Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v3 3/4] x86/alternative: Rewrite optimize_nops() some | Date | Wed, 8 Feb 2023 23:04:24 +0000 |
| |
From: Andrew.Cooper3@citrix.com > Sent: 08 February 2023 19:52 ... > Unconditional jmps cost branch prediction these days, and won't be > successfully predicted until taken.
That is sad :-(
Don't they also use the BTB for the target address? So even if predicted taken the cpu can speculate from the wrong address??
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
| |