Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -1223,6 +1223,8 @@
 def m64 : Flag<["-"], "m64">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
 def mx32 : Flag<["-"], "mx32">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
 def mabi_EQ : Joined<["-"], "mabi=">, Group<m_Group>;
+def miamcu : Flag<["-"], "miamcu">, Group<m_Group>, Flags<[DriverOption, CoreOption]>,
+  HelpText<"Use Intel MCU ABI.">;
 def malign_functions_EQ : Joined<["-"], "malign-functions=">, Group<clang_ignored_m_Group>;
 def malign_loops_EQ : Joined<["-"], "malign-loops=">, Group<clang_ignored_m_Group>;
 def malign_jumps_EQ : Joined<["-"], "malign-jumps=">, Group<clang_ignored_m_Group>;
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -1907,6 +1907,16 @@
           << A->getOption().getName() << Value;
     }
   }
+
+  // If -miamcu is set then set flags to support MCU ABI.
+  if (Args.getLastArg(options::OPT_miamcu)) {
+    if (getToolChain().getArch() != llvm::Triple::x86)
+      getToolChain().getDriver().Diag(diag::err_drv_unsupported_opt)
+          << "-miamcu";
+    CmdArgs.push_back("-mfloat-abi");
+    CmdArgs.push_back("soft");
+    CmdArgs.push_back("-mstack-alignment=4");
+  }
 }
 
 void Clang::AddHexagonTargetArgs(const ArgList &Args,
Index: test/Driver/iamcu-abi.c
===================================================================
--- /dev/null
+++ test/Driver/iamcu-abi.c
@@ -0,0 +1,5 @@
+// RUN: %clang -target i386-unknown-linux -m32 -miamcu %s -### -o %t.o 2>&1 \
+// RUN:   | FileCheck %s
+
+// CHECK: "-mfloat-abi" "soft"
+// CHECK: "-mstack-alignment=4"