diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index 349f04fc8..4bf81045b 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -3,7 +3,6 @@ TODO
 ====
 
 - 64tass doesn't output all labels anymore in the vice-mon-list, so %breakpoint labels are no longer present....
-- calling convention for builtin functions no longer via stack but via registers or statically allocated vars inside the subroutine proc (like normal subroutines)
 - make it possible to use cpu opcodes such as 'nop' as variable names by prefixing all asm vars with something such as '_'
 - option to load the built-in library files from a directory instead of the embedded ones (for easier library development/debugging)
 - see if we can group some errors together for instance the (now single) errors about unidentified symbols
diff --git a/examples/mandelbrot.p8 b/examples/mandelbrot.p8
index 50fd45f95..3a57abb01 100644
--- a/examples/mandelbrot.p8
+++ b/examples/mandelbrot.p8
@@ -4,6 +4,8 @@
 
 ; Note: this program is compatible with C64 and CX16.
 
+; TODO this is 5 seconds slower than the previous compiled version.  Caused by BinExprSplitter change?
+
 main {
     const uword width = 30
     const uword height = 20