[PATCH 1/9 v3] Optimized generic expf and exp2f with wrappers

[Szabolcs Nagy]

On 22/09/17 00:44, Joseph Myers wrote:
> On Tue, 19 Sep 2017, Szabolcs Nagy wrote:
>> +  /* x = k/N + r with r in [-1/(2N), 1/(2N)] and int k.  */
>> +  kd = (double) (xd + SHIFT); /* Rounding to double precision is required.  */
> 
> Remark (not an issue while this code isn't used for 32-bit x86): a cast 
> may not achieve that rounding with the default -fexcess-precision=fast so 
> using this code for 32-bit x86 might require math_narrow_eval here.
> 

it seems the generated code for i686 happens to be correct
with gcc-7, but i will add math_narrow_eval if that is
needed for guaranteed rounding here (in case it later gets
enabled for i686).