[PATCH] D74999: [WebAssembly] Fix a non-determinism problem in FixIrreducibleControlFlow

[Alon Zakai via Phabricator via llvm-commits]

kripken marked 2 inline comments as done.
kripken added a comment.

In D74999#1887675 <https://reviews.llvm.org/D74999#1887675>, @aheejin wrote:

> There seem to be multiple places that call `Graph.getLoopEntries()`. I guess we should sort all of them..? How about sort `LoopEntries` at the end of `calculate()` once and for all?


We actually don't need to sort all of them - just where it matters. For example at the end of processRegion the different sets are guaranteed to be disjoint, and so we can process them in any order (see comment inside the loop). And it might be a little faster to not sort unnecessarily.



================
Comment at: llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp:72
+  llvm::sort(SortedEntries,
+             [&](const MachineBasicBlock *A, const MachineBasicBlock *B) {
+               auto ANum = A->getNumber();
----------------
dschuff wrote:
> do we need to capture everything `[&]` here?
Ah, we don't good point. This code was just copied around but good idea to fix that.


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