[SYCL] Enable memcpy in libdevice

clang/lib/Driver/Driver.cpp

@@ -4184,6 +4184,7 @@ class OffloadingActionBuilder final {
       // default too.
       SmallVector<DeviceLibOptInfo, 5> sycl_device_fallback_libs = {
           {"libsycl-fallback-cassert", "libc"},
+          {"libsycl-fallback-cstring", "libc"},
           {"libsycl-fallback-complex", "libm-fp32"},
           {"libsycl-fallback-complex-fp64", "libm-fp64"},
           {"libsycl-fallback-cmath", "libm-fp32"},

clang/lib/Driver/ToolChains/SYCL.cpp

@@ -133,6 +133,7 @@ static llvm::SmallVector<StringRef, 10> SYCLDeviceLibList{
     "complex",
     "complex-fp64",
     "fallback-cassert",
+    "fallback-cstring",
     "fallback-cmath",
     "fallback-cmath-fp64",
     "fallback-complex",

clang/test/Driver/sycl-device-lib-win.cpp

@@ -21,6 +21,7 @@
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath.obj" "-outputs={{.*}}libsycl-cmath-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath-fp64.obj" "-outputs={{.*}}libsycl-cmath-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.obj" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
+// SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.obj" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex.obj" "-outputs={{.*}}libsycl-fallback-complex-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex-fp64.obj" "-outputs={{.*}}libsycl-fallback-complex-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cmath.obj" "-outputs={{.*}}libsycl-fallback-cmath-{{.*}}.o" "-unbundle"
@@ -44,6 +45,7 @@
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath.obj" "-outputs={{.*}}libsycl-cmath-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath-fp64.obj" "-outputs={{.*}}libsycl-cmath-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.obj" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
+// SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.obj" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex.obj" "-outputs={{.*}}libsycl-fallback-complex-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex-fp64.obj" "-outputs={{.*}}libsycl-fallback-complex-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cmath.obj" "-outputs={{.*}}libsycl-fallback-cmath-{{.*}}.o" "-unbundle"
@@ -69,7 +71,7 @@
 // RUN:   | FileCheck %s -check-prefix=SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM
 // SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-crt.obj" "-outputs={{.*}}libsycl-crt-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.obj" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
-
+// SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.obj" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 /// ###########################################################################
 
 /// test behavior of disabling all device libraries
@@ -109,6 +111,7 @@
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath.obj" "-outputs={{.*}}libsycl-cmath-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath-fp64.obj" "-outputs={{.*}}libsycl-cmath-fp64-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.obj" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
+// SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.obj" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex.obj" "-outputs={{.*}}libsycl-fallback-complex-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex-fp64.obj" "-outputs={{.*}}libsycl-fallback-complex-fp64-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cmath.obj" "-outputs={{.*}}libsycl-fallback-cmath-{{.*}}.o" "-unbundle"

clang/test/Driver/sycl-device-lib.cpp

@@ -21,6 +21,7 @@
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath.o" "-outputs={{.*}}libsycl-cmath-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath-fp64.o" "-outputs={{.*}}libsycl-cmath-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.o" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
+// SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.o" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex.o" "-outputs={{.*}}libsycl-fallback-complex-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex-fp64.o" "-outputs={{.*}}libsycl-fallback-complex-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cmath.o" "-outputs={{.*}}libsycl-fallback-cmath-{{.*}}.o" "-unbundle"
@@ -44,6 +45,7 @@
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath.o" "-outputs={{.*}}libsycl-cmath-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath-fp64.o" "-outputs={{.*}}libsycl-cmath-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.o" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
+// SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.o" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex.o" "-outputs={{.*}}libsycl-fallback-complex-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex-fp64.o" "-outputs={{.*}}libsycl-fallback-complex-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_WITH_FP64-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cmath.o" "-outputs={{.*}}libsycl-fallback-cmath-{{.*}}.o" "-unbundle"
@@ -69,6 +71,7 @@
 // RUN:   | FileCheck %s -check-prefix=SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM
 // SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-crt.o" "-outputs={{.*}}libsycl-crt-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.o" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
+// SYCL_DEVICE_LIB_UNBUNDLE_NO_LIBM-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.o" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 
 /// ###########################################################################
 
@@ -109,6 +112,7 @@
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath.o" "-outputs={{.*}}libsycl-cmath-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-cmath-fp64.o" "-outputs={{.*}}libsycl-cmath-fp64-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cassert.o" "-outputs={{.*}}libsycl-fallback-cassert-{{.*}}.o" "-unbundle"
+// SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cstring.o" "-outputs={{.*}}libsycl-fallback-cstring-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex.o" "-outputs={{.*}}libsycl-fallback-complex-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-complex-fp64.o" "-outputs={{.*}}libsycl-fallback-complex-fp64-{{.*}}.o" "-unbundle"
 // SYCL_LLVM_LINK_DEVICE_LIB-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown-sycldevice" "-inputs={{.*}}libsycl-fallback-cmath.o" "-outputs={{.*}}libsycl-fallback-cmath-{{.*}}.o" "-unbundle"

libdevice/cmake/modules/SYCLLibdevice.cmake

@@ -86,6 +86,15 @@ add_custom_command(OUTPUT ${spv_binary_dir}/libsycl-fallback-cassert.spv
                    DEPENDS wrapper.h device.h clang spirv_vars.h llvm-spirv
                    VERBATIM)
 
+add_custom_command(OUTPUT ${spv_binary_dir}/libsycl-fallback-cstring.spv
+                   COMMAND ${clang} -S -fsycl-device-only -fno-sycl-use-bitcode
+                           ${compile_opts}
+                           ${CMAKE_CURRENT_SOURCE_DIR}/fallback-cstring.cpp
+                           -o ${spv_binary_dir}/libsycl-fallback-cstring.spv
+                   MAIN_DEPENDENCY fallback-cstring.cpp
+                   DEPENDS wrapper.h device.h clang spirv_vars.h llvm-spirv
+                   VERBATIM)
+
 add_custom_command(OUTPUT ${obj_binary_dir}/libsycl-fallback-cassert.${lib-suffix}
                    COMMAND ${clang} -fsycl -c
                            ${compile_opts} ${sycl_targets_opt}
@@ -95,6 +104,15 @@ add_custom_command(OUTPUT ${obj_binary_dir}/libsycl-fallback-cassert.${lib-suffi
                    DEPENDS wrapper.h device.h clang spirv_vars.h clang-offload-bundler
                    VERBATIM)
 
+add_custom_command(OUTPUT ${obj_binary_dir}/libsycl-fallback-cstring.${lib-suffix}
+                   COMMAND ${clang} -fsycl -c
+                           ${compile_opts} ${sycl_targets_opt}
+                           ${CMAKE_CURRENT_SOURCE_DIR}/fallback-cstring.cpp
+                           -o ${obj_binary_dir}/libsycl-fallback-cstring.${lib-suffix}
+                   MAIN_DEPENDENCY fallback-cstring.cpp
+                   DEPENDS wrapper.h device.h clang spirv_vars.h clang-offload-bundler
+                   VERBATIM)
+
 add_custom_command(OUTPUT ${spv_binary_dir}/libsycl-fallback-complex.spv
                    COMMAND ${clang} -S -fsycl-device-only -fno-sycl-use-bitcode
                            ${compile_opts}
@@ -210,13 +228,15 @@ add_custom_target(libsycldevice-obj DEPENDS
 )
 add_custom_target(libsycldevice-spv DEPENDS
   ${spv_binary_dir}/libsycl-fallback-cassert.spv
+  ${spv_binary_dir}/libsycl-fallback-cstring.spv
   ${spv_binary_dir}/libsycl-fallback-complex.spv
   ${spv_binary_dir}/libsycl-fallback-complex-fp64.spv
   ${spv_binary_dir}/libsycl-fallback-cmath.spv
   ${spv_binary_dir}/libsycl-fallback-cmath-fp64.spv
   )
 add_custom_target(libsycldevice-fallback-obj DEPENDS
   ${obj_binary_dir}/libsycl-fallback-cassert.${lib-suffix}
+  ${obj_binary_dir}/libsycl-fallback-cstring.${lib-suffix}
   ${obj_binary_dir}/libsycl-fallback-complex.${lib-suffix}
   ${obj_binary_dir}/libsycl-fallback-complex-fp64.${lib-suffix}
   ${obj_binary_dir}/libsycl-fallback-cmath.${lib-suffix}
@@ -239,6 +259,7 @@ set(install_dest_lib lib${LLVM_LIBDIR_SUFFIX})
 
 install(FILES ${devicelib-obj-file}
 	      ${obj_binary_dir}/libsycl-fallback-cassert.${lib-suffix}
+	      ${obj_binary_dir}/libsycl-fallback-cstring.${lib-suffix}
               ${devicelib-obj-complex}
 	      ${obj_binary_dir}/libsycl-fallback-complex.${lib-suffix}
               ${devicelib-obj-complex-fp64}
@@ -252,6 +273,7 @@ install(FILES ${devicelib-obj-file}
         COMPONENT libsycldevice)
 
 install(FILES ${spv_binary_dir}/libsycl-fallback-cassert.spv
+              ${spv_binary_dir}/libsycl-fallback-cstring.spv
               ${spv_binary_dir}/libsycl-fallback-complex.spv
               ${spv_binary_dir}/libsycl-fallback-complex-fp64.spv
               ${spv_binary_dir}/libsycl-fallback-cmath.spv

libdevice/crt_wrapper.cpp

@@ -9,6 +9,10 @@
 #include "wrapper.h"
 
 #ifdef __SPIR__
+DEVICE_EXTERN_C
+void *memcpy(void *dest, const void *src, size_t n) {
+  return __devicelib_memcpy(dest, src, n);
+}
 #if defined(_WIN32)
 // Truncates a wide (16 or 32 bit) string (wstr) into an ASCII string (str).
 // Any non-ASCII characters are replaced by question mark '?'.

libdevice/fallback-cstring.cpp

@@ -0,0 +1,15 @@
+//==-- fallback-cstring.cpp - fallback implementation of C string functions--=//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "wrapper.h"
+
+#ifdef __SPIR__
+void *__devicelib_memcpy(void *dest, const void *src, size_t n) {
+  return __builtin_memcpy(dest, src, n);
+}
+#endif // __SPIR__

libdevice/wrapper.h

@@ -18,7 +18,8 @@
 // We need the following header to ensure the definition of all spirv variables
 // required by the wrapper libraries.
 #include "spirv_vars.h"
-
+DEVICE_EXTERN_C
+void *__devicelib_memcpy(void *dest, const void *src, size_t n);
 DEVICE_EXTERN_C
 void __devicelib_assert_fail(const char *expr, const char *file, int32_t line,
                              const char *func, uint64_t gid0, uint64_t gid1,

llvm/tools/sycl-post-link/SYCLDeviceLibReqMask.cpp

@@ -158,6 +158,7 @@ SYCLDeviceLibFuncMap SDLMap = {
     {"__devicelib_csqrt", DeviceLibExt::cl_intel_devicelib_complex_fp64},
     {"__devicelib_ctan", DeviceLibExt::cl_intel_devicelib_complex_fp64},
     {"__devicelib_ctanh", DeviceLibExt::cl_intel_devicelib_complex_fp64},
+    {"__devicelib_memcpy", DeviceLibExt::cl_intel_devicelib_cstring},
 };
 
 // Each fallback device library corresponds to one bit in "require mask" which
@@ -169,6 +170,7 @@ SYCLDeviceLibFuncMap SDLMap = {
 // fallback-cmath-fp64:   0x4
 // fallback-complex:      0x8
 // fallback-complex-fp64: 0x10
+// fallback-cstring:      0x20
 uint32_t getDeviceLibBits(const std::string &FuncName) {
   auto DeviceLibFuncIter = SDLMap.find(FuncName);
   return ((DeviceLibFuncIter == SDLMap.end())

llvm/tools/sycl-post-link/SYCLDeviceLibReqMask.h

@@ -28,7 +28,8 @@ enum class DeviceLibExt : std::uint32_t {
   cl_intel_devicelib_math,
   cl_intel_devicelib_math_fp64,
   cl_intel_devicelib_complex,
-  cl_intel_devicelib_complex_fp64
+  cl_intel_devicelib_complex_fp64,
+  cl_intel_devicelib_cstring,
 };
 
 using SYCLDeviceLibFuncMap = std::unordered_map<std::string, DeviceLibExt>;

sycl/include/CL/sycl/builtins.hpp

@@ -1630,6 +1630,8 @@ extern SYCL_EXTERNAL double atanh(double x);
 extern SYCL_EXTERNAL double frexp(double x, int *exp);
 extern SYCL_EXTERNAL double ldexp(double x, int exp);
 extern SYCL_EXTERNAL double hypot(double x, double y);
+
+extern SYCL_EXTERNAL void *memcpy(void *dest, const void *src, size_t n);
 }
 #ifdef __GLIBC__
 extern "C" {

sycl/source/detail/program_manager/program_manager.cpp

@@ -633,6 +633,8 @@ static const char *getDeviceLibFilename(DeviceLibExt Extension) {
     return "libsycl-fallback-complex.spv";
   case DeviceLibExt::cl_intel_devicelib_complex_fp64:
     return "libsycl-fallback-complex-fp64.spv";
+  case DeviceLibExt::cl_intel_devicelib_cstring:
+    return "libsycl-fallback-cstring.spv";
   }
   throw compile_program_error("Unhandled (new?) device library extension",
                               PI_INVALID_OPERATION);
@@ -650,6 +652,8 @@ static const char *getDeviceLibExtensionStr(DeviceLibExt Extension) {
     return "cl_intel_devicelib_complex";
   case DeviceLibExt::cl_intel_devicelib_complex_fp64:
     return "cl_intel_devicelib_complex_fp64";
+  case DeviceLibExt::cl_intel_devicelib_cstring:
+    return "cl_intel_devicelib_cstring";
   }
   throw compile_program_error("Unhandled (new?) device library extension",
                               PI_INVALID_OPERATION);
@@ -815,7 +819,8 @@ static std::vector<RT::PiProgram> getDeviceLibPrograms(
       {DeviceLibExt::cl_intel_devicelib_math, false},
       {DeviceLibExt::cl_intel_devicelib_math_fp64, false},
       {DeviceLibExt::cl_intel_devicelib_complex, false},
-      {DeviceLibExt::cl_intel_devicelib_complex_fp64, false}};
+      {DeviceLibExt::cl_intel_devicelib_complex_fp64, false},
+      {DeviceLibExt::cl_intel_devicelib_cstring, false}};
 
   // Disable all devicelib extensions requiring fp64 support if at least
   // one underlying device doesn't support cl_khr_fp64.

sycl/source/detail/program_manager/program_manager.hpp

@@ -53,7 +53,8 @@ enum class DeviceLibExt : std::uint32_t {
   cl_intel_devicelib_math,
   cl_intel_devicelib_math_fp64,
   cl_intel_devicelib_complex,
-  cl_intel_devicelib_complex_fp64
+  cl_intel_devicelib_complex_fp64,
+  cl_intel_devicelib_cstring
 };
 
 // Provides single loading and building OpenCL programs with unique contexts