rust/compiler/rustc_codegen_ssa/src
Chris Denton e082bf341f
Rollup merge of #140323 - tgross35:cfg-unstable-float, r=Urgau
Implement the internal feature `cfg_target_has_reliable_f16_f128`

Support for `f16` and `f128` is varied across targets, backends, and backend versions. Eventually we would like to reach a point where all backends support these approximately equally, but until then we have to work around some of these nuances of support being observable.

Introduce the `cfg_target_has_reliable_f16_f128` internal feature, which provides the following new configuration gates:

* `cfg(target_has_reliable_f16)`
* `cfg(target_has_reliable_f16_math)`
* `cfg(target_has_reliable_f128)`
* `cfg(target_has_reliable_f128_math)`

`reliable_f16` and `reliable_f128` indicate that basic arithmetic for the type works correctly. The `_math` versions indicate that anything relying on `libm` works correctly, since sometimes this hits a separate class of codegen bugs.

These options match configuration set by the build script at [1]. The logic for LLVM support is duplicated as-is from the same script. There are a few possible updates that will come as a follow up.

The config introduced here is not planned to ever become stable, it is only intended to replace the build scripts for `std` tests and `compiler-builtins` that don't have any way to configure based on the codegen backend.

MCP: https://github.com/rust-lang/compiler-team/issues/866
Closes: https://github.com/rust-lang/compiler-team/issues/866

[1]: 555e1d0386/library/std/build.rs (L84-L186)

---

The second commit makes use of this config to replace `cfg_{f16,f128}{,_math}` in `library/`. I omitted providing a `cfg(bootstrap)` configuration to keep things simpler since the next beta branch is in two weeks.

try-job: aarch64-gnu
try-job: i686-msvc-1
try-job: test-various
try-job: x86_64-gnu
try-job: x86_64-msvc-ext2
2025-04-28 23:29:17 +00:00
..
back AsyncDrop implementation using shim codegen of async_drop_in_place::{closure}, scoped async drop added. 2025-04-28 16:23:13 +07:00
debuginfo Flatten ifs in rustc_codegen_ssa 2025-03-17 18:56:52 +00:00
mir AsyncDrop implementation using shim codegen of async_drop_in_place::{closure}, scoped async drop added. 2025-04-28 16:23:13 +07:00
traits Implement the internal feature cfg_target_has_reliable_f16_f128 2025-04-27 19:58:44 +00:00
assert_module_sources.rs Move methods from Map to TyCtxt, part 4. 2025-03-12 08:55:37 +11:00
base.rs Auto merge of #139453 - compiler-errors:incr, r=jieyouxu 2025-04-11 13:59:33 +00:00
codegen_attrs.rs Rollup merge of #139615 - nnethercote:rm-name_or_empty, r=jdonszelmann 2025-04-18 05:16:29 +02:00
common.rs Test fixing raw-dylib 2024-09-24 10:10:31 -07:00
errors.rs Rollup merge of #137953 - RalfJung:simd-intrinsic-masks, r=WaffleLapkin 2025-04-20 13:02:48 +00:00
lib.rs Implement the internal feature cfg_target_has_reliable_f16_f128 2025-04-27 19:58:44 +00:00
meth.rs More assertions, tests, and miri coverage 2025-01-30 17:44:28 +00:00
mono_item.rs Make a fake body to store typeck results for global_asm 2025-02-22 00:12:07 +00:00
size_of_val.rs Set both nuw and nsw in slice size calculation 2025-02-13 21:26:48 -08:00
target_features.rs Simplify implied_target_features. 2025-03-05 09:20:28 +11:00