Changes between Version 17 and Version 18 of Status/May11

Timestamp:

04/29/11 01:38:34 (2 years ago)

Author:

simonpj

Comment:

--

Status/May11

@@ -26 +26 @@
 
  With the advent of GADTs and type families, the type system of the
- Core necessarily has to become a bit more complicated.  For a few
- years wa have been using an extension of System F, called System
- FC, as described in our paper [[http://research.microsoft.com/en-us/um/people/simonpj/papers/ext-f/ FC]].  However, the way that System FC
+ Core had to grow a little.  For a few
+ years we have been using an extension of System F, called System
+ FC, as described in our 2007 paper [[http://research.microsoft.com/en-us/um/people/simonpj/papers/ext-f/ FC]].  However, the way that System FC
  was actually ''implemented'' in GHC's Core language was a bit unsatisfactory
- so, with help from Brent Yorgey, Simon PJ is busy re-engineering it. 
+ so, with help from '''Brent Yorgey''', Simon PJ is busy re-engineering it. 
  In particular, FC has ''coercion terms'', and these will now 
  be represented by their own data type `Coercion`, rather than being
@@ -37 +37 @@
  equivalent smaller ones. All this is described in our new paper [http://research.microsoft.com/en-us/um/people/simonpj/papers/ext-f/ !NewFC].
  These changes will (finally) complete the type-family story by
- making so-called "equality superclasses" work for the first time.
+ making so-called "equality superclasses" work for the first time in GHC 7.2.
 
  * '''Pedro Magalhaes''' has nearly completed his implementation of the
@@ -43 +43 @@
    Haskell Symposium paper [[http://www.dreixel.net/research/pdf/gdmh_nocolor.pdf Derivable]].  It will be in GHC 7.2.
 
- * '''Edward Yang''' has done a lot of work on the long-promised new
-   code-generation path.  Hoopl is now fully part of GHC, and
-   the new path uses it extensively.  We are now working on making
-   the new pipeline generate better code than the old one.  Stay
-   tuned.
+ * '''Edward Yang''' has spearheaded a flurry of work on the new
+   code generation backend (`-fuse-new-codegen`, the rewrite of
+   the part of GHC that turns STG syntax into C--).  Hoopl is now
+   fully part of GHC [[http://research.microsoft.com/en-us/um/people/simonpj/papers/c--/ Hoopl]], and the new path uses it extensively; we’ve
+   ironed out most of the bugs in the backend; and now we’re
+   working on new optimization passes and fixing inefficiencies to
+   get the generated code as good (or better) than the old code
+   generator.  We’re still not at the point where the new code
+   generator will generate better code, but we’re pretty close!
+   Stay tuned.
 
  * '''Simon Marlow: Any update?''' Previous entry: ''In joint work with Phil Trinder and his colleagues at Herriot Watt, Simon M designed implemented a new '''parallel strategies library''', described in their 2010 Haskell Symposium paper [[http://www.haskell.org/~simonmar/papers/strategies.pdf Seq]].''
@@ -54 +59 @@
 sleeves and help us with GHC.  Amongst those who have been active recently are:
  * Mark Lentczner and Dan Knapp have been working on cross-compilation support
+ * Continued work on the new I/O manager by Johan Tibbe.
  * Various improvements and build fixes for OS X, from PHO, Greg Wright, Thorkil Naur and William Knop
  * Solaris fixes from Karel Gardas and Christian Maeder
@@ -64 +70 @@
  * General tidyups from Matthias Kilian
  * Primop improvements from Daniel Peebles
- * Some GHCi improvements from Vivian McPhail and Boris Lykah
+ * Some GHCi improvements from Vivian !McPhail and Boris Lykah
  * More GHCi debugger fixes from Pepe Iborra
  * LLVM development continues with David Terei
@@ -78 +84 @@
 Here's a selection that we know about.
 
- * '''Jeff Epstein''' has implemented a library that brings Erlang's programming model to Haskell programmers.  In particular, you can write a Haskell program that runs on a cluster of machines that do not share memory.  It is all based on a modest but powerful language extension that makes it possible for a programmer to work with "static" functions; that is, ones consisting of pure code with no free variables.  The paper that describes all this is called "Haskell for the cloud" [[http://research.microsoft.com/en-us/um/people/simonpj/papers/parallel/ Cloud]].
+ * '''Jeff Epstein''', in collaboration with Andrew Black, has implemented a library that brings Erlang's programming model to Haskell programmers.  In particular, you can write a Haskell program that runs on a cluster of machines that do not share memory.  It is all based on a modest but powerful language extension that makes it possible for a programmer to work with "static" functions; that is, ones consisting of pure code with no free variables.  The paper that describes all this is called "Haskell for the cloud" [[http://research.microsoft.com/en-us/um/people/simonpj/papers/parallel/ Cloud]].
 
  * ''David Mazieres at Stanford wants to implement '''Safe Haskell''', a flag for GHC that will guarantee that your program does not use `unsafePerformIO`, foreign calls, RULES, and other stuff stuff.''
@@ -116 +122 @@
  * [FC] "System F with type equality coercions", Sulzmann, Chakravarty, Peyton Jones, TLDI 2007, http://research.microsoft.com/en-us/um/people/simonpj/papers/ext-f/
 
+ * [Hoopl] "A modular, reusable library for dataflow analysis and transformation", Dias, Ramsey, and Peyton Jones, Haskell Symposium 2010, http://research.microsoft.com/en-us/um/people/simonpj/papers/c--/
+
  * [!NewFC] "Practical aspects of evidence-based compilation in System FC", Vytiniotis and Peyton Jones, submitted to ICFP 2011, http://research.microsoft.com/en-us/um/people/simonpj/papers/ext-f/