diff --git a/clang/include/clang/Basic/AddressSpaces.h b/clang/include/clang/Basic/AddressSpaces.h
--- a/clang/include/clang/Basic/AddressSpaces.h
+++ b/clang/include/clang/Basic/AddressSpaces.h
@@ -47,7 +47,6 @@
   // SYCL specific address spaces.
   sycl_global,
   sycl_local,
-  sycl_constant, // TBD: remove?
   sycl_private,
 
   // Pointer size and extension address spaces.
diff --git a/clang/include/clang/Sema/ParsedAttr.h b/clang/include/clang/Sema/ParsedAttr.h
--- a/clang/include/clang/Sema/ParsedAttr.h
+++ b/clang/include/clang/Sema/ParsedAttr.h
@@ -626,8 +626,6 @@
   /// representation in LangAS, otherwise returns default address space.
   LangAS asSYCLLangAS() const {
     switch (getKind()) {
-    case ParsedAttr::AT_OpenCLConstantAddressSpace:
-      return LangAS::sycl_constant;
     case ParsedAttr::AT_OpenCLGlobalAddressSpace:
       return LangAS::sycl_global;
     case ParsedAttr::AT_OpenCLLocalAddressSpace:
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -932,7 +932,6 @@
         9,  // cuda_shared
         1,  // sycl_global
         3,  // sycl_local
-        2,  // sycl_constant
         0,  // sycl_private
         10, // ptr32_sptr
         11, // ptr32_uptr
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -2082,7 +2082,6 @@
   case LangAS::sycl_private:
     return "__private";
   case LangAS::opencl_constant:
-  case LangAS::sycl_constant:
     return "__constant";
   case LangAS::opencl_generic:
     return "__generic";
diff --git a/clang/lib/Basic/Targets/AMDGPU.cpp b/clang/lib/Basic/Targets/AMDGPU.cpp
--- a/clang/lib/Basic/Targets/AMDGPU.cpp
+++ b/clang/lib/Basic/Targets/AMDGPU.cpp
@@ -53,7 +53,6 @@
     Local,    // cuda_shared
     Global,   // sycl_global
     Local,    // sycl_local
-    Constant, // sycl_constant
     Private,  // sycl_private
     Generic,  // ptr32_sptr
     Generic,  // ptr32_uptr
@@ -74,7 +73,6 @@
     Local,    // cuda_shared
     Global,   // sycl_global
     Local,    // sycl_local
-    Constant, // sycl_constant
     Private,  // sycl_private
     Generic,  // ptr32_sptr
     Generic,  // ptr32_uptr
diff --git a/clang/lib/Basic/Targets/NVPTX.h b/clang/lib/Basic/Targets/NVPTX.h
--- a/clang/lib/Basic/Targets/NVPTX.h
+++ b/clang/lib/Basic/Targets/NVPTX.h
@@ -37,7 +37,6 @@
     3, // cuda_shared
     1, // sycl_global
     3, // sycl_local
-    4, // sycl_constant
     0, // sycl_private
     0, // ptr32_sptr
     0, // ptr32_uptr
diff --git a/clang/lib/Basic/Targets/SPIR.h b/clang/lib/Basic/Targets/SPIR.h
--- a/clang/lib/Basic/Targets/SPIR.h
+++ b/clang/lib/Basic/Targets/SPIR.h
@@ -35,7 +35,6 @@
     0, // cuda_shared
     1, // sycl_global
     3, // sycl_local
-    2, // sycl_constant
     0, // sycl_private
     0, // ptr32_sptr
     0, // ptr32_uptr
@@ -56,7 +55,6 @@
     0, // cuda_shared
     1, // sycl_global
     3, // sycl_local
-    2, // sycl_constant
     0, // sycl_private
     0, // ptr32_sptr
     0, // ptr32_uptr
diff --git a/clang/lib/Basic/Targets/TCE.h b/clang/lib/Basic/Targets/TCE.h
--- a/clang/lib/Basic/Targets/TCE.h
+++ b/clang/lib/Basic/Targets/TCE.h
@@ -44,7 +44,6 @@
     0, // cuda_shared
     3, // sycl_global
     4, // sycl_local
-    5, // sycl_constant
     0, // sycl_private
     0, // ptr32_sptr
     0, // ptr32_uptr
diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h
--- a/clang/lib/Basic/Targets/X86.h
+++ b/clang/lib/Basic/Targets/X86.h
@@ -37,7 +37,6 @@
     0,   // cuda_shared
     0,   // sycl_global
     0,   // sycl_local
-    0,   // sycl_constant
     0,   // sycl_private
     270, // ptr32_sptr
     271, // ptr32_uptr
diff --git a/clang/test/SemaTemplate/address_space-dependent.cpp b/clang/test/SemaTemplate/address_space-dependent.cpp
--- a/clang/test/SemaTemplate/address_space-dependent.cpp
+++ b/clang/test/SemaTemplate/address_space-dependent.cpp
@@ -43,7 +43,7 @@
 
 template <long int I>
 void tooBig() {
-  __attribute__((address_space(I))) int *bounds; // expected-error {{address space is larger than the maximum supported (8388589)}}
+  __attribute__((address_space(I))) int *bounds; // expected-error {{address space is larger than the maximum supported (8388590)}}
 }
 
 template <long int I>