[PATCH] D116952: [ConstantFolding] Respect denormal handling mode attributes when folding instructions

[David Candler via Phabricator via llvm-commits]

dcandler added a comment.

When I originally checked the other calls to ConstantFoldBinaryOpOperands did not look like they would potentially be handling floating point instructions, although on second look, I missed InstructionSimplify::foldOrCommuteConstant. The same approach should work there too though, so I can expand the patch to cover that usage.

If the instruction lacks a parent function, then the alternative to defaulting to IEEE would be not folding at all. The impact to that could be limited to only instructions to where a denormal is detected in the input/output; if there's no denormal, there's no need for a parent function so folding can proceed.

Constant expressions won't be currently be affected by this, although potentially they could also follow the principle of only getting folded if denormals are not involved.


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https://reviews.llvm.org/D116952