From 2605b6ba2749a90c55a7f49bb91d6f20f256a20e Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@pobox.com>
Date: Wed, 21 Sep 2011 08:46:44 +0200
Subject: [PATCH] better pure-expression?

* module/language/tree-il/optimize.scm (peval): Allow dynref, fix, and
  let-values to be pure expressions.
---
 module/language/tree-il/optimize.scm | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/module/language/tree-il/optimize.scm b/module/language/tree-il/optimize.scm
index 0567b0cfa..f69ce557e 100644
--- a/module/language/tree-il/optimize.scm
+++ b/module/language/tree-il/optimize.scm
@@ -320,6 +320,7 @@ it does not handle <fix> and <let-values>, it should be called before
         (($ <lexical-ref>) #t)
         (($ <toplevel-ref>) #t)
         (($ <primitive-ref>) #t)
+        (($ <dynref> _ fluid) (loop fluid))
         (($ <conditional> _ condition subsequent alternate)
          (and (loop condition) (loop subsequent) (loop alternate)))
         (($ <application> _ ($ <primitive-ref> _ name) args)
@@ -334,6 +335,10 @@ it does not handle <fix> and <let-values>, it should be called before
          (and (every loop vals) (loop body)))
         (($ <letrec> _ _ _ _ vals body)
          (and (every loop vals) (loop body)))
+        (($ <fix> _ _ _ vals body)
+         (and (every loop vals) (loop body)))
+        (($ <let-values> _ exp body)
+         (and (loop exp) (loop body)))
         (_ #f))))
 
   (define (mutable? exp)