diff options
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/mod.rs | 70 |
1 files changed, 66 insertions, 4 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs index ea47d32ea03..fbbf93e2dc4 100644 --- a/compiler/rustc_codegen_ssa/src/mir/mod.rs +++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs @@ -3,7 +3,7 @@ use std::iter; use rustc_index::IndexVec; use rustc_index::bit_set::DenseBitSet; use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags; -use rustc_middle::mir::{Local, UnwindTerminateReason, traversal}; +use rustc_middle::mir::{Body, Local, UnwindTerminateReason, traversal}; use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, HasTypingEnv, TyAndLayout}; use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypeFoldable, TypeVisitableExt}; use rustc_middle::{bug, mir, span_bug}; @@ -173,7 +173,12 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( let tcx = cx.tcx(); let llfn = cx.get_fn(instance); - let mir = cx.tcx().instance_mir(instance.def); + let mir = tcx.instance_mir(instance.def); + let mir = instance.instantiate_mir_and_normalize_erasing_regions( + tcx, + ty::TypingEnv::fully_monomorphized(), + ty::EarlyBinder::bind(mir.clone()), + ); let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty()); debug!("fn_abi: {:?}", fn_abi); @@ -183,7 +188,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( return; } - let debug_context = cx.create_function_debug_context(instance, fn_abi, llfn, mir); + let debug_context = cx.create_function_debug_context(instance, fn_abi, llfn, &mir); let start_llbb = Bx::append_block(cx, llfn, "start"); let mut start_bx = Bx::build(cx, start_llbb); @@ -195,7 +200,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( } let cleanup_kinds = - base::wants_new_eh_instructions(tcx.sess).then(|| analyze::cleanup_kinds(mir)); + base::wants_new_eh_instructions(tcx.sess).then(|| analyze::cleanup_kinds(&mir)); let cached_llbbs: IndexVec<mir::BasicBlock, CachedLlbb<Bx::BasicBlock>> = mir.basic_blocks @@ -205,6 +210,8 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( }) .collect(); + let mir = tcx.arena.alloc(optimize_use_clone::<Bx>(cx, mir)); + let mut fx = FunctionCx { instance, mir, @@ -311,6 +318,61 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( } } +// FIXME: Move this function to mir::transform when post-mono MIR passes land. +fn optimize_use_clone<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( + cx: &'a Bx::CodegenCx, + mut mir: Body<'tcx>, +) -> Body<'tcx> { + let tcx = cx.tcx(); + + if tcx.features().ergonomic_clones() { + for bb in mir.basic_blocks.as_mut() { + let mir::TerminatorKind::Call { + args, + destination, + target, + call_source: mir::CallSource::Use, + .. + } = &bb.terminator().kind + else { + continue; + }; + + // CallSource::Use calls always use 1 argument. + assert_eq!(args.len(), 1); + let arg = &args[0]; + + // These types are easily available from locals, so check that before + // doing DefId lookups to figure out what we're actually calling. + let arg_ty = arg.node.ty(&mir.local_decls, tcx); + + let ty::Ref(_region, inner_ty, mir::Mutability::Not) = *arg_ty.kind() else { continue }; + + if !tcx.type_is_copy_modulo_regions(cx.typing_env(), inner_ty) { + continue; + } + + let Some(arg_place) = arg.node.place() else { continue }; + + let destination_block = target.unwrap(); + + bb.statements.push(mir::Statement { + source_info: bb.terminator().source_info, + kind: mir::StatementKind::Assign(Box::new(( + *destination, + mir::Rvalue::Use(mir::Operand::Copy( + arg_place.project_deeper(&[mir::ProjectionElem::Deref], tcx), + )), + ))), + }); + + bb.terminator_mut().kind = mir::TerminatorKind::Goto { target: destination_block }; + } + } + + mir +} + /// Produces, for each argument, a `Value` pointing at the /// argument's value. As arguments are places, these are always /// indirect. |