Index: lib/Target/AArch64/AArch64FastISel.cpp
===================================================================
--- lib/Target/AArch64/AArch64FastISel.cpp
+++ lib/Target/AArch64/AArch64FastISel.cpp
@@ -4832,7 +4832,7 @@
   for (auto OI = std::next(I->op_begin()), E = I->op_end(); OI != E; ++OI) {
     const Value *Idx = *OI;
     if (auto *StTy = dyn_cast<StructType>(Ty)) {
-      unsigned Field = cast<ConstantInt>(Idx)->getZExtValue();
+      uint64_t Field = cast<ConstantInt>(Idx)->getZExtValue();
       // N = N + Offset
       if (Field)
         TotalOffs += DL.getStructLayout(StTy)->getElementOffset(Field);
@@ -4844,8 +4844,8 @@
         if (CI->isZero())
           continue;
         // N = N + Offset
-        TotalOffs +=
-            DL.getTypeAllocSize(Ty) * cast<ConstantInt>(CI)->getSExtValue();
+        uint64_t IdxN = CI->getValue().sextOrTrunc(64).getSExtValue();
+        TotalOffs += DL.getTypeAllocSize(Ty) * IdxN;
         continue;
       }
       if (TotalOffs) {
Index: test/CodeGen/X86/getelementptr.ll
===================================================================
--- test/CodeGen/X86/getelementptr.ll
+++ test/CodeGen/X86/getelementptr.ll
@@ -1,7 +1,19 @@
 ; RUN: llc < %s -O0 -march=x86
 ; RUN: llc < %s -O0 -march=x86-64
+; RUN: llc < %s -O0 -march=arm64
+; RUN: llc < %s -O0 -march=mips64
+; RUN: llc < %s -O0 -march=ppc64
+; RUN: llc < %s -O0 -march=hexagon
+; RUN: llc < %s -O0 -march=sparc
+; RUN: llc < %s -O0 -march=systemz
 ; RUN: llc < %s -O2 -march=x86
 ; RUN: llc < %s -O2 -march=x86-64
+; RUN: llc < %s -O2 -march=arm64
+; RUN: llc < %s -O2 -march=mips64
+; RUN: llc < %s -O2 -march=ppc64
+; RUN: llc < %s -O2 -march=hexagon
+; RUN: llc < %s -O2 -march=sparc
+; RUN: llc < %s -O2 -march=systemz
 
 
 ; Test big index trunc to pointer size: