diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -3280,13 +3280,15 @@
       Allocator->containsUnexpandedParameterPack())
     return OMPAllocateDeclAttr::OMPUserDefinedMemAlloc;
   auto AllocatorKindRes = OMPAllocateDeclAttr::OMPUserDefinedMemAlloc;
+  llvm::FoldingSetNodeID AEId;
   const Expr *AE = Allocator->IgnoreParenImpCasts();
+  AE->IgnoreImpCasts()->Profile(AEId, S.getASTContext(), /*Canonical=*/true);
   for (int I = 0; I < OMPAllocateDeclAttr::OMPUserDefinedMemAlloc; ++I) {
     auto AllocatorKind = static_cast<OMPAllocateDeclAttr::AllocatorTypeTy>(I);
     const Expr *DefAllocator = Stack->getAllocator(AllocatorKind);
-    llvm::FoldingSetNodeID AEId, DAEId;
-    AE->Profile(AEId, S.getASTContext(), /*Canonical=*/true);
-    DefAllocator->Profile(DAEId, S.getASTContext(), /*Canonical=*/true);
+    llvm::FoldingSetNodeID DAEId;
+    DefAllocator->IgnoreImpCasts()->Profile(DAEId, S.getASTContext(),
+                                            /*Canonical=*/true);
     if (AEId == DAEId) {
       AllocatorKindRes = AllocatorKind;
       break;
@@ -16496,10 +16498,22 @@
 /// Tries to find omp_allocator_handle_t type.
 static bool findOMPAllocatorHandleT(Sema &S, SourceLocation Loc,
                                     DSAStackTy *Stack) {
-  QualType OMPAllocatorHandleT = Stack->getOMPAllocatorHandleT();
-  if (!OMPAllocatorHandleT.isNull())
+  if (!Stack->getOMPAllocatorHandleT().isNull())
     return true;
-  // Build the predefined allocator expressions.
+
+  // Set the allocator handle type.
+  IdentifierInfo *II = &S.PP.getIdentifierTable().get("omp_allocator_handle_t");
+  ParsedType PT = S.getTypeName(*II, Loc, S.getCurScope());
+  if (!PT.getAsOpaquePtr() || PT.get().isNull()) {
+    S.Diag(Loc, diag::err_omp_implied_type_not_found)
+        << "omp_allocator_handle_t";
+    return false;
+  }
+  QualType AllocatorHandleEnumTy = PT.get();
+  AllocatorHandleEnumTy.addConst();
+  Stack->setOMPAllocatorHandleT(AllocatorHandleEnumTy);
+
+  // Fill the predefined allocator map.
   bool ErrorFound = false;
   for (int I = 0; I < OMPAllocateDeclAttr::OMPUserDefinedMemAlloc; ++I) {
     auto AllocatorKind = static_cast<OMPAllocateDeclAttr::AllocatorTypeTy>(I);
@@ -16519,9 +16533,10 @@
       ErrorFound = true;
       break;
     }
-    if (OMPAllocatorHandleT.isNull())
-      OMPAllocatorHandleT = AllocatorType;
-    if (!S.getASTContext().hasSameType(OMPAllocatorHandleT, AllocatorType)) {
+    Res = S.PerformImplicitConversion(Res.get(), AllocatorHandleEnumTy,
+                                      Sema::AA_Initializing,
+                                      /* AllowExplicit */ true);
+    if (!Res.isUsable()) {
       ErrorFound = true;
       break;
     }
@@ -16532,8 +16547,7 @@
         << "omp_allocator_handle_t";
     return false;
   }
-  OMPAllocatorHandleT.addConst();
-  Stack->setOMPAllocatorHandleT(OMPAllocatorHandleT);
+
   return true;
 }
 
@@ -23656,17 +23670,26 @@
       AllocatorExpr = D.Allocator->IgnoreParenImpCasts();
       auto *DRE = dyn_cast<DeclRefExpr>(AllocatorExpr);
       bool IsPredefinedAllocator = false;
-      if (DRE)
-        IsPredefinedAllocator = PredefinedAllocators.count(DRE->getDecl());
-      if (!DRE ||
-          !(Context.hasSameUnqualifiedType(
-                AllocatorExpr->getType(), DSAStack->getOMPAllocatorHandleT()) ||
-            Context.typesAreCompatible(AllocatorExpr->getType(),
-                                       DSAStack->getOMPAllocatorHandleT(),
-                                       /*CompareUnqualified=*/true)) ||
-          (!IsPredefinedAllocator &&
-           (AllocatorExpr->getType().isConstant(Context) ||
-            !AllocatorExpr->isLValue()))) {
+      if (DRE) {
+        OMPAllocateDeclAttr::AllocatorTypeTy AllocatorTy =
+            getAllocatorKind(*this, DSAStack, AllocatorExpr);
+        IsPredefinedAllocator =
+            AllocatorTy !=
+            OMPAllocateDeclAttr::AllocatorTypeTy::OMPUserDefinedMemAlloc;
+      }
+      QualType OMPAllocatorHandleT = DSAStack->getOMPAllocatorHandleT();
+      QualType AllocatorExprType = AllocatorExpr->getType();
+      bool IsTypeCompatible = IsPredefinedAllocator;
+      IsTypeCompatible = IsTypeCompatible ||
+                         Context.hasSameUnqualifiedType(AllocatorExprType,
+                                                        OMPAllocatorHandleT);
+      IsTypeCompatible =
+          IsTypeCompatible ||
+          Context.typesAreCompatible(AllocatorExprType, OMPAllocatorHandleT);
+      bool IsNonConstantLValue =
+          !AllocatorExprType.isConstant(Context) && AllocatorExpr->isLValue();
+      if (!DRE || !IsTypeCompatible ||
+          (!IsPredefinedAllocator && !IsNonConstantLValue)) {
         Diag(D.Allocator->getExprLoc(), diag::err_omp_var_expected)
             << "omp_allocator_handle_t" << (DRE ? 1 : 0)
             << AllocatorExpr->getType() << D.Allocator->getSourceRange();
diff --git a/clang/test/OpenMP/bug54082.c b/clang/test/OpenMP/bug54082.c
new file mode 100644
--- /dev/null
+++ b/clang/test/OpenMP/bug54082.c
@@ -0,0 +1,114 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --function-signature --include-generated-funcs --prefix-filecheck-ir-name _
+// RUN: %clang_cc1 -fopenmp -O1 -x c -triple x86_64-apple-darwin10 -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK
+
+typedef enum omp_allocator_handle_t {
+  omp_null_allocator = 0,
+  omp_default_mem_alloc = 1,
+  omp_large_cap_mem_alloc = 2,
+  omp_const_mem_alloc = 3,
+  omp_high_bw_mem_alloc = 4,
+  omp_low_lat_mem_alloc = 5,
+  omp_cgroup_mem_alloc = 6,
+  omp_pteam_mem_alloc = 7,
+  omp_thread_mem_alloc = 8,
+  KMP_ALLOCATOR_MAX_HANDLE = __UINTPTR_MAX__
+} omp_allocator_handle_t;
+
+typedef enum omp_memspace_handle_t {
+  omp_default_mem_space = 0,
+  omp_large_cap_mem_space = 1,
+  omp_const_mem_space = 2,
+  omp_high_bw_mem_space = 3,
+  omp_low_lat_mem_space = 4,
+  llvm_omp_target_host_mem_space = 100,
+  llvm_omp_target_shared_mem_space = 101,
+  llvm_omp_target_device_mem_space = 102,
+  KMP_MEMSPACE_MAX_HANDLE = __UINTPTR_MAX__
+} omp_memspace_handle_t;
+
+typedef enum {
+  omp_atk_sync_hint = 1,
+  omp_atk_alignment = 2,
+  omp_atk_access = 3,
+  omp_atk_pool_size = 4,
+  omp_atk_fallback = 5,
+  omp_atk_fb_data = 6,
+  omp_atk_pinned = 7,
+  omp_atk_partition = 8
+} omp_alloctrait_key_t;
+
+typedef unsigned long long omp_uintptr_t;
+typedef unsigned long long size_t;
+
+typedef struct {
+  omp_alloctrait_key_t key;
+  omp_uintptr_t value;
+} omp_alloctrait_t;
+
+extern omp_allocator_handle_t
+omp_init_allocator(omp_memspace_handle_t memspace, int ntraits,
+                   const omp_alloctrait_t traits[]);
+
+#define N 1024
+
+void foo() {
+  int *x;
+
+  omp_memspace_handle_t x_memspace = omp_default_mem_space;
+  omp_alloctrait_t x_traits[1] = {omp_atk_alignment, 64};
+  omp_allocator_handle_t x_alloc = omp_init_allocator(x_memspace, 1, x_traits);
+
+#pragma omp parallel for allocate(x_alloc : x) private(x)
+  for (int i = 0; i < N; i++) {
+    (void)x;
+  }
+}
+// CHECK-LABEL: define {{[^@]+}}@foo
+// CHECK-SAME: () local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[X_TRAITS:%.*]] = alloca [1 x %struct.omp_alloctrait_t], align 16
+// CHECK-NEXT:    [[X_ALLOC:%.*]] = alloca i64, align 8
+// CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 16, ptr nonnull [[X_TRAITS]]) #[[ATTR5:[0-9]+]]
+// CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr noundef nonnull align 16 dereferenceable(16) [[X_TRAITS]], ptr noundef nonnull align 16 dereferenceable(16) @__const.foo.x_traits, i64 16, i1 false)
+// CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 8, ptr nonnull [[X_ALLOC]]) #[[ATTR5]]
+// CHECK-NEXT:    [[CALL:%.*]] = call i64 @omp_init_allocator(i64 noundef 0, i32 noundef 1, ptr noundef nonnull [[X_TRAITS]]) #[[ATTR5]]
+// CHECK-NEXT:    store i64 [[CALL]], ptr [[X_ALLOC]], align 8, !tbaa [[TBAA3:![0-9]+]]
+// CHECK-NEXT:    call void (ptr, i32, ptr, ...) @__kmpc_fork_call(ptr nonnull @[[GLOB2:[0-9]+]], i32 1, ptr nonnull @.omp_outlined., ptr nonnull [[X_ALLOC]])
+// CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 8, ptr nonnull [[X_ALLOC]]) #[[ATTR5]]
+// CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 16, ptr nonnull [[X_TRAITS]]) #[[ATTR5]]
+// CHECK-NEXT:    ret void
+//
+//
+// CHECK-LABEL: define {{[^@]+}}@.omp_outlined.
+// CHECK-SAME: (ptr noalias nocapture noundef readonly [[DOTGLOBAL_TID_:%.*]], ptr noalias nocapture readnone [[DOTBOUND_TID_:%.*]], ptr nocapture noundef nonnull readonly align 8 dereferenceable(8) [[X_ALLOC:%.*]]) #[[ATTR4:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[DOTOMP_LB:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[DOTOMP_UB:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[DOTOMP_STRIDE:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[DOTOMP_IS_LAST:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr nonnull [[DOTOMP_LB]]) #[[ATTR5]]
+// CHECK-NEXT:    store i32 0, ptr [[DOTOMP_LB]], align 4, !tbaa [[TBAA6:![0-9]+]]
+// CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr nonnull [[DOTOMP_UB]]) #[[ATTR5]]
+// CHECK-NEXT:    store i32 1023, ptr [[DOTOMP_UB]], align 4, !tbaa [[TBAA6]]
+// CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr nonnull [[DOTOMP_STRIDE]]) #[[ATTR5]]
+// CHECK-NEXT:    store i32 1, ptr [[DOTOMP_STRIDE]], align 4, !tbaa [[TBAA6]]
+// CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr nonnull [[DOTOMP_IS_LAST]]) #[[ATTR5]]
+// CHECK-NEXT:    store i32 0, ptr [[DOTOMP_IS_LAST]], align 4, !tbaa [[TBAA6]]
+// CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[DOTGLOBAL_TID_]], align 4, !tbaa [[TBAA6]]
+// CHECK-NEXT:    [[TMP1:%.*]] = load i64, ptr [[X_ALLOC]], align 8, !tbaa [[TBAA3]]
+// CHECK-NEXT:    [[CONV:%.*]] = inttoptr i64 [[TMP1]] to ptr
+// CHECK-NEXT:    [[DOTX__VOID_ADDR:%.*]] = tail call ptr @__kmpc_alloc(i32 [[TMP0]], i64 8, ptr [[CONV]])
+// CHECK-NEXT:    call void @__kmpc_for_static_init_4(ptr nonnull @[[GLOB1:[0-9]+]], i32 [[TMP0]], i32 34, ptr nonnull [[DOTOMP_IS_LAST]], ptr nonnull [[DOTOMP_LB]], ptr nonnull [[DOTOMP_UB]], ptr nonnull [[DOTOMP_STRIDE]], i32 1, i32 1)
+// CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr [[DOTOMP_UB]], align 4, !tbaa [[TBAA6]]
+// CHECK-NEXT:    [[COND:%.*]] = call i32 @llvm.smin.i32(i32 [[TMP2]], i32 1023)
+// CHECK-NEXT:    store i32 [[COND]], ptr [[DOTOMP_UB]], align 4, !tbaa [[TBAA6]]
+// CHECK-NEXT:    call void @__kmpc_for_static_fini(ptr nonnull @[[GLOB1]], i32 [[TMP0]])
+// CHECK-NEXT:    [[TMP3:%.*]] = load i64, ptr [[X_ALLOC]], align 8, !tbaa [[TBAA3]]
+// CHECK-NEXT:    [[CONV5:%.*]] = inttoptr i64 [[TMP3]] to ptr
+// CHECK-NEXT:    call void @__kmpc_free(i32 [[TMP0]], ptr [[DOTX__VOID_ADDR]], ptr [[CONV5]])
+// CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[DOTOMP_IS_LAST]]) #[[ATTR5]]
+// CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[DOTOMP_STRIDE]]) #[[ATTR5]]
+// CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[DOTOMP_UB]]) #[[ATTR5]]
+// CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[DOTOMP_LB]]) #[[ATTR5]]
+// CHECK-NEXT:    ret void
+//
diff --git a/clang/test/OpenMP/target_uses_allocators.c b/clang/test/OpenMP/target_uses_allocators.c
--- a/clang/test/OpenMP/target_uses_allocators.c
+++ b/clang/test/OpenMP/target_uses_allocators.c
@@ -6,7 +6,7 @@
 #ifndef HEADER
 #define HEADER
 
-enum omp_allocator_handle_t {
+typedef enum omp_allocator_handle_t {
   omp_null_allocator = 0,
   omp_default_mem_alloc = 1,
   omp_large_cap_mem_alloc = 2,
@@ -17,7 +17,7 @@
   omp_pteam_mem_alloc = 7,
   omp_thread_mem_alloc = 8,
   KMP_ALLOCATOR_MAX_HANDLE = __UINTPTR_MAX__
-};
+} omp_allocator_handle_t;
 
 // CHECK: define {{.*}}[[FIE:@.+]]()
 void fie(void) {
@@ -105,4 +105,4 @@
 // CHECK-NEXT: %.x..void.addr = call ptr @__kmpc_alloc(i32 %[[#R0]], i64 4, ptr inttoptr (i64 8 to ptr))
 // CHECK-NEXT: %[[#R1:]] = load i32, ptr %x.addr, align 4
 // CHECK-NEXT: store i32 %[[#R1]], ptr %.x..void.addr, align 4
-// CHECK-NEXT: call void @__kmpc_free(i32 %[[#R0]], ptr %.x..void.addr, ptr inttoptr (i64 8 to ptr))
\ No newline at end of file
+// CHECK-NEXT: call void @__kmpc_free(i32 %[[#R0]], ptr %.x..void.addr, ptr inttoptr (i64 8 to ptr))
diff --git a/openmp/runtime/test/parallel/bug54082.c b/openmp/runtime/test/parallel/bug54082.c
new file mode 100644
--- /dev/null
+++ b/openmp/runtime/test/parallel/bug54082.c
@@ -0,0 +1,54 @@
+// This test is adapted from test_parallel_for_allocate.c in SOLLVE V&V.
+// https://github.com/SOLLVE/sollve_vv/blob/master/tests/5.0/parallel_for/test_parallel_for_allocate.c
+// RUN: %libomp-compile-and-run
+#include <omp.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+#define N 1024
+
+int main(int argc, char *argv[]) {
+  int errors = 0;
+  int *x;
+  int result[N][N];
+  int successful_alloc = 0;
+
+  omp_memspace_handle_t x_memspace = omp_default_mem_space;
+  omp_alloctrait_t x_traits[1] = {omp_atk_alignment, 64};
+  omp_allocator_handle_t x_alloc = omp_init_allocator(x_memspace, 1, x_traits);
+
+  for (int i = 0; i < N; i++) {
+    for (int j = 0; j < N; j++) {
+      result[i][j] = -1;
+    }
+  }
+
+#pragma omp parallel for allocate(x_alloc: x) private(x) shared(result)
+  for (int i = 0; i < N; i++) {
+    x = (int *)malloc(N * sizeof(int));
+    if (x != NULL) {
+#pragma omp simd simdlen(16) aligned(x : 64)
+      for (int j = 0; j < N; j++) {
+        x[j] = j * i;
+      }
+      for (int j = 0; j < N; j++) {
+        result[i][j] = x[j];
+      }
+      free(x);
+      successful_alloc++;
+    }
+  }
+
+  errors += successful_alloc < 1;
+
+  for (int i = 0; i < N; i++) {
+    for (int j = 0; j < N; j++) {
+      errors += result[i][j] != i * j;
+    }
+  }
+
+  omp_destroy_allocator(x_alloc);
+
+  return errors;
+}