[PATCH] D155087: [CodeGen] Fix assertion failure caused by inline assembly

[Qi Hu via Phabricator via llvm-commits]

Qi-Hu added inline comments.


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Comment at: llvm/lib/CodeGen/RegAllocFast.cpp:838
       MI.emitError("inline assembly requires more registers than available");
+      report_fatal_error("inline assembly requires more registers than available", false);
+    }
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bryanpkc wrote:
> bryanpkc wrote:
> > `MachineInstr::emitError` falls back to calling `report_fatal_error` if it cannot find a `MCContext`. Making an additional call to `report_fatal_error` here doesn't feel right. Why isn't `MI.emitError` able to stop the compiler before it crashes?
> > `MachineInstr::emitError` falls back to calling `report_fatal_error` if it cannot find a `MCContext`.
> 
> I meant `LLVMContext`, not `MCContext`.
`emitError` is designed to return and does not stop the pass. In fact, given the same test case, `RegAllocGreedy` also reports the error but ends up generating bogus assembly, without crashing. I have updated the patch to mimic that behaviour, by copying some existing logic from `useVirtReg`.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D155087/new/

https://reviews.llvm.org/D155087