[PATCH] D96098: [X86] Don't pass a 1 to the secon argument of ISD::FP_ROUND in LowerFCOPYSIGN.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

In D96098#2544235 <https://reviews.llvm.org/D96098#2544235>, @pengfei wrote:

> LGTM. But if there's benefit for optimization if we use 1 here?

We're reconstructing an FP_ROUND that was removed by DAGCombine:visitFCOPYSIGN. DAGCombine didn't check the second operand before doing the combine. So we have to do the conservative thing when reconstructing it. I'm not sure how to retain the information unless we also add the operand to FCOPYSIGN.


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