Index: llvm/lib/Analysis/Loads.cpp
===================================================================
--- llvm/lib/Analysis/Loads.cpp
+++ llvm/lib/Analysis/Loads.cpp
@@ -29,9 +29,7 @@
 static bool isAligned(const Value *Base, const APInt &Offset, Align Alignment,
                       const DataLayout &DL) {
   Align BA = Base->getPointerAlignment(DL);
-  const APInt APAlign(Offset.getBitWidth(), Alignment.value());
-  assert(APAlign.isPowerOf2() && "must be a power of 2!");
-  return BA >= Alignment && !(Offset & (APAlign - 1));
+  return BA >= Alignment && Offset.isAligned(BA);
 }
 
 /// Test if V is always a pointer to allocated and suitably aligned memory for
Index: llvm/test/Transforms/ArgumentPromotion/load-alignment-value-overflows-addrspace-size.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/ArgumentPromotion/load-alignment-value-overflows-addrspace-size.ll
@@ -0,0 +1,137 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -S -passes=argpromotion < %s | FileCheck %s
+target datalayout = "e-p:64:64-p5:32:32-p6:128:128:128:128"
+
+; Maximum alignment value of the load in a 64-bit address space
+; exceeds the bitwidth of the definition address space.
+define void @entry0() {
+; CHECK-LABEL: define void @entry0() {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    call void @call_load_maxalign_alloca_16()
+; CHECK-NEXT:    ret void
+;
+bb:
+  call void @call_load_maxalign_alloca_16()
+  ret void
+}
+
+define internal void @call_load_maxalign_alloca_16() {
+; CHECK-LABEL: define internal void @call_load_maxalign_alloca_16() {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[ALLOCA:%.*]] = alloca [13 x i16], align 16, addrspace(5)
+; CHECK-NEXT:    [[ADDRSPACECAST:%.*]] = addrspacecast ptr addrspace(5) [[ALLOCA]] to ptr
+; CHECK-NEXT:    call void @load_maxalign0(ptr [[ADDRSPACECAST]])
+; CHECK-NEXT:    ret void
+;
+bb:
+  %alloca = alloca [13 x i16], align 16, addrspace(5)
+  %addrspacecast = addrspacecast ptr addrspace(5) %alloca to ptr
+  call void @load_maxalign0(ptr %addrspacecast)
+  ret void
+}
+
+define internal void @load_maxalign0(ptr %arg) {
+; CHECK-LABEL: define internal void @load_maxalign0
+; CHECK-SAME: (ptr [[ARG:%.*]]) {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    br label [[BB1:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[LOAD:%.*]] = load i32, ptr [[ARG]], align 4294967296
+; CHECK-NEXT:    ret void
+;
+bb:
+  br label %bb1
+
+bb1:                                              ; preds = %bb
+  %load = load i32, ptr %arg, align 4294967296
+  ret void
+}
+
+; Make sure the early exit alignment check isn't hiding the offset
+; overflow.
+define void @entry1() {
+; CHECK-LABEL: define void @entry1() {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    call void @call_load_maxalign_alloca_maxalign()
+; CHECK-NEXT:    ret void
+;
+bb:
+  call void @call_load_maxalign_alloca_maxalign()
+  ret void
+}
+
+define internal void @call_load_maxalign_alloca_maxalign() {
+; CHECK-LABEL: define internal void @call_load_maxalign_alloca_maxalign() {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[ALLOCA:%.*]] = alloca [13 x i16], align 4294967296, addrspace(5)
+; CHECK-NEXT:    [[ADDRSPACECAST:%.*]] = addrspacecast ptr addrspace(5) [[ALLOCA]] to ptr
+; CHECK-NEXT:    [[ADDRSPACECAST_VAL:%.*]] = load i32, ptr [[ADDRSPACECAST]], align 4294967296
+; CHECK-NEXT:    call void @load_maxalign1(i32 [[ADDRSPACECAST_VAL]])
+; CHECK-NEXT:    ret void
+;
+bb:
+  %alloca = alloca [13 x i16], align 4294967296, addrspace(5)
+  %addrspacecast = addrspacecast ptr addrspace(5) %alloca to ptr
+  call void @load_maxalign1(ptr %addrspacecast)
+  ret void
+}
+
+define internal void @load_maxalign1(ptr %arg) {
+; CHECK-LABEL: define internal void @load_maxalign1
+; CHECK-SAME: (i32 [[ARG_0_VAL:%.*]]) {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    br label [[BB1:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    ret void
+;
+bb:
+  br label %bb1
+
+bb1:                                              ; preds = %bb
+  %load = load i32, ptr %arg, align 4294967296
+  ret void
+}
+
+; Alignment value exceeds pointer size, more than 1 past the end
+define void @entry2() {
+; CHECK-LABEL: define void @entry2() {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    call void @call_load_maxalign_alloca_ptr128()
+; CHECK-NEXT:    ret void
+;
+bb:
+  call void @call_load_maxalign_alloca_ptr128()
+  ret void
+}
+
+define internal void @call_load_maxalign_alloca_ptr128() {
+; CHECK-LABEL: define internal void @call_load_maxalign_alloca_ptr128() {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[ALLOCA:%.*]] = alloca [13 x i16], align 4294967296, addrspace(6)
+; CHECK-NEXT:    [[ADDRSPACECAST:%.*]] = addrspacecast ptr addrspace(6) [[ALLOCA]] to ptr
+; CHECK-NEXT:    [[ADDRSPACECAST_VAL:%.*]] = load i32, ptr [[ADDRSPACECAST]], align 4294967296
+; CHECK-NEXT:    call void @load_maxalign2(i32 [[ADDRSPACECAST_VAL]])
+; CHECK-NEXT:    ret void
+;
+bb:
+  %alloca = alloca [13 x i16], align 4294967296, addrspace(6)
+  %addrspacecast = addrspacecast ptr addrspace(6) %alloca to ptr
+  call void @load_maxalign2(ptr %addrspacecast)
+  ret void
+}
+
+define internal void @load_maxalign2(ptr %arg) {
+; CHECK-LABEL: define internal void @load_maxalign2
+; CHECK-SAME: (i32 [[ARG_0_VAL:%.*]]) {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    br label [[BB1:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    ret void
+;
+bb:
+  br label %bb1
+
+bb1:                                              ; preds = %bb
+  %load = load i32, ptr %arg, align 4294967296
+  ret void
+}