[PATCH] D124308: [MachineScheduler] exclude INLINEASM from schedule when it would increase register pressure

[Nick Desaulniers via Phabricator via llvm-commits]

nickdesaulniers added inline comments.


================
Comment at: llvm/lib/Target/X86/X86RegisterInfo.cpp:275
   case X86::VR64RegClassID:
     return 4;
   }
----------------
nickdesaulniers wrote:
> pengfei wrote:
> > I wonder why return 4 for it.
> Good question. Some comments could be added to this function to help retain more context as to WHY these magic constants have these values. I'm happy to do so in these commits, if we can document _why_.
> 
> I'm running `git log -S X86TargetLowering::getRegPressureLimit` to see if I can find additional context.
This code was added by commit:

commit 37b740c4bfbb ("Add an ILP scheduler.)
Author:     Evan Cheng <evan.cheng at apple.com>
AuthorDate: Sat Jul 24 00:39:05 2010 +0000


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D124308/new/

https://reviews.llvm.org/D124308