[PATCH] D103382: [LoopDeletion] Consider infinite loops alive, unless mustprogress.

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

This looks okay with one caveat: We could still have an irreducible inner cycle, which will not be represented in LoopInfo. Any thoughts on what to do about that?



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Comment at: llvm/lib/Transforms/Scalar/LoopDeletion.cpp:118
+  };
+  return LoopFinite(L) && all_of(*L, LoopFinite);
 }
----------------
Just to double check, subloops also includes recursive subloops, right?


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Comment at: llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll:217
 ; as mustprogress. The loops can be removed.
 define void @inner_loop_may_be_infinite_but_top_loop_mustprogress(i1 %c1, i1 %c2) mustprogress {
 ; CHECK-LABEL: @inner_loop_may_be_infinite_but_top_loop_mustprogress(
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This is probably not checking what you want, because you also have the `mustprogress` function attribute, next to the loop metadata.


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Comment at: llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll:298
 loop3:
   br i1 %c2, label %loop1.latch, label %loop3
 
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You probably meant to use `%c3` here.


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Comment at: llvm/test/Transforms/LoopDeletion/unreachable-loops.ll:339
 ; REMARKS-LABEL: Function: test9
 ; REMARKS: Loop deleted because it never executes
 entry:
----------------
This remark shouldn't be there anymore ... possibly matches a future remark?


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