diff --git a/CMakeLists.txt b/CMakeLists.txt
index d97ac8d..bacb07a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -257,6 +257,7 @@
 add_subdirectory(lib/MC)
 
  set(LLVM_ENUM_ASM_PRINTERS "")
+ set(LLVM_ENUM_ASM_PARSERS "")
  foreach(t ${LLVM_TARGETS_TO_BUILD})
   message(STATUS "Targeting ${t}")
   add_subdirectory(lib/Target/${t})
@@ -266,6 +267,11 @@
     set(LLVM_ENUM_ASM_PRINTERS 
         "${LLVM_ENUM_ASM_PRINTERS}LLVM_ASM_PRINTER(${t})\n")
  endif( EXISTS ${LLVM_MAIN_SRC_DIR}/lib/Target/${t}/AsmPrinter/CMakeLists.txt )
+  if( EXISTS ${LLVM_MAIN_SRC_DIR}/lib/Target/${t}/AsmParser/CMakeLists.txt )
+   add_subdirectory(lib/Target/${t}/AsmParser)
+    set(LLVM_ENUM_ASM_PARSERS 
+        "${LLVM_ENUM_ASM_PARSERS}LLVM_ASM_PARSER(${t})\n")
+ endif( EXISTS ${LLVM_MAIN_SRC_DIR}/lib/Target/${t}/AsmParser/CMakeLists.txt )
 endforeach(t)
 
 # Produce llvm/Config/AsmPrinters.def
@@ -274,6 +280,12 @@
   ${LLVM_BINARY_DIR}/include/llvm/Config/AsmPrinters.def
   )
 
+# Produce llvm/Config/AsmParsers.def
+configure_file(
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm/Config/AsmParsers.def.in
+  ${LLVM_BINARY_DIR}/include/llvm/Config/AsmParsers.def
+  )
+
 add_subdirectory(lib/ExecutionEngine)
 add_subdirectory(lib/ExecutionEngine/Interpreter)
 add_subdirectory(lib/ExecutionEngine/JIT)
diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 189c2d6..43fbc4f 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -458,17 +458,22 @@
 done
 
 # Build the LLVM_TARGET and LLVM_ASM_PRINTER macro uses for
-# Targets.def and AsmPrinters.def.
+# Targets.def, AsmPrinters.def, and AsmParsers.def.
 LLVM_ENUM_TARGETS=""
 LLVM_ENUM_ASM_PRINTERS=""
+LLVM_ENUM_ASM_PARSERS=""
 for target_to_build in $TARGETS_TO_BUILD; do
   LLVM_ENUM_TARGETS="LLVM_TARGET($target_to_build) $LLVM_ENUM_TARGETS"
   if test -f ${srcdir}/lib/Target/${target_to_build}/AsmPrinter/Makefile ; then
     LLVM_ENUM_ASM_PRINTERS="LLVM_ASM_PRINTER($target_to_build) $LLVM_ENUM_ASM_PRINTERS";
   fi
+  if test -f ${srcdir}/lib/Target/${target_to_build}/AsmParser/Makefile ; then
+    LLVM_ENUM_ASM_PARSERS="LLVM_ASM_PARSER($target_to_build) $LLVM_ENUM_ASM_PARSERS";
+  fi
 done
 AC_SUBST(LLVM_ENUM_TARGETS)
 AC_SUBST(LLVM_ENUM_ASM_PRINTERS)
+AC_SUBST(LLVM_ENUM_ASM_PARSERS)
 
 dnl Prevent the CBackend from using printf("%a") for floating point so older
 dnl C compilers that cannot deal with the 0x0p+0 hex floating point format
@@ -1257,6 +1262,7 @@
 AC_CONFIG_HEADERS([include/llvm/Config/config.h])
 AC_CONFIG_FILES([include/llvm/Config/Targets.def])
 AC_CONFIG_FILES([include/llvm/Config/AsmPrinters.def])
+AC_CONFIG_FILES([include/llvm/Config/AsmParser.def])
 AC_CONFIG_HEADERS([include/llvm/Support/DataTypes.h])
 AC_CONFIG_HEADERS([include/llvm/ADT/iterator.h])
 
diff --git a/cmake/modules/LLVMConfig.cmake b/cmake/modules/LLVMConfig.cmake
index a401795..6b65645 100755
--- a/cmake/modules/LLVMConfig.cmake
+++ b/cmake/modules/LLVMConfig.cmake
@@ -35,7 +35,7 @@
 function(explicit_map_components_to_libraries out_libs)
   set( link_components ${ARGN} )
   foreach(c ${link_components})
-    # add codegen/asmprinter
+    # add codegen, asmprinter, asmparser
     list(FIND LLVM_TARGETS_TO_BUILD ${c} idx)
     if( NOT idx LESS 0 )
       list(FIND llvm_libs "LLVM${c}CodeGen" idx)
@@ -53,6 +53,10 @@
       if( NOT asmidx LESS 0 )
         list(APPEND expanded_components "LLVM${c}AsmPrinter")
       endif()
+      list(FIND llvm_libs "LLVM${c}AsmParser" asmidx)
+      if( NOT asmidx LESS 0 )
+        list(APPEND expanded_components "LLVM${c}AsmParser")
+      endif()
       list(FIND llvm_libs "LLVM${c}Info" asmidx)
       if( NOT asmidx LESS 0 )
         list(APPEND expanded_components "LLVM${c}Info")
diff --git a/include/llvm/Config/AsmParsers.def.in b/include/llvm/Config/AsmParsers.def.in
new file mode 100644
index 0000000..041af83
--- /dev/null
+++ b/include/llvm/Config/AsmParsers.def.in
@@ -0,0 +1,29 @@
+//===- llvm/Config/AsmParsers.def - LLVM Assembly Parsers -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file enumerates all of the assembly-language parsers
+// supported by this build of LLVM. Clients of this file should define
+// the LLVM_ASM_PARSER macro to be a function-like macro with a
+// single parameter (the name of the target whose assembly can be
+// generated); including this file will then enumerate all of the
+// targets with assembly parsers.
+//
+// The set of targets supported by LLVM is generated at configuration
+// time, at which point this header is generated. Do not modify this
+// header directly.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ASM_PARSER
+#  error Please define the macro LLVM_ASM_PARSER(TargetName)
+#endif
+
+@LLVM_ENUM_ASM_PARSERS@
+
+#undef LLVM_ASM_PARSER
diff --git a/include/llvm/Target/TargetAsmParser.h b/include/llvm/Target/TargetAsmParser.h
new file mode 100644
index 0000000..bf96bf7
--- /dev/null
+++ b/include/llvm/Target/TargetAsmParser.h
@@ -0,0 +1,34 @@
+//===-- llvm/Target/TargetAsmParser.h - Target Assembly Parser --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TARGET_TARGETPARSER_H
+#define LLVM_TARGET_TARGETPARSER_H
+
+namespace llvm {
+class Target;
+
+/// TargetAsmParser - Generic interface to target specific assembly parsers.
+class TargetAsmParser {
+  TargetAsmParser(const TargetAsmParser &);   // DO NOT IMPLEMENT
+  void operator=(const TargetAsmParser &);  // DO NOT IMPLEMENT
+protected: // Can only create subclasses.
+  TargetAsmParser(const Target &);
+ 
+  /// TheTarget - The Target that this machine was created for.
+  const Target &TheTarget;
+
+public:
+  virtual ~TargetAsmParser();
+
+  const Target &getTarget() const { return TheTarget; }
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/include/llvm/Target/TargetRegistry.h b/include/llvm/Target/TargetRegistry.h
index 63ff5f0..026338e 100644
--- a/include/llvm/Target/TargetRegistry.h
+++ b/include/llvm/Target/TargetRegistry.h
@@ -25,6 +25,7 @@
 namespace llvm {
   class FunctionPass;
   class Module;
+  class TargetAsmParser;
   class TargetMachine;
   class formatted_raw_ostream;
 
@@ -48,6 +49,7 @@
     typedef FunctionPass *(*AsmPrinterCtorTy)(formatted_raw_ostream &,
                                               TargetMachine &,
                                               bool);
+    typedef TargetAsmParser *(*AsmParserCtorTy)(const Target &);
 
     friend struct TargetRegistry;
 
@@ -81,6 +83,10 @@
     /// if registered.
     AsmPrinterCtorTy AsmPrinterCtorFn;
 
+    /// AsmParserCtorFn - Construction function for this target's AsmParser,
+    /// if registered.
+    AsmParserCtorTy AsmParserCtorFn;
+
   public:
     // getNext - Return the next registered target.
     const Target *getNext() const { return Next; }
@@ -101,6 +107,9 @@
     /// hasAsmPrinter - Check if this target supports .s printing.
     bool hasAsmPrinter() const { return AsmPrinterCtorFn != 0; }
 
+    /// hasAsmParser - Check if this target supports .s parsing.
+    bool hasAsmParser() const { return AsmParserCtorFn != 0; }
+
     /// createTargetMachine - Create a target specific machine implementation.
     TargetMachine *createTargetMachine(const Module &M,
                                        const std::string &Features) const {
@@ -117,6 +126,13 @@
         return 0;
       return AsmPrinterCtorFn(OS, M, Verbose);
     }
+
+    /// createAsmParser - Create a target specific assembly parser.
+    TargetAsmParser *createAsmParser() const {
+      if (!AsmParserCtorFn)
+        return 0;
+      return AsmParserCtorFn(*this);
+    }
   };
 
   /// TargetRegistry - Generic interface to target specific features.
@@ -225,8 +241,9 @@
     /// @param Fn - A function to construct a TargetMachine for the target.
     static void RegisterTargetMachine(Target &T, 
                                       Target::TargetMachineCtorTy Fn) {
-      assert(!T.TargetMachineCtorFn && "Constructor already registered!");
-      T.TargetMachineCtorFn = Fn;
+      // Ignore duplicate registration.
+      if (!T.TargetMachineCtorFn)
+        T.TargetMachineCtorFn = Fn;
     }
 
     /// RegisterAsmPrinter - Register an AsmPrinter implementation for the given
@@ -239,8 +256,23 @@
     /// @param T - The target being registered.
     /// @param Fn - A function to construct an AsmPrinter for the target.
     static void RegisterAsmPrinter(Target &T, Target::AsmPrinterCtorTy Fn) {
-      assert(!T.AsmPrinterCtorFn && "Constructor already registered!");
-      T.AsmPrinterCtorFn = Fn;
+      // Ignore duplicate registration.
+      if (!T.AsmPrinterCtorFn)
+        T.AsmPrinterCtorFn = Fn;
+    }
+
+    /// RegisterAsmParser - Register a TargetAsmParser implementation for the
+    /// given target.
+    /// 
+    /// Clients are responsible for ensuring that registration doesn't occur
+    /// while another thread is attempting to access the registry. Typically
+    /// this is done by initializing all targets at program startup.
+    ///
+    /// @param T - The target being registered.
+    /// @param Fn - A function to construct an AsmPrinter for the target.
+    static void RegisterAsmParser(Target &T, Target::AsmParserCtorTy Fn) {
+      if (!T.AsmParserCtorFn)
+        T.AsmParserCtorFn = Fn;
     }
 
     /// @}
diff --git a/lib/Target/X86/AsmParser/CMakeLists.txt b/lib/Target/X86/AsmParser/CMakeLists.txt
new file mode 100644
index 0000000..034d5ab
--- /dev/null
+++ b/lib/Target/X86/AsmParser/CMakeLists.txt
@@ -0,0 +1,6 @@
+include_directories( ${CMAKE_CURRENT_BINARY_DIR}/.. ${CMAKE_CURRENT_SOURCE_DIR}/.. )
+
+add_llvm_library(LLVMX86AsmParser
+  X86AsmParser.cpp
+  )
+add_dependencies(LLVMX86AsmParser X86CodeGenTable_gen)
diff --git a/lib/Target/X86/AsmParser/Makefile b/lib/Target/X86/AsmParser/Makefile
new file mode 100644
index 0000000..25fb0a2
--- /dev/null
+++ b/lib/Target/X86/AsmParser/Makefile
@@ -0,0 +1,15 @@
+##===- lib/Target/X86/AsmParser/Makefile -------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+LEVEL = ../../../..
+LIBRARYNAME = LLVMX86AsmParser
+
+# Hack: we need to include 'main' x86 target directory to grab private headers
+CPPFLAGS = -I$(PROJ_OBJ_DIR)/.. -I$(PROJ_SRC_DIR)/..
+
+include $(LEVEL)/Makefile.common
diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
new file mode 100644
index 0000000..0871148
--- /dev/null
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -0,0 +1,40 @@
+//===-- X86AsmParser.cpp - Parse X86 assembly to MCInst instructions ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Target/TargetRegistry.h"
+#include "llvm/Target/TargetAsmParser.h"
+using namespace llvm;
+
+namespace {
+
+class X86ATTAsmParser : public TargetAsmParser {
+ public:
+  explicit X86ATTAsmParser(const Target &);
+};
+
+}
+
+X86ATTAsmParser::X86ATTAsmParser(const Target &T) 
+  : TargetAsmParser(T)
+{
+}
+
+namespace {
+  TargetAsmParser *createAsmParser(const Target &T) {
+    return new X86ATTAsmParser(T);
+  }
+}
+
+// Force static initialization.
+extern "C" void LLVMInitializeX86AsmParser() {
+  extern Target TheX86_32Target;
+  TargetRegistry::RegisterAsmParser(TheX86_32Target, &createAsmParser);
+  extern Target TheX86_64Target;
+  TargetRegistry::RegisterAsmParser(TheX86_64Target, &createAsmParser);
+}
diff --git a/lib/Target/X86/Makefile b/lib/Target/X86/Makefile
index 51571a0..220831d 100644
--- a/lib/Target/X86/Makefile
+++ b/lib/Target/X86/Makefile
@@ -18,6 +18,6 @@
                 X86GenFastISel.inc \
                 X86GenCallingConv.inc X86GenSubtarget.inc
 
-DIRS = AsmPrinter TargetInfo
+DIRS = AsmPrinter AsmParser TargetInfo
 
 include $(LEVEL)/Makefile.common
diff --git a/tools/llvm-config/llvm-config.in.in b/tools/llvm-config/llvm-config.in.in
index 303bffb..b949711 100644
--- a/tools/llvm-config/llvm-config.in.in
+++ b/tools/llvm-config/llvm-config.in.in
@@ -340,6 +340,11 @@
             $NAME_MAP{$target} = [$target.'info',
                                   $NAME_MAP{$target}[0]]
         }
+
+        if (defined $NAME_MAP{$target.'asmparser'}) {
+            $NAME_MAP{$target} = [$target.'asmparser',
+                                  $NAME_MAP{$target}[0]]
+        }
     }
 
     # Add virtual entries.