[cfe-dev] fp-contract at -O0

David Greene via cfe-dev cfe-dev at lists.llvm.org
Tue Feb 18 11:01:44 PST 2020

Stephen Canon via cfe-dev <cfe-dev at lists.llvm.org> writes:

> If anything, preserving FMA formation at O0 _helps_ debuggability,
> because it means that numerical behavior is more likely to match what
> a user observed at Os, allowing them to debug the problem.

The user can always pass -ffp-contract=on to do that.

There are many cases where FMA is not desired and most users don't
expect fused operations at -O0 unless they specifically ask for it.


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