Expand the improved notation for state and pipelining sections.

[matthijs/master-project/report.git] / Chapters / Normalization.tex

diff --git a/Chapters/Normalization.tex b/Chapters/Normalization.tex
index f1b53dfa7bc681969763e478045cec681ca62b09..1e5b200c0a82922b4f1b0c0350b09d6212372980 100644 (file)
--- a/Chapters/Normalization.tex
+++ b/Chapters/Normalization.tex
@@ -7,9 +7,9 @@
   % space at the start of the frame.
   \define[1]\example{
     \framed[offset=1mm,align=right,strut=no,background=box,frame=off]{
-      \setuptyping[option=LAM,style=sans,before=,after=]
+      \setuptyping[option=LAM,style=sans,before=,after=,strip=auto]
       \typebuffer[#1]
-      \setuptyping[option=none,style=\tttf]
+      \setuptyping[option=none,style=\tttf,strip=auto]
     }
   }
 
@@ -862,8 +862,50 @@
         Since its exact role and need is not clear yet, this transformation is
         not yet specified.
 
-      \subsubsection{Compiler generated top level binding inlining}
-        TODO
+      \subsubsection{Top level binding inlining}
+        This transform takes simple top level bindings generated by the
+        \small{GHC} compiler. \small{GHC} sometimes generates very simple
+        \quote{wrapper} bindings, which are bound to just a variable
+        reference, or a partial application to constants or other variable
+        references.
+
+        Note that this transformation is completely optional. It is not
+        required to get any function into normal form, but it does help making
+        the resulting VHDL output easier to read (since it removes a bunch of
+        components that are really boring).
+
+        This transform takes any top level binding generated by the compiler,
+        whose normalized form contains only a single let binding.
+
+        \starttrans
+        x = λa0 ... λan.let y = E in y
+        ~
+        x
+        --------------------------------------         \lam{x} is generated by the compiler
+        λa0 ... λan.let y = E in y
+        \stoptrans
+
+        \startbuffer[from]
+        (+) :: Word -> Word -> Word
+        (+) = GHC.Num.(+) @Word $dNum
+        ~
+        (+) a b
+        \stopbuffer
+        \startbuffer[to]
+        GHC.Num.(+) @ Alu.Word $dNum a b
+        \stopbuffer
+
+        \transexample{Top level binding inlining}{from}{to}
+       
+        Without this transformation, the (+) function would generate an
+        architecture which would just add its inputs. This generates a lot of
+        overhead in the VHDL, which is particularly annoying when browsing the
+        generated RTL schematic (especially since + is not allowed in VHDL
+        architecture names\footnote{Technically, it is allowed to use
+        non-alphanumerics when using extended identifiers, but it seems that
+        none of the tooling likes extended identifiers in filenames, so it
+        effectively doesn't work}, so the entity would be called
+        \quote{w7aA7f} or something similarly unreadable and autogenerated).
 
     \subsection{Program structure}
       These transformations are aimed at normalizing the overall structure
@@ -908,7 +950,7 @@
 
         \starttrans
         (letrec binds in E) M
-        -----------------
+        ------------------------
         letrec binds in E M
         \stoptrans