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78 lines
2.0 KiB
C
78 lines
2.0 KiB
C
/*
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Copyright 1982
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Alcyon Corporation
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8716 Production Ave.
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San Diego, Ca. 92121
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*/
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/*char *version "@(#) _ieeetof - dec 29, 1982"; */
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/*
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* IEEE Floating Point Representation to Internal Representation :
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* IEEE Standard Single Precision Representation Floating Point
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*
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* float
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* _ieeetof(lf)
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* long lf;
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*
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* Largest positive number is 3.4 * 10^33 and the smallest positive
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* number is 1.2 * 10^-38.
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* Rely's on the fact that a long and a float are both 32 bits.
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*/
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#define BIAS 127L
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float
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_ieeetof(lf)
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long lf;
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{
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register long exp;
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register int count, fsign;
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float f;
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if (lf == 0L)
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return(0.0);
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if (lf < 0L) {
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fsign = 1;
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lf =& 0x7fffffff; /* mask MSB (sign) */
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}
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else
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fsign = 0;
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exp = (lf >> 23) & 0xff; /* biased ieee exponent */
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exp =- BIAS;
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lf =& 0x7fffff; /* 23 bits of fraction */
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f = lf;
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if (lf != 0) /* don't need to do floating point test !!! */
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f = f / 8388608.0; /* 2 ^ 23 */
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f = f + 1.0; /* ieee fraction : 1.F */
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while (exp < 0) { /* negative exp : 2^-? */
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f = f / 2.0;
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exp++;
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}
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while (exp > 0) { /* positive exp : 2^+? */
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f = f * 2.0;
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exp--;
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}
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if (fsign)
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f = -f;
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return(f);
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}
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exp--;
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}
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if (fsign)
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f = -f;
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return(f);
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}
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exp--;
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}
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if (fsign)
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f = -f;
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return(f);
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}
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exp--;
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}
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if (fsign)
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f = -f;
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return(f);
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}
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