- /// isLoopGuardedByCond - Test whether entry to the loop is protected by
- /// a conditional between LHS and RHS. This is used to help avoid max
- /// expressions in loop trip counts.
- bool isLoopGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
- const SCEV *LHS, const SCEV *RHS);
+ /// isLoopEntryGuardedByCond - Test whether entry to the loop is protected
+ /// by a conditional between LHS and RHS. This is used to help avoid max
+ /// expressions in loop trip counts, and to eliminate casts.
+ bool isLoopEntryGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS);
+
+ /// isLoopBackedgeGuardedByCond - Test whether the backedge of the loop is
+ /// protected by a conditional between LHS and RHS. This is used to
+ /// to eliminate casts.
+ bool isLoopBackedgeGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS);
+
+ /// getSmallConstantTripCount - Returns the maximum trip count of this loop
+ /// as a normal unsigned value. Returns 0 if the trip count is unknown or
+ /// not constant. This "trip count" assumes that control exits via
+ /// ExitingBlock. More precisely, it is the number of times that control may
+ /// reach ExitingBlock before taking the branch. For loops with multiple
+ /// exits, it may not be the number times that the loop header executes if
+ /// the loop exits prematurely via another branch.
+ unsigned getSmallConstantTripCount(Loop *L, BasicBlock *ExitingBlock);
+
+ /// getSmallConstantTripMultiple - Returns the largest constant divisor of
+ /// the trip count of this loop as a normal unsigned value, if
+ /// possible. This means that the actual trip count is always a multiple of
+ /// the returned value (don't forget the trip count could very well be zero
+ /// as well!). As explained in the comments for getSmallConstantTripCount,
+ /// this assumes that control exits the loop via ExitingBlock.
+ unsigned getSmallConstantTripMultiple(Loop *L, BasicBlock *ExitingBlock);
+
+ // getExitCount - Get the expression for the number of loop iterations for
+ // which this loop is guaranteed not to exit via ExitingBlock. Otherwise
+ // return SCEVCouldNotCompute.
+ const SCEV *getExitCount(Loop *L, BasicBlock *ExitingBlock);