1 /* w_powf.c -- float version of w_pow.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@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 #if defined(LIBM_SCCS) && !defined(lint) 17 static char rcsid[] = "$Id: w_powf.c,v 1.2 1994/09/22 16:46:00 jtc Exp $"; 18 #endif 19 20 /* 21 * wrapper powf(x,y) return x**y 22 */ 23 24 #include "math.h" 25 #include "math_private.h" 26 27 28 #ifdef __STDC__ 29 float powf(float x, float y) /* wrapper powf */ 30 #else 31 float powf(x,y) /* wrapper powf */ 32 float x,y; 33 #endif 34 { 35 #ifdef _IEEE_LIBM 36 return __ieee754_powf(x,y); 37 #else 38 float z; 39 z=__ieee754_powf(x,y); 40 if(_LIB_VERSION == _IEEE_|| isnanf(y)) return z; 41 if(isnanf(x)) { 42 if(y==(float)0.0) 43 /* powf(NaN,0.0) */ 44 return (float)__kernel_standard((double)x,(double)y,142); 45 else 46 return z; 47 } 48 if(x==(float)0.0){ 49 if(y==(float)0.0) 50 /* powf(0.0,0.0) */ 51 return (float)__kernel_standard((double)x,(double)y,120); 52 if(finitef(y)&&y<(float)0.0) 53 /* powf(0.0,negative) */ 54 return (float)__kernel_standard((double)x,(double)y,123); 55 return z; 56 } 57 if(!finitef(z)) { 58 if(finitef(x)&&finitef(y)) { 59 if(isnanf(z)) 60 /* powf neg**non-int */ 61 return (float)__kernel_standard((double)x,(double)y,124); 62 else 63 /* powf overflow */ 64 return (float)__kernel_standard((double)x,(double)y,121); 65 } 66 } 67 if(z==(float)0.0&&finitef(x)&&finitef(y)) 68 /* powf underflow */ 69 return (float)__kernel_standard((double)x,(double)y,122); 70 return z; 71 #endif 72 } 73