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by gpderetta 834 days ago
Oh, wow, forgot about fp-contract. It says it is off in C by default, what about C++?
1 comments
zokier 834 days ago
Read closer, it defaults to fast, not off
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planede 833 days ago
I would have expected to be a bug in the documentation? Why would they turn FMA off for standard compliant C mode, but not for standard compliant C++ mode?

But the documentation does appear to be correct: https://godbolt.org/z/3bvP136oc

Crazy.

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gpderetta 833 days ago
it defaults to off for standard-compliant mode. Which in my mind was the default mode as that's what we use everywhere I have worked in the last 15 years. But of course that's not the case.

In any case, according to the sibling comment, the default is 'fast' even in std-compliant mode in C++, which I find very surprising. I'm not very familiar with that corner of the standard, but it must be looser than the equivalent wording in the C standard.

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