[PATCH] D70066: [MacroFusion] Limit the max fused number as 2 to reduce the dependency

[Qing Shan Zhang via Phabricator via llvm-commits]

steven.zhang created this revision.
steven.zhang added reviewers: fhahn, evandro, MatzeB, arsenm, jsji, PowerPC, hfinkel.
Herald added subscribers: hiraditya, nhaehnle, wdng, jvesely.
Herald added a project: LLVM.
steven.zhang added a parent revision: D69998: [MacroFusion] Create the missing artificial edges if there are more than 2 SU fused..

This is the continue work for https://reviews.llvm.org/D36704. And I have described the problems of allowing more than two instructions fused together in https://reviews.llvm.org/D69998 . We will create unnecessary dependency edges that hurt the scheduler and break the fusion. Therefore, we should change the interface to leave it to the target to determine the max fuse instruction number it wants.


https://reviews.llvm.org/D70066

Files:
  llvm/include/llvm/CodeGen/MacroFusion.h
  llvm/lib/CodeGen/MacroFusion.cpp
  llvm/lib/Target/AArch64/AArch64MacroFusion.cpp
  llvm/lib/Target/AMDGPU/AMDGPUMacroFusion.cpp
  llvm/lib/Target/ARM/ARMMacroFusion.cpp
  llvm/lib/Target/X86/X86MacroFusion.cpp
  llvm/test/CodeGen/AArch64/macro-fusion.ll

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