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Re: Auto-generated .rodata contents and __attribute__((section))

Hi,

On Fri, 18 May 2018, Richard Biener wrote:

> Interesting.  Do they allow merging across such sections?  Consider a 8 
> byte entity 0x12345678 and 4 byte entities 0x1234 0x5678, will the 4 
> byte entities share the rodata with the 8 byte one?

There's no language to forbid this (as long as the alignments 
are respected), but at least GNU ld currently only merges same-sized 
entities.

> I believe GCC pulls off such tricks in its internal constant pool 
> merging code.
> 
> It might be worth gathering statistics on the size of constant pool
> entries for this.
> 
> Now the question is of course if BFD contains support for optimizing
> those sections.

You mean to ask if GNU ld is actually uniquifying contents of such 
mergable sections over object files?  If so the answer is yes.


Ciao,
Michael.
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