[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.
More information about the cfe-dev