Index: lib/Target/X86/X86InstrInfo.td
===================================================================
--- lib/Target/X86/X86InstrInfo.td
+++ lib/Target/X86/X86InstrInfo.td
@@ -2540,9 +2540,9 @@
 def : MnemonicAlias<"popa",   "popal",  "att">, Requires<[In32BitMode]>;
 def : MnemonicAlias<"pusha",  "pushal", "att">, Requires<[In32BitMode]>;
 
-def : MnemonicAlias<"repe",  "rep",   "att">;
-def : MnemonicAlias<"repz",  "rep",   "att">;
-def : MnemonicAlias<"repnz", "repne", "att">;
+def : MnemonicAlias<"repe",  "rep">;
+def : MnemonicAlias<"repz",  "rep">;
+def : MnemonicAlias<"repnz", "repne">;
 
 def : MnemonicAlias<"ret", "retw", "att">, Requires<[In16BitMode]>;
 def : MnemonicAlias<"ret", "retl", "att">, Requires<[In32BitMode]>;
Index: test/MC/X86/intel-syntax.s
===================================================================
--- test/MC/X86/intel-syntax.s
+++ test/MC/X86/intel-syntax.s
@@ -681,3 +681,16 @@
 // CHECK: outsb (%rsi), %dx
 // CHECK: outsw (%rsi), %dx
 // CHECK: outsl (%rsi), %dx
+
+repe cmpsb
+repz cmpsb
+repne cmpsb
+repnz cmpsb
+// CHECK: rep
+// CHECK: cmpsb	%es:(%rdi), (%rsi)
+// CHECK: rep
+// CHECK: cmpsb	%es:(%rdi), (%rsi)
+// CHECK: repne
+// CHECK: cmpsb	%es:(%rdi), (%rsi)
+// CHECK: repne
+// CHECK: cmpsb	%es:(%rdi), (%rsi)