[PATCH] Fix DCE REG_LIBCALL note moving from noop move insns (PR rtl-optimization/33644)

[Kenneth Zadeck]

Paolo Bonzini wrote:
>
>>
>> So that would mean that you don't even need libcall notes to CSE
>> _tls_get_addr calls?
>
> CALL_INSNs are never DCE'd:
>
> static bool
> deletable_insn_p (rtx insn, bool fast)
> {
>   rtx body, x;
>   int i;
>
>   if (!NONJUMP_INSN_P (insn))
>     return false;
>
>
> Paolo
this could be too conservative, there is no reason not dce pure or const
calls.

kenny