mirror of
https://github.com/rust-lang/rust.git
synced 2025-10-08 05:06:52 +00:00
1762f018f7
rustc_target: Add msync target feature and enable it on powerpcspe targets Some older PowerPC processors do not have the `sync` (`sync 0`) and `lwsync` (`sync 1`) instructions, but instead have the `msync` instruction. (IIRC `msync` and `sync` will be assembled into the same bit-pattern, but `lwsync` will be SIGILL. See also https://gcc.gnu.org/legacy-ml/gcc-patches/2006-11/msg01238.html.) LLVM recognizes this as the [`msync` feature](cc5d8a4b2f/llvm/lib/Target/PowerPC/PPC.td (L140)) and enables for some cpus such as [e500](cc5d8a4b2f/llvm/lib/Target/PowerPC/PPC.td (L644)). powerpcspe is a target for CPUs such as e500 ([Debian Wiki](https://wiki.debian.org/PowerPCSPEPort)). However, the `msync` feature is currently not enabled except for vxworks, and at least since 2022-04, powerpc-unknown-linux-gnuspe was known to not work on real hardware without `-C target-cpu` (e.g., #96394, #117361).8c392966a0/compiler/rustc_target/src/spec/targets/powerpc_wrs_vxworks_spe.rs (L28)Fixes #117361 cc `@BKPepe` ([powerpc-unknown-linux-muslspe target maintainer](https://doc.rust-lang.org/nightly/rustc/platform-support/powerpc-unknown-linux-muslspe.html#target-maintainers)) cc `@glaubitz` (who added powerpc-unknown-linux-gnuspe in https://github.com/rust-lang/rust/pull/48484) cc `@th0ma7` (who opened #117361) r? workingjubilee `@rustbot` label +O-PowerPC +A-target-feature
rustc_target contains some very low-level details that are
specific to different compilation targets and so forth.
For more information about how rustc works, see the rustc dev guide.