https://gcc.gnu.org/bugzilla/show_bug.cgi?id=20785
--- Comment #10 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- On Fri, 21 Feb 2020, vincent-gcc at vinc17 dot net wrote: > Concerning the STDC FP_CONTRACT pragma, implementing it would not be > sufficient. GCC would also need to restrict how it does contraction, as it > currently does not contract only expressions, but also sequences of > expressions, which is invalid. Example: Note that -ffp-contract=on is currently equivalent to -ffp-contract=off for this reason. It's only -ffp-contract=fast that contracts outside expressions (and C standards conformance modes disable contraction).