[PATCH 3/4] libm/stdlib: Realloc when shrinking by 2* or more

[Keith Packard]

This reduces memory usage when reallocating objects much smaller.

Signed-off-by: Keith Packard <keithp@keithp.com>
---
 newlib/libc/stdlib/nano-mallocr.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/newlib/libc/stdlib/nano-mallocr.c b/newlib/libc/stdlib/nano-mallocr.c
index cef23977e..83234c618 100644
--- a/newlib/libc/stdlib/nano-mallocr.c
+++ b/newlib/libc/stdlib/nano-mallocr.c
@@ -476,10 +476,8 @@ void * nano_realloc(RARG void * ptr, malloc_size_t size)
         return NULL;
     }
 
-    /* TODO: There is chance to shrink the chunk if newly requested
-     * size is much small */
     old_size = nano_malloc_usable_size(RCALL ptr);
-    if (old_size >= size)
+    if (size <= old_size && (old_size >> 1) < size)
       return ptr;
 
     mem = nano_malloc(RCALL size);
-- 
2.28.0