Re: [PATCH v2] ARM: Use udiv/sdiv for __aeabi_{u}idiv libraryfunctions

[Nicolas Pitre]

On Tue, 12 Nov 2013, Nicolas Pitre wrote:

> On Tue, 12 Nov 2013, Måns Rullgård wrote:
> 
> > It might be possible to extract this information from relocation tables.
> 
> True, but only for individual .o files.  Once the linker puts them 
> together the information is lost, and trying to infer what the linker 
> has done is insane.
> 
> Filtering the compiler output to annotate idiv calls before it is 
> assembled would probably be a better solution.

Another solution is to patch the call site from within __aeabi_idiv at 
run time using lr.  That wouldn't work in the presence of tail call 
optimization though.

Again this might not be worth it and patching __aeabi_idiv instead might 
be a good enough compromize.


Nicolas