Re: [PATCH 6/7] stdlib: Optimization qsort{_r} swap implementation

[Paul Eggert <eggert at cs dot ucla dot edu>]

Adhemerval Zanella wrote:
> At the cost of large text sizes and slight more code:

Yes, that's a common tradeoff for this sort of optimization. My guess is that 
most glibc users these days would like to spend 4 kB of text space to gain a 
2%-or-so CPU speedup. (But it's just a guess. :-)
> I still prefer my version where generates shorter text segment and also
> optimizes for uint32_t.

The more-inlined version could also optimize for uint32_t. Such an optimization 
should not change the machine code on platforms with 32-bit pointers (since 
uint32_t has the same size and alignment restrictions as void *, and GCC should 
be smart enough to figure this out) but should speed up the size-4 case on 
platforms with 64-bit pointers.

Any thoughts on why the more-inlined version is a bit slower when input is 
already sorted?