static void bitrv216neg( double* a ) {
double x1r, x1i, x2r, x2i, x3r, x3i, x4r, x4i,
x5r, x5i, x6r, x6i, x7r, x7i, x8r, x8i,
x9r, x9i, x10r, x10i, x11r, x11i, x12r, x12i,
x13r, x13i, x14r, x14i, x15r, x15i;
x1r = a[2];
x1i = a[3];
x2r = a[4];
x2i = a[5];
x3r = a[6];
x3i = a[7];
x4r = a[8];
x4i = a[9];
x5r = a[10];
x5i = a[11];
x6r = a[12];
x6i = a[13];
x7r = a[14];
x7i = a[15];
x8r = a[16];
x8i = a[17];
x9r = a[18];
x9i = a[19];
x10r = a[20];
x10i = a[21];
x11r = a[22];
x11i = a[23];
x12r = a[24];
x12i = a[25];
x13r = a[26];
x13i = a[27];
x14r = a[28];
x14i = a[29];
x15r = a[30];
x15i = a[31];
a[2] = x15r;
a[3] = x15i;
a[4] = x7r;
a[5] = x7i;
a[6] = x11r;
a[7] = x11i;
a[8] = x3r;
a[9] = x3i;
a[10] = x13r;
a[11] = x13i;
a[12] = x5r;
a[13] = x5i;
a[14] = x9r;
a[15] = x9i;
a[16] = x1r;
a[17] = x1i;
a[18] = x14r;
a[19] = x14i;
a[20] = x6r;
a[21] = x6i;
a[22] = x10r;
a[23] = x10i;
a[24] = x2r;
a[25] = x2i;
a[26] = x12r;
a[27] = x12i;
a[28] = x4r;
a[29] = x4i;
a[30] = x8r;
a[31] = x8i;
}
