AArch64: don't drop GlobalAddress offset when handling extern_weak decls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176258 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -1864,10 +1864,16 @@ AArch64TargetLowering::LowerGlobalAddressELF(SDValue Op,
                            DAG.getTargetConstantPool(GV, PtrVT, 0, 0,
                                                      AArch64II::MO_LO12),
                            DAG.getConstant(8, MVT::i32));
-    return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), PoolAddr,
+    SDValue GlobalAddr = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), PoolAddr,
-                       MachinePointerInfo::getConstantPool(),
+                                     MachinePointerInfo::getConstantPool(),
-                       /*isVolatile=*/ false,  /*isNonTemporal=*/ true,
+                                     /*isVolatile=*/ false,
-                       /*isInvariant=*/ true, 8);
+                                     /*isNonTemporal=*/ true,
+                                     /*isInvariant=*/ true, 8);
+    if (GN->getOffset() != 0)
+      return DAG.getNode(ISD::ADD, dl, PtrVT, GlobalAddr,
+                         DAG.getConstant(GN->getOffset(), PtrVT));
+
+    return GlobalAddr;
   }
 
   if (Alignment == 0) {

test/CodeGen/AArch64/extern-weak.ll

@@ -12,3 +12,16 @@ define i32()* @foo() {
 ; CHECK: ldr x0, [{{x[0-9]+}}, #:lo12:.LCPI0_0]
 
 }
+
+
+@arr_var = extern_weak global [10 x i32]
+
+define i32* @bar() {
+  %addr = getelementptr [10 x i32]* @arr_var, i32 0, i32 5
+; CHECK: .LCPI1_0:
+; CHECK-NEXT: .xword arr_var
+
+; CHECK: ldr [[BASE:x[0-9]+]], [{{x[0-9]+}}, #:lo12:.LCPI1_0]
+; CHECK: add x0, [[BASE]], #20
+  ret i32* %addr
+}