From: Chris Hanson <org/chris-hanson/cph>
Date: Tue, 14 Aug 2001 01:15:05 +0000 (+0000)
Subject: Add optimization to link_variables so that it does nothing if the
X-Git-Tag: 20090517-FFI~2603
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=4ca9ba899f723385bcc1eb900e3be2f446cf06e2;p=mit-scheme.git

Add optimization to link_variables so that it does nothing if the
variables are already linked.
---

diff --git a/v7/src/microcode/lookup.c b/v7/src/microcode/lookup.c
index 3710a9397..6eda3f47c 100644
--- a/v7/src/microcode/lookup.c
+++ b/v7/src/microcode/lookup.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Id: lookup.c,v 9.64 2001/08/07 01:26:29 cph Exp $
+$Id: lookup.c,v 9.65 2001/08/14 01:15:05 cph Exp $
 
 Copyright (c) 1988-2001 Massachusetts Institute of Technology
 
@@ -549,6 +549,9 @@ link_variables (SCHEME_OBJECT target_environment, SCHEME_OBJECT target_symbol,
       if (source_kind == TRAP_COMPILER_CACHED)
 	{
 	  SCHEME_OBJECT source_cache = (GET_TRAP_CACHE (*source_cell));
+	  if (source_cache == target_cache)
+	    /* Already linked.  */
+	    return (PRIM_DONE);
 	  GC_CHECK
 	    (((count_references (GET_CACHE_OPERATOR_REFERENCES (target_cache)))
 	      * SPACE_PER_UUO_LINK)