2 files changed, 28 insertions, 4 deletions
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index f64cd55d8f3..f7815810401 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1173,6 +1173,8 @@ std::error_code BitcodeReader::ParseValueSymbolTable() {
   }
 }
 
+static int64_t unrotateSign(uint64_t U) { return U & 1 ? ~(U >> 1) : U >> 1; }
+
 std::error_code BitcodeReader::ParseMetadata() {
   unsigned NextMDValueNo = MDValueList.size();
 
@@ -1349,6 +1351,16 @@ std::error_code BitcodeReader::ParseMetadata() {
                               NextMDValueNo++);
       break;
     }
+    case bitc::METADATA_SUBRANGE: {
+      if (Record.size() != 3)
+        return Error("Invalid record");
+
+      MDValueList.AssignValue(
+          GET_OR_DISTINCT(MDSubrange, Record[0],
+                          (Context, Record[1], unrotateSign(Record[2]))),
+          NextMDValueNo++);
+      break;
+    }
     case bitc::METADATA_STRING: {
       std::string String(Record.begin(), Record.end());
       llvm::UpgradeMDStringConstant(String);
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 1c2424ce11b..3d1e82d8f8c 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -809,11 +809,23 @@ static void WriteGenericDebugNode(const GenericDebugNode *N,
   Record.clear();
 }
 
-static void WriteMDSubrange(const MDSubrange *, const ValueEnumerator &,
-                            BitstreamWriter &, SmallVectorImpl<uint64_t> &,
-                            unsigned) {
-  llvm_unreachable("write not implemented");
+static uint64_t rotateSign(int64_t I) {
+  uint64_t U = I;
+  return I < 0 ? ~(U << 1) : U << 1;
+}
+
+static void WriteMDSubrange(const MDSubrange *N, const ValueEnumerator &,
+                            BitstreamWriter &Stream,
+                            SmallVectorImpl<uint64_t> &Record,
+                            unsigned Abbrev) {
+  Record.push_back(N->isDistinct());
+  Record.push_back(N->getCount());
+  Record.push_back(rotateSign(N->getLo()));
+
+  Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
+  Record.clear();
 }
+
 static void WriteMDEnumerator(const MDEnumerator *, const ValueEnumerator &,
                               BitstreamWriter &, SmallVectorImpl<uint64_t> &,
                               unsigned) {