1 files changed, 25 insertions, 0 deletions

diff --git a/src/x86_64/postlude.asm b/src/x86_64/postlude.asm
index 139c4e1..5c8e56f 100644
--- a/src/x86_64/postlude.asm
+++ b/src/x86_64/postlude.asm
@@ -1,7 +1,32 @@
+
+_start_return:
     ;; return the last value in the stack
     pop     rdi
+
+    ;; is nil?
+    mov     rax, rdi
+    cmp     rax, NIL_VAL
+    je      exit
+
+    ;; is boolean?
+    mov     rax, rdi
+    and     rax, BOOL_MASK
+    cmp     rax, BOOL_TAG
+    jne     not_bool
+    call    printbool
+    jmp     exit
+not_bool:
+
+    ;; is fixnum?
+    mov     rax, rdi
+    and     rax, FIXNUM_MASK
+    cmp     rax, FIXNUM_TAG
+    jne     not_fixnum
     call    printdln
+    jmp     exit
+not_fixnum:
 
+exit:
     ; exit syscall
     mov     rax, 60
     xor     rdi, rdi