| 18 | 	*quo = 0; |
| 19 | 	if (y == 0 || isnan(y) || ex == 0x7fff) |
| 20 | 		return (x*y)/(x*y); |
| 21 | 	if (x == 0) |
| 22 | 		return x; |
| 23 | |
| 24 | 	/* normalize x and y */ |
| 25 | 	if (!ex) { |
| 26 | 		ux.i.se = ex; |
| 27 | 		ux.f *= 0x1p120f; |
| 28 | 		ex = ux.i.se - 120; |
| 29 | 	} |
| 30 | 	if (!ey) { |
| 31 | 		uy.i.se = ey; |
| 32 | 		uy.f *= 0x1p120f; |
| 33 | 		ey = uy.i.se - 120; |
| 34 | 	} |
| 35 | |
| 36 | 	q = 0; |
| 37 | 	if (ex >= ey) { |
| 38 | 		/* x mod y */ |
| 39 | #if LDBL_MANT_DIG == 64 |
| 40 | 		uint64_t i, mx, my; |
| 41 | 		mx = ux.i.m; |
| 42 | 		my = uy.i.m; |
| 43 | 		for (; ex > ey; ex--) { |
| 44 | 			i = mx - my; |
| 45 | 			if (mx >= my) { |
| 46 | 				mx = 2*i; |
| 47 | 				q++; |
| 48 | 				q <<= 1; |
| 49 | 			} else if (2*mx < mx) { |
| 50 | 				mx = 2*mx - my; |
| 51 | 				q <<= 1; |
| 52 | 				q++; |
| 53 | 			} else { |
| 54 | 				mx = 2*mx; |
| 55 | 				q <<= 1; |
| 56 | 			} |
| 57 | 		} |
| 58 | 		i = mx - my; |
| 59 | 		if (mx >= my) { |
| 60 | 			mx = i; |
| 61 | 			q++; |
| 62 | 		} |
| 63 | 		if (mx == 0) |
| 64 | 			ex = -120; |
| 65 | 		else |
| 66 | 			for (; mx >> 63 == 0; mx *= 2, ex--); |
| 67 | 		ux.i.m = mx; |
| 68 | #elif LDBL_MANT_DIG == 113 |
| 69 | 		uint64_t hi, lo, xhi, xlo, yhi, ylo; |
| 70 | 		xhi = (ux.i2.hi & -1ULL>>16) | 1ULL<<48; |
| 71 | 		yhi = (uy.i2.hi & -1ULL>>16) | 1ULL<<48; |
| 72 | 		xlo = ux.i2.lo; |
| 73 | 		ylo = ux.i2.lo; |
| 74 | 		for (; ex > ey; ex--) { |
| 75 | 			hi = xhi - yhi; |
| 76 | 			lo = xlo - ylo; |
| 77 | 			if (xlo < ylo) |
| 78 | 				hi -= 1; |
| 79 | 			if (hi >> 63 == 0) { |
| 80 | 				xhi = 2*hi + (lo>>63); |
| 81 | 				xlo = 2*lo; |
| 82 | 				q++; |
| 83 | 			} else { |
| 84 | 				xhi = 2*xhi + (xlo>>63); |
| 85 | 				xlo = 2*xlo; |
| 86 | 			} |
| 87 | 			q <<= 1; |
| 88 | 		} |
| 89 | 		hi = xhi - yhi; |
| 90 | 		lo = xlo - ylo; |
| 91 | 		if (xlo < ylo) |
| 92 | 			hi -= 1; |
| 93 | 		if (hi >> 63 == 0) { |
| 94 | 			xhi = hi; |
| 95 | 			xlo = lo; |
| 96 | 			q++; |
| 97 | 		} |
| 98 | 		if ((xhi|xlo) == 0) |
| 99 | 			ex = -120; |
| 100 | 		else |
| 101 | 			for (; xhi >> 48 == 0; xhi = 2*xhi + (xlo>>63), xlo = 2*xlo, ex--); |
| 102 | 		ux.i2.hi = xhi; |
| 103 | 		ux.i2.lo = xlo; |
| 104 | #endif |
| 105 | 	} |
| 106 | |
| 107 | 	/* scale result and decide between |x| and |x|-|y| */ |
| 108 | 	if (ex <= 0) { |
| 109 | 		ux.i.se = ex + 120; |
| 110 | 		ux.f *= 0x1p-120f; |
| 111 | 	} else |
| 112 | 		ux.i.se = ex; |
| 113 | 	x = ux.f; |
| 114 | 	if (sy) |
| 115 | 		y = -y; |
| 116 | 	if (ex == ey || (ex+1 == ey && (2*x > y || (2*x == y && q%2)))) { |
| 117 | 		x -= y; |
| 118 | 		q++; |
| 119 | 	} |
| 120 | 	q &= 0x7fffffff; |
| 121 | 	*quo = sx^sy ? -(int)q : (int)q; |
| 122 | 	return sx ? -x : x; |
| 123 | } |
| 124 | #endif |