Avoid unnecessary evaluation in argument defaulting.

* lib.h (default_arg): Inline function becomes macro,
so we can avoid evaluating the default value expression
when it is not needed.

* lib.c (default_arg): Declaration removed.

2 files changed, 1 insertions, 5 deletions

diff --git a/lib.c b/lib.c
index 51a862b5..c5d0b27e 100644
--- a/lib.c
+++ b/lib.c
@@ -140,7 +140,6 @@ val chr(wchar_t ch);
 val eq(val a, val b);
 val null(val v);
 int null_or_missing_p(val v);
-val default_arg(val arg, val dfl);
 val default_bool_arg(val arg);
 #endif
 
diff --git a/lib.h b/lib.h
index 3dc75d61..18f7f6d9 100644
--- a/lib.h
+++ b/lib.h
@@ -1024,10 +1024,7 @@ INLINE int null_or_missing_p(val v) { return (nilp(v) || missingp(v)); }
 
 #define tnil(c_cond) ((c_cond) ? t : nil)
 
-INLINE val default_arg(val arg, val dfl)
-{
-  return if3(null_or_missing_p(arg), dfl, arg);
-}
+#define default_arg(arg, dfl) if3(null_or_missing_p(arg), dfl, arg)
 
 INLINE val default_bool_arg(val arg)
 {