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      1 
      2 
      3 /* @(#)w_pow.c 5.2 93/10/01 */
      4 /*
      5  * ====================================================
      6  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
      7  *
      8  * Developed at SunPro, a Sun Microsystems, Inc. business.
      9  * Permission to use, copy, modify, and distribute this
     10  * software is freely granted, provided that this notice
     11  * is preserved.
     12  * ====================================================
     13  */
     14 
     15 #include <sys/cdefs.h>
     16 #if defined(LIBM_SCCS) && !defined(lint)
     17 __RCSID("$NetBSD: w_pow.c,v 1.7 2002/05/26 22:02:02 wiz Exp $");
     18 #endif
     19 
     20 /*
     21  * wrapper pow(x,y) return x**y
     22  */
     23 
     24 #include "math.h"
     25 #include "math_private.h"
     26 
     27 
     28 double
     29 pow(double x, double y)	/* wrapper pow */
     30 {
     31 #ifdef _IEEE_LIBM
     32 	return  __ieee754_pow(x,y);
     33 #else
     34 	double z;
     35 	z=__ieee754_pow(x,y);
     36 	if(_LIB_VERSION == _IEEE_|| isnan(y)) return z;
     37 	if(isnan(x)) {
     38 	    if(y==0.0)
     39 	        return __kernel_standard(x,y,42); /* pow(NaN,0.0) */
     40 	    else
     41 		return z;
     42 	}
     43 	if(x==0.0){
     44 	    if(y==0.0)
     45 	        return __kernel_standard(x,y,20); /* pow(0.0,0.0) */
     46 	    if(finite(y)&&y<0.0)
     47 	        return __kernel_standard(x,y,23); /* pow(0.0,negative) */
     48 	    return z;
     49 	}
     50 	if(!finite(z)) {
     51 	    if(finite(x)&&finite(y)) {
     52 	        if(isnan(z))
     53 	            return __kernel_standard(x,y,24); /* pow neg**non-int */
     54 	        else
     55 	            return __kernel_standard(x,y,21); /* pow overflow */
     56 	    }
     57 	}
     58 	if(z==0.0&&finite(x)&&finite(y))
     59 	    return __kernel_standard(x,y,22); /* pow underflow */
     60 	return z;
     61 #endif
     62 }
     63