From daaae11f4dd49285ee5cebf8f02586606401c22a Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Thu, 24 Apr 2025 22:11:23 +0000 Subject: [PATCH 1/2] 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]: https://github.com/rust-lang/rust/blob/555e1d0386f024a8359645c3217f4b3eae9be042/library/std/build.rs#L84-L186 --- src/lib.rs | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/src/lib.rs b/src/lib.rs index 9d9e790289cf..ab09a6f8b38e 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -41,8 +41,8 @@ use cranelift_codegen::isa::TargetIsa; use cranelift_codegen::settings::{self, Configurable}; -use rustc_codegen_ssa::CodegenResults; use rustc_codegen_ssa::traits::CodegenBackend; +use rustc_codegen_ssa::{CodegenResults, TargetConfig}; use rustc_metadata::EncodedMetadata; use rustc_middle::dep_graph::{WorkProduct, WorkProductId}; use rustc_session::Session; @@ -178,7 +178,7 @@ fn init(&self, sess: &Session) { } } - fn target_features_cfg(&self, sess: &Session) -> (Vec, Vec) { + fn target_config(&self, sess: &Session) -> TargetConfig { // FIXME return the actually used target features. this is necessary for #[cfg(target_feature)] let target_features = if sess.target.arch == "x86_64" && sess.target.os != "none" { // x86_64 mandates SSE2 support and rustc requires the x87 feature to be enabled @@ -197,7 +197,16 @@ fn target_features_cfg(&self, sess: &Session) -> (Vec, Vec) { }; // FIXME do `unstable_target_features` properly let unstable_target_features = target_features.clone(); - (target_features, unstable_target_features) + + TargetConfig { + target_features, + unstable_target_features, + // Cranelift does not yet support f16 or f128 + has_reliable_f16: false, + has_reliable_f16_math: false, + has_reliable_f128: false, + has_reliable_f128_math: false, + } } fn print_version(&self) { From c179f96fa923514906361af40a956a5284685822 Mon Sep 17 00:00:00 2001 From: Andrew Zhogin Date: Mon, 26 Aug 2024 16:45:15 +0300 Subject: [PATCH 2/2] AsyncDrop implementation using shim codegen of async_drop_in_place::{closure}, scoped async drop added. --- src/abi/mod.rs | 9 +++++---- src/base.rs | 6 +++++- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/src/abi/mod.rs b/src/abi/mod.rs index ddd119e0c610..5f631405a9a4 100644 --- a/src/abi/mod.rs +++ b/src/abi/mod.rs @@ -441,7 +441,9 @@ pub(crate) fn codegen_terminator_call<'tcx>( Err(instance) => Some(instance), } } - InstanceKind::DropGlue(_, None) | ty::InstanceKind::AsyncDropGlueCtorShim(_, None) => { + // We don't need AsyncDropGlueCtorShim here because it is not `noop func`, + // it is `func returning noop future` + InstanceKind::DropGlue(_, None) => { // empty drop glue - a nop. let dest = target.expect("Non terminating drop_in_place_real???"); let ret_block = fx.get_block(dest); @@ -707,9 +709,8 @@ pub(crate) fn codegen_drop<'tcx>( let ty = drop_place.layout().ty; let drop_instance = Instance::resolve_drop_in_place(fx.tcx, ty); - if let ty::InstanceKind::DropGlue(_, None) | ty::InstanceKind::AsyncDropGlueCtorShim(_, None) = - drop_instance.def - { + // AsyncDropGlueCtorShim can't be here + if let ty::InstanceKind::DropGlue(_, None) = drop_instance.def { // we don't actually need to drop anything } else { match ty.kind() { diff --git a/src/base.rs b/src/base.rs index adaa754491e5..e9c7186b03c9 100644 --- a/src/base.rs +++ b/src/base.rs @@ -565,7 +565,11 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) { | TerminatorKind::CoroutineDrop => { bug!("shouldn't exist at codegen {:?}", bb_data.terminator()); } - TerminatorKind::Drop { place, target, unwind: _, replace: _ } => { + TerminatorKind::Drop { place, target, unwind: _, replace: _, drop, async_fut } => { + assert!( + async_fut.is_none() && drop.is_none(), + "Async Drop must be expanded or reset to sync before codegen" + ); let drop_place = codegen_place(fx, *place); crate::abi::codegen_drop(fx, source_info, drop_place, *target); }