DHRYSTONES V2.0 cc cc -O4 cc -O fccO fccCE ack ack -O4 compile time: real 4.0 12.0 10.0 6.4 8.0 31.0 user 1.6 7.3 4.1 1.9 1.8 2.0 9.3 sys 0.9 2.1 1.8 2.5 1.5 2.0 7.7 run time: 7263 16250 15250 4730 3430 8474 10434 (stones/sec) SIEVE cc cc -O4 fccO fccCE ack ack -O4 compile time: real 2.4 4.4 x 3.3 6.4 17.0 user 0.8 1.6 x 0.7 0.7 3.2 sys 0.7 1.0 x 0.8 1.3 6.2 run time: 7.43 2.02 x 12.18 2.93 2.26 All ack-derived compilers are shell script driven