easier to #define USING_NOREGS if the opcode does not use any registers

diff --git a/id_regs.py b/id_regs.py
index 3f5290d41ca77b2871da5dbdbe7e60d3076032d3..830ef95f7c405d6d8ac01e96368642c1889b4566 100644 (file)
--- a/id_regs.py
+++ b/id_regs.py
@@ -58,6 +58,8 @@ def find_registers(fname):
             if p.startswith('WRITE_'):
                 p = p[6:]
             res.append('#define USING_REG_%s' % p)
+    if not res:
+        return '#define USING_NOREGS'
     return '\n'.join(res)
 
 if __name__ == '__main__':