rust/src/test/codegen/float_math.rs, branch 1.24.0https://github.com/rust-lang/rust
http://git.dreamy.place/mirrors/rust/atom?h=1.24.02017-10-07T16:04:23+00:00Fix typo in codegen test2017-10-07T16:04:23+00:00Robin Krupperobin.kruppe@gmail.com2017-10-07T16:04:23+00:00urn:sha1:7d1c14a32d9b09681d8050b30e35c30c7058d8b7Add intrinsics for float arithmetic with `fast` flag enabled2016-03-18T16:31:41+00:00Ulrik Sverdrupbluss@users.noreply.github.com2016-03-14T23:01:12+00:00urn:sha1:2dbac1fb8ed43cbcd160855803d50a51c38b8cee
`fast` a.k.a UnsafeAlgebra is the flag for enabling all "unsafe"
(according to llvm) float optimizations.
See LangRef for more information http://llvm.org/docs/LangRef.html#fast-math-flags
Providing these operations with less precise associativity rules (for
example) is useful to numerical applications.
For example, the summation loop:
let sum = 0.;
for element in data {
sum += *element;
}
Using the default floating point semantics, this loop expresses the
floats must be added in a sequence, one after another. This constraint
is usually completely unintended, and it means that no autovectorization
is possible.