diff --git a/llvm/include/llvm/ProfileData/ProfileCommon.h b/llvm/include/llvm/ProfileData/ProfileCommon.h
--- a/llvm/include/llvm/ProfileData/ProfileCommon.h
+++ b/llvm/include/llvm/ProfileData/ProfileCommon.h
@@ -33,8 +33,8 @@
 
 } // end namespace sampleprof
 
-inline const char *getHotSectionPrefix() { return ".hot"; }
-inline const char *getUnlikelySectionPrefix() { return ".unlikely"; }
+inline const char *getHotSectionPrefix() { return "hot"; }
+inline const char *getUnlikelySectionPrefix() { return "unlikely"; }
 
 class ProfileSummaryBuilder {
 private:
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -473,12 +473,12 @@
   OptSize = F.hasOptSize();
   if (ProfileGuidedSectionPrefix) {
     if (PSI->isFunctionHotInCallGraph(&F, *BFI))
-      F.setSectionPrefix(".hot");
+      F.setSectionPrefix("hot");
     else if (PSI->isFunctionColdInCallGraph(&F, *BFI))
-      F.setSectionPrefix(".unlikely");
+      F.setSectionPrefix("unlikely");
     else if (ProfileUnknownInSpecialSection && PSI->hasPartialSampleProfile() &&
              PSI->isFunctionHotnessUnknown(F))
-      F.setSectionPrefix(".unknown");
+      F.setSectionPrefix("unknown");
   }
 
   /// This optimization identifies DIV instructions that can be
diff --git a/llvm/lib/CodeGen/MachineFunctionSplitter.cpp b/llvm/lib/CodeGen/MachineFunctionSplitter.cpp
--- a/llvm/lib/CodeGen/MachineFunctionSplitter.cpp
+++ b/llvm/lib/CodeGen/MachineFunctionSplitter.cpp
@@ -107,8 +107,8 @@
   // or functions of unknown hotness. Lukewarm functions have no prefix.
   Optional<StringRef> SectionPrefix = MF.getFunction().getSectionPrefix();
   if (SectionPrefix.hasValue() &&
-      (SectionPrefix.getValue().equals(".unlikely") ||
-       SectionPrefix.getValue().equals(".unknown"))) {
+      (SectionPrefix.getValue().equals("unlikely") ||
+       SectionPrefix.getValue().equals("unknown"))) {
     return false;
   }
 
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -621,7 +621,7 @@
   bool HasPrefix = false;
   if (const auto *F = dyn_cast<Function>(GO)) {
     if (Optional<StringRef> Prefix = F->getSectionPrefix()) {
-      Name += *Prefix;
+      raw_svector_ostream(Name) << '.' << *Prefix;
       HasPrefix = true;
     }
   }
@@ -1573,6 +1573,10 @@
       MCSymbol *Sym = TM.getSymbol(ComdatGV);
       StringRef COMDATSymName = Sym->getName();
 
+      if (const auto *F = dyn_cast<Function>(GO))
+        if (Optional<StringRef> Prefix = F->getSectionPrefix())
+          raw_svector_ostream(Name) << '$' << *Prefix;
+
       // Append "$symbol" to the section name *before* IR-level mangling is
       // applied when targetting mingw. This is what GCC does, and the ld.bfd
       // COFF linker will not properly handle comdats otherwise.
@@ -2020,7 +2024,7 @@
   if (const auto *F = dyn_cast<Function>(GO)) {
     const auto &OptionalPrefix = F->getSectionPrefix();
     if (OptionalPrefix)
-      Name += *OptionalPrefix;
+      raw_svector_ostream(Name) << '.' << *OptionalPrefix;
   }
 
   if (EmitUniqueSection && UniqueSectionNames) {
diff --git a/llvm/test/CodeGen/X86/text-section-prefix.ll b/llvm/test/CodeGen/X86/text-section-prefix.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/X86/text-section-prefix.ll
@@ -0,0 +1,13 @@
+; RUN: llc -function-sections < %s
+
+define void @foo0(i1 zeroext %0) nounwind !section_prefix !0 {
+  ret void
+}
+
+define void @foo1(i1 zeroext %0) nounwind !section_prefix !1 {
+  ret void
+}
+
+!0 = !{!"function_section_prefix", !"hot"}
+!1 = !{!"function_section_prefix", !"unlikely"}
+