1824250 - Generate better masm for argument-copying loops

Status: NEW

(Core :: JavaScript Engine: JIT, task, P2)

Description

[Iain Ireland [:iain]]

While reviewing Denis's patch here, I recommended that he rewrite his loop pushing arguments onto the stack to use the source address as the iteration variable (after precomputing an end address) to avoid having to increment the source and the iteration counter separately. (example) Then I looked at our current argument-copying code in BaselineCacheIRCompiler.cpp, which mostly doesn't do that (example).

I think we can do a little better here.