Index: lld/test/COFF/pgo-warn-mismatch.ll
===================================================================
--- lld/test/COFF/pgo-warn-mismatch.ll
+++ lld/test/COFF/pgo-warn-mismatch.ll
@@ -6,9 +6,11 @@
 
 ; Ensure lld generates warnings for profile cfg mismatch.
 ; RUN: lld-link /dll /noentry /export:f /lto-cs-profile-file:%t/cs.profdata /lto-pgo-warn-mismatch /opt:lldlto=2 %t/a.bc /out:%t/a.dll 2>&1 | FileCheck %s
+; RUN: lld-link /lto-legacy-pass-manager:no /dll /noentry /export:f /lto-cs-profile-file:%t/cs.profdata /lto-pgo-warn-mismatch /opt:lldlto=2 %t/a.bc /out:%t/a.dll 2>&1 | FileCheck %s
 
 ; Ensure lld will not generate warnings for profile cfg mismatch.
 ; RUN: lld-link /dll /noentry /export:f /lto-cs-profile-file:%t/cs.profdata /lto-pgo-warn-mismatch:no /opt:lldlto=2 %t/a.bc /out:%t/a.dll 2>&1 | count 0
+; RUN: lld-link /lto-legacy-pass-manager:no /dll /noentry /export:f /lto-cs-profile-file:%t/cs.profdata /lto-pgo-warn-mismatch:no /opt:lldlto=2 %t/a.bc /out:%t/a.dll 2>&1 | count 0
 
 ; CHECK: warning: {{.*}} function control flow change detected (hash mismatch) f Hash = [[#]]
 
Index: lld/test/ELF/lto/pgo-warn-mismatch.ll
===================================================================
--- lld/test/ELF/lto/pgo-warn-mismatch.ll
+++ lld/test/ELF/lto/pgo-warn-mismatch.ll
@@ -6,9 +6,11 @@
 
 ;; Ensure lld generates warnings for profile cfg mismatch.
 ; RUN: ld.lld --lto-cs-profile-file=%t/cs.profdata --lto-pgo-warn-mismatch -shared %t/a.bc -o /dev/null 2>&1 | FileCheck %s
+; RUN: ld.lld --no-lto-legacy-pass-manager --lto-cs-profile-file=%t/cs.profdata --lto-pgo-warn-mismatch -shared %t/a.bc -o /dev/null 2>&1 | FileCheck %s
 
 ;; Ensure lld will not generate warnings for profile cfg mismatch.
 ; RUN: ld.lld --lto-cs-profile-file=%t/cs.profdata --no-lto-pgo-warn-mismatch -shared --fatal-warnings %t/a.bc -o /dev/null
+; RUN: ld.lld --no-lto-legacy-pass-manager --lto-cs-profile-file=%t/cs.profdata --no-lto-pgo-warn-mismatch -shared --fatal-warnings %t/a.bc -o /dev/null
 
 ; CHECK: warning: {{.*}} function control flow change detected (hash mismatch) f Hash = [[#]]
 
Index: llvm/lib/LTO/LTOBackend.cpp
===================================================================
--- llvm/lib/LTO/LTOBackend.cpp
+++ llvm/lib/LTO/LTOBackend.cpp
@@ -317,6 +317,8 @@
   legacy::PassManager passes;
   passes.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
 
+  NoPGOWarnMismatch = !Conf.PGOWarnMismatch;
+
   PassManagerBuilder PMB;
   PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM->getTargetTriple()));
   if (Conf.Freestanding)