1 files changed, 45 insertions, 0 deletions
diff --git a/docs/comm/rts-libs/stgc.html b/docs/comm/rts-libs/stgc.html
new file mode 100644
index 0000000000..196ec9150d
--- /dev/null
+++ b/docs/comm/rts-libs/stgc.html
@@ -0,0 +1,45 @@
+<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
+<html>
+  <head>
+    <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1">
+    <title>The GHC Commentary - Spineless Tagless C</title>
+  </head>
+
+  <body BGCOLOR="FFFFFF">
+    <h1>The GHC Commentary - Spineless Tagless C</h1>
+    <p>
+      The C code generated by GHC doesn't use higher-level features of C to be
+      able to control as precisely as possible what code is generated.
+      Moreover, it uses special features of gcc (such as, first class labels)
+      to produce more efficient code.
+    <p>
+      STG C makes ample use of C's macro language to define idioms, which also
+      reduces the size of the generated C code (thus, reducing I/O times).
+      These macros are defined in the C headers located in GHC's <a
+	href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/includes/"><code>includes</code></a>
+      directory.
+
+    <h4><code>TailCalls.h</code></h4>
+    <p>
+      <a
+	href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/includes/TailCalls.h"><code>TailCalls.h</code></a>
+      defines how tail calls are implemented - and in particular - optimised
+      in GHC generated code.  The default case, for an architecture for which
+      GHC is not optimised, is to use the mini interpreter described in the <a
+	href="http://research.microsoft.com/copyright/accept.asp?path=/users/simonpj/papers/spineless-tagless-gmachine.ps.gz&pub=34">STG paper.</a>
+    <p>
+      For supported architectures, various tricks are used to generate
+      assembler implementing proper tail calls.  On i386, gcc's first class
+      labels are used to directly jump to a function pointer.  Furthermore,
+      markers of the form <code>--- BEGIN ---</code> and <code>--- END
+      ---</code> are added to the assembly right after the function prologue
+      and before the epilogue.  These markers are used by <a
+	href="../the-beast/mangler.html">the Evil Mangler.</a>
+
+    <p><small>
+<!-- hhmts start -->
+Last modified: Wed Aug  8 19:28:29 EST 2001
+<!-- hhmts end -->
+    </small>
+  </body>
+</html>