[Bug tree-optimization/88605] vector extensions: Widening or conversion generates inefficient or scalar code.

[husseydevin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88605

--- Comment #4 from Devin Hussey <husseydevin at gmail dot com> ---
I also want to note that LLVM is probably a good place to look. They have been
pushing to remove as many intrinsic builtins as they can in favor of idiomatic
code.

This has multiple advantages:
 1. You can open up <emmintrin.h> and see what x intrinsic really does (many
SIMD instructions have inadequate documentation)
 2. Platform independent intrinsic headers
 3. More useful vector extensions

Should we make a metabug for this?
Such as "Improve vector extension pattern recognition" or something?