[PATCH] D70226: Add an option to disable strict float node mutating to an normal float node

[Ulrich Weigand via Phabricator via llvm-commits]

uweigand added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:2668
+    return false;
+  }
+
----------------
I'm not sure this is always correct, I think it might be possible that a target might want to select Expand for a strict operation even if they use e.g. Custom for the non-strict version (obviously, that would have to be an operation where common code implements an Expand algorithm that respects the constrained FP semantics).

More importantly, even if you do this, you **still** need to add the checks in STRICT_FP_ROUND and STRICT_FP_EXTEND I mentioned in my earlier comment: note that in those cases, even if the target uses Expand for both the strict and non-strict operation, the code below still cannot be used if isStrictFPEnabled is true (since it does not respect constrained FP semantics).


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70226/new/

https://reviews.llvm.org/D70226