2 files changed, 6 insertions, 24 deletions
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index 4151e02..15e2386b 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -554,7 +554,7 @@ class MetadataLoader::MetadataLoaderImpl {
   }
 
   /// Upgrade the expression from previous versions.
-  Error upgradeDIExpression(uint64_t FromVersion, bool &IsDistinct,
+  Error upgradeDIExpression(uint64_t FromVersion,
                             MutableArrayRef<uint64_t> &Expr,
                             SmallVectorImpl<uint64_t> &Buffer) {
     auto N = Expr.size();
@@ -628,9 +628,6 @@ class MetadataLoader::MetadataLoaderImpl {
       LLVM_FALLTHROUGH;
     }
     case 3:
-      IsDistinct = false;
-      LLVM_FALLTHROUGH;
-    case 4:
       // Up-to-date!
       break;
     }
@@ -2005,13 +2002,11 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     auto Elts = MutableArrayRef<uint64_t>(Record).slice(1);
 
     SmallVector<uint64_t, 6> Buffer;
-    if (Error Err = upgradeDIExpression(Version, IsDistinct, Elts, Buffer))
+    if (Error Err = upgradeDIExpression(Version, Elts, Buffer))
       return Err;
 
-    if (IsDistinct)
-      return error("Invalid record");
-
-    MetadataList.assignValue(DIExpression::get(Context, Elts), NextMetadataNo);
+    MetadataList.assignValue(
+        GET_OR_DISTINCT(DIExpression, (Context, Elts)), NextMetadataNo);
     NextMetadataNo++;
     break;
   }
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index a92c11e..fd77a8c 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1766,6 +1766,7 @@ void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
                                              SmallVectorImpl<uint64_t> &Record,
                                              unsigned Abbrev) {
+  assert(N->isDistinct() && "Expected distinct compile units");
   Record.push_back(/* IsDistinct */ true);
   Record.push_back(N->getSourceLanguage());
   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
@@ -2019,7 +2020,7 @@ void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
                                             SmallVectorImpl<uint64_t> &Record,
                                             unsigned Abbrev) {
   Record.reserve(N->getElements().size() + 1);
-  const uint64_t Version = 4 << 1;
+  const uint64_t Version = 3 << 1;
   Record.push_back((uint64_t)N->isDistinct() | Version);
   Record.append(N->elements_begin(), N->elements_end());
 
@@ -2165,20 +2166,6 @@ void ModuleBitcodeWriter::writeMetadataRecords(
     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
       assert(N->isResolved() && "Expected forward references to be resolved");
 
-#ifndef NDEBUG
-      switch (N->getMetadataID()) {
-#define HANDLE_MDNODE_LEAF_UNIQUED(CLASS)                                      \
-  case Metadata::CLASS##Kind:                                                  \
-    assert(!N->isDistinct() && "Expected non-distinct " #CLASS);               \
-    break;
-#define HANDLE_MDNODE_LEAF_DISTINCT(CLASS)                                     \
-  case Metadata::CLASS##Kind:                                                  \
-    assert(N->isDistinct() && "Expected distinct " #CLASS);                    \
-    break;
-#include "llvm/IR/Metadata.def"
-      }
-#endif
-
       switch (N->getMetadataID()) {
       default:
         llvm_unreachable("Invalid MDNode subclass");