Re: Speed up COPY FROM text/CSV parsing using SIMD

Currently we are at 200-400Mbps which isn't that terrible compared to production and non production grade parsers (of course we don't only parse in our case), also we are using SSE2 only so theoretically if we add support for avx later on we'll have even better numbers.

Maybe more micro optimizations to the current heuristic can squeeze it more.

[1] https://branchfree.org/2019/03/06/code-fragment-finding-quote-pairs-with-carry-less-multiply-pclmulqdq/
[2] https://github.com/AyoubKaz07/postgres/commit/73c6ecfedae4cce5c3f375fd6074b1ca9dfe1daf

[3] https://agner.org/optimize/instruction_tables.pdf

[4] https://www.uops.info/table.html

Regards,

Ayoub Kazar.