diff --git a/arch/sim/pipe/ncopy.ys b/arch/sim/pipe/ncopy.ys
index 0f04c28..4f4b37c 100644
--- a/arch/sim/pipe/ncopy.ys
+++ b/arch/sim/pipe/ncopy.ys
@@ -17,7 +17,7 @@ ncopy:
 # You can modify this portion
 
   xorq %rax, %rax
-  iaddq $0xfffffffffffffff7, %rdx
+  iaddq $-9, %rdx
   jle Remaining
 
 Loop:
@@ -83,28 +83,24 @@ F9:
 F10:
   iaddq $80, %rdi
   iaddq $80, %rsi
-  iaddq $0xfffffffffffffff6, %rdx
+  iaddq $-10, %rdx
   jg Loop
 
 Remaining:
-  addq %rdx, %rdx
-  addq %rdx, %rdx
-  addq %rdx, %rdx
-  mrmovq JT(%rdx), %rdx
-  pushq %rdx
-  ret
-
-  .quad Done
-  .quad J1
-  .quad J2
-  .quad J3
-  .quad J4
-  .quad J5
-  .quad J6
-  .quad J7
-  .quad J8
-JT:
-  .quad J9
+  iaddq $8, %rdx
+  jl Done
+  je J1
+  iaddq $-2, %rdx
+  jl J2
+  je J3
+  iaddq $-2, %rdx
+  jl J4
+  je J5
+  iaddq $-2, %rdx
+  jl J6
+  je J7
+  iaddq $-1, %rdx
+  je J8
 
 J9:
   mrmovq 64(%rdi), %r10