diff --git a/lld/test/COFF/thinlto-index-only.ll b/lld/test/COFF/thinlto-index-only.ll
--- a/lld/test/COFF/thinlto-index-only.ll
+++ b/lld/test/COFF/thinlto-index-only.ll
@@ -39,6 +39,7 @@
 ; BACKEND2-NEXT: <FLAGS
 ; BACKEND2-NEXT: <VALUE_GUID op0=1 op1=-5300342847281564238
 ; BACKEND2-NEXT: <COMBINED
+; BACKEND2-NEXT: <BLOCK_COUNT op0=2/>
 ; BACKEND2-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 
 ; Thin archive tests. Check that the module paths point to the original files.
diff --git a/lld/test/ELF/lto/thinlto-index-only.ll b/lld/test/ELF/lto/thinlto-index-only.ll
--- a/lld/test/ELF/lto/thinlto-index-only.ll
+++ b/lld/test/ELF/lto/thinlto-index-only.ll
@@ -71,6 +71,7 @@
 ; BACKEND2-NEXT: <FLAGS
 ; BACKEND2-NEXT: <VALUE_GUID op0=1 op1=-5300342847281564238
 ; BACKEND2-NEXT: <COMBINED
+; BACKEND2-NEXT: <BLOCK_COUNT op0=2/>
 ; BACKEND2-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
diff --git a/llvm/include/llvm/Bitcode/LLVMBitCodes.h b/llvm/include/llvm/Bitcode/LLVMBitCodes.h
--- a/llvm/include/llvm/Bitcode/LLVMBitCodes.h
+++ b/llvm/include/llvm/Bitcode/LLVMBitCodes.h
@@ -290,6 +290,8 @@
   //                                        numrefs, numrefs x valueid,
   //                                        n x (valueid, offset)]
   FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS = 23,
+  // The total number of basic blocks in the module.
+  FS_BLOCK_COUNT = 24,
 };
 
 enum MetadataCodes {
diff --git a/llvm/include/llvm/IR/ModuleSummaryIndex.h b/llvm/include/llvm/IR/ModuleSummaryIndex.h
--- a/llvm/include/llvm/IR/ModuleSummaryIndex.h
+++ b/llvm/include/llvm/IR/ModuleSummaryIndex.h
@@ -1007,6 +1007,9 @@
   StringSaver Saver;
   BumpPtrAllocator Alloc;
 
+  // The total number of basic blocks in the module.
+  uint64_t BlockCount;
+
   // YAML I/O support.
   friend yaml::MappingTraits<ModuleSummaryIndex>;
 
@@ -1019,15 +1022,15 @@
 public:
   // See HaveGVs variable comment.
   ModuleSummaryIndex(bool HaveGVs, bool EnableSplitLTOUnit = false)
-      : HaveGVs(HaveGVs), EnableSplitLTOUnit(EnableSplitLTOUnit), Saver(Alloc) {
-  }
+      : HaveGVs(HaveGVs), EnableSplitLTOUnit(EnableSplitLTOUnit), Saver(Alloc),
+        BlockCount(0) {}
 
   // Current version for the module summary in bitcode files.
   // The BitcodeSummaryVersion should be bumped whenever we introduce changes
   // in the way some record are interpreted, like flags for instance.
   // Note that incrementing this may require changes in both BitcodeReader.cpp
   // and BitcodeWriter.cpp.
-  static constexpr uint64_t BitcodeSummaryVersion = 8;
+  static constexpr uint64_t BitcodeSummaryVersion = 9;
 
   // Regular LTO module name for ASM writer
   static constexpr const char *getRegularLTOModuleName() {
@@ -1039,6 +1042,10 @@
   uint64_t getFlags() const;
   void setFlags(uint64_t Flags);
 
+  uint64_t getBlockCount() const { return BlockCount; }
+  void addBlockCount(uint64_t C) { BlockCount += C; }
+  void setBlockCount(uint64_t C) { BlockCount = C; }
+
   gvsummary_iterator begin() { return GlobalValueMap.begin(); }
   const_gvsummary_iterator begin() const { return GlobalValueMap.begin(); }
   gvsummary_iterator end() { return GlobalValueMap.end(); }
diff --git a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
--- a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
+++ b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
@@ -249,6 +249,7 @@
   assert(F.hasName());
 
   unsigned NumInsts = 0;
+  uint64_t NumBlocks = 0;
   // Map from callee ValueId to profile count. Used to accumulate profile
   // counts for all static calls to a given callee.
   MapVector<ValueInfo, CalleeInfo> CallGraphEdges;
@@ -268,7 +269,8 @@
   std::vector<const Instruction *> NonVolatileStores;
 
   bool HasInlineAsmMaybeReferencingInternal = false;
-  for (const BasicBlock &BB : F)
+  for (const BasicBlock &BB : F) {
+    ++NumBlocks;
     for (const Instruction &I : BB) {
       if (isa<DbgInfoIntrinsic>(I))
         continue;
@@ -390,6 +392,8 @@
               .updateHotness(getHotness(Candidate.Count, PSI));
       }
     }
+  }
+  Index.addBlockCount(NumBlocks);
 
   std::vector<ValueInfo> Refs;
   if (IsThinLTO) {
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -741,6 +741,7 @@
   KEYWORD(name);
   KEYWORD(summaries);
   KEYWORD(flags);
+  KEYWORD(blockcount);
   KEYWORD(linkage);
   KEYWORD(notEligibleToImport);
   KEYWORD(live);
diff --git a/llvm/lib/AsmParser/LLParser.h b/llvm/lib/AsmParser/LLParser.h
--- a/llvm/lib/AsmParser/LLParser.h
+++ b/llvm/lib/AsmParser/LLParser.h
@@ -341,6 +341,7 @@
     bool ParseModuleReference(StringRef &ModulePath);
     bool ParseGVReference(ValueInfo &VI, unsigned &GVId);
     bool ParseSummaryIndexFlags();
+    bool ParseBlockCount();
     bool ParseGVEntry(unsigned ID);
     bool ParseFunctionSummary(std::string Name, GlobalValue::GUID, unsigned ID);
     bool ParseVariableSummary(std::string Name, GlobalValue::GUID, unsigned ID);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -853,6 +853,9 @@
   case lltok::kw_flags:
     result = ParseSummaryIndexFlags();
     break;
+  case lltok::kw_blockcount:
+    result = ParseBlockCount();
+    break;
   default:
     result = Error(Lex.getLoc(), "unexpected summary kind");
     break;
@@ -8091,6 +8094,21 @@
   return false;
 }
 
+/// ParseBlockCount
+///   ::= 'blockcount' ':' UInt64
+bool LLParser::ParseBlockCount() {
+  assert(Lex.getKind() == lltok::kw_blockcount);
+  Lex.Lex();
+
+  if (ParseToken(lltok::colon, "expected ':' here"))
+    return true;
+  uint64_t BlockCount;
+  if (ParseUInt64(BlockCount))
+    return true;
+  Index->setBlockCount(BlockCount);
+  return false;
+}
+
 /// ParseGVEntry
 ///   ::= 'gv' ':' '(' ('name' ':' STRINGCONSTANT | 'guid' ':' UInt64)
 ///         [',' 'summaries' ':' Summary[',' Summary]* ]? ')'
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -374,6 +374,7 @@
   kw_name,
   kw_summaries,
   kw_flags,
+  kw_blockcount,
   kw_linkage,
   kw_notEligibleToImport,
   kw_live,
diff --git a/llvm/lib/Bitcode/Reader/BitcodeAnalyzer.cpp b/llvm/lib/Bitcode/Reader/BitcodeAnalyzer.cpp
--- a/llvm/lib/Bitcode/Reader/BitcodeAnalyzer.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeAnalyzer.cpp
@@ -305,6 +305,7 @@
       STRINGIFY_CODE(FS, CFI_FUNCTION_DECLS)
       STRINGIFY_CODE(FS, TYPE_ID)
       STRINGIFY_CODE(FS, TYPE_ID_METADATA)
+      STRINGIFY_CODE(FS, BLOCK_COUNT)
     }
   case bitc::METADATA_ATTACHMENT_ID:
     switch (CodeID) {
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -6239,6 +6239,10 @@
     case bitc::FS_TYPE_ID_METADATA:
       parseTypeIdCompatibleVtableSummaryRecord(Record);
       break;
+
+    case bitc::FS_BLOCK_COUNT:
+      // TheIndex.setBlockCount(Record[0]);
+      TheIndex.addBlockCount(Record[0]);
     }
   }
   llvm_unreachable("Exit infinite loop");
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -3909,6 +3909,9 @@
     NameVals.clear();
   }
 
+  Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
+                    ArrayRef<uint64_t>{Index->getBlockCount()});
+
   Stream.ExitBlock();
 }
 
@@ -4192,6 +4195,9 @@
     }
   }
 
+  Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
+                    ArrayRef<uint64_t>{Index.getBlockCount()});
+
   Stream.ExitBlock();
 }
 
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -2797,8 +2797,13 @@
   }
 
   // Don't emit flags when it's not really needed (value is zero by default).
-  if (TheIndex->getFlags())
+  if (TheIndex->getFlags()) {
     Out << "^" << NumSlots << " = flags: " << TheIndex->getFlags() << "\n";
+    ++NumSlots;
+  }
+
+  Out << "^" << NumSlots << " = blockcount: " << TheIndex->getBlockCount()
+      << "\n";
 }
 
 static const char *
diff --git a/llvm/test/Assembler/thinlto-vtable-summary.ll b/llvm/test/Assembler/thinlto-vtable-summary.ll
--- a/llvm/test/Assembler/thinlto-vtable-summary.ll
+++ b/llvm/test/Assembler/thinlto-vtable-summary.ll
@@ -36,3 +36,4 @@
 ^6 = typeidCompatibleVTable: (name: "_ZTS1A", summary: ((offset: 16, ^2), (offset: 16, ^4))) ; guid = 7004155349499253778
 ^7 = typeidCompatibleVTable: (name: "_ZTS1B", summary: ((offset: 16, ^2))) ; guid = 6203814149063363976
 ^8 = typeidCompatibleVTable: (name: "_ZTS1C", summary: ((offset: 16, ^4))) ; guid = 1884921850105019584
+^9 = blockcount: 0
diff --git a/llvm/test/Bitcode/summary_version.ll b/llvm/test/Bitcode/summary_version.ll
--- a/llvm/test/Bitcode/summary_version.ll
+++ b/llvm/test/Bitcode/summary_version.ll
@@ -2,7 +2,7 @@
 ; RUN: opt  -module-summary  %s -o - | llvm-bcanalyzer -dump | FileCheck %s
 
 ; CHECK: <GLOBALVAL_SUMMARY_BLOCK
-; CHECK: <VERSION op0=8/>
+; CHECK: <VERSION op0=9/>
 
 
 
diff --git a/llvm/test/Bitcode/thinlto-alias.ll b/llvm/test/Bitcode/thinlto-alias.ll
--- a/llvm/test/Bitcode/thinlto-alias.ll
+++ b/llvm/test/Bitcode/thinlto-alias.ll
@@ -22,6 +22,7 @@
 ; See if the call to func is registered.
 ; The value id 1 matches the second FUNCTION record above.
 ; CHECK-NEXT:    <PERMODULE {{.*}} op7=1/>
+; CHECK-NEXT:    <BLOCK_COUNT op0=1/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; CHECK: <STRTAB_BLOCK
@@ -37,6 +38,7 @@
 ; COMBINED-NEXT:    <COMBINED {{.*}} op9=[[ALIASID]]/>
 ; COMBINED-NEXT:    <COMBINED {{.*}}
 ; COMBINED-NEXT:    <COMBINED_ALIAS  {{.*}} op3=[[ALIASEEID]]
+; COMBINED-NEXT:    <BLOCK_COUNT op0=2/>
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK
 
 ; ModuleID = 'thinlto-function-summary-callgraph.ll'
@@ -55,9 +57,11 @@
 ; DIS: ^0 = module: (path: "{{.*}}", hash: (0, 0, 0, 0, 0))
 ; DIS: ^1 = gv: (name: "analias", summaries: (alias: (module: ^0, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), aliasee: ^2))) ; guid = 12695095382722328222
 ; DIS: ^2 = gv: (name: "aliasee", summaries: (function: (module: ^0, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), insts: 1))) ; guid = 17407585008595848568
+; DIS: ^3 = blockcount: 1
 
 ; COMBINED-DIS: ^0 = module: (path: "{{.*}}thinlto-alias.ll.tmp.o", hash: (0, 0, 0, 0, 0))
 ; COMBINED-DIS: ^1 = module: (path: "{{.*}}thinlto-alias.ll.tmp2.o", hash: (0, 0, 0, 0, 0))
 ; COMBINED-DIS: ^2 = gv: (guid: 12695095382722328222, summaries: (alias: (module: ^1, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), aliasee: ^4)))
 ; COMBINED-DIS: ^3 = gv: (guid: 15822663052811949562, summaries: (function: (module: ^0, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), insts: 2, calls: ((callee: ^2)))))
 ; COMBINED-DIS: ^4 = gv: (guid: 17407585008595848568, summaries: (function: (module: ^1, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), insts: 1)))
+; COMBINED-DIS: ^5 = blockcount: 2
diff --git a/llvm/test/Bitcode/thinlto-alias2.ll b/llvm/test/Bitcode/thinlto-alias2.ll
--- a/llvm/test/Bitcode/thinlto-alias2.ll
+++ b/llvm/test/Bitcode/thinlto-alias2.ll
@@ -8,6 +8,7 @@
 ; CHECK-NEXT:    <PERMODULE {{.*}} op4=0 op5=0 op6=0 op7=[[ALIASID:[0-9]+]]/>
 ; CHECK-NEXT:    <PERMODULE {{.*}} op0=[[ALIASEEID:[0-9]+]]
 ; CHECK-NEXT:    <ALIAS {{.*}} op0=[[ALIASID]] {{.*}} op2=[[ALIASEEID]]/>
+; CHECK-NEXT:    <BLOCK_COUNT op0=2/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; ModuleID = 'thinlto-alias2.ll'
diff --git a/llvm/test/Bitcode/thinlto-function-summary-callgraph-cast.ll b/llvm/test/Bitcode/thinlto-function-summary-callgraph-cast.ll
--- a/llvm/test/Bitcode/thinlto-function-summary-callgraph-cast.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary-callgraph-cast.ll
@@ -12,6 +12,7 @@
 ; CHECK-NEXT:    <PERMODULE {{.*}} op4=3 {{.*}} op9={{[0-9]+}}/>
 ; CHECK-NEXT:    <PERMODULE {{.*}} op0=[[ALIASEEID:[0-9]+]]
 ; CHECK-NEXT:    <ALIAS {{.*}} op0=[[ALIASID]] {{.*}} op2=[[ALIASEEID]]/>
+; CHECK-NEXT:    <BLOCK_COUNT op0=3/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; ModuleID = 'thinlto-function-summary-callgraph-cast.ll'
diff --git a/llvm/test/Bitcode/thinlto-function-summary-callgraph-pgo.ll b/llvm/test/Bitcode/thinlto-function-summary-callgraph-pgo.ll
--- a/llvm/test/Bitcode/thinlto-function-summary-callgraph-pgo.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary-callgraph-pgo.ll
@@ -19,6 +19,7 @@
 ; CHECK-NEXT:    <FLAGS
 ; See if the call to func is registered, using the expected hotness type.
 ; CHECK-NEXT:    <PERMODULE_PROFILE {{.*}} op7=1 op8=2/>
+; CHECK-NEXT:    <BLOCK_COUNT op0=1/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; CHECK: <STRTAB_BLOCK
 ; CHECK-NEXT: blob data = 'mainfunc{{.*}}'
@@ -32,6 +33,7 @@
 ; See if the call to func is registered, using the expected hotness type.
 ; op6=2 which is hotnessType::None.
 ; COMBINED-NEXT:    <COMBINED_PROFILE {{.*}} op9=[[FUNCID]] op10=2/>
+; COMBINED-NEXT:    <BLOCK_COUNT op0=2/>
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; ModuleID = 'thinlto-function-summary-callgraph.ll'
diff --git a/llvm/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll b/llvm/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll
--- a/llvm/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary-callgraph-profile-summary.ll
@@ -50,6 +50,7 @@
 ; CHECK-NEXT:    <VALUE_GUID op0=25 op1=123/>
 ; op4=hot1 op6=cold op8=hot2 op10=hot4 op12=none1 op14=hot3 op16=none2 op18=none3 op20=123
 ; CHECK-NEXT:    <PERMODULE_PROFILE {{.*}} op7=1 op8=3 op9=5 op10=1 op11=2 op12=3 op13=4 op14=1 op15=6 op16=2 op17=3 op18=3 op19=7 op20=2 op21=8 op22=2 op23=25 op24=4/>
+; CHECK-NEXT:    <BLOCK_COUNT op0=6/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; CHECK: <STRTAB_BLOCK
@@ -73,8 +74,9 @@
 ; COMBINED-NEXT:    <COMBINED abbrevid=
 ; COMBINED-NEXT:    <COMBINED abbrevid=
 ; COMBINED-NEXT:    <COMBINED_PROFILE {{.*}} op9=[[HOT1:.*]] op10=3 op11=[[COLD:.*]] op12=1 op13=[[HOT2:.*]] op14=3 op15=[[NONE1:.*]] op16=2 op17=[[HOT3:.*]] op18=3 op19=[[NONE2:.*]] op20=2 op21=[[NONE3:.*]] op22=2/>
-; COMBINED_NEXT:    <COMBINED abbrevid=
-; COMBINED_NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <BLOCK_COUNT op0=13/>
+; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 
 ; ModuleID = 'thinlto-function-summary-callgraph.ll'
diff --git a/llvm/test/Bitcode/thinlto-function-summary-callgraph-relbf.ll b/llvm/test/Bitcode/thinlto-function-summary-callgraph-relbf.ll
--- a/llvm/test/Bitcode/thinlto-function-summary-callgraph-relbf.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary-callgraph-relbf.ll
@@ -15,6 +15,7 @@
 ; CHECK-NEXT:    <FLAGS
 ; See if the call to func is registered.
 ; CHECK-NEXT:    <PERMODULE_RELBF {{.*}} op4=1 {{.*}} op9=256
+; CHECK-NEXT:    <BLOCK_COUNT op0=1/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; CHECK: <STRTAB_BLOCK
 ; CHECK-NEXT: blob data = 'undefinedglobmainfunc{{.*}}'
diff --git a/llvm/test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll b/llvm/test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll
--- a/llvm/test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary-callgraph-sample-profile-summary.ll
@@ -33,6 +33,7 @@
 ; CHECK-NEXT:    <VALUE_GUID op0=26 op1=123/>
 ; op4=none1 op6=hot1 op8=cold1 op10=none2 op12=hot2 op14=cold2 op16=none3 op18=hot3 op20=cold3 op22=123
 ; CHECK-NEXT:    <PERMODULE_PROFILE {{.*}} op7=7 op8=0 op9=1 op10=3 op11=4 op12=1 op13=8 op14=0 op15=2 op16=3 op17=5 op18=1 op19=9 op20=0 op21=3 op22=3 op23=6 op24=1 op25=26 op26=4/>
+; CHECK-NEXT:    <BLOCK_COUNT op0=4/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; CHECK: <STRTAB_BLOCK
@@ -60,8 +61,9 @@
 ; COMBINED-NEXT:    <COMBINED abbrevid=
 ; COMBINED-NEXT:    <COMBINED abbrevid=
 ; COMBINED-NEXT:    <COMBINED_PROFILE {{.*}} op9=[[NONE1:.*]] op10=0 op11=[[HOT1:.*]] op12=3 op13=[[COLD1:.*]] op14=1 op15=[[NONE2:.*]] op16=0 op17=[[HOT2:.*]] op18=3 op19=[[COLD2:.*]] op20=1 op21=[[NONE3:.*]] op22=0 op23=[[HOT3:.*]] op24=3 op25=[[COLD3:.*]] op26=1/>
-; COMBINED_NEXT:    <COMBINED abbrevid=
-; COMBINED_NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
+; COMBINED-NEXT:    <COMBINED abbrevid=
+; COMBINED-NEXT:    <BLOCK_COUNT op0=13/>
+; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 
 ; ModuleID = 'thinlto-function-summary-callgraph.ll'
diff --git a/llvm/test/Bitcode/thinlto-function-summary-callgraph.ll b/llvm/test/Bitcode/thinlto-function-summary-callgraph.ll
--- a/llvm/test/Bitcode/thinlto-function-summary-callgraph.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary-callgraph.ll
@@ -20,6 +20,7 @@
 ; CHECK-NEXT:    <FLAGS
 ; See if the call to func is registered
 ; CHECK-NEXT:    <PERMODULE {{.*}} op4=1
+; CHECK-NEXT:    <BLOCK_COUNT op0=1/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; CHECK: <STRTAB_BLOCK
 ; CHECK-NEXT: blob data = 'undefinedglobmainfunc{{.*}}'
@@ -35,6 +36,7 @@
 ; COMBINED-NEXT:    <COMBINED
 ; See if the call to func is registered.
 ; COMBINED-NEXT:    <COMBINED {{.*}} op9=[[FUNCID]]/>
+; COMBINED-NEXT:    <BLOCK_COUNT op0=2/>
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 ; ModuleID = 'thinlto-function-summary-callgraph.ll'
diff --git a/llvm/test/Bitcode/thinlto-function-summary-originalnames.ll b/llvm/test/Bitcode/thinlto-function-summary-originalnames.ll
--- a/llvm/test/Bitcode/thinlto-function-summary-originalnames.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary-originalnames.ll
@@ -15,6 +15,7 @@
 ; COMBINED-DAG:    <COMBINED_ORIGINAL_NAME op0=-2012135647395072713/>
 ; COMBINED-DAG:    <COMBINED_ALIAS
 ; COMBINED-DAG:    <COMBINED_ORIGINAL_NAME op0=-4170563161550796836/>
+; COMBINED-NEXT:   <BLOCK_COUNT op0=1/>
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 
 source_filename = "/path/to/source.c"
diff --git a/llvm/test/Bitcode/thinlto-function-summary.ll b/llvm/test/Bitcode/thinlto-function-summary.ll
--- a/llvm/test/Bitcode/thinlto-function-summary.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary.ll
@@ -25,6 +25,7 @@
 ; BC-NEXT: <PERMODULE {{.*}} op0=3 op1=7
 ; BC-NEXT: <PERMODULE {{.*}} op0=4 op1=0 op2=4 op3=0
 ; BC-NEXT: <ALIAS {{.*}} op0=6 op1=0 op2=3
+; BC-NEXT: <BLOCK_COUNT op0=5/>
 ; BC-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 ; BC: <STRTAB_BLOCK
 ; BC-NEXT: blob data = 'hfoobaranon.{{................................}}.0variadicllvm.va_startf{{.*}}'
diff --git a/llvm/test/ThinLTO/X86/distributed_indexes.ll b/llvm/test/ThinLTO/X86/distributed_indexes.ll
--- a/llvm/test/ThinLTO/X86/distributed_indexes.ll
+++ b/llvm/test/ThinLTO/X86/distributed_indexes.ll
@@ -23,6 +23,7 @@
 ; BACKEND1-DAG: <COMBINED {{.*}} op1=0
 ; BACKEND1-DAG: <COMBINED {{.*}} op1=1
 ; BACKEND1-DAG: <COMBINED_ALIAS {{.*}} op1=1
+; BACKEND1-NEXT: <BLOCK_COUNT op0=3/>
 ; BACKEND1-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 
 ; The backend index for Input/distributed_indexes.ll contains summaries from
@@ -38,6 +39,7 @@
 ; BACKEND2-NEXT: <COMBINED
 ; BACKEND2-NEXT: <COMBINED
 ; BACKEND2-NEXT: <COMBINED_ALIAS
+; BACKEND2-NEXT: <BLOCK_COUNT op0=3/>
 ; BACKEND2-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 
 ; Make sure that when the alias is imported as a copy of the aliasee, but the
diff --git a/llvm/test/tools/llvm-lto/thinlto.ll b/llvm/test/tools/llvm-lto/thinlto.ll
--- a/llvm/test/tools/llvm-lto/thinlto.ll
+++ b/llvm/test/tools/llvm-lto/thinlto.ll
@@ -16,6 +16,7 @@
 ; COMBINED-NEXT: <VALUE_GUID op0={{1|2}} op1={{-3706093650706652785|-5300342847281564238}}
 ; COMBINED-NEXT: <COMBINED
 ; COMBINED-NEXT: <COMBINED
+; COMBINED-NEXT: <BLOCK_COUNT op0=2/>
 ; COMBINED-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"