Index: lib/Target/Mips/AsmParser/MipsAsmParser.cpp
===================================================================
--- lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -988,7 +988,7 @@
   void addConstantUImmOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     uint64_t Imm = getConstantImm() - Offset;
-    Imm &= (1 << Bits) - 1;
+    Imm &= (1ULL << Bits) - 1;
     Imm += Offset;
     Imm += AdjustOffset;
     Inst.addOperand(MCOperand::createImm(Imm));
@@ -1086,7 +1086,8 @@
   bool isRegIdx() const { return Kind == k_RegisterIndex; }
   bool isImm() const override { return Kind == k_Immediate; }
   bool isConstantImm() const {
-    return isImm() && isa<MCConstantExpr>(getImm());
+    int64_t Res;
+    return isImm() && getImm()->evaluateAsAbsolute(Res);
   }
   bool isConstantImmz() const {
     return isConstantImm() && getConstantImm() == 0;
@@ -1251,7 +1252,9 @@
 
   int64_t getConstantImm() const {
     const MCExpr *Val = getImm();
-    return static_cast<const MCConstantExpr *>(Val)->getValue();
+    int64_t Value = 0;
+    (void)Val->evaluateAsAbsolute(Value);
+    return Value;
   }
 
   MipsOperand *getMemBase() const {
@@ -3997,6 +4000,9 @@
   case Match_SImm32_Relaxed:
     return Error(RefineErrorLoc(IDLoc, Operands, ErrorInfo),
                  "expected 32-bit signed immediate");
+  case Match_UImm32_Coerced:
+    return Error(RefineErrorLoc(IDLoc, Operands, ErrorInfo),
+                 "expected 32-bit immediate");
   case Match_MemSImm9:
     return Error(RefineErrorLoc(IDLoc, Operands, ErrorInfo),
                  "expected memory with 9-bit signed offset");
Index: lib/Target/Mips/MipsInstrInfo.td
===================================================================
--- lib/Target/Mips/MipsInstrInfo.td
+++ lib/Target/Mips/MipsInstrInfo.td
@@ -450,6 +450,16 @@
   let DiagnosticType = "UImm" # Bits;
 }
 
+// Generic case - only to support certain assembly pseudo instructions.
+class UImmAnyAsmOperandClass<int Bits, list<AsmOperandClass> Supers = []>
+    : AsmOperandClass {
+  let Name = "ImmAny";
+  let RenderMethod = "addConstantUImmOperands<32>";
+  let PredicateMethod = "isSImm<" # Bits # ">";
+  let SuperClasses = Supers;
+  let DiagnosticType = "ImmAny";
+}
+
 // AsmOperandClasses require a strict ordering which is difficult to manage
 // as a hierarchy. Instead, we use a linear ordering and impose an order that
 // is in some places arbitrary.
@@ -473,8 +483,13 @@
 //     uimm5 < uimm5_64, and uimm5 < vsplat_uimm5
 //   This is entirely arbitrary. We need an ordering and what we pick is
 //   unimportant since only one is possible for a given mnemonic.
+
+def UImm32CoercedAsmOperandClass : UImmAnyAsmOperandClass<33, []> {
+  let Name = "UImm32_Coerced";
+  let DiagnosticType = "UImm32_Coerced";
+}
 def SImm32RelaxedAsmOperandClass
-    : SImmAsmOperandClass<32, []> {
+    : SImmAsmOperandClass<32, [UImm32CoercedAsmOperandClass]> {
   let Name = "SImm32_Relaxed";
   let PredicateMethod = "isAnyImm<32>";
   let DiagnosticType = "SImm32_Relaxed";
@@ -491,6 +506,8 @@
   let PredicateMethod = "isAnyImm<16>";
   let DiagnosticType = "UImm16_Relaxed";
 }
+// FIXME: One of these should probably have UImm16AsmOperandClass as the
+//        superclass instead of UImm16RelaxedasmOPerandClass.
 def UImm16AsmOperandClass
     : UImmAsmOperandClass<16, [UImm16RelaxedAsmOperandClass]>;
 def SImm16RelaxedAsmOperandClass
@@ -845,6 +862,10 @@
   let ParserMatchClass = !cast<AsmOperandClass>("SImm16AsmOperandClass");
 }
 
+// like simm32 but coerces simm32 to uimm32.
+def uimm32_coerced : Operand<i32> {
+  let ParserMatchClass = !cast<AsmOperandClass>("UImm32CoercedAsmOperandClass");
+}
 // Like simm32 but coerces uimm32 to simm32.
 def simm32_relaxed : Operand<i32> {
   let DecoderMethod = "DecodeSImmWithOffsetAndScale<32>";
@@ -2364,7 +2385,7 @@
 class LoadImmediate32<string instr_asm, Operand Od, RegisterOperand RO> :
   MipsAsmPseudoInst<(outs RO:$rt), (ins Od:$imm32),
                      !strconcat(instr_asm, "\t$rt, $imm32")> ;
-def LoadImm32 : LoadImmediate32<"li", i32imm, GPR32Opnd>;
+def LoadImm32 : LoadImmediate32<"li", uimm32_coerced, GPR32Opnd>;
 
 class LoadAddressFromReg32<string instr_asm, Operand MemOpnd,
                            RegisterOperand RO> :
Index: test/MC/Mips/macro-li-bad.s
===================================================================
--- test/MC/Mips/macro-li-bad.s
+++ test/MC/Mips/macro-li-bad.s
@@ -7,5 +7,5 @@
 
   .text
   li $5, 0x100000000
-  # 32-BIT: :[[@LINE-1]]:3: error: instruction requires a 32-bit immediate
-  # 64-BIT: :[[@LINE-2]]:3: error: instruction requires a 32-bit immediate
+  # 32-BIT: :[[@LINE-1]]:10: error: expected 32-bit immediate
+  # 64-BIT: :[[@LINE-2]]:10: error: expected 32-bit immediate
Index: test/MC/Mips/macro-li.s
===================================================================
--- test/MC/Mips/macro-li.s
+++ test/MC/Mips/macro-li.s
@@ -65,3 +65,11 @@
                   # CHECK: ori $5, $5, 32768    # encoding: [0x34,0xa5,0x80,0x00]
 li $5, 0x80008000 # CHECK: lui $5, 32768        # encoding: [0x3c,0x05,0x80,0x00]
                   # CHECK: ori $5, $5, 32768    # encoding: [0x34,0xa5,0x80,0x00]
+li $4, ~0xffffffff # CHECK; addiu $4, $zero, 0  # encoding: [0x24,0x04,0x00,0x00]
+li $4, ~0x80000001 # CHECK: lui $4, 32767       # encoding: [0x3c,0x04,0x7f,0xff]
+                   # CHECK: ori $4, $4, 65534   # encoding: [0x34,0x84,0xff,0xfe]
+li $4, ~0x80000000 # CHECK: lui $4, 32767       # encoding: [0x3c,0x04,0x7f,0xff]
+                   # CHECK: ori $4, $4, 65535   # encoding: [0x34,0x84,0xff,0xff]
+li $4, ~0x7fffffff # CHECK: lui $4, 32768       # encoding: [0x3c,0x04,0x80,0x00]
+li $4, ~0x00000001 # CHECK: addiu $4, $zero, -2 # encoding: [0x24,0x04,0xff,0xfe]
+li $4, ~0x00000000 # CHECK: addiu $4, $zero, -1 # encoding: [0x24,0x04,0xff,0xff]