On 14/02/14 14:34, Kugan wrote: > > > On 14/02/14 11:24, Andrew Pinski wrote: >> On Thu, Feb 13, 2014 at 4:15 PM, Kugan >> <kugan.vivekanandara...@linaro.org> wrote: >>> Hi, >>> >>> Is there any reason why HFmode is not there in arm_preferred_simd_mode? >>> NEON does support this. >> >> Most likely because there is no support for Half-float in the vectorizer. >> > > I can see that get_vectype_for_scalar_type_and_size failing while > building vector type (with build_vector_type) for Half-float. I guess we > should add support there first.
Just for records, I was wrong here. ARM NEON that supports half float does not support vector arithmetic operations in half float; it supports vector conversions to float and operate on 32bit. Therefore HFmode is not really a preferred mode. And also, gcc vectorizer can support half floats. It is not valid in this case and hence ARM backend does not provide required patterns and hooks. Thanks, Kugan
