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| author | Trevor Gross <tmgross@umich.edu> | 2024-07-30 18:11:46 -0400 |
|---|---|---|
| committer | Trevor Gross <tmgross@umich.edu> | 2024-08-01 15:38:53 -0400 |
| commit | 8e2ca0c9d500ea435fbf9858a4d8cec8ee7dfde3 (patch) | |
| tree | 2265067e15a36eaa99529325b4d5f50502893448 | |
| parent | 43836421f8ddb872976f50e05f164b27159966c5 (diff) | |
| download | rust-8e2ca0c9d500ea435fbf9858a4d8cec8ee7dfde3.tar.gz rust-8e2ca0c9d500ea435fbf9858a4d8cec8ee7dfde3.zip | |
Add a disclaimer about x86 `f128` math functions
Due to a LLVM bug, `f128` math functions link successfully but LLVM chooses the wrong symbols (`long double` symbols rather than those for binary128). Since this is a notable problem that may surprise a number of users, add a note about it. Link: https://github.com/llvm/llvm-project/issues/44744
| -rw-r--r-- | library/core/src/primitive_docs.rs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/library/core/src/primitive_docs.rs b/library/core/src/primitive_docs.rs index 5989bcbcc52..09ebef89fb0 100644 --- a/library/core/src/primitive_docs.rs +++ b/library/core/src/primitive_docs.rs @@ -1244,6 +1244,9 @@ mod prim_f64 {} /// actually implement it. For x86-64 and AArch64, ISA support is not even specified, /// so it will always be a software implementation significantly slower than `f64`. /// +/// _Note: `f128` support is incomplete. Many platforms will not be able to link math functions. On +/// x86 in particular, these functions do link but their results are always incorrect._ +/// /// *[See also the `std::f128::consts` module](crate::f128::consts).* /// /// [wikipedia]: https://en.wikipedia.org/wiki/Quadruple-precision_floating-point_format |