[Bug target/80878] -mcx16 (enable 128 bit CAS) on x86_64 seems not to work on 7.1.0

2023-12-10 Thread admin_public at liblfds dot org via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80878 --- Comment #43 from admin_public at liblfds dot org --- > I tested CMPXCHG16B with inline assembly on an i7-1165G7 (Dell XPS 13 9305) > and it turned out to be much slower than CMPXCHG, even slower than a pair of > calls to `pthread_mutex_lock(

[Bug target/80878] -mcx16 (enable 128 bit CAS) on x86_64 seems not to work on 7.1.0

2022-11-03 Thread admin_public at liblfds dot org via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80878 --- Comment #40 from admin_public at liblfds dot org --- On 03/11/2022 12:04, jakub at gcc dot gnu.org wrote: > --- Comment #38 from Jakub Jelinek --- > Please see PR104688 . We got a response from Intel, where they guaranteed > atomicity of cer