[Bug other/48696] Horrible bitfield code generation on x86

[torvalds@linux-foundation.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48696

--- Comment #1 from Linus Torvalds <torvalds@linux-foundation.org> 2011-04-20 04:28:18 UTC ---
Side note, this is talked about in the Intel optimization manual

  3.6.4 Store Forwarding

Under "General Optimization Guidelines" -> "Optimizing Memory Accesses" ->
"Store Forwarding".

I'm sure people are aware of it, but I'm not certain people realize how
horrible the performance hit can be. I have to admit to having been a bit
surprised myself just _how_ clearly it shows up in profiles.