2 * ====================================================
3 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 * Developed at SunSoft, a Sun Microsystems, Inc. business.
6 * Permission to use, copy, modify, and distribute this
7 * software is freely granted, provided that this notice
9 * ====================================================
12 /* long double version of hypot(). See e_hypot.c for most comments. */
18 #include "math_private.h"
20 #define GET_LDBL_MAN(h, l, v) do { \
21 union IEEEl2bits uv; \
29 #define GET_HIGH_WORD(i, v) GET_LDBL_EXPSIGN(i, v)
31 #define SET_HIGH_WORD(v, i) SET_LDBL_EXPSIGN(v, i)
33 #define DESW(exp) (exp) /* delta expsign word */
34 #define ESW(exp) (MAX_EXP - 1 + (exp)) /* expsign word */
35 #define MANT_DIG LDBL_MANT_DIG
36 #define MAX_EXP LDBL_MAX_EXP
38 #if LDBL_MANL_SIZE > 32
39 typedef uint64_t man_t;
41 typedef uint32_t man_t;
45 hypotl(long double x, long double y)
47 long double a=x,b=y,t1,t2,y1,y2,w;
54 if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
57 if((ha-hb)>DESW(MANT_DIG+7)) {return a+b;} /* x/y > 2**(MANT_DIG+7) */
59 if(ha > ESW(MAX_EXP/2-12)) { /* a>2**(MAX_EXP/2-12) */
60 if(ha >= ESW(MAX_EXP)) { /* Inf or NaN */
62 /* Use original arg order iff result is NaN; quieten sNaNs. */
63 w = fabsl(x+0.0L)-fabsl(y+0);
64 GET_LDBL_MAN(manh,manl,a);
65 if (manh == LDBL_NBIT && manl == 0) w = a;
66 GET_LDBL_MAN(manh,manl,b);
67 if (hb >= ESW(MAX_EXP) && manh == LDBL_NBIT && manl == 0) w = b;
70 /* scale a and b by 2**-(MAX_EXP/2+88) */
71 ha -= DESW(MAX_EXP/2+88); hb -= DESW(MAX_EXP/2+88);
76 if(hb < ESW(-(MAX_EXP/2-12))) { /* b < 2**-(MAX_EXP/2-12) */
77 if(hb <= 0) { /* subnormal b or 0 */
79 GET_LDBL_MAN(manh,manl,b);
80 if((manh|manl)==0) return a;
82 SET_HIGH_WORD(t1,ESW(MAX_EXP-2)); /* t1=2^(MAX_EXP-2) */
86 } else { /* scale a and b by 2^(MAX_EXP/2+88) */
87 ha += DESW(MAX_EXP/2+88);
88 hb += DESW(MAX_EXP/2+88);
94 /* medium size a and b */
99 uv.e = t1; uv.bits.manl = 0; t1 = uv.e;
101 w = sqrtl(t1*t1-(b*(-b)-t2*(a+t1)));
106 uv.e = y1; uv.bits.manl = 0; y1 = uv.e;
109 uv.e = t1; uv.bits.manl = 0; t1 = uv.e;
111 w = sqrtl(t1*y1-(w*(-w)-(t1*y2+t2*b)));
116 GET_HIGH_WORD(high,t1);
117 SET_HIGH_WORD(t1,high+DESW(k));