2 files changed, 12 insertions, 1 deletions
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index cb703f6efc6..aeb1257754f 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -260,6 +260,17 @@ ConstantRange::isSizeStrictlySmallerThan(const ConstantRange &Other) const {
   return (Upper - Lower).ult(Other.Upper - Other.Lower);
 }
 
+bool
+ConstantRange::isSizeLargerThan(uint64_t MaxSize) const {
+  assert(MaxSize && "MaxSize can't be 0.");
+  // If this a full set, we need special handling to avoid needing an extra bit
+  // to represent the size.
+  if (isFullSet())
+    return APInt::getMaxValue(getBitWidth()).ugt(MaxSize - 1);
+
+  return (Upper - Lower).ugt(MaxSize);
+}
+
 APInt ConstantRange::getUnsignedMax() const {
   if (isFullSet() || isWrappedSet())
     return APInt::getMaxValue(getBitWidth());
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 7a3e8b9ae91..b44bc74d655 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -596,7 +596,7 @@ private:
       Span = Span.inverse();
 
     // If there are a ton of values, we don't want to make a ginormous switch.
-    if (Span.getSetSize().ugt(8) || Span.isEmptySet()) {
+    if (Span.isSizeLargerThan(8) || Span.isEmptySet()) {
       return false;
     }