Added subtract and calling

tests/call.asm

@@ -0,0 +1,15 @@
+include "fvm.inc"
+
+org 0x4000000000000000
+start:
+  MovI64 r95, UART_TX
+  call function
+  MovI64 r2, 0x69
+  St8 r2, r95
+  MovI64 r2, 0x0a
+  St8 r2, r95
+  Halt
+function:
+  MovI64 r2, 0x48
+  St8 r2, r95
+  Ret

tests/fvm.inc

@@ -13,7 +13,8 @@ define r9 9
 define r10 10
 define r11 11
 define r12 12
-define r13 13 define r14 14
+define r13 13 
+define r14 14
 define r15 15
 define r16 16
 define r17 17
@@ -217,6 +218,12 @@ macro MovI64 dst, val
   _dq_be val
 end macro
 
+macro Mov64 dst, src
+  db 0x94
+  db dst
+  db src
+end macro
+
 macro Ld8 dst, addr
   db 0x93
   db dst
@@ -230,7 +237,13 @@ macro St8 dst, addr
 end macro
 
 macro AddR64 dst, src
-  db 0x60
+  db 0x6E
+  db dst
+  db src
+end macro
+
+macro SubR64 dst, src
+  db 0x6F
   db dst
   db src
 end macro
@@ -278,6 +291,21 @@ macro JmpIZ addr
   JmpRIZ 127
 end macro
 
+macro callR addr
+  db 0x46
+  db addr
+end macro
+
+macro call val
+  MovI64 127, val
+  db 0x46
+  db 127
+end macro
+
+macro Ret
+  db 2
+end macro
+
 macro Halt
   db 0
 end macro