1 files changed, 17 insertions, 0 deletions
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 08041c96ffe5..19041704a40b 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -364,6 +364,23 @@ ConstantRange ConstantRange::makeExactNoWrapRegion(Instruction::BinaryOps BinOp,
   return makeGuaranteedNoWrapRegion(BinOp, ConstantRange(Other), NoWrapKind);
 }
 
+ConstantRange ConstantRange::makeMaskNotEqualRange(const APInt &Mask,
+                                                   const APInt &C) {
+  unsigned BitWidth = Mask.getBitWidth();
+
+  if ((Mask & C) != C)
+    return getFull(BitWidth);
+
+  if (Mask.isZero())
+    return getEmpty(BitWidth);
+
+  // If (Val & Mask) != C, constrained to the non-equality being
+  // satisfiable, then the value must be larger than the lowest set bit of
+  // Mask, offset by constant C.
+  return ConstantRange::getNonEmpty(
+      APInt::getOneBitSet(BitWidth, Mask.countr_zero()) + C, C);
+}
+
 bool ConstantRange::isFullSet() const {
   return Lower == Upper && Lower.isMaxValue();
 }