3 ms·
It didn't have a SIMD unit. Although x86 only had MMX at the time, which wasn't much better.
by astrange 3y ago
It didn't have a SIMD unit. Although x86 only had MMX at the time, which wasn't much better.
- acdha 3y agoAlso MMX was basically the first mainstream use of SIMD so adoption was glacially slow since you had not only limited compiler support but also no libraries and little programmer familiarity with the style. That took a long time for knowledge and tools to improve, especially in the nascent internet era where people couldn’t just look things up on a comprehensive reference site or get help on GitHub.
- astrange 3y agoI'd say there's still limited compiler support for MMX. Because of the strange way you have to use it (it trashes the floating point registers until the next `emms`) compilers won't use it even if it's beneficial, so no autovectorization.