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vnmakarov / mir

A lightweight JIT compiler based on MIR (Medium Internal Representation) and C11 JIT compiler and interpreter based on MIR
MIT License
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Automated Meta Code Generation of MIR Code and Infrastructure #43

Open sirinath opened 4 years ago

sirinath commented 4 years ago

This might not be immediately actionable but can we have and DSL which describes the passing of a language MIR mapping and the optimisations applied where the code needed will be automatically generated. Also, the DSL should be able to describe itself so a future version of the DSL can be described in an older version. This way the code base will not be C but a purpose-built language on its own right. This way MIR will become more easy to understand, modify and improve.

vnmakarov commented 4 years ago

In some way, the current mapping description is already kind of DSL implemented on the top of C:

https://github.com/vnmakarov/mir/blob/ced76203bf5c4d27ade5f21b15208fedfecf1fc4/mir-gen-x86_64.c#L725-L779

For example, binutils is using even more primitive approach based on C macros and binutils supports much more architectures than one.

To create a general DSL to describe insns (and MIR mapping) of existing processors is a pretty big job. Architectures are so different.

I know one attempt https://sourceware.org/cgen written by one my former colleague. I would not say that its description is more understandable. It failed to be used by binutils, gcc, gdb, simulators etc.

So I prefer a natural approach, informal MIR insn defs in MIR.md and approach currently used by x86_64 mir generator. As I add more architectures, I may be will see that I need implementation of more general DSL.