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91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
/* j/3/rub.c
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**
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** This file is in the public domain.
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*/
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#include "all.h"
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#include "../pit.h"
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/* functions
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*/
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u2_noun // produce
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j2_mby(Pt5, rub)(
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u2_atom a, // retain
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u2_atom b) // retain
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{
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u2_atom c, d, e;
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u2_atom w, x, y, z;
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u2_atom p, q;
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u2_atom m = j2_mbc(Pt1, add)(a, u2_cr_met(0, b));
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// Compute c and d.
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{
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x = u2k(a);
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while ( 0 == j2_mbc(Pt3, cut)(0, x, 1, b) ) {
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u2_atom y = j2_mbc(Pt1, inc)(x);
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// Sanity check: crash if decoding more bits than available
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if ( u2_yes == j2_mbc(Pt1, gth)(x, m)) {
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// fprintf(stderr, "[%%rub-hard %d %d %d]\r\n", a, x, m);
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return u2_cm_bail(c3__exit);
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}
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u2z(x);
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x = y;
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}
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if ( u2_yes == u2_cr_sing(x, a) ) {
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u2z(x);
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return u2nc(1, 0);
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}
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c = j2_mbc(Pt1, sub)(x, a);
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d = j2_mbc(Pt1, inc)(x);
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u2z(x);
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}
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// Compute e, p, q.
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{
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x = j2_mbc(Pt1, dec)(c);
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y = j2_mbc(Pt3, bex)(x);
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z = j2_mbc(Pt3, cut)(0, d, x, b);
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e = j2_mbc(Pt1, add)(y, z);
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u2z(y); u2z(z);
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w = j2_mbc(Pt1, add)(c, c);
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y = j2_mbc(Pt1, add)(w, e);
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z = j2_mbc(Pt1, add)(d, x);
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p = j2_mbc(Pt1, add)(w, e);
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q = j2_mbc(Pt3, cut)(0, z, e, b);
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u2z(w); u2z(x); u2z(y); u2z(z);
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return u2nc(p, q);
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}
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}
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u2_noun // transfer
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j2_mb(Pt5, rub)(
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u2_noun cor) // retain
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{
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u2_noun a, b;
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if ( (u2_no == u2_cr_mean(cor, u2_cv_sam_2, &a, u2_cv_sam_3, &b, 0)) ||
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(u2_no == u2ud(a)) ||
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(u2_no == u2ud(b)) )
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{
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return u2_cm_bail(c3__fail);
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} else {
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return j2_mby(Pt5, rub)(a, b);
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}
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}
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/* structures
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*/
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u2_ho_jet
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j2_mbj(Pt5, rub)[] = {
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{ ".2", c3__hevy, j2_mb(Pt5, rub), Tier5, u2_none, u2_none },
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{ }
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};
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