Correct comments.

compiler/rustc_mir_dataflow/src/move_paths/mod.rs

@@ -1,15 +1,14 @@
-//! The move-analysis portion of borrowck needs to work in an abstract
+//! The move-analysis portion of borrowck needs to work in an abstract domain of lifted `Place`s.
-//! domain of lifted `Place`s. Most of the `Place` variants fall into a
+//! Most of the `Place` variants fall into a one-to-one mapping between the concrete and abstract
-//! one-to-one mapping between the concrete and abstract (e.g., a
+//! (e.g., a field projection on a local variable, `x.field`, has the same meaning in both
-//! field-deref on a local variable, `x.field`, has the same meaning
+//! domains). In other words, all field projections for the same field on the same local do not
-//! in both domains). Indexed projections are the exception: `a[x]`
+//! have meaningfully different types if ever. Indexed projections are the exception: `a[x]` needs
-//! needs to be treated as mapping to the same move path as `a[y]` as
+//! to be treated as mapping to the same move path as `a[y]` as well as `a[13]`, etc. So we map
-//! well as `a[13]`, etc. So we map these `x`/`y` values to `()`.
+//! these `x`/`y` values to `()`.
 //!
-//! (In theory, the analysis could be extended to work with sets of
+//! (In theory, the analysis could be extended to work with sets of paths, so that `a[0]` and
-//! paths, so that `a[0]` and `a[13]` could be kept distinct, while
+//! `a[13]` could be kept distinct, while `a[x]` would still overlap them both. But that is not
-//! `a[x]` would still overlap them both. But that is not this
+//! what this representation does today.)
-//! representation does today.)
 
 use std::fmt;
 use std::ops::{Index, IndexMut};

compiler/rustc_mir_transform/src/gvn.rs

@@ -447,7 +447,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
 
             Projection(base, elem) => {
                 let base = self.evaluated[base].as_ref()?;
-                // `Index` by constants should have been replaces by `ConstantIndex` by
+                // `Index` by constants should have been replaced by `ConstantIndex` by
                 // `simplify_place_projection`.
                 let elem = elem.try_map(|_| None, |()| ty.ty)?;
                 self.ecx.project(base, elem).discard_err()?
@@ -460,7 +460,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 let pointer = self.evaluated[local].as_ref()?;
                 let mut mplace = self.ecx.deref_pointer(pointer).discard_err()?;
                 for elem in place.projection.iter().skip(1) {
-                    // `Index` by constants should have been replaces by `ConstantIndex` by
+                    // `Index` by constants should have been replaced by `ConstantIndex` by
                     // `simplify_place_projection`.
                     let elem = elem.try_map(|_| None, |ty| ty)?;
                     mplace = self.ecx.project(&mplace, elem).discard_err()?;