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      1 /* w_powf.c -- float version of w_pow.c.
      2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian (at) cygnus.com.
      3  */
      4 
      5 /*
      6  * ====================================================
      7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
      8  *
      9  * Developed at SunPro, a Sun Microsystems, Inc. business.
     10  * Permission to use, copy, modify, and distribute this
     11  * software is freely granted, provided that this notice
     12  * is preserved.
     13  * ====================================================
     14  */
     15 
     16 #include <sys/cdefs.h>
     17 #if defined(LIBM_SCCS) && !defined(lint)
     18 __RCSID("$NetBSD: w_powf.c,v 1.6 2002/05/26 22:02:02 wiz Exp $");
     19 #endif
     20 
     21 /*
     22  * wrapper powf(x,y) return x**y
     23  */
     24 
     25 #include "math.h"
     26 #include "math_private.h"
     27 
     28 
     29 float
     30 powf(float x, float y)	/* wrapper powf */
     31 {
     32 #ifdef _IEEE_LIBM
     33 	return  __ieee754_powf(x,y);
     34 #else
     35 	float z;
     36 	z=__ieee754_powf(x,y);
     37 	if(_LIB_VERSION == _IEEE_|| isnanf(y)) return z;
     38 	if(isnanf(x)) {
     39 	    if(y==(float)0.0)
     40 	        /* powf(NaN,0.0) */
     41 	        return (float)__kernel_standard((double)x,(double)y,142);
     42 	    else
     43 		return z;
     44 	}
     45 	if(x==(float)0.0){
     46 	    if(y==(float)0.0)
     47 	        /* powf(0.0,0.0) */
     48 	        return (float)__kernel_standard((double)x,(double)y,120);
     49 	    if(finitef(y)&&y<(float)0.0)
     50 	        /* powf(0.0,negative) */
     51 	        return (float)__kernel_standard((double)x,(double)y,123);
     52 	    return z;
     53 	}
     54 	if(!finitef(z)) {
     55 	    if(finitef(x)&&finitef(y)) {
     56 	        if(isnanf(z))
     57 		    /* powf neg**non-int */
     58 	            return (float)__kernel_standard((double)x,(double)y,124);
     59 	        else
     60 		    /* powf overflow */
     61 	            return (float)__kernel_standard((double)x,(double)y,121);
     62 	    }
     63 	}
     64 	if(z==(float)0.0&&finitef(x)&&finitef(y))
     65 	    /* powf underflow */
     66 	    return (float)__kernel_standard((double)x,(double)y,122);
     67 	return z;
     68 #endif
     69 }
     70