diff --git a/evm/src/cpu/kernel/asm/curve_add.asm b/evm/src/cpu/kernel/asm/curve_add.asm
index 541b1605..15f9df05 100644
--- a/evm/src/cpu/kernel/asm/curve_add.asm
+++ b/evm/src/cpu/kernel/asm/curve_add.asm
@@ -104,7 +104,7 @@ ec_add_snd_zero:
     JUMPDEST
     // stack: x0, y0, x1, y1, retdest
 
-    // Just return (x1,y1)
+    // Just return (x0,y0)
     %stack (x0, y0, x1, y1, retdest) -> (retdest, x0, y0)
     JUMP
 
diff --git a/evm/src/cpu/kernel/stack_manipulation.rs b/evm/src/cpu/kernel/stack_manipulation.rs
index 6f20ead6..63d0566c 100644
--- a/evm/src/cpu/kernel/stack_manipulation.rs
+++ b/evm/src/cpu/kernel/stack_manipulation.rs
@@ -214,8 +214,11 @@ impl StackOp {
                 // This is just a rough estimate; we can update it after implementing PUSH.
                 (bytes, bytes)
             }
-            Pop => (1, 1),
+            // A POP takes one cycle, and doesn't involve memory, it just decrements a pointer.
+            Pop => (1, 0),
+            // A DUP takes one cycle, and a read and a write.
             StackOp::Dup(_) => (1, 2),
+            // A SWAP takes one cycle with four memory ops, to read both values then write to them.
             StackOp::Swap(_) => (1, 4),
         };