[PATCH] D157750: Properly handle -fsplit-machine-functions for fatbinary compilation

[Han Shen via Phabricator via cfe-commits]

shenhan added inline comments.


================
Comment at: clang/test/Driver/fsplit-machine-functions-with-cuda-nvptx.c:9
+
+// Check that -fsplit-machine-functions is passed to both x86 and cuda compilation and does not cause driver error.
+// MFS2: -fsplit-machine-functions
----------------
tra wrote:
> We will still see a warning, right? So, for someone compiling with `-Werror` that's going to be a problem.
> 
> Also, if the warning is issued from the top-level driver, we may not even be able to suppress it when we disable splitting on GPU side with `-Xarch_device -fno-split-machine-functions`.
> 
> 
> We will still see a warning, right?
Yes, there still will be a warning. We've discussed it and we think that pass -fsplit-machine-functions in this case is not a proper usage and a warning is warranted, and it is not good that skip doing split silently while uses explicitly ask for it.

> Also, if the warning is issued from the top-level driver
The warning will not be issued from the top-level driver, it will be issued when configuring optimization passes.
So:


  - -fsplit-machine-functions -Xarch_device -fno-split-machine-functions
Will enable MFS for host, disable MFS for gpus and without any warnings.

  - -Xarch_host -fsplit-machine-functions
The same as the above

  - -Xarch_host -fsplit-machine-functions -Xarch_device -fno-split-machine-functions
The same as the above



Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157750/new/

https://reviews.llvm.org/D157750