Implement hypotl(). This is bde's conversion of fdlibm hypot(), with minor

fixes for ld128 by me.

1 files changed, 139 insertions, 0 deletions

diff --git a/lib/msun/src/e_hypotl.c b/lib/msun/src/e_hypotl.c
new file mode 100644
index 0000000..a8453df
--- /dev/null
+++ b/lib/msun/src/e_hypotl.c
@@ -0,0 +1,139 @@
+/* From: @(#)e_hypot.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/* long double version of hypot().  See e_hypot.c for most comments. */
+
+#include <float.h>
+
+#include "fpmath.h"
+#include "math.h"
+#include "math_private.h"
+
+#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)) {return a+b;} /* x/y > 2**(MANT_DIG+7) */
+	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 &= ~0xffffffffULL; 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) {
+	    u_int32_t high;
+	    t1 = 1.0;
+	    GET_HIGH_WORD(high,t1);
+	    SET_HIGH_WORD(t1,high+DESW(k));
+	    return t1*w;
+	} else return w;
+}