From 98255cc2424b8ad3de462dc4241e14e23b1aa5c5 Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Tue, 4 Apr 2023 17:14:53 +0000
Subject: [PATCH] Comment logic around worklist.
---
compiler/rustc_mir_transform/src/const_prop_lint.rs | 3 +++
1 file changed, 3 insertions(+)
diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs
index 99bdb831c75..942ccd5a9d1 100644
--- a/compiler/rustc_mir_transform/src/const_prop_lint.rs
+++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs
@@ -675,10 +675,13 @@ impl<'tcx> Visitor<'tcx> for ConstPropagator<'_, 'tcx> {
&& let Ok(constant) = value_const.try_to_int()
&& let Ok(constant) = constant.to_bits(constant.size())
{
+ // We managed to evaluate the discriminant, so we know we only need to visit
+ // one target.
let target = targets.target_for_value(constant);
self.worklist.push(target);
return;
}
+ // We failed to evaluate the discriminant, fallback to visiting all successors.
}
// None of these have Operands to const-propagate.
TerminatorKind::Goto { .. }