Index: llvm/lib/Transforms/IPO/GlobalOpt.cpp
===================================================================
--- llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -630,6 +630,23 @@
     }
     GEP->replaceAllUsesWith(NewPtr);
 
+    // We changed the pointer of any memory access user. Recalculate alignments.
+    for (User *U : NewPtr->users()) {
+      if (auto *Load = dyn_cast<LoadInst>(U)) {
+        Align PrefAlign = DL.getPrefTypeAlign(Load->getType());
+        Align NewAlign = getOrEnforceKnownAlignment(Load->getPointerOperand(),
+                                                    PrefAlign, DL, Load);
+        Load->setAlignment(NewAlign);
+      }
+      if (auto *Store = dyn_cast<StoreInst>(U)) {
+        Align PrefAlign =
+            DL.getPrefTypeAlign(Store->getValueOperand()->getType());
+        Align NewAlign = getOrEnforceKnownAlignment(Store->getPointerOperand(),
+                                                    PrefAlign, DL, Store);
+        Store->setAlignment(NewAlign);
+      }
+    }
+
     if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(GEP))
       GEPI->eraseFromParent();
     else
Index: llvm/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll
===================================================================
--- llvm/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll
+++ llvm/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll
@@ -17,7 +17,9 @@
 @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__I_a, i8* null }]
 @llvm.used = appending global [2 x i8*] [i8* getelementptr inbounds ([7 x i8], [7 x i8]* @"\01L_OBJC_METH_VAR_NAME_40", i32 0, i32 0),  i8* bitcast (i8** @"\01L_OBJC_SELECTOR_REFERENCES_41" to i8*)]
 
-; CHECK: @[[_ZL14BUTTONINITDATA_0_0:[a-zA-Z0-9_$"\\.-]+]] = internal unnamed_addr global i8* null, align 4
+; Choose the preferred alignment.
+
+; CHECK: @[[_ZL14BUTTONINITDATA_0_0:[a-zA-Z0-9_$"\\.-]+]] = internal unnamed_addr global i8* null, align 16
 ;.
 define internal void @__cxx_global_var_init() section "__TEXT,__StaticInit,regular,pure_instructions" {
   %1 = load i8*, i8** @"\01L_OBJC_SELECTOR_REFERENCES_41", !invariant.load !2009
@@ -32,9 +34,11 @@
 
 declare void @test(i8*)
 
+; The preferred alignment is available.
+
 define void @print() {
 ; CHECK-LABEL: @print(
-; CHECK-NEXT:    [[TMP1:%.*]] = load i8*, i8** @_ZL14buttonInitData.0.0, align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = load i8*, i8** @_ZL14buttonInitData.0.0, align 16
 ; CHECK-NEXT:    call void @test(i8* [[TMP1]])
 ; CHECK-NEXT:    ret void
 ;
Index: llvm/test/Transforms/GlobalOpt/globalsra-align.ll
===================================================================
--- llvm/test/Transforms/GlobalOpt/globalsra-align.ll
+++ llvm/test/Transforms/GlobalOpt/globalsra-align.ll
@@ -5,7 +5,6 @@
 
 @a = internal global [2 x [7 x i32*]] zeroinitializer, align 16
 
-; FIXME:
 ; PR50253
 ; The store alignments are correct initially, but they should be updated
 ; after transforming the global. The global pointer retains its original
@@ -17,7 +16,7 @@
 ;.
 define i32* @reduce_align_0() {
 ; CHECK-LABEL: @reduce_align_0(
-; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 0), align 4
+; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 0), align 16
 ; CHECK-NEXT:    ret i32* null
 ;
   %x = load i32*, i32** getelementptr inbounds ([2 x [7 x i32*]], [2 x [7 x i32*]]* @a, i64 0, i64 0, i64 0), align 1
@@ -27,7 +26,7 @@
 
 define i32* @reduce_align_1() {
 ; CHECK-LABEL: @reduce_align_1(
-; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 1), align 16
+; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 1), align 4
 ; CHECK-NEXT:    ret i32* null
 ;
   %x = load i32*, i32** getelementptr inbounds ([2 x [7 x i32*]], [2 x [7 x i32*]]* @a, i64 0, i64 0, i64 0), align 1
@@ -37,7 +36,7 @@
 
 define i32* @reduce_align_2() {
 ; CHECK-LABEL: @reduce_align_2(
-; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 2), align 4
+; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 2), align 8
 ; CHECK-NEXT:    ret i32* null
 ;
   %x = load i32*, i32** getelementptr inbounds ([2 x [7 x i32*]], [2 x [7 x i32*]]* @a, i64 0, i64 0, i64 0), align 1
@@ -47,7 +46,7 @@
 
 define i32* @reduce_align_3() {
 ; CHECK-LABEL: @reduce_align_3(
-; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 3), align 8
+; CHECK-NEXT:    store i32* null, i32** getelementptr inbounds ([7 x i32*], [7 x i32*]* @a.1, i32 0, i64 3), align 4
 ; CHECK-NEXT:    ret i32* null
 ;
   %x = load i32*, i32** getelementptr inbounds ([2 x [7 x i32*]], [2 x [7 x i32*]]* @a, i64 0, i64 0, i64 0), align 1