1/*
  2    Copyright 2018 0KIMS association.
  3
  4    This file is part of circom (Zero Knowledge Circuit Compiler).
  5
  6    circom is a free software: you can redistribute it and/or modify it
  7    under the terms of the GNU General Public License as published by
  8    the Free Software Foundation, either version 3 of the License, or
  9    (at your option) any later version.
 10
 11    circom is distributed in the hope that it will be useful, but WITHOUT
 12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 13    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
 14    License for more details.
 15
 16    You should have received a copy of the GNU General Public License
 17    along with circom. If not, see <https://www.gnu.org/licenses/>.
 18*/
 19
 20template MultiMux4(n) {
 21    signal input c[n][16];  // Constants
 22    signal input s[4];   // Selector
 23    signal output out[n];
 24
 25    signal a3210[n];
 26    signal a321[n];
 27    signal a320[n];
 28    signal a310[n];
 29    signal a32[n];
 30    signal a31[n];
 31    signal a30[n];
 32    signal a3[n];
 33
 34    signal a210[n];
 35    signal a21[n];
 36    signal a20[n];
 37    signal a10[n];
 38    signal a2[n];
 39    signal a1[n];
 40    signal a0[n];
 41    signal a[n];
 42
 43    // 4 constrains for the intermediary variables
 44    signal  s10;
 45    s10 <== s[1] * s[0];
 46    signal  s20;
 47    s20 <== s[2] * s[0];
 48    signal  s21;
 49    s21 <== s[2] * s[1];
 50    signal s210;
 51    s210 <==  s21 * s[0];
 52
 53
 54    for (var i=0; i<n; i++) {
 55
 56        a3210[i] <==  ( c[i][15]-c[i][14]-c[i][13]+c[i][12] - c[i][11]+c[i][10]+c[i][ 9]-c[i][ 8]
 57                       -c[i][ 7]+c[i][ 6]+c[i][ 5]-c[i][ 4] + c[i][ 3]-c[i][ 2]-c[i][ 1]+c[i][ 0] ) * s210;
 58         a321[i] <==  ( c[i][14]-c[i][12]-c[i][10]+c[i][ 8] - c[i][ 6]+c[i][ 4]+c[i][ 2]-c[i][ 0] ) * s21;
 59         a320[i] <==  ( c[i][13]-c[i][12]-c[i][ 9]+c[i][ 8] - c[i][ 5]+c[i][ 4]+c[i][ 1]-c[i][ 0] ) * s20;
 60         a310[i] <==  ( c[i][11]-c[i][10]-c[i][ 9]+c[i][ 8] - c[i][ 3]+c[i][ 2]+c[i][ 1]-c[i][ 0] ) * s10;
 61          a32[i] <==  ( c[i][12]-c[i][ 8]-c[i][ 4]+c[i][ 0] ) * s[2];
 62          a31[i] <==  ( c[i][10]-c[i][ 8]-c[i][ 2]+c[i][ 0] ) * s[1];
 63          a30[i] <==  ( c[i][ 9]-c[i][ 8]-c[i][ 1]+c[i][ 0] ) * s[0];
 64           a3[i] <==  ( c[i][ 8]-c[i][ 0] );
 65
 66         a210[i] <==  ( c[i][ 7]-c[i][ 6]-c[i][ 5]+c[i][ 4] - c[i][ 3]+c[i][ 2]+c[i][ 1]-c[i][ 0] ) * s210;
 67          a21[i] <==  ( c[i][ 6]-c[i][ 4]-c[i][ 2]+c[i][ 0] ) * s21;
 68          a20[i] <==  ( c[i][ 5]-c[i][ 4]-c[i][ 1]+c[i][ 0] ) * s20;
 69          a10[i] <==  ( c[i][ 3]-c[i][ 2]-c[i][ 1]+c[i][ 0] ) * s10;
 70           a2[i] <==  ( c[i][ 4]-c[i][ 0] ) * s[2];
 71           a1[i] <==  ( c[i][ 2]-c[i][ 0] ) * s[1];
 72           a0[i] <==  ( c[i][ 1]-c[i][ 0] ) * s[0];
 73            a[i] <==  ( c[i][ 0] )
 74
 75          out[i] <== ( a3210[i] + a321[i] + a320[i] + a310[i] + a32[i] + a31[i] + a30[i] + a3[i] ) * s[3] +
 76                     (  a210[i] +  a21[i] +  a20[i] +  a10[i] +  a2[i] +  a1[i] +  a0[i] +  a[i] );
 77
 78/*
 79        out[i] <== (  s210 * ( c[i][15]-c[i][14]-c[i][13]+c[i][12] - c[i][11]+c[i][10]+c[i][ 9]-c[i][ 8]
 80                              -c[i][ 7]+c[i][ 6]+c[i][ 5]-c[i][ 4] + c[i][ 3]-c[i][ 2]-c[i][ 1]+c[i][ 0] ) +
 81                       s21 * ( c[i][14]-c[i][12]-c[i][10]+c[i][ 8] - c[i][ 6]+c[i][ 4]+c[i][ 2]-c[i][ 0] ) +
 82                       s20 * ( c[i][13]-c[i][12]-c[i][ 9]+c[i][ 8] - c[i][ 5]+c[i][ 4]+c[i][ 1]-c[i][ 0] ) +
 83                       s10 * ( c[i][11]-c[i][10]-c[i][ 9]+c[i][ 8] - c[i][ 3]+c[i][ 2]+c[i][ 1]-c[i][ 0] ) +
 84                      s[2] * ( c[i][12]-c[i][ 8]-c[i][ 4]+c[i][ 0] ) +
 85                      s[1] * ( c[i][10]-c[i][ 8]-c[i][ 2]+c[i][ 0] ) +
 86                      s[0] * ( c[i][ 9]-c[i][ 8]-c[i][ 1]+c[i][ 0] ) +
 87                             ( c[i][ 8]-c[i][ 0] ) ) * s[3]  +
 88                (     s210 * ( c[i][ 7]-c[i][ 6]-c[i][ 5]+c[i][ 4] - c[i][ 3]+c[i][ 2]+c[i][ 1]-c[i][ 0] ) +
 89                       s21 * ( c[i][ 6]-c[i][ 4]-c[i][ 2]+c[i][ 0] ) +
 90                       s20 * ( c[i][ 5]-c[i][ 4]-c[i][ 1]+c[i][ 0] ) +
 91                       s10 * ( c[i][ 3]-c[i][ 2]-c[i][ 1]+c[i][ 0] ) +
 92                      s[2] * ( c[i][ 4]-c[i][ 0] ) +
 93                      s[1] * ( c[i][ 2]-c[i][ 0] ) +
 94                      s[0] * ( c[i][ 1]-c[i][ 0] ) +
 95                             ( c[i][ 0] ));
 96
 97*/
 98    }
 99}
100
101template Mux4() {
102    var i;
103    signal input c[16];  // Constants
104    signal input s[4];   // Selector
105    signal output out;
106
107    component mux = MultiMux4(1);
108
109    for (i=0; i<16; i++) {
110        mux.c[0][i] <== c[i];
111    }
112
113    for (i=0; i<4; i++) {
114      s[i] ==> mux.s[i];
115    }
116
117    mux.out[0] ==> out;
118}