[PATCH] D85632: [Attributor] Implement AAPotentialValues

[Shinji Okumura via Phabricator via llvm-commits]

okura added inline comments.


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Comment at: llvm/lib/Transforms/IPO/AttributorAttributes.cpp:7343
+                                       const APInt &LHS, const APInt &RHS,
+                                       bool &Valid) {
+    Instruction::BinaryOps BinOpcode = BinOp->getOpcode();
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jdoerfert wrote:
> Add a TODO that we should look at `nsw` and `nuw` to help, e.g., to exclude certain results that cannot happen without creating `undef`. Similarly, division by `undef` should not make the result invalid but simply skip this operand pair.
I understand you mean that we can assume the operation result is not a poison value or undef and that we can ignore such operand pair. Is that right?
I'm thinking of adding a new argument `bool &Unsupported` to this to distinguish the above case from the case opcode is unsupported. 
In the former case we skip the operand pair, and in the latter case we give up (i.e. call `indicatePessimisticFixpoint`).


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  https://reviews.llvm.org/D85632/new/

https://reviews.llvm.org/D85632