string-extend: grow faster.

* lib.c (string_extend): When more space is needed in the
string, grow by 50% rather than 25%. This speeds up code
at the expense of some wasted space. Waste space can be
dealt with by the final flag in programs where it matters.

1 files changed, 2 insertions, 2 deletions

diff --git a/lib.c b/lib.c
index 4f5cb11d..99674be5 100644
--- a/lib.c
+++ b/lib.c
@@ -5416,10 +5416,10 @@ val string_extend(val str, val tail, val finish_in)
     if (needed > alloc || finish) {
       if (finish)
         alloc = needed;
-      else if (alloc >= (NUM_MAX - NUM_MAX / 5))
+      else if (alloc >= (NUM_MAX - NUM_MAX / 3))
         alloc = NUM_MAX;
       else
-        alloc = max(alloc + alloc / 4, needed);
+        alloc = max(alloc + alloc / 2, needed);
 
       if (alloc != oalloc) {
         str->st.str = chk_wrealloc(str->st.str, alloc);