[PATCH] D14750: Support for function-live-in virtual registers

[Quentin Colombet via llvm-commits]

qcolombet added a comment.

Hi Dan,

I am puzzled by the following statement:

> however it's awkward to prevent other instructions from being scheduled above them, and subsequently to prevent register coloring from clobbering the argument registers before they are properly defined.


Since you have an infinite number of registers, how do you end up with other registers clobbering the arguments registers?
Are these arguments registers actual physical registers?!

To be frank, I do not like the approach that’s why I would prefer to understand what are the constraints of the problem first.

That being said, let me comment a bit on the proposal. You are restricting the live-in information to the entry block and that sounds wrong. Indeed, I guess if you go down that road, you want to model arguments of landing pad the same way and the related blocks are not the entry block anymore!

Thanks,
-Quentin


Repository:
  rL LLVM

http://reviews.llvm.org/D14750