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

[Adhemerval Zanella]

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.