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49 lines
902 B
C
49 lines
902 B
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 "@(#) _ffptof - Feb 1, 1983"; */
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/*
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* FFP Floating Point Representation to Internal Representation :
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* FFP Standard Single Precision Representation Floating Point
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*
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* float
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* ffptof(lf)
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* long lf;
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*
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* Largest positive number is 3.4 * 10^18 and the smallest positive
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* number is 1.2 * 10^-20.
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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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float
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ffptof(lf)
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long lf;
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{
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register int exp, 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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fsign = (lf & 0x80);
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exp = (lf & 0x7f) - 0x40;
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lf = (lf>>8) & 0xffffff; /* 24 bits of fraction */
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f = lf;
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f = f / 16777216.0; /* 2 ^ 24 */
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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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