87 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			87 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
| /* wf_log.c -- float version of w_log.c.
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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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|  * ====================================================
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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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| 
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| /*
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|  * wrapper logf(x)
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|  */
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| 
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| #include "fdlibm.h"
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| #include <errno.h>
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| 
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| #ifdef __STDC__
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| 	float logf(float x)		/* wrapper logf */
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| #else
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| 	float logf(x)			/* wrapper logf */
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| 	float x;
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| #endif
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| {
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| #ifdef _IEEE_LIBM
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| 	return __ieee754_logf(x);
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| #else
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| 	float z;
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| 	struct exception exc;
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| 	z = __ieee754_logf(x);
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| 	if(_LIB_VERSION == _IEEE_ || isnanf(x) || x > (float)0.0) return z;
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| #ifndef HUGE_VAL 
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| #define HUGE_VAL inf
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| 	double inf = 0.0;
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| 
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| 	SET_HIGH_WORD(inf,0x7ff00000);	/* set inf to infinite */
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| #endif
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| 	exc.name = "logf";
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| 	exc.err = 0;
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| 	exc.arg1 = exc.arg2 = (double)x;
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| 	if (_LIB_VERSION == _SVID_)
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|            exc.retval = -HUGE;
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| 	else
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| 	   exc.retval = -HUGE_VAL;
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| 	if(x==(float)0.0) {
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| 	    /* logf(0) */
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| 	    exc.type = SING;
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| 	    if (_LIB_VERSION == _POSIX_)
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| 	       errno = ERANGE;
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| 	    else if (!matherr(&exc)) {
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| 	       errno = ERANGE;
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| 	    }
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| 	} else { 
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| 	    /* logf(x<0) */
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| 	    exc.type = DOMAIN;
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| 	    if (_LIB_VERSION == _POSIX_)
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| 	       errno = EDOM;
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| 	    else if (!matherr(&exc)) {
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| 	       errno = EDOM;
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| 	    }
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|             exc.retval = nan("");
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|         }
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| 	if (exc.err != 0)
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|            errno = exc.err;
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|         return (float)exc.retval; 
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| #endif
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| }
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| 
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| #ifdef _DOUBLE_IS_32BITS
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| 
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| #ifdef __STDC__
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| 	double log(double x)
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| #else
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| 	double log(x)
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| 	double x;
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| #endif
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| {
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| 	return (double) logf((float) x);
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| }
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| 
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| #endif /* defined(_DOUBLE_IS_32BITS) */
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