[PATCH] D106396: Prevent dead uses in register coalescer after rematerialization

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec created this revision.
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The coalescer does not check if register uses are available
at the point of rematerialization. If it attempts to rematerialize
an instruction with such uses it can end up with use without a def.

LiveRangeEdit does such check during rematerialization, so just
call LiveRangeEdit::allUsesAvailableAt() to avoid the problem.


https://reviews.llvm.org/D106396

Files:
  llvm/include/llvm/CodeGen/LiveRangeEdit.h
  llvm/lib/CodeGen/RegisterCoalescer.cpp
  llvm/test/CodeGen/AMDGPU/coalescer-remat-dead-use.mir

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