[llvm] r316146 - [NFC][IRCE] Filter out empty ranges early

[Max Kazantsev via llvm-commits]

Author: mkazantsev
Date: Wed Oct 18 22:33:28 2017
New Revision: 316146

URL: http://llvm.org/viewvc/llvm-project?rev=316146&view=rev
Log:
[NFC][IRCE] Filter out empty ranges early

Modified:
    llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp?rev=316146&r1=316145&r2=316146&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp Wed Oct 18 22:33:28 2017
@@ -1655,12 +1655,14 @@ static Optional<InductiveRangeCheck::Ran
 IntersectRange(ScalarEvolution &SE,
                const Optional<InductiveRangeCheck::Range> &R1,
                const InductiveRangeCheck::Range &R2) {
-  if (!R1.hasValue()) {
-    if (!R2.isEmpty())
-      return R2;
+  if (R2.isEmpty())
     return None;
-  }
+  if (!R1.hasValue())
+    return R2;
   auto &R1Value = R1.getValue();
+  // We never return empty ranges from this function, and R1 is supposed to be
+  // a result of intersection. Thus, R1 is never empty.
+  assert(!R1Value.isEmpty() && "We should never have empty R1!");
 
   // TODO: we could widen the smaller range and have this work; but for now we
   // bail out to keep things simple.