mirror of
https://github.com/fluencelabs/musl
synced 2025-06-01 17:11:53 +00:00
529a8de46c
this also fixes overflow/underflow raising and excess precision issues (as those are handled well in scalbn)
87 lines
2.0 KiB
C
87 lines
2.0 KiB
C
/* origin: FreeBSD /usr/src/lib/msun/src/e_hypotf.c */
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/*
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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 "libm.h"
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float hypotf(float x, float y)
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{
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float a,b,t1,t2,y1,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) {
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a = y;
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b = x;
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j=ha; ha=hb; hb=j;
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} else {
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a = x;
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b = y;
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}
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a = fabsf(a);
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b = fabsf(b);
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if (ha - hb > 0xf000000) /* x/y > 2**30 */
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return a+b;
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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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/* Use original arg order iff result is NaN; quieten sNaNs. */
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w = fabsf(x+0.0f) - fabsf(y+0.0f);
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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)
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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(y1, hb&0xfffff000);
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y2 = b - y1;
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SET_FLOAT_WORD(t1,(ha+0x00800000)&0xfffff000);
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t2 = a - t1;
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w = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
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}
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if (k)
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w = scalbnf(w, k);
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return w;
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}
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