Index: llvm/trunk/lib/Target/Mips/MipsISelLowering.h
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsISelLowering.h
+++ llvm/trunk/lib/Target/Mips/MipsISelLowering.h
@@ -653,6 +653,8 @@
 
     unsigned
     getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
+      if (ConstraintCode == "o")
+        return InlineAsm::Constraint_o;
       if (ConstraintCode == "R")
         return InlineAsm::Constraint_R;
       if (ConstraintCode == "ZC")
Index: llvm/trunk/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
+++ llvm/trunk/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
@@ -1237,6 +1237,7 @@
     OutOps.push_back(CurDAG->getTargetConstant(0, SDLoc(Op), MVT::i32));
     return false;
   case InlineAsm::Constraint_m:
+  case InlineAsm::Constraint_o:
     if (selectAddrRegImm16(Op, Base, Offset)) {
       OutOps.push_back(Base);
       OutOps.push_back(Offset);
Index: llvm/trunk/test/CodeGen/Mips/inlineasm_constraint_o.ll
===================================================================
--- llvm/trunk/test/CodeGen/Mips/inlineasm_constraint_o.ll
+++ llvm/trunk/test/CodeGen/Mips/inlineasm_constraint_o.ll
@@ -0,0 +1,61 @@
+; RUN: llc -march=mipsel -relocation-model=pic < %s | FileCheck %s
+
+@data = global [8193 x i32] zeroinitializer
+
+define void @o(i32 *%p) nounwind {
+entry:
+  ; CHECK-LABEL: o:
+
+  call void asm sideeffect "lw $$1, $0", "*o,~{$1}"(i32* getelementptr inbounds ([8193 x i32], [8193 x i32]* @data, i32 0, i32 0))
+
+  ; CHECK: lw $[[BASEPTR:[0-9]+]], %got(data)(
+  ; CHECK: #APP
+  ; CHECK: lw $1, 0($[[BASEPTR]])
+  ; CHECK: #NO_APP
+
+  ret void
+}
+
+define void @o_offset_4(i32 *%p) nounwind {
+entry:
+  ; CHECK-LABEL: o_offset_4:
+
+  call void asm sideeffect "lw $$1, $0", "*o,~{$1}"(i32* getelementptr inbounds ([8193 x i32], [8193 x i32]* @data, i32 0, i32 1))
+
+  ; CHECK: lw $[[BASEPTR:[0-9]+]], %got(data)(
+  ; CHECK: #APP
+  ; CHECK: lw $1, 4($[[BASEPTR]])
+  ; CHECK: #NO_APP
+
+  ret void
+}
+
+define void @o_offset_32764(i32 *%p) nounwind {
+entry:
+  ; CHECK-LABEL: o_offset_32764:
+
+  call void asm sideeffect "lw $$1, $0", "*o,~{$1}"(i32* getelementptr inbounds ([8193 x i32], [8193 x i32]* @data, i32 0, i32 8191))
+
+  ; CHECK-DAG: lw $[[BASEPTR:[0-9]+]], %got(data)(
+  ; CHECK: #APP
+  ; CHECK: lw $1, 32764($[[BASEPTR]])
+  ; CHECK: #NO_APP
+
+  ret void
+}
+
+define void @o_offset_32768(i32 *%p) nounwind {
+entry:
+  ; CHECK-LABEL: o_offset_32768:
+
+  call void asm sideeffect "lw $$1, $0", "*o,~{$1}"(i32* getelementptr inbounds ([8193 x i32], [8193 x i32]* @data, i32 0, i32 8192))
+
+  ; CHECK-DAG: lw $[[BASEPTR:[0-9]+]], %got(data)(
+  ; CHECK-DAG: ori $[[T0:[0-9]+]], $zero, 32768
+  ; CHECK: addu $[[BASEPTR2:[0-9]+]], $[[BASEPTR]], $[[T0]]
+  ; CHECK: #APP
+  ; CHECK: lw $1, 0($[[BASEPTR2]])
+  ; CHECK: #NO_APP
+
+  ret void
+}