[SCEV] Exploit A < B => (A+K) < (B+K) when possible

[oota-llvm.git] / include / llvm / Analysis / ScalarEvolution.h

diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 988534369c251e30a1b2930464cdc0b4cd824400..f1efeb877fa1d8527dfe626801930963eab7b106 100644 (file)
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -529,6 +529,17 @@ namespace llvm {
                                         const SCEV *FoundLHS,
                                         const SCEV *FoundRHS);
 
+    /// Test whether the condition described by Pred, LHS, and RHS is true
+    /// whenever the condition described by Pred, FoundLHS, and FoundRHS is
+    /// true.
+    ///
+    /// This routine tries to rule out certain kinds of integer overflow, and
+    /// then tries to reason about arithmetic properties of the predicates.
+    bool isImpliedCondOperandsViaNoOverflow(ICmpInst::Predicate Pred,
+                                            const SCEV *LHS, const SCEV *RHS,
+                                            const SCEV *FoundLHS,
+                                            const SCEV *FoundRHS);
+
     /// If we know that the specified Phi is in the header of its containing
     /// loop, we know the loop executes a constant number of times, and the PHI
     /// node is just a recurrence involving constants, fold it.