For the visually inclined SIMD programmer, Stefano Tommesani’s site is the best introduction to x86 SIMD programming.
http://www.tommesani.com/index.php/simd/46-sse-arithmetic.html
The diagrams are only provided for MMX and SSE2, but once a learner gets proficient with SSE2, it is relatively easy to move on and read the formal specifications.
Intel IA-32 Instructions beginning with A to M
http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-2a-manual.pdf
Intel IA-32 Instructions beginning with N to Z
http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-2b-manual.pdf
In addition, it is important for Intel SIMD programmers to know the minimum required architecture for instructions that are outside the SSE2 generation.
Browsing by generations on Wikipedia:
- http://en.wikipedia.org/wiki/SSE3
- http://en.wikipedia.org/wiki/SSSE3
- http://en.wikipedia.org/wiki/SSE4.1#SSE4.1
- http://en.wikipedia.org/wiki/SSE4.2#SSE4.2
Searching for a given Intel SIMD mnemonic on a single page (via a text search):
- http://en.wikipedia.org/wiki/X86_instruction_listings