diff --git a/clang/lib/Driver/ToolChains/BareMetal.h b/clang/lib/Driver/ToolChains/BareMetal.h
--- a/clang/lib/Driver/ToolChains/BareMetal.h
+++ b/clang/lib/Driver/ToolChains/BareMetal.h
@@ -70,6 +70,9 @@
   void AddLinkRuntimeLib(const llvm::opt::ArgList &Args,
                          llvm::opt::ArgStringList &CmdArgs) const;
   std::string computeSysRoot() const override;
+
+private:
+  llvm::SmallVector<Multilib> getOrderedMultilibs() const;
 };
 
 } // namespace toolchains
diff --git a/clang/lib/Driver/ToolChains/BareMetal.cpp b/clang/lib/Driver/ToolChains/BareMetal.cpp
--- a/clang/lib/Driver/ToolChains/BareMetal.cpp
+++ b/clang/lib/Driver/ToolChains/BareMetal.cpp
@@ -102,9 +102,12 @@
   findMultilibs(D, Triple, Args);
   SmallString<128> SysRoot(computeSysRoot());
   if (!SysRoot.empty()) {
-    llvm::sys::path::append(SysRoot, "lib");
-    getFilePaths().push_back(std::string(SysRoot));
-    getLibraryPaths().push_back(std::string(SysRoot));
+    for (const Multilib &M : getOrderedMultilibs()) {
+      SmallString<128> Dir(SysRoot);
+      llvm::sys::path::append(Dir, M.osSuffix(), "lib");
+      getFilePaths().push_back(std::string(Dir));
+      getLibraryPaths().push_back(std::string(Dir));
+    }
   }
 }
 
@@ -226,9 +229,18 @@
 }
 
 std::string BareMetal::computeSysRoot() const {
-  std::string Result = computeBaseSysRoot(getDriver(), getTriple());
-  if (!SelectedMultilibs.empty()) {
-    Result += SelectedMultilibs.back().osSuffix();
+  return computeBaseSysRoot(getDriver(), getTriple());
+}
+
+llvm::SmallVector<Multilib> BareMetal::getOrderedMultilibs() const {
+  llvm::SmallVector<Multilib> Result;
+  // Get multilibs in reverse order because they're ordered most-specific last.
+  for (auto It = SelectedMultilibs.rbegin(), End = SelectedMultilibs.rend();
+       It != End; ++It) {
+    Result.push_back(*It);
+  }
+  if (Result.empty()) {
+    Result.push_back(Multilib());
   }
   return Result;
 }
@@ -245,10 +257,14 @@
   }
 
   if (!DriverArgs.hasArg(options::OPT_nostdlibinc)) {
-    SmallString<128> Dir(computeSysRoot());
-    if (!Dir.empty()) {
-      llvm::sys::path::append(Dir, "include");
-      addSystemInclude(DriverArgs, CC1Args, Dir.str());
+    const SmallString<128> SysRoot(computeSysRoot());
+    if (!SysRoot.empty()) {
+      for (const Multilib &M : getOrderedMultilibs()) {
+        SmallString<128> Dir(SysRoot);
+        llvm::sys::path::append(Dir, M.includeSuffix());
+        llvm::sys::path::append(Dir, "include");
+        addSystemInclude(DriverArgs, CC1Args, Dir.str());
+      }
     }
   }
 }
@@ -271,44 +287,47 @@
   if (SysRoot.empty())
     return;
 
-  switch (GetCXXStdlibType(DriverArgs)) {
-  case ToolChain::CST_Libcxx: {
-    // First check sysroot/usr/include/c++/v1 if it exists.
-    SmallString<128> TargetDir(SysRoot);
-    llvm::sys::path::append(TargetDir, "usr", "include", "c++", "v1");
-    if (D.getVFS().exists(TargetDir)) {
-      addSystemInclude(DriverArgs, CC1Args, TargetDir.str());
+  for (const Multilib &M : getOrderedMultilibs()) {
+    SmallString<128> Dir(SysRoot);
+    llvm::sys::path::append(Dir, M.gccSuffix());
+    switch (GetCXXStdlibType(DriverArgs)) {
+    case ToolChain::CST_Libcxx: {
+      // First check sysroot/usr/include/c++/v1 if it exists.
+      SmallString<128> TargetDir(Dir);
+      llvm::sys::path::append(TargetDir, "usr", "include", "c++", "v1");
+      if (D.getVFS().exists(TargetDir)) {
+        addSystemInclude(DriverArgs, CC1Args, TargetDir.str());
+        break;
+      }
+      // Add generic path if nothing else succeeded so far.
+      llvm::sys::path::append(Dir, "include", "c++", "v1");
+      addSystemInclude(DriverArgs, CC1Args, Dir.str());
+      break;
+    }
+    case ToolChain::CST_Libstdcxx: {
+      llvm::sys::path::append(Dir, "include", "c++");
+      std::error_code EC;
+      Generic_GCC::GCCVersion Version = {"", -1, -1, -1, "", "", ""};
+      // Walk the subdirs, and find the one with the newest gcc version:
+      for (llvm::vfs::directory_iterator
+               LI = D.getVFS().dir_begin(Dir.str(), EC),
+               LE;
+           !EC && LI != LE; LI = LI.increment(EC)) {
+        StringRef VersionText = llvm::sys::path::filename(LI->path());
+        auto CandidateVersion = Generic_GCC::GCCVersion::Parse(VersionText);
+        if (CandidateVersion.Major == -1)
+          continue;
+        if (CandidateVersion <= Version)
+          continue;
+        Version = CandidateVersion;
+      }
+      if (Version.Major != -1) {
+        llvm::sys::path::append(Dir, Version.Text);
+        addSystemInclude(DriverArgs, CC1Args, Dir.str());
+      }
       break;
     }
-    // Add generic path if nothing else succeeded so far.
-    SmallString<128> Dir(SysRoot);
-    llvm::sys::path::append(Dir, "include", "c++", "v1");
-    addSystemInclude(DriverArgs, CC1Args, Dir.str());
-    break;
-  }
-  case ToolChain::CST_Libstdcxx: {
-    SmallString<128> Dir(SysRoot);
-    llvm::sys::path::append(Dir, "include", "c++");
-    std::error_code EC;
-    Generic_GCC::GCCVersion Version = {"", -1, -1, -1, "", "", ""};
-    // Walk the subdirs, and find the one with the newest gcc version:
-    for (llvm::vfs::directory_iterator LI = D.getVFS().dir_begin(Dir.str(), EC),
-                                       LE;
-         !EC && LI != LE; LI = LI.increment(EC)) {
-      StringRef VersionText = llvm::sys::path::filename(LI->path());
-      auto CandidateVersion = Generic_GCC::GCCVersion::Parse(VersionText);
-      if (CandidateVersion.Major == -1)
-        continue;
-      if (CandidateVersion <= Version)
-        continue;
-      Version = CandidateVersion;
     }
-    if (Version.Major == -1)
-      return;
-    llvm::sys::path::append(Dir, Version.Text);
-    addSystemInclude(DriverArgs, CC1Args, Dir.str());
-    break;
-  }
   }
 }
 
diff --git a/clang/test/Driver/Inputs/baremetal_multilib/multilib.yaml b/clang/test/Driver/Inputs/baremetal_multilib/multilib.yaml
--- a/clang/test/Driver/Inputs/baremetal_multilib/multilib.yaml
+++ b/clang/test/Driver/Inputs/baremetal_multilib/multilib.yaml
@@ -65,6 +65,14 @@
   flags: [target=thumbv8.1m.main-none-unknown-eabihf, march=+mve]
   printArgs: [--target=arm-none-eabihf, -march=armv8.1m.main+nofp+mve]
 
+# A specialisation of v8.1-m.main/fp without exceptions.
+# This layers over the top of the regular v8.1-m.main/fp so it doesn't
+# need to have its own include directory or C library, thereby saving
+# disk space.
+- dir: arm-none-eabi/thumb/v8.1-m.main/fp/noexcept
+  flags: [target=thumbv8.1m.main-none-unknown-eabihf, hasfpu, fno-exceptions]
+  printArgs: [--target=thumbv8.1m.main-none-eabihf, -fno-exceptions]
+
 
 # The second section of the file is a map from auto-detected flags
 # to custom flags. The auto-detected flags can be printed out
diff --git a/clang/test/Driver/baremetal-multilib.cpp b/clang/test/Driver/baremetal-multilib.cpp
--- a/clang/test/Driver/baremetal-multilib.cpp
+++ b/clang/test/Driver/baremetal-multilib.cpp
@@ -25,6 +25,23 @@
 // RUN:   | FileCheck --check-prefix=CHECK-PRINT-MULTI-DIRECTORY %s
 // CHECK-PRINT-MULTI-DIRECTORY: arm-none-eabi/thumb/v8-m.main/fp
 
+// RUN: %T/baremetal_multilib/bin/clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=thumbv8.1m.main-none-eabihf -fno-exceptions --sysroot= \
+// RUN:   | FileCheck --check-prefix=CHECK-LAYERED-MULTILIB %s
+// CHECK-LAYERED-MULTILIB: "{{.*}}clang{{.*}}" "-cc1" "-triple" "thumbv8.1m.main-none-unknown-eabihf"
+// CHECK-LAYERED-MULTILIB-SAME: "-internal-isystem" "{{.*}}/baremetal_multilib/bin/../lib/clang-runtimes/arm-none-eabi/thumb/v8.1-m.main/fp/noexcept/include/c++/v1"
+// CHECK-LAYERED-MULTILIB-SAME: "-internal-isystem" "{{.*}}/baremetal_multilib/bin/../lib/clang-runtimes/arm-none-eabi/thumb/v8.1-m.main/fp/include/c++/v1"
+// CHECK-LAYERED-MULTILIB-SAME: "-internal-isystem" "{{.*}}/baremetal_multilib/bin/../lib/clang-runtimes/arm-none-eabi/thumb/v8.1-m.main/fp/noexcept/include"
+// CHECK-LAYERED-MULTILIB-SAME: "-internal-isystem" "{{.*}}/baremetal_multilib/bin/../lib/clang-runtimes/arm-none-eabi/thumb/v8.1-m.main/fp/include"
+// CHECK-LAYERED-MULTILIB-NEXT: "-L{{.*}}/baremetal_multilib/bin/../lib/clang-runtimes/arm-none-eabi/thumb/v8.1-m.main/fp/noexcept/lib"
+// CHECK-LAYERED-MULTILIB-SAME: "-L{{.*}}/baremetal_multilib/bin/../lib/clang-runtimes/arm-none-eabi/thumb/v8.1-m.main/fp/lib"
+
+// RUN: %T/baremetal_multilib/bin/clang -no-canonical-prefixes -print-multi-directory 2>&1 \
+// RUN:     --target=thumbv8.1m.main-none-eabihf -fno-exceptions --sysroot= \
+// RUN:   | FileCheck --check-prefix=CHECK-LAYERED-PRINT-MULTI-DIRECTORY %s
+// CHECK-LAYERED-PRINT-MULTI-DIRECTORY: arm-none-eabi/thumb/v8.1-m.main/fp
+// CHECK-LAYERED-PRINT-MULTI-DIRECTORY-NEXT: arm-none-eabi/thumb/v8.1-m.main/fp/noexcept
+
 // RUN: %T/baremetal_multilib/bin/clang -no-canonical-prefixes -print-multi-lib 2>&1 \
 // RUN:     --target=arm-none-eabi --sysroot= \
 // RUN:   | FileCheck --check-prefix=CHECK-PRINT-MULTI-LIB %s
@@ -38,6 +55,7 @@
 // CHECK-PRINT-MULTI-LIB: arm-none-eabi/thumb/v8-m.main/fp;@-target=thumbv8m.main-none-eabihf
 // CHECK-PRINT-MULTI-LIB: arm-none-eabi/thumb/v8.1-m.main/fp;@-target=thumbv8.1m.main-none-eabihf
 // CHECK-PRINT-MULTI-LIB: arm-none-eabi/thumb/v8.1-m.main/nofp/mve;@-target=arm-none-eabihf@march=armv8.1m.main+nofp+mve
+// CHECK-PRINT-MULTI-LIB: arm-none-eabi/thumb/v8.1-m.main/fp/noexcept;@-target=thumbv8.1m.main-none-eabihf@fno-exceptions
 
 // RUN: %T/baremetal_multilib/bin/clang -no-canonical-prefixes -x assembler -mexecute-only \
 // RUN:     --target=arm-none-eabi --sysroot= %s -c -### 2>&1 \