[PATCH] D149775: [AMDGPU] Reserve SGPR pair when long branches are present

[Matt Arsenault via Phabricator via llvm-commits]

arsenm accepted this revision.
arsenm added inline comments.
This revision is now accepted and ready to land.


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Comment at: llvm/lib/Target/AMDGPU/GCNPreRALongBranchReg.cpp:116-117
+  constexpr bool ReserveHighestRegister = true;
+  Register LongBranchReservedReg = TRI->findUnusedRegister(
+      MRI, &AMDGPU::SGPR_64RegClass, MF, ReserveHighestRegister);
+  if (!LongBranchReservedReg) {
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crobeck wrote:
> arsenm wrote:
> > I don't see how this can fail unless you're using amdgpu-num-sgprs (and this is one of the reasons it should be removed)
> It failed in some test cases where all the SGPRs were already used from inline asm
oh right


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https://reviews.llvm.org/D149775