Index: include/llvm/MC/MCParser/MCAsmParser.h
===================================================================
--- include/llvm/MC/MCParser/MCAsmParser.h
+++ include/llvm/MC/MCParser/MCAsmParser.h
@@ -84,6 +84,8 @@
   virtual void addDirectiveHandler(StringRef Directive,
                                    ExtensionDirectiveHandler Handler) = 0;
 
+  virtual void addAliasForDirective(StringRef Directive, StringRef Alias) = 0;
+
   virtual SourceMgr &getSourceManager() = 0;
 
   virtual MCAsmLexer &getLexer() = 0;
Index: lib/MC/MCParser/AsmParser.cpp
===================================================================
--- lib/MC/MCParser/AsmParser.cpp
+++ lib/MC/MCParser/AsmParser.cpp
@@ -184,6 +184,10 @@
     ExtensionDirectiveMap[Directive] = Handler;
   }
 
+  void addAliasForDirective(StringRef Directive, StringRef Alias) override {
+    DirectiveKindMap[Directive] = DirectiveKindMap[Alias];
+  }
+
 public:
   /// @name MCAsmParser Interface
   /// {
Index: lib/Target/Mips/AsmParser/MipsAsmParser.cpp
===================================================================
--- lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -345,6 +345,8 @@
                                           sti.getCPU(), Options)) {
     MCAsmParserExtension::Initialize(parser);
 
+    parser.addAliasForDirective(".asciiz", ".asciz");
+
     // Initialize the set of available features.
     setAvailableFeatures(ComputeAvailableFeatures(STI.getFeatureBits()));
     
Index: test/MC/Mips/asciiz-directive-bad.s
===================================================================
--- /dev/null
+++ test/MC/Mips/asciiz-directive-bad.s
@@ -0,0 +1,8 @@
+# RUN: not llvm-mc -triple mips-unknown-linux %s 2>&1 | FileCheck %s
+
+  .asciiz 12
+# CHECK: :[[@LINE-1]]:11: error: expected string in '.asciiz' directive
+  .asciiz "a"3
+# CHECK: :[[@LINE-1]]:14: error: unexpected token in '.asciiz' directive
+  .asciiz "a",
+# CHECK: :[[@LINE-1]]:15: error: expected string in '.asciiz' directive
Index: test/MC/Mips/asciiz-directive.s
===================================================================
--- /dev/null
+++ test/MC/Mips/asciiz-directive.s
@@ -0,0 +1,28 @@
+# RUN: llvm-mc -triple mips-unknown-linux %s | FileCheck %s
+# .asciiz is exactly the same as .asciz, except it's MIPS-specific.
+
+t1:
+  .asciiz
+# CHECK-LABEL: t1
+
+t2:
+  .asciiz "a"
+# CHECK-LABEL: t2
+# CHECK: .byte 97
+# CHECK: .byte 0
+
+t3:
+  .asciiz "a", "b", "c"
+# CHECK-LABEL: t3
+# CHECK: .byte 97
+# CHECK: .byte 0
+# CHECK: .byte 98
+# CHECK: .byte 0
+# CHECK: .byte 99
+# CHECK: .byte 0
+
+t4:
+  .asciiz "abcdefghijklmnop"
+# CHECK-LABEL: t4
+# CHECK: .ascii "abcdefghijklmnop"
+# CHECK: .byte 0