3 ms·
Parallel, speculative execution is what's unavoidable. The VLIW idea of statically compiler-scheduled parallelism and speculation has not been successful for ge
by WallWextra 11y ago
Parallel, speculative execution is what's unavoidable. The VLIW idea of statically compiler-scheduled parallelism and speculation has not been successful for general-purpose code. The last generation of Itanium abandoned explicit, statically-scheduled parallelism and switched to out of order execution, like every fast general-purpose CPU uses.
- anon4 11y ago> has not been successful for general-purpose code Let me interject that it has also not been successful for AMD's line of videocards - they used a VLIW architecture before transitioning to a SIMD architecture codenamed Graphics Core Next or GCN in 2011. nVidia had been using SIMD for quite a while before that, but some of their latest cards have a few VLIW features like the option to explicitly specify parallelism between instructions.
- WallWextra 11y agoApparently they switched because VLIW wasn't good for GPGPU workloads, which is in keeping with the general theme, that VLIW works very well on certain highly-specific DSP-ish workloads.