w_powf.c (1802B)
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 #ifndef lint 17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/w_powf.c,v 1.7 2002/05/28 18:15:04 alfred 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 float 29 powf(float x, float y) /* wrapper powf */ 30 { 31 #ifdef _IEEE_LIBM 32 return __ieee754_powf(x,y); 33 #else 34 float z; 35 z=__ieee754_powf(x,y); 36 if(_LIB_VERSION == _IEEE_|| isnanf(y)) return z; 37 if(isnanf(x)) { 38 if(y==(float)0.0) 39 /* powf(NaN,0.0) */ 40 return (float)__kernel_standard((double)x,(double)y,142); 41 else 42 return z; 43 } 44 if(x==(float)0.0){ 45 if(y==(float)0.0) 46 /* powf(0.0,0.0) */ 47 return (float)__kernel_standard((double)x,(double)y,120); 48 if(finitef(y)&&y<(float)0.0) 49 /* powf(0.0,negative) */ 50 return (float)__kernel_standard((double)x,(double)y,123); 51 return z; 52 } 53 if(!finitef(z)) { 54 if(finitef(x)&&finitef(y)) { 55 if(isnanf(z)) 56 /* powf neg**non-int */ 57 return (float)__kernel_standard((double)x,(double)y,124); 58 else 59 /* powf overflow */ 60 return (float)__kernel_standard((double)x,(double)y,121); 61 } 62 } 63 if(z==(float)0.0&&finitef(x)&&finitef(y)) 64 /* powf underflow */ 65 return (float)__kernel_standard((double)x,(double)y,122); 66 return z; 67 #endif 68 }