X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Fhypotl.c;fp=src%2Fmath%2Fhypotl.c;h=f4a64f74f0879626bdf058883c3f31bb0c9e43e5;hb=b69f695acedd4ce2798ef9ea28d834ceccc789bd;hp=0000000000000000000000000000000000000000;hpb=d46cf2e14cc4df7cc75e77d7009fcb6df1f48a33;p=musl

diff --git a/src/math/hypotl.c b/src/math/hypotl.c
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+++ b/src/math/hypotl.c
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+/* origin: FreeBSD /usr/src/lib/msun/src/e_hypotl.c */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+/* long double version of hypot().  See comments in hypot.c. */
+
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double hypotl(long double x, long double y)
+{
+	return hypot(x, y);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+
+#define GET_LDBL_EXPSIGN(i, v) do {     \
+	union IEEEl2bits uv;            \
+					\
+	uv.e = v;                       \
+	i = uv.xbits.expsign;           \
+} while (0)
+
+#define GET_LDBL_MAN(h, l, v) do {      \
+	union IEEEl2bits uv;            \
+					\
+	uv.e = v;                       \
+	h = uv.bits.manh;               \
+	l = uv.bits.manl;               \
+} while (0)
+
+#define SET_LDBL_EXPSIGN(v, i) do {     \
+	union IEEEl2bits uv;            \
+					\
+	uv.e = v;                       \
+	uv.xbits.expsign = i;           \
+	v = uv.e;                       \
+} while (0)
+
+#undef GET_HIGH_WORD
+#define GET_HIGH_WORD(i, v)     GET_LDBL_EXPSIGN(i, v)
+#undef SET_HIGH_WORD
+#define SET_HIGH_WORD(v, i)     SET_LDBL_EXPSIGN(v, i)
+
+#define DESW(exp)       (exp)           /* delta expsign word */
+#define ESW(exp)        (MAX_EXP - 1 + (exp))   /* expsign word */
+#define MANT_DIG        LDBL_MANT_DIG
+#define MAX_EXP         LDBL_MAX_EXP
+
+#if LDBL_MANL_SIZE > 32
+typedef uint64_t man_t;
+#else
+typedef uint32_t man_t;
+#endif
+
+long double hypotl(long double x, long double y)
+{
+	long double a=x,b=y,t1,t2,y1,y2,w;
+	int32_t j,k,ha,hb;
+
+	GET_HIGH_WORD(ha, x);
+	ha &= 0x7fff;
+	GET_HIGH_WORD(hb, y);
+	hb &= 0x7fff;
+	if (hb > ha) {
+		a = y;
+		b = x;
+		j=ha; ha=hb; hb=j;
+	} else {
+		a = x;
+		b = y;
+	}
+	a = fabsl(a);
+	b = fabsl(b);
+	if (ha - hb > DESW(MANT_DIG+7))  /* x/y > 2**(MANT_DIG+7) */
+		return a+b;
+	k = 0;
+	if (ha > ESW(MAX_EXP/2-12)) {    /* a>2**(MAX_EXP/2-12) */
+		if (ha >= ESW(MAX_EXP)) {  /* Inf or NaN */
+			man_t manh, manl;
+			/* Use original arg order iff result is NaN; quieten sNaNs. */
+			w = fabsl(x+0.0)-fabsl(y+0.0);
+			GET_LDBL_MAN(manh,manl,a);
+			if (manh == LDBL_NBIT && manl == 0) w = a;
+			GET_LDBL_MAN(manh,manl,b);
+			if (hb >= ESW(MAX_EXP) && manh == LDBL_NBIT && manl == 0) w = b;
+			return w;
+		}
+		/* scale a and b by 2**-(MAX_EXP/2+88) */
+		ha -= DESW(MAX_EXP/2+88); hb -= DESW(MAX_EXP/2+88);
+		k += MAX_EXP/2+88;
+		SET_HIGH_WORD(a, ha);
+		SET_HIGH_WORD(b, hb);
+	}
+	if (hb < ESW(-(MAX_EXP/2-12))) {  /* b < 2**-(MAX_EXP/2-12) */
+		if (hb <= 0) {  /* subnormal b or 0 */
+			man_t manh, manl;
+			GET_LDBL_MAN(manh,manl,b);
+			if ((manh|manl) == 0)
+				return a;
+			t1 = 0;
+			SET_HIGH_WORD(t1, ESW(MAX_EXP-2));  /* t1 = 2^(MAX_EXP-2) */
+			b *= t1;
+			a *= t1;
+			k -= MAX_EXP-2;
+		} else {            /* scale a and b by 2^(MAX_EXP/2+88) */
+			ha += DESW(MAX_EXP/2+88);
+			hb += DESW(MAX_EXP/2+88);
+			k -= MAX_EXP/2+88;
+			SET_HIGH_WORD(a, ha);
+			SET_HIGH_WORD(b, hb);
+		}
+	}
+	/* medium size a and b */
+	w = a - b;
+	if (w > b) {
+		t1 = a;
+		union IEEEl2bits uv;
+		uv.e = t1; uv.bits.manl = 0; t1 = uv.e;
+		t2 = a-t1;
+		w  = sqrtl(t1*t1-(b*(-b)-t2*(a+t1)));
+	} else {
+		a  = a+a;
+		y1 = b;
+		union IEEEl2bits uv;
+		uv.e = y1; uv.bits.manl = 0; y1 = uv.e;
+		y2 = b - y1;
+		t1 = a;
+		uv.e = t1; uv.bits.manl = 0; t1 = uv.e;
+		t2 = a - t1;
+		w  = sqrtl(t1*y1-(w*(-w)-(t1*y2+t2*b)));
+	}
+	if(k!=0) {
+		uint32_t high;
+		t1 = 1.0;
+		GET_HIGH_WORD(high, t1);
+		SET_HIGH_WORD(t1, high+DESW(k));
+		return t1*w;
+	}
+	return w;
+}
+#endif