Index: clang/include/clang/Basic/CodeGenOptions.h
===================================================================
--- clang/include/clang/Basic/CodeGenOptions.h
+++ clang/include/clang/Basic/CodeGenOptions.h
@@ -97,6 +97,11 @@
     Embed_Marker    // Embed a marker as a placeholder for bitcode.
   };
 
+  enum InlineAsmDialectKind {
+    IAD_ATT,
+    IAD_Intel,
+  };
+
   // This field stores one of the allowed values for the option
   // -fbasic-block-sections=.  The allowed values with this option are:
   // {"labels", "all", "list=<file>", "none"}.
Index: clang/include/clang/Basic/CodeGenOptions.def
===================================================================
--- clang/include/clang/Basic/CodeGenOptions.def
+++ clang/include/clang/Basic/CodeGenOptions.def
@@ -92,6 +92,8 @@
 CODEGENOPT(ExplicitEmulatedTLS , 1, 0) ///< Set if -f[no-]emulated-tls is used.
 /// Embed Bitcode mode (off/all/bitcode/marker).
 ENUM_CODEGENOPT(EmbedBitcode, EmbedBitcodeKind, 2, Embed_Off)
+/// Inline asm dialect, -masm=(att|intel)
+ENUM_CODEGENOPT(InlineAsmDialect, InlineAsmDialectKind, 1, IAD_ATT)
 CODEGENOPT(ForbidGuardVariables , 1, 0) ///< Issue errors if C++ guard variables
                                         ///< are required.
 CODEGENOPT(FunctionSections  , 1, 0) ///< Set when -ffunction-sections is enabled.
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -3131,6 +3131,7 @@
 def mwatchsimulator_version_min_EQ : Joined<["-"], "mwatchsimulator-version-min=">, Alias<mwatchos_simulator_version_min_EQ>;
 def march_EQ : Joined<["-"], "march=">, Group<m_Group>, Flags<[CoreOption]>;
 def masm_EQ : Joined<["-"], "masm=">, Group<m_Group>, Flags<[NoXarchOption]>;
+def inline_asm_EQ : Joined<["-"], "inline-asm=">, Group<m_Group>, Flags<[CC1Option]>;
 def mcmodel_EQ : Joined<["-"], "mcmodel=">, Group<m_Group>, Flags<[CC1Option]>,
   MarshallingInfoString<TargetOpts<"CodeModel">, [{"default"}]>;
 def mtls_size_EQ : Joined<["-"], "mtls-size=">, Group<m_Group>, Flags<[NoXarchOption, CC1Option]>,
Index: clang/lib/CodeGen/CGStmt.cpp
===================================================================
--- clang/lib/CodeGen/CGStmt.cpp
+++ clang/lib/CodeGen/CGStmt.cpp
@@ -2629,8 +2629,14 @@
     llvm::FunctionType::get(ResultType, ArgTypes, false);
 
   bool HasSideEffect = S.isVolatile() || S.getNumOutputs() == 0;
+
+  llvm::InlineAsm::AsmDialect GnuAsmDialect =
+      CGM.getCodeGenOpts().getInlineAsmDialect() == CodeGenOptions::IAD_ATT
+          ? llvm::InlineAsm::AD_ATT
+          : llvm::InlineAsm::AD_Intel;
   llvm::InlineAsm::AsmDialect AsmDialect = isa<MSAsmStmt>(&S) ?
-    llvm::InlineAsm::AD_Intel : llvm::InlineAsm::AD_ATT;
+    llvm::InlineAsm::AD_Intel : GnuAsmDialect;
+
   llvm::InlineAsm *IA = llvm::InlineAsm::get(
       FTy, AsmString, Constraints, HasSideEffect,
       /* IsAlignStack */ false, AsmDialect, HasUnwindClobber);
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -2200,6 +2200,7 @@
     if (Value == "intel" || Value == "att") {
       CmdArgs.push_back("-mllvm");
       CmdArgs.push_back(Args.MakeArgString("-x86-asm-syntax=" + Value));
+      CmdArgs.push_back(Args.MakeArgString("-inline-asm=" + Value));
     } else {
       D.Diag(diag::err_drv_unsupported_option_argument)
           << A->getOption().getName() << Value;
Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -1614,6 +1614,18 @@
     }
   }
 
+  if (Arg *A = Args.getLastArg(options::OPT_inline_asm_EQ)) {
+    StringRef Value = A->getValue();
+    if (Value == "att") {
+      Opts.InlineAsmDialect = CodeGenOptions::IAD_ATT;
+    } else if (Value == "intel") {
+      Opts.InlineAsmDialect = CodeGenOptions::IAD_Intel;
+    } else {
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args)
+                                                << A->getValue();
+    }
+  }
+
   // PIC defaults to -fno-direct-access-external-data while non-PIC defaults to
   // -fdirect-access-external-data.
   Opts.DirectAccessExternalData =
Index: clang/test/CodeGen/inline-asm-intel.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/inline-asm-intel.c
@@ -0,0 +1,14 @@
+// REQUIRES: x86-registered-target
+
+/// Accept intel inline asm but write it out as att:
+// RUN: %clang_cc1 -triple i386-unknown-unknown -mllvm -x86-asm-syntax=att -inline-asm=intel -O0 -emit-llvm -S %s -o - | FileCheck --check-prefix=ATT %s
+
+/// Accept intel inline asm and write it out as intel:
+// RUN: %clang_cc1 -triple i386-unknown-unknown -mllvm -x86-asm-syntax=intel -inline-asm=intel -O0 -emit-llvm -S %s -o - | FileCheck  --check-prefix=INTEL %s
+
+void f() {
+  __asm__("mov eax, ebx");
+  // ATT: movl %ebx, %eax
+  // INTEL: mov eax, ebx
+}
+
Index: clang/test/Driver/masm.c
===================================================================
--- clang/test/Driver/masm.c
+++ clang/test/Driver/masm.c
@@ -5,10 +5,11 @@
 // RUN: %clang_cl --target=x86_64 /FA -### -- %s 2>&1 | FileCheck --check-prefix=CHECK-CL %s
 
 int f() {
-// CHECK-INTEL: -x86-asm-syntax=intel
-// CHECK-ATT: -x86-asm-syntax=att
+// CHECK-INTEL: -x86-asm-syntax=intel -inline-asm=intel
+// CHECK-ATT: -x86-asm-syntax=att -inline-asm=att
 // CHECK-SOMEREQUIRED: error: unsupported argument 'somerequired' to option 'masm='
 // CHECK-ARM: warning: argument unused during compilation: '-masm=intel'
 // CHECK-CL: -x86-asm-syntax=intel
+// CHECK-CL-NOT: -inline-asm=intel
   return 0;
 }