Wasmtime GitHub notifications bot (Jul 25 2022 at 14:16): Wasmtime GitHub notifications bot (Jul 25 2022 at 14:16):alexcrichton commented on issue #4517:
Since this is just for the interpreter one possibility would be to use
libm::fmawhich is a port of musl's implementation to Rust which should provide stability across platforms perhaps.
Wasmtime GitHub notifications bot (Jul 26 2022 at 07:57):afonso360 commented on issue #4517:
libm's
fmaseems a lot better than MinGW's and it think it's implementation is correct.However, CI's still failing and I can't quite pin down why.
libmdisagrees with the nativefmaddinstruction inaarch64by exactly 1 bit, in the failing input. This seems like a rounding issue somewhere,libmhas the LSB as 1 andfmaddhas it as 0.I've checked
fegetroundand we are running with the default rounding mode.The other weird issue is that when I try to extract the failing input into a separate rust program and execute there, everything works and I get the correct result that agrees with the native instructions.
I'll keep looking into this, but if anyone has any ideas, let me know.
Wasmtime GitHub notifications bot (Jul 26 2022 at 08:17):afonso360 edited a comment on issue #4517:
libm's
fmaseems a lot better than MinGW's we are now only off by 1 LSB.I've filed https://github.com/rust-lang/libm/issues/263 to follow up with libm.
Wasmtime GitHub notifications bot (Jul 29 2022 at 05:28):afonso360 commented on issue #4517:
@alexcrichton since there is no way to know how long this is going to take with libm. What do you think about disabling the interpreter on the
fmatests temporarily?An alternative could be to have a reduced set of inputs that does not fail in a separate file.
That way we can resolve this now and move ahead with the CI upgrades.
Wasmtime GitHub notifications bot (Jul 29 2022 at 14:09):alexcrichton commented on issue #4517:
Sounds reasonable to me, thanks for helping to push on this @afonso360!
Last updated: Dec 23 2024 at 13:07 UTC