diff options
Diffstat (limited to 'include/llvm/Analysis/ScalarEvolution.h')
| -rw-r--r-- | include/llvm/Analysis/ScalarEvolution.h | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h index dd3c80860e..727bf1bbd5 100644 --- a/include/llvm/Analysis/ScalarEvolution.h +++ b/include/llvm/Analysis/ScalarEvolution.h @@ -730,16 +730,21 @@ namespace llvm { const SCEV *LHS, const SCEV *RHS); /// getSmallConstantTripCount - Returns the maximum trip count of this loop - /// as a normal unsigned value, if possible. Returns 0 if the trip count is - /// unknown or not constant. - unsigned getSmallConstantTripCount(Loop *L, BasicBlock *ExitBlock); + /// 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!). - unsigned getSmallConstantTripMultiple(Loop *L, BasicBlock *ExitBlock); + /// 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 |