Index: llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -1756,9 +1756,13 @@
          "Not enough operands to replace all defs");
   unsigned NumElems = MI.getNumOperands() - 1;
   Builder.setInstrAndDebugLoc(MI);
+  bool IsBigEndianTarget =
+      MI.getParent()->getParent()->getDataLayout().isBigEndian();
   for (unsigned Idx = 0; Idx < NumElems; ++Idx) {
     Register DstReg = MI.getOperand(Idx).getReg();
-    Builder.buildConstant(DstReg, Csts[Idx]);
+    unsigned CstsIdx = IsBigEndianTarget ? bigEndianByteAt(NumElems, Idx)
+                                         : littleEndianByteAt(NumElems, Idx);
+    Builder.buildConstant(DstReg, Csts[CstsIdx]);
   }
 
   MI.eraseFromParent();