51 lines
1.1 KiB
C
51 lines
1.1 KiB
C
/* unfortunately, we cannot just do an atof and convert result to float
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is neccessary, because that might result in over/underflow at an
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unexpected moment. For the time being, overflow in floating point
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constants goes undetected
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*/
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con_float(argval, str, res)
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char *str, *res;
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{
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double f;
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double atof();
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int i;
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double frexp(), ldexp();
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int j;
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float fl;
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char *p;
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f = atof(str);
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if (f == 0 || argval == 8) {
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p = (char *) &f;
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while (argval--) *res++ = *p++;
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return;
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}
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f = frexp(f, &i);
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fl = f;
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fl = frexp(fl,&j);
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if (i+j > 127) {
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/* overflow situation. Unfortunately we don't have the
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slightest idea where the floating point constant came
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from, so, for the time being, just ignore
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*/
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*res++ = f < 0 ? 0377 : 0177;
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*res++ = 0377;
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*res++ = 0377;
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*res = 0377;
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return;
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}
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if (i+j < -127) {
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/* underflow situation. Unfortunately we don't have the
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slightest idea where the floating point constant came
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from, so, for the time being, just ignore
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*/
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*res++ = f < 0 ? 0200 : 0;
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*res++ = 0200;
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*res++ = 0;
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*res = 0;
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return;
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}
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fl = ldexp(fl, i+j);
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p = (char *) &fl;
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while (argval--) *res++ = *p++;
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}
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