ref: e2136d60b2db6c714a0c7c84f38bbcad5c519b71 dir: /test/asm/rs.out/
a1 = $0 a2 = $1 a3 = $3 _RS = $7 b1 = $7 b2 = $8 b3 = $A _RS = $E c1 = $2A c2 = $2B c3 = $2D _RS = $31 d1 = $0 d2 = $1 d3 = $3 _RS = $7