[PATCH] D138044: AMDGPU/GlobalISel: Fix crash after mad/fma_mix fails selection

[Pierre van Houtryve via Phabricator via llvm-commits]

Pierre-vh added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp:4817
+    // to avoid creating dead copy instruction.
+    std::tie(Src, Mods) = selectVOP3ModsImpl(Root);
+    MachineInstr *MI = getDefIgnoringCopies(Src, *MRI);
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With this it looks like we will end up calling `getVOP3ModsImpl` twice. I guess this isn't called often enough (and the "get" function seems simple enough) to cause performance issues but it still feels suboptimal
Could this be refactored to make it so selectVOP3ModsImpl doesn't need to call "get" again?
If not then I suppose it's fine as is



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https://reviews.llvm.org/D138044