https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103065
Bug ID: 103065
Summary: [meta] atomic operations aren't optimized
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: meta-bug
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: crazylht at gmail dot com, wwwhhhyyy333 at gmail dot com
Target Milestone: ---
Target: i386,x86-64
>From the CPU's point of view, getting a cache line for writing is more
expensive than reading. See Appendix A.2 Spinlock in:
https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/xeon-lock-scaling-analysis-paper.pdf
The full compare and swap will grab the cache line exclusive and causes
excessive cache line bouncing.
