[PATCH] D71373: [ConstantFolding] Disable constant folding for bitcasts to x86_fp80

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

I was looking into trying to see if we could store this in APFloat. And I just noticed that we mark pseudonan, pseudoinfinity, and unnformals all as fcnan, and copy their original significand from the apint. I believe since the integer bit was 0, this makes apfloat encode them as a pseudonan. Then I think arithmetic operations with one of these as an operand will propagate the pseudonan. Should we have forced the integer bit of the significand when we created it to make it a true nan?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D71373/new/

https://reviews.llvm.org/D71373