Index: lib/Target/Mips/MipsSEISelLowering.cpp
===================================================================
--- lib/Target/Mips/MipsSEISelLowering.cpp
+++ lib/Target/Mips/MipsSEISelLowering.cpp
@@ -746,7 +746,7 @@
 
   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
     if (!VT.isVector())
-      return genConstMult(N->getOperand(0), C->getZExtValue(), SDLoc(N), VT,
+      return genConstMult(N->getOperand(0), C->getSExtValue(), SDLoc(N), VT,
                           TL->getScalarShiftAmountTy(DAG.getDataLayout(), VT),
                           DAG);
 
Index: test/CodeGen/Mips/mips64-int128-negative-multiply.ll
===================================================================
--- /dev/null
+++ test/CodeGen/Mips/mips64-int128-negative-multiply.ll
@@ -0,0 +1,10 @@
+; RUN: llc -mtriple=mips64-unknown-linux-gnu < %s
+; REQUIRES: asserts
+
+define void @mul_negative(i128* nocapture %in) {
+entry:
+  %0 = load i128, i128* %in, align 16
+  %sub = mul i128 %0, -65535
+  store i128 %sub, i128* %in, align 16
+  ret void
+}