added a few operations and expanded standard library

codegen.lisp

@@ -313,7 +313,8 @@
 
 ;; ( -- a)
 (defop (push-int a) (:lex nil :targets :nasm)
-  ("push ~d" a))
+  ("mov rax, ~a" a)
+  ("push rax"))
 
 (defop (push-str len addr str) (:lex nil :targets :nasm)
   (progn (:write ("push ~d" len)
@@ -359,6 +360,17 @@
         (:write ("pop ~a" (aref call-regs i)))
         (finally (:write "syscall"))))
 
+(defop divmod (:targets :nasm)
+  "mov rdx, 0"
+  (rax rcx -- )
+  "div rcx"
+  (-- rax rdx))
+
+(defop * (:targets :nasm)
+  (rbx rax -- )
+  "mul rbx"
+  ( -- rax))
+
 (defun gen-dump (str)
   (format str "~{~a~%~}"
           '("dump:"