Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4973 | right-hear | 1 | /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */ |
| 2 | /* e_hypotf.c -- float version of e_hypot.c. |
||
| 3 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
||
| 4 | */ |
||
| 5 | |||
| 6 | /* |
||
| 7 | * ==================================================== |
||
| 8 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
||
| 9 | * |
||
| 10 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
||
| 11 | * Permission to use, copy, modify, and distribute this |
||
| 12 | * software is freely granted, provided that this notice |
||
| 13 | * is preserved. |
||
| 14 | * ==================================================== |
||
| 15 | */ |
||
| 16 | |||
| 17 | #if defined(LIBM_SCCS) && !defined(lint) |
||
| 18 | static char rcsid[] = "$Id: e_hypotf.c,v 1.2 1994/08/18 23:05:26 jtc Exp $"; |
||
| 19 | #endif |
||
| 20 | |||
| 21 | #include "math.h" |
||
| 22 | #include "math_private.h" |
||
| 23 | |||
| 24 | #ifdef __STDC__ |
||
| 25 | float __ieee754_hypotf(float x, float y) |
||
| 26 | #else |
||
| 27 | float __ieee754_hypot(x,y) |
||
| 28 | float x, y; |
||
| 29 | #endif |
||
| 30 | { |
||
| 31 | float a=x,b=y,t1,t2,y1,y2,w; |
||
| 32 | int32_t j,k,ha,hb; |
||
| 33 | |||
| 34 | GET_FLOAT_WORD(ha,x); |
||
| 35 | ha &= 0x7fffffff; |
||
| 36 | GET_FLOAT_WORD(hb,y); |
||
| 37 | hb &= 0x7fffffff; |
||
| 38 | if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;} |
||
| 39 | SET_FLOAT_WORD(a,ha); /* a <- |a| */ |
||
| 40 | SET_FLOAT_WORD(b,hb); /* b <- |b| */ |
||
| 41 | if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */ |
||
| 42 | k=0; |
||
| 43 | if(ha > 0x58800000) { /* a>2**50 */ |
||
| 44 | if(ha >= 0x7f800000) { /* Inf or NaN */ |
||
| 45 | w = a+b; /* for sNaN */ |
||
| 46 | if(ha == 0x7f800000) w = a; |
||
| 47 | if(hb == 0x7f800000) w = b; |
||
| 48 | return w; |
||
| 49 | } |
||
| 50 | /* scale a and b by 2**-60 */ |
||
| 51 | ha -= 0x5d800000; hb -= 0x5d800000; k += 60; |
||
| 52 | SET_FLOAT_WORD(a,ha); |
||
| 53 | SET_FLOAT_WORD(b,hb); |
||
| 54 | } |
||
| 55 | if(hb < 0x26800000) { /* b < 2**-50 */ |
||
| 56 | if(hb <= 0x007fffff) { /* subnormal b or 0 */ |
||
| 57 | if(hb==0) return a; |
||
| 58 | SET_FLOAT_WORD(t1,0x3f000000); /* t1=2^126 */ |
||
| 59 | b *= t1; |
||
| 60 | a *= t1; |
||
| 61 | k -= 126; |
||
| 62 | } else { /* scale a and b by 2^60 */ |
||
| 63 | ha += 0x5d800000; /* a *= 2^60 */ |
||
| 64 | hb += 0x5d800000; /* b *= 2^60 */ |
||
| 65 | k -= 60; |
||
| 66 | SET_FLOAT_WORD(a,ha); |
||
| 67 | SET_FLOAT_WORD(b,hb); |
||
| 68 | } |
||
| 69 | } |
||
| 70 | /* medium size a and b */ |
||
| 71 | w = a-b; |
||
| 72 | if (w>b) { |
||
| 73 | SET_FLOAT_WORD(t1,ha&0xfffff000); |
||
| 74 | t2 = a-t1; |
||
| 75 | w = sqrtf(t1*t1-(b*(-b)-t2*(a+t1))); |
||
| 76 | } else { |
||
| 77 | a = a+a; |
||
| 78 | SET_FLOAT_WORD(y1,hb&0xfffff000); |
||
| 79 | y2 = b - y1; |
||
| 80 | SET_FLOAT_WORD(t1,ha+0x00800000); |
||
| 81 | t2 = a - t1; |
||
| 82 | w = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b))); |
||
| 83 | } |
||
| 84 | if(k!=0) { |
||
| 85 | SET_FLOAT_WORD(t1,0x3f800000+(k<<23)); |
||
| 86 | return t1*w; |
||
| 87 | } else return w; |
||
| 88 | } |