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- (** Convert boolean operations to equivalent operations on different CiviC data
- types. *)
- (** This phase transforms operations on boolean values to equivalent operations
- on different data types. This transformation is necessary, because the CiviC
- VM does not define some operations for boolean arguments.
- This phase also handles the first step of short-circuit evaluation, by
- transforming conjunction and disjunction operators into conditional
- operations of the form [a ? b : c]. This operation is supported by the
- assembly phase, which handles them similarly to if-else statements. The
- benefit of using conditional operations, is that they are still expressions.
- A transformation into actual if-else statements would require adding
- additional statements, which is not only more difficult to implement, but
- also changes the evaluation order, which (however in agreement with the C
- standard) may lead to confusing behaviour.
- The applied transformations are as follows:
- {v b1 == b2 ==> (int)b1 == (int)b2
- b1 != b2 ==> (int)b1 != (int)b2
- b1 && b2 ==> b1 ? b2 : false
- b1 || b2 ==> b1 ? true : b2
- (bool)i ==> i != 0
- (bool)f ==> f != 0.0
- (int)b ==> b ? 1 : 0
- (float)b ==> b ? 1.0 : 0.0 v}
- *)
- (** Main phase function, called by {!Main}. *)
- val phase : Main.phase_func
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