1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 47388c2..105edb9 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -8164,6 +8164,14 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(unsigned ID) {
           ContextSizes.reserve(NumContextSizeInfoEntries);
           for (unsigned J = 0; J < NumContextSizeInfoEntries; J++) {
             assert(ContextIdIndex < PendingContextIds.size());
+            // Skip any 0 entries for MIBs without the context size info.
+            if (PendingContextIds[ContextIdIndex] == 0) {
+              // The size should also be 0 if the context was 0.
+              assert(!Record[I]);
+              ContextIdIndex++;
+              I++;
+              continue;
+            }
             // PendingContextIds read from the preceding FS_ALLOC_CONTEXT_IDS
             // should be in the same order as the total sizes.
             ContextSizes.push_back(