SIGN_EXT
nf[i] = SIGN_EXT(nf[i]);
nf_ext[i] = SIGN_EXT(nf_ext[i]);
nf[i] = SIGN_EXT(nf[i]);
nf_ext[i] = SIGN_EXT(nf_ext[i]);
m = SIGN_EXT(val[i][j].m);
p = SIGN_EXT(val[i][j].p);
c = SIGN_EXT(val[i][j].c);