diff --git a/lib/Target/Mips/MipsRegisterInfo.td b/lib/Target/Mips/MipsRegisterInfo.td
index a72e3b8..391c19e 100644
--- a/lib/Target/Mips/MipsRegisterInfo.td
+++ b/lib/Target/Mips/MipsRegisterInfo.td
@@ -73,7 +73,7 @@
 let Namespace = "Mips" in {
   // General Purpose Registers
   def ZERO : MipsGPRReg< 0, "zero">, DwarfRegNum<[0]>;
-  def AT   : MipsGPRReg< 1, "at">,   DwarfRegNum<[1]>;
+  def AT   : MipsGPRReg< 1, "1">,    DwarfRegNum<[1]>;
   def V0   : MipsGPRReg< 2, "2">,    DwarfRegNum<[2]>;
   def V1   : MipsGPRReg< 3, "3">,    DwarfRegNum<[3]>;
   def A0   : MipsGPRReg< 4, "4">,    DwarfRegNum<[4]>;
@@ -107,7 +107,7 @@
 
   // General Purpose 64-bit Registers
   def ZERO_64 : Mips64GPRReg< 0, "zero", [ZERO]>, DwarfRegNum<[0]>;
-  def AT_64   : Mips64GPRReg< 1, "at",   [AT]>, DwarfRegNum<[1]>;
+  def AT_64   : Mips64GPRReg< 1, "1",    [AT]>, DwarfRegNum<[1]>;
   def V0_64   : Mips64GPRReg< 2, "2",    [V0]>, DwarfRegNum<[2]>;
   def V1_64   : Mips64GPRReg< 3, "3",    [V1]>, DwarfRegNum<[3]>;
   def A0_64   : Mips64GPRReg< 4, "4",    [A0]>, DwarfRegNum<[4]>;
diff --git a/test/CodeGen/Mips/largeimm1.ll b/test/CodeGen/Mips/largeimm1.ll
index d65cc02..1c0f69c 100644
--- a/test/CodeGen/Mips/largeimm1.ll
+++ b/test/CodeGen/Mips/largeimm1.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -march=mipsel < %s | FileCheck %s
 
-; CHECK: lui $at, 49152
-; CHECK: lui $at, 16384
+; CHECK: lui ${{[0-9]+}}, 49152
+; CHECK: lui ${{[0-9]+}}, 16384
 define void @f() nounwind {
 entry:
   %a1 = alloca [1073741824 x i8], align 1
diff --git a/test/CodeGen/Mips/largeimmprinting.ll b/test/CodeGen/Mips/largeimmprinting.ll
index 2e548790..5224570 100644
--- a/test/CodeGen/Mips/largeimmprinting.ll
+++ b/test/CodeGen/Mips/largeimmprinting.ll
@@ -6,9 +6,9 @@
 
 define void @f() nounwind {
 entry:
-; CHECK:  lui $at, 65535
-; CHECK:  addiu $at, $at, -16
-; CHECK:  addu  $sp, $sp, $at
+; CHECK:  lui $[[R0:[0-9]+]], 65535
+; CHECK:  addiu $[[R0]], $[[R0]], -16
+; CHECK:  addu $sp, $sp, $[[R0]]
 
   %agg.tmp = alloca %struct.S1, align 1
   %tmp = getelementptr inbounds %struct.S1* %agg.tmp, i32 0, i32 0, i32 0
diff --git a/test/CodeGen/Mips/longbranch.ll b/test/CodeGen/Mips/longbranch.ll
index 873b9f1..1a4f79c 100644
--- a/test/CodeGen/Mips/longbranch.ll
+++ b/test/CodeGen/Mips/longbranch.ll
@@ -6,15 +6,15 @@
 define void @foo1(i32 %s) nounwind {
 entry:
 ; O32: bal
-; O32: lui $at, 0
-; O32: addiu $at, $at, {{[0-9]+}} 
-; N64: lui $at, 0
-; N64: daddiu $at, $at, 0
-; N64: dsll $at, $at, 16
-; N64: daddiu $at, $at, 0
+; O32: lui $1, 0
+; O32: addiu $1, $1, {{[0-9]+}} 
+; N64: lui $1, 0
+; N64: daddiu $1, $1, 0
+; N64: dsll $1, $1, 16
+; N64: daddiu $1, $1, 0
 ; N64: bal
-; N64: dsll $at, $at, 16
-; N64: daddiu $at, $at, {{[0-9]+}}  
+; N64: dsll $1, $1, 16
+; N64: daddiu $1, $1, {{[0-9]+}}  
 
   %tobool = icmp eq i32 %s, 0
   br i1 %tobool, label %if.end, label %if.then