[PATCH] remove nested function hack_digit

[Konstantin Serebryany]

Here is a better formatted and tested patch that uses a single parameter.
The generated code is nearly identical (same instructions, differences
only in constant offsets).


On Mon, Sep 22, 2014 at 3:52 PM, Konstantin Serebryany
<konstantin.s.serebryany@gmail.com> wrote:
> On Mon, Sep 22, 2014 at 3:45 PM, Roland McGrath <roland@hack.frob.com> wrote:
>>> hack_digit becomes longer too due to longer function prologue epilogue:
>>
>> Clearly that cannot be the only difference.  Was the function's code itself
>> actually all nearly identical, modulo trivial differences like different
>> register allocation choices?  Each access to one of the parent's locals
>> surely looks different, and how different that code looks is probably where
>> the most important differences are.
>
> Another difference is that the compile decided to rearrange the order
> of basic blocks, so the calls go in different orders.
> I've attached the disassembly for both variants.
>
>>
>>> I considered doing such a patch but it turned out a huge textual
>>> change that will make the code much less readable.
>>> Still, let me do it and send it here anyway, unless you tell me no to.
>>
>> Of course readability is very subjective, so there really is no substitute
>> for each interested person just seeing how things look and giving their
>> opinion.  The most trivial mechanical change might harm readability in ways
>> that can be improved with a little thought.
>
> Attached is a patch with "trivial mechanical change" (not properly
> formatted yet).
> To me it looks horrible. Does it make sense to invest more time in it?
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