[LLVMdev] Parametric polymorphism

[DeLesley Hutchins]

> It's done by the front-end. There are a variety of attributes and
> mechanisms which are used to convolute data and marshall it through
> call sites in an ABI-conformant manner.

Oh dear.  :-(   Do the attributes change depending on the type?
I would assume that attributes like "ccc" are type-invariant; i.e.
every instantiation should use the C-calling convention, whatever
that happens to be for the types in question.

>> I want llvm to do the specialization, because specialization is
>> inextricably tied to similar optimizations, like inlining and
>> partial evaluation.  Doing it within llvm has many advantages, such
>> as JIT support and link-time optimization.
>
> These are IR-level optimizations, which LLVM does not magically do of
> its own accord. If LLVM transparently performs specialization, then no
> post-specialization IR optimizations can be performed.

Since these are IR-level optimizations, the logical place to put type
variables is in the IR.  If type variables only exist in the high-level
language, then it's impossible for the llvm linker, JIT, or optimizers,
or code generators to do anything intelligent with them.  :-)

I don't expect magic.  If type specialization is implemented as an IR
pass, then why couldn't post-specialization IR optimizations be
performed?

  -DeLesley