Related to dotnet/coreclr#22454. An optimization was previously introduced in coreclr which eliminates unnecessary mov instructions when zero-extending registers. However, that optimization only looks back one instruction to determine if the elimination is worthwhile.

Per dotnet/coreclr#23665, we have evidence that there's benefit to be realized from looking back more than one instruction when performing this optimization. We should be more aggressive about eliminating these mov instructions.

category:cq
theme:basic-cq
skill-level:intermediate
cost:medium