[vpr][place] apply Vaughn's comments

vpr/src/place/place_delay_model.cpp

@@ -235,7 +235,7 @@ void SimpleDelayModel::read(const std::string& file) {
     // ToNdMatrix is a generic function for converting a Matrix capnproto
     // to a vtr::NdMatrix.
     //
-    // The use must supply the matrix dimension (2 in this case), the source
+    // The user must supply the matrix dimension (5 in this case), the source
     // capnproto type (VprFloatEntry),
     // target C++ type (flat), and a function to convert from the source capnproto
     // type to the target C++ type (ToFloat).
@@ -246,7 +246,7 @@ void SimpleDelayModel::read(const std::string& file) {
 }
 
 void SimpleDelayModel::write(const std::string& file) const {
-    // MallocMessageBuilder object is the generate capnproto message builder,
+    // MallocMessageBuilder object generates capnproto message builder,
     // using malloc for buffer allocation.
     ::capnp::MallocMessageBuilder builder;
 

vpr/src/place/place_delay_model.h

@@ -235,6 +235,15 @@ class SimpleDelayModel : public PlaceDelayModel {
   public:
     SimpleDelayModel() {}
 
+    /**
+     * @brief Initializes the `delays_` data structure. This involves retrieving the corresponding delays for each entry from
+     * the router lookahead and storing the minimum among them.
+     *
+     * @param router The router used to retrieve information from the router lookahead.
+     * @param placer_opts Placment parameters.
+     * @param router_opts Routing parameters.
+     * @param longest_length The length of the longest routing track.
+    */
     void compute(
         RouterDelayProfiler& router,
         const t_placer_opts& placer_opts,
@@ -245,6 +254,9 @@ class SimpleDelayModel : public PlaceDelayModel {
 
     void read(const std::string& /*file*/) override;
     void write(const std::string& /*file*/) const override;
+    /**
+     @brief Returns a reference to the array containing the placement delay matrix.
+    */
     const vtr::NdMatrix<float, 5>& delays() const {
         return delays_;
     }