Index: llvm/trunk/lib/Passes/PassBuilder.cpp
===================================================================
--- llvm/trunk/lib/Passes/PassBuilder.cpp
+++ llvm/trunk/lib/Passes/PassBuilder.cpp
@@ -710,7 +710,9 @@
   MainCGPipeline.addPass(createCGSCCToFunctionPassAdaptor(
       buildFunctionSimplificationPipeline(Level, Phase, DebugLogging)));
 
-  if (EnableHotColdSplit)
+  // We only want to do hot cold splitting once for ThinLTO, during the
+  // post-link ThinLTO.
+  if (EnableHotColdSplit && Phase != ThinLTOPhase::PreLink)
     MPM.addPass(HotColdSplittingPass());
 
   for (auto &C : CGSCCOptimizerLateEPCallbacks)
Index: llvm/trunk/test/Other/new-pm-thinlto-defaults.ll
===================================================================
--- llvm/trunk/test/Other/new-pm-thinlto-defaults.ll
+++ llvm/trunk/test/Other/new-pm-thinlto-defaults.ll
@@ -26,6 +26,10 @@
 ; RUN: opt -disable-verify -debug-pass-manager -new-pm-debug-info-for-profiling \
 ; RUN:     -passes='thinlto-pre-link<O2>,name-anon-globals' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK-DIS,CHECK-O,CHECK-O2,CHECK-PRELINK-O,CHECK-PRELINK-O2
+; Enabling the hot-cold-split pass should not affect the ThinLTO pre-link
+; RUN: opt -disable-verify -debug-pass-manager \
+; RUN:     -passes='thinlto-pre-link<O2>,name-anon-globals' -hot-cold-split -S  %s 2>&1 \
+; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O2,CHECK-PRELINK-O,CHECK-PRELINK-O-NODIS,CHECK-PRELINK-O2
 ;
 ; Postlink pipelines:
 ; RUN: opt -disable-verify -debug-pass-manager \