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/* e_hypotf.c -- float version of e_hypot.c. |
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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*/ |
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/* |
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* ==================================================== |
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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* |
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* Developed at SunPro, a Sun Microsystems, Inc. business. |
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* Permission to use, copy, modify, and distribute this |
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* software is freely granted, provided that this notice |
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* is preserved. |
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* ==================================================== |
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*/ |
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#include "math.h" |
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#include "math_private.h" |
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float |
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hypotf(float x, float y) |
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{ |
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float a=x,b=y,t1,t2,yy1,y2,w; |
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int32_t j,k,ha,hb; |
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GET_FLOAT_WORD(ha,x); |
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ha &= 0x7fffffff; |
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GET_FLOAT_WORD(hb,y); |
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hb &= 0x7fffffff; |
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if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;} |
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SET_FLOAT_WORD(a,ha); /* a <- |a| */ |
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SET_FLOAT_WORD(b,hb); /* b <- |b| */ |
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if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */ |
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k=0; |
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if(ha > 0x58800000) { /* a>2**50 */ |
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if(ha >= 0x7f800000) { /* Inf or NaN */ |
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w = a+b; /* for sNaN */ |
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if(ha == 0x7f800000) w = a; |
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if(hb == 0x7f800000) w = b; |
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return w; |
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} |
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/* scale a and b by 2**-68 */ |
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ha -= 0x22000000; hb -= 0x22000000; k += 68; |
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SET_FLOAT_WORD(a,ha); |
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SET_FLOAT_WORD(b,hb); |
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} |
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if(hb < 0x26800000) { /* b < 2**-50 */ |
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if(hb <= 0x007fffff) { /* subnormal b or 0 */ |
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if(hb==0) return a; |
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SET_FLOAT_WORD(t1,0x7e800000); /* t1=2^126 */ |
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b *= t1; |
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a *= t1; |
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k -= 126; |
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} else { /* scale a and b by 2^68 */ |
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ha += 0x22000000; /* a *= 2^68 */ |
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hb += 0x22000000; /* b *= 2^68 */ |
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k -= 68; |
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SET_FLOAT_WORD(a,ha); |
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SET_FLOAT_WORD(b,hb); |
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} |
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} |
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/* medium size a and b */ |
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w = a-b; |
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if (w>b) { |
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SET_FLOAT_WORD(t1,ha&0xfffff000); |
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t2 = a-t1; |
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w = sqrtf(t1*t1-(b*(-b)-t2*(a+t1))); |
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} else { |
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a = a+a; |
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SET_FLOAT_WORD(yy1,hb&0xfffff000); |
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y2 = b - yy1; |
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SET_FLOAT_WORD(t1,ha+0x00800000); |
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t2 = a - t1; |
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w = sqrtf(t1*yy1-(w*(-w)-(t1*y2+t2*b))); |
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} |
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if(k!=0) { |
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SET_FLOAT_WORD(t1,0x3f800000+(k<<23)); |
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return t1*w; |
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} else return w; |
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} |
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DEF_STD(hypotf); |