From 42526e142aa697db9391c7df0810ca4a4f73a164 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 24 Mar 2024 12:53:03 +0100
Subject: [PATCH] simplify_branches: add comment

---
 compiler/rustc_mir_transform/src/simplify_branches.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/compiler/rustc_mir_transform/src/simplify_branches.rs b/compiler/rustc_mir_transform/src/simplify_branches.rs
index 35a052166bd93..c746041ebd8ac 100644
--- a/compiler/rustc_mir_transform/src/simplify_branches.rs
+++ b/compiler/rustc_mir_transform/src/simplify_branches.rs
@@ -19,6 +19,7 @@ impl<'tcx> MirPass<'tcx> for SimplifyConstCondition {
         let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
         'blocks: for block in body.basic_blocks_mut() {
             for stmt in block.statements.iter_mut() {
+                // Simplify `assume` of a known value: either a NOP or unreachable.
                 if let StatementKind::Intrinsic(box ref intrinsic) = stmt.kind
                     && let NonDivergingIntrinsic::Assume(discr) = intrinsic
                     && let Operand::Constant(ref c) = discr