David Holland skrev den 2015-06-03 07:56:
> PCC, to the best of my knowledge is still in the [very early] planning > stages. One of its design choices would be to go pure SSA. Another > option, closer to GCC (RTL), would be to retain existing code-gen > passes. Tough choices. I'm not sure why it's such a big deal, except that everything in gcc is a big deal because gcc is such a mess inside. Moving an existing representation to SSA just requires adding phi nodes to the representation, writing a check pass to enforce the single assignment property, and updating existing passes to maintain the property -- in a language without proper algebraic data types this is a bigger deal than otherwise but it does not seem like a particularly major undertaking. Unless the representation is totally wrong in other ways that need to be rectified first.
SSA representation was added to pcc in 2008.
> > backend is an orthogonal issue. > > I'm being fast and loose. My reading of the code was that debug info > was being generated by the back of the front end (very roughly > "gimplify" in this diagram of GCC > https://gcc.gnu.org/projects/tree-ssa/#ssa). It was pretty much hard > wired printfs, and explained to me why "-g -O" wasn't supported. printfing from the back of the front end is definitely "totally wrong in other ways that need to be rectified first" :(
Hm, I may be missing something, but what is wrong? Where should you print it out otherwise? -- Ragge