added more functions

src/comp.c

@@ -54,6 +54,17 @@ void csub()
     cpush(a-b);
 }
 
+void crsub()
+{
+    if(cstack_size<2)
+	return;
+    int a=cpeek();
+    cpop();
+    int b=cpeek();
+    cpop();
+    cpush(b-a);
+}
+
 void cdiv()
 {
     if(cstack_size<2)
@@ -64,3 +75,14 @@ void cdiv()
     cpop();
     cpush(a/b);
 }
+
+void crdiv()
+{
+    if(cstack_size<2)
+	return;
+    int a=cpeek();
+    cpop();
+    int b=cpeek();
+    cpop();
+    cpush(b/a);
+}

src/comp.h

@@ -7,5 +7,7 @@ int cpeek();
 void cadd();
 void cmult();
 void csub();
+void crsub();
 void cdiv();
+void crdiv();
 #endif

src/io.c

@@ -72,12 +72,25 @@ void io_process(char* s, int ss)
 	terminal_writeint(cpeek());
 	terminal_putchar('\n');
     }
+    
+    else if(strncmp(s,"rsub",3)==0)
+    {
+	crsub();
+	terminal_writeint(cpeek());
+	terminal_putchar('\n');
+    }
     else if(strncmp(s,"div",3)==0)
     {
 	cdiv();
 	terminal_writeint(cpeek());
 	terminal_putchar('\n');
     }
+    else if(strncmp(s,"rdiv",3)==0)
+    {
+	crdiv();
+	terminal_writeint(cpeek());
+	terminal_putchar('\n');
+    }
 }
 
 void kbd_irq()