Minor performance tweak, avoid zeroing things we'll immediately write

to. Helps more than I would have thought.

1 files changed, 1 insertions, 2 deletions

diff --git a/src/math/bigint/monty_generic/mp_monty.cpp b/src/math/bigint/monty_generic/mp_monty.cpp
index d8c88a7e7..bce35259a 100644
--- a/src/math/bigint/monty_generic/mp_monty.cpp
+++ b/src/math/bigint/monty_generic/mp_monty.cpp
@@ -63,9 +63,8 @@ void bigint_monty_redc(word z[], u32bit z_size,
 
    copy_mem(ws + x_size + 1, z + x_size, x_size + 1);
 
-   clear_mem(z, z_size);
-
    copy_mem(z, ws + borrow*(x_size+1), x_size + 1);
+   clear_mem(z + x_size + 1, z_size - x_size - 1);
    }
 
 }