[phicoh]

My experience with the Amsterdam Compile Kit (ACK) is that while ACK successfully managed to separate frontends, optimizers and backends using a single intermediate language, at the end it was the intermediate language that held it back.

The intermediate language was strongly stack oriented, to the extend that local CPU registers were mapped to stack locations. This worked well for pdp-11, vax, mc68k, and to some extent x86.

But when Sun's SPARC got popular it became clear that mapping stack register windows was not going to result in good performance.

One option would have been define a new register oriented intermediate language, just like llvm has now. But by that time research interests at the VU Amsterdam had shifted and this was never done.

[teddyh]

Interesting historical anecdote: ACK was briefly considered as a base for implementing GCC, but was rejected for licensing reasons.