[PATCH] D94039: [WebAssembly] Update WasmEHPrepare for the new spec

[Thomas Lively via Phabricator via cfe-commits]

tlively added inline comments.


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Comment at: llvm/lib/CodeGen/WasmEHPrepare.cpp:374-375
+  // be lowered to wasm 'catch' instruction. We do this mainly because
+  // instruction selection cannot handle wasm.get.exception intrinsic's token
+  // argument.
+  Instruction *CatchCI =
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dschuff wrote:
> tlively wrote:
> > What is the token argument used for? Could clang generate `llvm.wasm.catch` directly?
> Token arguments (https://llvm.org/docs/ExceptionHandling.html#wineh) are used to preserve the original scoping structure in mid-level optimization passes. I haven't looked at this intrinsic recently but I'd guess that maybe the token keeps it from getting moved out of its containing scope?
Ah, that makes sense, thanks!


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  https://reviews.llvm.org/D94039/new/

https://reviews.llvm.org/D94039