1 files changed, 5 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index 5d68d4463a6..1000eb0b268 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -2083,8 +2083,11 @@ bool MIParser::getHexUint(APInt &Result) {
     return true;
   StringRef V = S.substr(2);
   APInt A(V.size()*4, V, 16);
-  Result = APInt(A.getActiveBits(),
-                 ArrayRef<uint64_t>(A.getRawData(), A.getNumWords()));
+
+  // If A is 0, then A.getActiveBits() is 0. This isn't a valid bitwidth. Make
+  // sure it isn't the case before constructing result.
+  unsigned NumBits = (A == 0) ? 32 : A.getActiveBits();
+  Result = APInt(NumBits, ArrayRef<uint64_t>(A.getRawData(), A.getNumWords()));
   return false;
 }