switch ( opcode[ pc++ ] ) {
case NOP: nop(); break;
case ACONST_NULL: aconst_null(); break;
case ICONST_NULL: iconst_m1(); break;
...
case IFNONNULL: ifnonnull(); break;
case GOTO_W: goto_w(); break;
case JSR_W: jsr_w(); break;
default: unknown_opcode();
}