From cda06eba58c24c607cc5905a9381310813b78d41 Mon Sep 17 00:00:00 2001
From: Abdulaziz Ghuloum <aghuloum@cs.indiana.edu>
Date: Mon, 6 Jul 2009 12:07:18 +0300
Subject: [PATCH] added a parameter to switch between different letrec handling
 routines

---
 scheme/ikarus.compiler.optimize-letrec.ss | 18 ++++++++++++++----
 scheme/ikarus.compiler.ss                 |  4 ++--
 scheme/last-revision                      |  2 +-
 scheme/makefile.ss                        |  2 ++
 4 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/scheme/ikarus.compiler.optimize-letrec.ss b/scheme/ikarus.compiler.optimize-letrec.ss
index 5deb478..347e068 100644
--- a/scheme/ikarus.compiler.optimize-letrec.ss
+++ b/scheme/ikarus.compiler.optimize-letrec.ss
@@ -1,6 +1,6 @@
 
 
-(module (debug-scc optimize-letrec)
+(module (debug-scc optimize-letrec current-letrec-pass)
 
 
   (define (unique-prelex x) 
@@ -467,11 +467,21 @@
 
   (define debug-scc (make-parameter #f))
 
-  (define current-letrec-pass 
-    (make-parameter optimize-letrec/scc))
+  (define current-letrec-pass
+    (make-parameter 'scc
+      (lambda (x)
+        (if (memq x '(scc waddell basic))
+            x
+            (die 'current-letrec-pass "invalid" x)))))
+      
 
   (define (optimize-letrec x)
-    ((current-letrec-pass) x)))
+    (case (current-letrec-pass)
+      [(scc)     (optimize-letrec/scc x)]
+      [(waddell) (optimize-letrec/waddell x)]
+      [(basic)   (optimize-letrec/basic x)]
+      [else (die 'optimize-letrec "invalid" (current-letrec-pass))]))
+)
 
 
 
diff --git a/scheme/ikarus.compiler.ss b/scheme/ikarus.compiler.ss
index e71acf0..669ae96 100644
--- a/scheme/ikarus.compiler.ss
+++ b/scheme/ikarus.compiler.ss
@@ -22,7 +22,7 @@
           expand expand/optimize expand/scc-letrec optimizer-output
           cp0-effort-limit cp0-size-limit optimize-level 
           perform-tag-analysis tag-analysis-output
-          strip-source-info generate-debug-calls)
+          strip-source-info generate-debug-calls current-letrec-pass)
   (import 
     (rnrs hashtables)
     (ikarus system $fx)
@@ -37,7 +37,7 @@
         cp0-size-limit cp0-effort-limit 
         expand/optimize expand/scc-letrec expand optimizer-output
         tag-analysis-output perform-tag-analysis
-        current-core-eval)
+        current-core-eval current-letrec-pass)
     (ikarus include)
     (ikarus.fasl.write)
     (ikarus.intel-assembler))
diff --git a/scheme/last-revision b/scheme/last-revision
index 91d59b9..eebf2dd 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1823
+1824
diff --git a/scheme/makefile.ss b/scheme/makefile.ss
index c8fa99e..419ed1e 100755
--- a/scheme/makefile.ss
+++ b/scheme/makefile.ss
@@ -17,6 +17,7 @@
 ;;; vim:syntax=scheme
 (import (only (ikarus) import))
 (import (except (ikarus) 
+          current-letrec-pass
           current-core-eval
           assembler-output optimize-cp optimize-level
           cp0-size-limit cp0-effort-limit expand/optimize
@@ -1502,6 +1503,7 @@
     [cp0-effort-limit i]
     [tag-analysis-output i]
     [perform-tag-analysis i]
+    [current-letrec-pass i]
     [pointer?                          $for]
     [pointer->integer                  $for]
     [integer->pointer                  $for]