[PATCH] D72737: [AMDGPU] Bundle loads before post-RA scheduler

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec marked an inline comment as done.
rampitec added inline comments.


================
Comment at: llvm/test/CodeGen/AMDGPU/cross-block-use-is-not-abi-copy.ll:188
+; GCN-NEXT:    global_store_dword v[0:1], v0, off
+; GCN-NEXT:    s_endpgm
 ; GCN-NEXT:  BB4_2: ; %if.else
----------------
rampitec wrote:
> foad wrote:
> > What happened here? Has some cost estimate changed because of the bundling? Can we fix it?
> It was duplicated by Branch Probability Basic Block Placement immediately after the post-RA scheduler.
> It is now duplicated because of -tail-dup-placement-threshold default value of 2. If you use 3 it will be duplicated w/o bundling.
> That is because TailDuplicator::shouldTailDuplicate() simply count instructions and compare against the threshold: https://llvm.org/doxygen/TailDuplicator_8cpp_source.html#l00622
> 
> It can be fixed in a separate follow-up patch to add a bundle's size if it is a bundle, I am not sure if it may affect other targets or not.
Apparently that does not affect any other target: D72783


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72737/new/

https://reviews.llvm.org/D72737