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90 lines
1.6 KiB
Plaintext
90 lines
1.6 KiB
Plaintext
#
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/*
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*
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* FPRINT - Floating-Point Print Routine
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*
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* requires:
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*
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* i = dtruncate (d)
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* i = dround (d)
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* d = dabs (d)
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* cputc (c, fd)
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*
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* internal routines and tables:
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*
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* fp3, fp4, fp5, fp6, ft0, ft1, ft10
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*
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*/
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static double ft0[] {1e1, 1e2, 1e4, 1e8, 1e16, 1e32};
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static double ft1[] {1e-1, 1e-2, 1e-4, 1e-8, 1e-16, 1e-32};
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static double ft10[] {1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7};
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double dabs ();
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fprint (d, fd)
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double d;
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{if (d<0) {cputc ('-', fd); d = dabs (d);}
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if (d>0)
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{if (d < 1.0) {fp4 (d, 0, fd); return;}
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else if (d >= 1e8) {fp4 (d, 1, fd); return;}
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}
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fp3 (d, fd);
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}
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fp3 (d, fd) /* print positive double */
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double d;
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{int i, n;
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double fraction;
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i = dtruncate (d);
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fraction = d - i;
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n = fp5 (i, fd); /* return # of digits printed */
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cputc ('.', fd);
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n = 8 - n;
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fraction =* ft10[n];
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i = dround (fraction);
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fp6 (i, n, fd); /* prints n digits */
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}
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fp4 (d, flag, fd)
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double d;
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{int c, e;
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c = 6;
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e = 0;
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while (--c >= 0)
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{e =<< 1;
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if (flag ? d >= ft0[c] : d <= ft1[c])
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{++e;
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d =* (flag ? ft1[c] : ft0[c]);
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}
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}
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if (d < 1.0) {++e; d =* 10.0;}
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fp3 (d, fd);
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cputc ('e', fd);
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cputc (flag ? '+' : '-', fd);
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fp5 (e, fd);
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}
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int fp5 (i, fd) /* print decimal integer, return # of digits printed */
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{int a;
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if (a = i/10) a = fp5 (a, fd);
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else a = 0;
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cputc (i%10 + '0', fd);
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return (a+1);
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}
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int fp6 (i, n, fd) /* print decimal integer given # of digits */
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{if (n>0)
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{if (n>1) fp6 (i/10, n-1, fd);
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cputc (i%10 + '0', fd);
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}
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}
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