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63 lines
2.8 KiB
C
63 lines
2.8 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2021 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "tool/plinko/lib/plinko.h"
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/**
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* Matches
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*
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* (ζ (X Y) (Z))
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*
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* @return MAKE4(X,Y,Z,0) on success, or ZERO4 on mismatch
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* @note ζ means COND
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*/
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struct qword IsIf(int x_) {
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dword w_;
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if (x_ >= 0) return ZERO4;
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w_ = Get(x_); // (ζ (X Y) (Z))
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int ax_ = LO(w_);
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int dx_ = HI(w_);
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if (ax_ != kCond) return ZERO4;
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if (dx_ >= 0) return ZERO4;
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w_ = Get(dx_); // ((X Y) (Z))
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int adx_ = LO(w_);
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int ddx_ = HI(w_);
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if (adx_ >= 0) return ZERO4;
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w_ = Get(adx_); // (X Y)
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int aadx_ = LO(w_);
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int dadx_ = HI(w_);
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if (ddx_ >= 0) return ZERO4;
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w_ = Get(ddx_); // ((Z))
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int addx_ = LO(w_);
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int dddx_ = HI(w_);
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int X = aadx_;
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if (addx_ >= 0) return ZERO4;
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w_ = Get(addx_); // (Z)
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int aaddx_ = LO(w_);
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int daddx_ = HI(w_);
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if (dadx_ >= 0) return ZERO4;
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w_ = Get(dadx_); // (Y)
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int adadx_ = LO(w_);
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int ddadx_ = HI(w_);
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if (dddx_) return ZERO4;
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int Y = adadx_;
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int Z = aaddx_;
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if (ddadx_) return ZERO4;
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if (daddx_) return ZERO4;
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return MAKE4(X, Y, Z, 0);
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}
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