[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #10 from CVS Commits --- The master branch has been updated by Hans-Peter Nilsson : https://gcc.gnu.org/g:8e6757b30d0f3f13d47d0f842801a751ba6293c2 commit r14-4286-g8e6757b30d0f3f13d47d0f842801a751ba6293c2 Author: Hans-Peter

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #9 from Hans-Peter Nilsson --- (In reply to Richard Earnshaw from comment #8) > I'm going to close this as WONTFIX. I guess I'll have to find another PR to lean on, for fixing the underlying cause for the nonatomic code.

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 Richard Earnshaw changed: What|Removed |Added Resolution|--- |WONTFIX Status|NEW

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #7 from Hans-Peter Nilsson --- (In reply to Hans-Peter Nilsson from comment #6) > The cause I guess, is just a bad fall-through in the arm/sync.md. Or rather, optabs.cc:expand_atomic_test_and_set, which makes this issue somewhat

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 Hans-Peter Nilsson changed: What|Removed |Added Status|UNCONFIRMED |NEW Ever confirmed|0

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #5 from Jan Dubiec --- I read that thread a few days ago and I understand concerns regarding SWP, in particular on ARMv6 which has made SWP obsolete (AFAIR it is optional on ARMv6-A/R, ARMv6-M has neither SWP nor LDREX/STREX).

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #4 from Andrew Pinski --- Read that thread I pointed to.

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #3 from Jan Dubiec --- I do not get what "but that requires more" means in this context. Lets assume that two threads test and set the same memory location which initial value is 0 ("unlocked"/"false"). Now, when the first thread

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #2 from Andrew Pinski --- Armv4t does not have smp so the question is how do you think the below is not atomic? Yes interrupts but that requires more.

[Bug target/109166] Built-in __atomic_test_and_set does not seem to be atomic on ARMv4T

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109166 --- Comment #1 from Andrew Pinski --- https://inbox.sourceware.org/gcc-patches/4f596367.2050...@redhat.com/