From c725637dc24fbe47704e92b7e8a8875f60ccd2be Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 2 Feb 2026 11:22:33 +0100
Subject: [PATCH] explain why we dont skip some of this work when there are
 field projections

---
 compiler/rustc_middle/src/mir/statement.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_middle/src/mir/statement.rs b/compiler/rustc_middle/src/mir/statement.rs
index 393e9c59c355..973ceccc67f9 100644
--- a/compiler/rustc_middle/src/mir/statement.rs
+++ b/compiler/rustc_middle/src/mir/statement.rs
@@ -441,6 +441,8 @@ impl<'tcx> Place<'tcx> {
     where
         D: ?Sized + HasLocalDecls<'tcx>,
     {
+        // If there's a field projection element in `projection`, we *could* skip everything
+        // before that, but on 2026-01-31 a perf experiment showed no benefit from doing so.
         PlaceTy::from_ty(local_decls.local_decls()[local].ty).multi_projection_ty(tcx, projection)
     }