[PATCH] D119216: [AMDGPU] replace hostcall module flag with function attribute

[Sameer Sahasrabuddhe via Phabricator via cfe-commits]

sameerds added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp:566
+      return false;
+    };
+
----------------
jdoerfert wrote:
> You can use AAPointerInfo for the call site return IRPosition. It will (through the iterations) gather all accesses and put them into "bins" based on offset and size. It deals with uses in calls, etc. and if there is stuff missing it is better to add it in one place so we benefit throughout. 
I am not following what you have in mind. "implicitarg_ptr" is a pointer returned by an intrinsic that reads an ABI-defined register. I need to check that for a given call-graph, a particular range of bytes relative to that base pointer are never accessed. The above DFS on the uses conservatively assumes that such a load exists unless it can conclusively trace every use of the base pointer. This may include the pointer being passed to an extern function or being stored into a different memory location (although we don't expect ABI registers being capture this way). I am not seeing how to construct this around AAPointerInfo. As far as I can see, the public interface only talks about uses that are recognized as loads and stores.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D119216/new/

https://reviews.llvm.org/D119216