Is it correct to treat SSE as the legacy version of AVX, in the same way that IA32 is the legacy version of x86-64?
@xingdaz Yes, but SSE and IA32 are still in use and are in many cases necessary. For example, if there are 128-bit vectors scattered in the memory and you need to load them, do some calculations and store back, it is only appropriate to use SSE instructions, because AVX instructions will load extra data and undesirably overwrite the following 128 bits. Same to IA32, movl instruction is essential even if operating systems do not use legacy 32-bit mode. So I would say AVX is an extension to SSE, just like x86_64 is an extension to IA32.