Auto merge of #125025 - saethlin:clone-your-body, r=<try>

[perf experiments] Clone all MIR bodies We keep saying things like cloning all the MIR would be expensive, but... how expensive actually?
rust-lang · May 11, 2024 · c0bcf54 · c0bcf54
2 parents 3349155 + bedbc3c
commit c0bcf54
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -166,6 +166,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     let llfn = cx.get_fn(instance);
 
     let mir = cx.tcx().instance_mir(instance.def);
+    drop(std::hint::black_box(mir.clone()));
 
     let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty());
     debug!("fn_abi: {:?}", fn_abi);