Post #2797250

2026-04-14 21:25 UTC

@zeux@mastodon.gamedev.place @lisyarus@mastodon.gamedev.place IEEE 754 at least seems to allow this as long as it can be switched off, doesn't require it to be disabled by default - or at least that's what the C/C++ standards and/or compilerwriters think (GCC is extra fun because it only allows using -ffp-contract but ignores the FP_CONTRACT pragma)

Replies (2)

@rygorous@mastodon.gamedev.place 2026-04-14 21:36

@Doomed_Daniel@mastodon.gamedev.place @zeux@mastodon.gamedev.place @lisyarus@mastodon.gamedev.place again, that's not IEEE 754. But it's not like the FP standard gets a vote on this. The language standards do whatever they want. See also Kahan's rants on Java's choices wrt FP implementation in the 90s and early 2000s. Mind, in a lot of that he's railing against the idea of trying to aim for exact reproducibility since it was at the time impractical. By now it wouldn't be, though.

Open ##2797251
@amonakov@mastodon.gamedev.place 2026-04-15 12:36

@Doomed_Daniel@mastodon.gamedev.place @zeux@mastodon.gamedev.place @lisyarus@mastodon.gamedev.place as far as I'm aware, C++ standards do not have anything analogous to C's Annex F that would say how the language binds to IEEE 754 / IEC 60559.

Open ##2797263