[SYCL] Remove volatile variants of GenericCastToPtrExplicit built-ins (#18346)

The built-ins are implemented with pointer comparison. Volatile is not
needed because memory pointed to by the pointer isn't accessed.

Author: wenju-he

clang/lib/Sema/SPIRVBuiltins.td

@@ -850,7 +850,7 @@ foreach AS = [GlobalAS, LocalAS, PrivateAS] in {
   def : SPVBuiltin<"GenericCastToPtrExplicit", [PointerType<Char, AS>, PointerType<Char, GenericAS>], Attr.Const>;
 }
 
-foreach Ty = [Void, ConstType<Void>, VolatileType<Void>, VolatileType<ConstType<Void>>] in {
+foreach Ty = [Void, ConstType<Void>] in {
   def : SPVBuiltin<"GenericCastToPtrExplicit_ToGlobal", [PointerType<Ty, GlobalAS>, PointerType<Ty, DefaultAS>, Int], Attr.Const>;
   def : SPVBuiltin<"GenericCastToPtrExplicit_ToLocal", [PointerType<Ty, LocalAS>, PointerType<Ty, DefaultAS>, Int], Attr.Const>;
   def : SPVBuiltin<"GenericCastToPtrExplicit_ToPrivate", [PointerType<Ty, PrivateAS>, PointerType<Ty, DefaultAS>, Int], Attr.Const>;

libclc/libspirv/lib/amdgcn-amdhsa/conversion/GenericCastToPtrExplicit.cl

@@ -32,18 +32,6 @@ _CLC_DEF static bool __clc_amdgcn_is_global(generic void *ptr) {
           generic const void *ptr, int unused) {                               \
     return __spirv_GenericCastToPtrExplicit_To##NAME((generic void *)ptr,      \
                                                      unused);                  \
-  }                                                                            \
-  _CLC_DECL _CLC_OVERLOAD                                                      \
-      ADDRSPACE volatile void *__spirv_GenericCastToPtrExplicit_To##NAME(      \
-          generic volatile void *ptr, int unused) {                            \
-    return __spirv_GenericCastToPtrExplicit_To##NAME((generic void *)ptr,      \
-                                                     unused);                  \
-  }                                                                            \
-  _CLC_DECL _CLC_OVERLOAD ADDRSPACE const volatile void                        \
-      *__spirv_GenericCastToPtrExplicit_To##NAME(                              \
-          generic const volatile void *ptr, int unused) {                      \
-    return __spirv_GenericCastToPtrExplicit_To##NAME((generic void *)ptr,      \
-                                                     unused);                  \
   }
 
 GenericCastToPtrExplicit_To(global, Global)

libclc/libspirv/lib/ptx-nvidiacl/conversion/GenericCastToPtrExplicit.cl

@@ -31,18 +31,6 @@ _CLC_DEF static bool __clc_nvvm_is_global(generic void *ptr) {
           generic const void *ptr, int unused) {                               \
     return __spirv_GenericCastToPtrExplicit_To##NAME((generic void *)ptr,      \
                                                      unused);                  \
-  }                                                                            \
-  _CLC_DECL _CLC_OVERLOAD                                                      \
-      ADDRSPACE volatile void *__spirv_GenericCastToPtrExplicit_To##NAME(      \
-          generic volatile void *ptr, int unused) {                            \
-    return __spirv_GenericCastToPtrExplicit_To##NAME((generic void *)ptr,      \
-                                                     unused);                  \
-  }                                                                            \
-  _CLC_DECL _CLC_OVERLOAD ADDRSPACE const volatile void                        \
-      *__spirv_GenericCastToPtrExplicit_To##NAME(                              \
-          generic const volatile void *ptr, int unused) {                      \
-    return __spirv_GenericCastToPtrExplicit_To##NAME((generic void *)ptr,      \
-                                                     unused);                  \
   }
 
 GenericCastToPtrExplicit_To(global, Global)

sycl/include/sycl/access/access.hpp

@@ -381,6 +381,7 @@ auto dynamic_address_cast(ElementType *Ptr) {
   constexpr auto SrcAS = deduce_AS<ElementType *>::value;
   using dst_type = typename DecoratedType<
       std::remove_pointer_t<remove_decoration_t<ElementType *>>, Space>::type *;
+  using RemoveCvT = std::remove_cv_t<ElementType>;
 
   if constexpr (!address_space_cast_is_possible(SrcAS, Space)) {
     return (dst_type) nullptr;
@@ -403,18 +404,18 @@ auto dynamic_address_cast(ElementType *Ptr) {
 #endif
   } else if constexpr (Space == global_space) {
     return (dst_type)__spirv_GenericCastToPtrExplicit_ToGlobal(
-        Ptr, __spv::StorageClass::CrossWorkgroup);
+        const_cast<RemoveCvT *>(Ptr), __spv::StorageClass::CrossWorkgroup);
   } else if constexpr (Space == local_space) {
     return (dst_type)__spirv_GenericCastToPtrExplicit_ToLocal(
-        Ptr, __spv::StorageClass::Workgroup);
+        const_cast<RemoveCvT *>(Ptr), __spv::StorageClass::Workgroup);
   } else if constexpr (Space == private_space) {
     return (dst_type)__spirv_GenericCastToPtrExplicit_ToPrivate(
-        Ptr, __spv::StorageClass::Function);
+        const_cast<RemoveCvT *>(Ptr), __spv::StorageClass::Function);
 #if !defined(__ENABLE_USM_ADDR_SPACE__)
   } else if constexpr (SrcAS == generic_space &&
                        (Space == global_device || Space == global_host)) {
     return (dst_type)__spirv_GenericCastToPtrExplicit_ToGlobal(
-        Ptr, __spv::StorageClass::CrossWorkgroup);
+        const_cast<RemoveCvT *>(Ptr), __spv::StorageClass::CrossWorkgroup);
 #endif
   } else {
     static_assert(SupressNotImplementedAssert || Space != Space,