# Re: \[PATCH/RFC\] Reduce call chain length in netfilter

- From: Patrick McHardy \<hidden\>
- Date: 2005-01-27 22:48:04 
- List: netdev
- Page: https://ratatoskr.run/netdev/2005/01/10748647
- Thread: https://ratatoskr.run/bridge/2005/01/10747758/t.md

```text
David S. Miller wrote:

>In the generated asm on sparc64, invoke2() gets a tail-call
>whereas invoke() does not.  Hmmm...
>
>
Apparently support for indirect tail-calls was added to gcc 3.4.

gcc-3.3.5:
0x0000000000000000 <invoke+0>:  sub    $0x8,%rsp
0x0000000000000004 <invoke+4>:  callq  *%esi
0x0000000000000006 <invoke+6>:  add    $0x8,%rsp
0x000000000000000a <invoke+10>: retq 

gcc-3.4.4:
0x0000000000000000 <invoke+0>:  mov    %rsi,%r11
0x0000000000000003 <invoke+3>:  jmpq   *%r11d

Regards
Patrick
```