memory-model/Documentation/control-dependencies.txt

12 Therefore, a load-load control dependency will not preserve ordering
32 (usually) guaranteed for load-store control dependencies, as in the
45 by a store, and this compiler-generated load would not be ordered by
49 "a" is always non-zero, it would be well within its rights to optimize
60 identical stores on both branches of the "if" statement as follows:
80 		/* WRITE_ONCE(b, 1); -- moved up, BUG!!! */
83 		/* WRITE_ONCE(b, 1); -- moved up, BUG!!! */
90 assembly code, after all of the compiler and link-time optimizations
103 Without explicit memory ordering, control-dependency-based ordering is
132 If MAX is compile-time defined to be 1, then the compiler knows that
160 values were identical, the compiler could pull this store outside of the
163 You must also be careful avoid relying too much on boolean short-circuit
178 compiler from out-guessing your code.  Again, although READ_ONCE() really
182 In addition, control dependencies apply only to the then-clause and
183 else-clause of the "if" statement in question.  In particular, they do
198 conditional-move instructions, as in this fanciful pseudo-assembly
212 only to the stores in the then-clause and else-clause of the "if" statement
226   (*) If both legs of the "if" statement contain identical stores to
235   (*) Control dependencies require at least one run-time conditional
246   (*) Control dependencies apply only to the then-clause and else-clause