[Bug target/63672] New: xbegin/xend/xabort missing memory barriers

[andi-gcc at firstfloor dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63672

            Bug ID: 63672
           Summary: xbegin/xend/xabort missing memory barriers
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: andi-gcc at firstfloor dot org

Created attachment 33835
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33835&action=edit
proposed patch adding barriers

No test case currently, but we got a report that the builtins for x86 RTM
xbegin/xend/xabort are missing implicit memory barriers. This can cause code to
be moved outside the critical sections, breaking the program.