[PATCH] powerpc: Fix logbl on power7 [BZ# 21280]

[Tulio Magno Quites Machado Filho]

Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:

> On 20/03/2017 18:02, Tulio Magno Quites Machado Filho wrote:
>>  1. Fix the results for negative subnormals by ignoring the signal when
>>     normalizing the value.
>>  2. Fix the output when the high part is a power of 2 and the low part
>>     is a nonzero number with opposite sign.  This fix is based on commit
>>     380bd0fd2418f8988217de950f8b8ff18af0cb2b.
>
> It is not a blocker, but based on the complexity of the change and the 
> optimization real case usage, I wonder if it would be better to just remove 
> it and use the default implementation instead.

I tried to do that before fixing these, but the performance difference is
still around 2x.

-- 
Tulio Magno