* lib.c (plusv): Recognize cases to eliminate a wasteful plus call

with an initial element of zero.

2 files changed, 10 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 8b219237..1751e296 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2011-12-10  Kaz Kylheku  <kaz@kylheku.com>
 
+	* lib.c (plusv): Recognize cases to eliminate a wasteful plus call
+	with an initial element of zero.
+
+2011-12-10  Kaz Kylheku  <kaz@kylheku.com>
+
 	* arith.c: File is now generated using TXR.
 	(NOOP): New macro.
 	(plus): Use NOOP macro.
diff --git a/lib.c b/lib.c
index acd7d643..6109a5b3 100644
--- a/lib.c
+++ b/lib.c
@@ -834,7 +834,11 @@ val bignump(val num)
 
 val plusv(val nlist)
 {
-  return reduce_left(func_n2(plus), nlist, num(0), nil);
+  if (!nlist)
+    return num(0);
+  else if (!cdr(nlist))
+    return car(nlist);
+  return reduce_left(func_n2(plus), cdr(nlist), car(nlist), nil);
 }
 
 val minusv(val minuend, val nlist)