Quite decent is perhaps a bit pessimistic. Yes, you need to be fairly fluent if you want to write hand-optimised vector code. On the other hand, you only need to know a little assembly to be able to write C code that compiles better; that compilers are frequently not stupid doesn't mean the level below has nothing to teach.
I personally find it a shame that there are so many juicy instructions that compilers have no hope of ever using effectively. How often is a compiler smart enough to solve a problem with PDEP/PEXT, for example? Those functions are versatile as heck, but you need to plan for them if you want them to show up.
I personally find it a shame that there are so many juicy instructions that compilers have no hope of ever using effectively. How often is a compiler smart enough to solve a problem with PDEP/PEXT, for example? Those functions are versatile as heck, but you need to plan for them if you want them to show up.