[llvm] r190773 - Implement function prefix data as an IR feature.

[Richard Mitton]

Right that makes sense, thanks :)

Richard Mitton
richard at codersnotes.com

On 09/23/2013 01:23 PM, Peter Collingbourne wrote:
> On Mon, Sep 23, 2013 at 01:14:05PM -0700, Richard Mitton wrote:
>> Hi,
>>
>> I have a small question about this -
>>
>> Why does the prefix data have to begin with a jump?
>> Couldn't you just make the entry point label appear after the prefix
>> data? And then use negative offsets to access it given the function's
>> address? It seems like the jump adds a performance hit which isn't
>> needed.
>>
>> e.g.
>>
>> .word 0x1234 // prefix data
>> myfunction:
>>      push rbp
>>      // etc
>>      ret
> Hi Richard,
>
> I answered this question here:
> http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-July/063950.html
>
> In general I hope to include an FAQ in the blog post which will answer
> these sorts of questions.
>
> Thanks,