doc: Update control-dependencies section of memory-barriers.txt
In the following example, if MAX is defined to be 1, then the compiler knows (Q % MAX) is equal to zero. The compiler can therefore throw away the "then" branch (and the "if"), retaining only the "else" branch. q = READ_ONCE(a); if (q % MAX) { WRITE_ONCE(b, 1); do_something(); } else { WRITE_ONCE(b, 2); do_something_else(); } It is therefore necessary to modify the example like this: q = READ_ONCE(a); - WRITE_ONCE(b, 1); + WRITE_ONCE(b, 2); do_something_else(); Signed-off-by: Npierre Kuo <vichy.kuo@gmail.com> Acked-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
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