[PATCH] D46265: StackColoring: better handling of statically unreachable code

[Than McIntosh via Phabricator via llvm-commits]

thanm added a comment.

@thanm You can take the reproducer in the bug report, produce LLVM-IR from it (-S -emit-llvm), then run it through llc with "-stop-before stack-slot-coloring" to get MIR output. The test file would then be invoked with the same options as before except you'd add '-start-before stack-slot-coloring'.

> Thank you! I will look into doing that.

Well, I am not having much luck creating a runnable MIR test case using this recipe. I tried:

clang -S -emit-llvm ... 
llc llvm-pr-37130.opt.ll -stop-before stack-coloring -o abc.mir

then edited the resulting file to introduce the statically unreachable block. When I run it using

llc ../llvm/test/CodeGen/X86/stack-coloring-unreachable-bb.mir -no-stack-coloring=false -start-before stack-coloring

I get a fatal error in the pass manager: "Unable to schedule 'Slot index numbering' required by 'Merge disjoint stack slots'".

I am probably making some sort of rookie mistake here somewhere, but I am not sure what.


Repository:
  rL LLVM

https://reviews.llvm.org/D46265