jhuber6 created this revision.
jhuber6 added reviewers: jdoerfert, tianshilei1992, sivachandra, lntue,
michaelrj, tra, JonChesterfield.
Herald added projects: libc-project, All.
Herald added a subscriber: libc-commits.
jhuber6 requested review of this revision.
Herald added subscribers: cfe-commits, jplehr, sstefan1, MaskRay.
Herald added a project: clang.
This is an alternate approach to the patches proposed in D153897
<https://reviews.llvm.org/D153897> and
D153794 <https://reviews.llvm.org/D153794>. Rather than exporting a single
header that can be included on
the GPU in all circumstances, this patch chooses to instead generate a
separate set of headers that only provides the declarations. This can
then be used by external tooling to set up what's on the GPU. This
leaves room for header hacks for offloading languages without needing to
worry about the `libc` implementation.
Currently this generates a set of headers that only contain the
declarations. These will then be installed to a new clang resource
directory called `llvm_libc_wrappers/` which will house the shim code.
We can then automaticlaly include this from `clang` when offloading to
wrap around the headers while specifying what's on the GPU.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D154036
Files:
clang/lib/Driver/ToolChains/Clang.cpp
clang/lib/Headers/CMakeLists.txt
clang/lib/Headers/llvm_libc_wrappers/ctype.h
clang/lib/Headers/llvm_libc_wrappers/llvm-libc-decls/README.txt
clang/lib/Headers/llvm_libc_wrappers/stdio.h
clang/lib/Headers/llvm_libc_wrappers/stdlib.h
clang/lib/Headers/llvm_libc_wrappers/string.h
clang/test/Driver/gpu-libc-headers.c
libc/cmake/modules/LLVMLibCHeaderRules.cmake
libc/include/CMakeLists.txt
libc/utils/HdrGen/Generator.cpp
libc/utils/HdrGen/Generator.h
libc/utils/HdrGen/Main.cpp
Index: libc/utils/HdrGen/Main.cpp
===================================================================
--- libc/utils/HdrGen/Main.cpp
+++ libc/utils/HdrGen/Main.cpp
@@ -32,6 +32,9 @@
llvm::cl::list<std::string> ReplacementValues(
"args", llvm::cl::desc("Command separated <argument name>=<value> pairs."),
llvm::cl::value_desc("<name=value>[,name=value]"));
+llvm::cl::opt<bool> ExportDecls(
+ "export-decls",
+ llvm::cl::desc("Output a new header containing only the entrypoints."));
void ParseArgValuePairs(std::unordered_map<std::string, std::string> &Map) {
for (std::string &R : ReplacementValues) {
@@ -48,7 +51,10 @@
std::unordered_map<std::string, std::string> ArgMap;
ParseArgValuePairs(ArgMap);
Generator G(HeaderDefFile, EntrypointNamesOption, StandardHeader, ArgMap);
- G.generate(OS, Records);
+ if (ExportDecls)
+ G.generateDecls(OS, Records);
+ else
+ G.generate(OS, Records);
return false;
}
Index: libc/utils/HdrGen/Generator.h
===================================================================
--- libc/utils/HdrGen/Generator.h
+++ libc/utils/HdrGen/Generator.h
@@ -52,6 +52,7 @@
ArgMap(Map) {}
void generate(llvm::raw_ostream &OS, llvm::RecordKeeper &Records);
+ void generateDecls(llvm::raw_ostream &OS, llvm::RecordKeeper &Records);
};
} // namespace llvm_libc
Index: libc/utils/HdrGen/Generator.cpp
===================================================================
--- libc/utils/HdrGen/Generator.cpp
+++ libc/utils/HdrGen/Generator.cpp
@@ -10,6 +10,7 @@
#include "IncludeFileCommand.h"
#include "PublicAPICommand.h"
+#include "utils/LibcTableGenUtil/APIIndexer.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/MemoryBuffer.h"
@@ -116,4 +117,78 @@
}
}
+void Generator::generateDecls(llvm::raw_ostream &OS,
+ llvm::RecordKeeper &Records) {
+
+ OS << "//===-- C standard declarations for " << StdHeader << " "
+ << std::string(80 - (42 + StdHeader.size()), '-') << "===//\n"
+ << "//\n"
+ << "// Part of the LLVM Project, under the Apache License v2.0 with LLVM "
+ "Exceptions.\n"
+ << "// See https://llvm.org/LICENSE.txt for license information.\n"
+ << "// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception\n"
+ << "//\n"
+ << "//"
+ "===-------------------------------------------------------------------"
+ "---===//\n\n";
+
+ std::string HeaderGuard(StdHeader.size(), '\0');
+ llvm::transform(StdHeader, HeaderGuard.begin(), [](const char C) -> char {
+ return !isalnum(C) ? '_' : llvm::toUpper(C);
+ });
+ OS << "#ifndef __LLVM_LIBC_DECLARATIONS_" << HeaderGuard << "\n"
+ << "#define __LLVM_LIBC_DECLARATIONS_" << HeaderGuard << "\n\n";
+
+ OS << "#ifndef __LIBC_ATTRS\n"
+ << "#define __LIBC_ATTRS\n"
+ << "#endif\n\n";
+
+ OS << "#ifdef __cplusplus\n"
+ << "extern \"C\" {\n"
+ << "#endif\n\n";
+
+ APIIndexer G(StdHeader, Records);
+ for (auto &Name : EntrypointNameList) {
+ // Filter out functions not exported by this header.
+ if (G.FunctionSpecMap.find(Name) == G.FunctionSpecMap.end())
+ continue;
+
+ llvm::Record *FunctionSpec = G.FunctionSpecMap[Name];
+ llvm::Record *RetValSpec = FunctionSpec->getValueAsDef("Return");
+ llvm::Record *ReturnType = RetValSpec->getValueAsDef("ReturnType");
+
+ OS << G.getTypeAsString(ReturnType) << " " << Name << "(";
+
+ auto ArgsList = FunctionSpec->getValueAsListOfDefs("Args");
+ for (size_t i = 0; i < ArgsList.size(); ++i) {
+ llvm::Record *ArgType = ArgsList[i]->getValueAsDef("ArgType");
+ OS << G.getTypeAsString(ArgType);
+ if (i < ArgsList.size() - 1)
+ OS << ", ";
+ }
+
+ OS << ") __LIBC_ATTRS;\n\n";
+ }
+
+ // Make another pass over entrypoints to emit object declarations.
+ for (const auto &Name : EntrypointNameList) {
+ if (G.ObjectSpecMap.find(Name) == G.ObjectSpecMap.end())
+ continue;
+ llvm::Record *ObjectSpec = G.ObjectSpecMap[Name];
+ auto Type = ObjectSpec->getValueAsString("Type");
+ OS << "extern " << Type << " " << Name << " __LIBC_ATTRS;\n";
+ }
+
+ // Emit a final newline if we emitted any object declarations.
+ if (llvm::any_of(EntrypointNameList, [&](const std::string &Name) {
+ return G.ObjectSpecMap.find(Name) != G.ObjectSpecMap.end();
+ }))
+ OS << "\n";
+
+ OS << "#ifdef __cplusplus\n"
+ << "}\n"
+ << "#endif\n\n";
+ OS << "#endif\n";
+}
+
} // namespace llvm_libc
Index: libc/include/CMakeLists.txt
===================================================================
--- libc/include/CMakeLists.txt
+++ libc/include/CMakeLists.txt
@@ -3,6 +3,11 @@
include(LLVMLibCHeaderRules)
+# The GPU build wants to install files in the compiler's resource directory.
+if(LIBC_TARGET_ARCHITECTURE_IS_GPU)
+ include(GetClangResourceDir)
+endif()
+
add_subdirectory(llvm-libc-macros)
add_subdirectory(llvm-libc-types)
@@ -539,4 +544,21 @@
install(FILES ${header_file}
DESTINATION ${LIBC_INSTALL_INCLUDE_DIR}/${nested_dir}
COMPONENT libc-headers)
+ # The GPU optionally provides the supported declarations externally so
+ # offloading languages like CUDA and OpenMP know what is supported by libc. We
+ # install these in the compiler's resource directory at a preset location.
+ if(LIBC_TARGET_ARCHITECTURE_IS_GPU)
+ get_target_property(decls_file ${target} DECLS_FILE_PATH)
+ if(NOT decls_file)
+ continue()
+ endif()
+ get_clang_resource_dir(resource_dir SUBDIR include)
+ file(RELATIVE_PATH relative_path ${LIBC_INCLUDE_BINARY_DIR} ${decls_file})
+ get_filename_component(nested_dir ${relative_path} DIRECTORY)
+ set(install_dir
+ ${CMAKE_INSTALL_PREFIX}/${resource_dir}/llvm_libc_wrappers/${nested_dir})
+ install(FILES ${decls_file}
+ DESTINATION ${install_dir}
+ COMPONENT libc-headers)
+ endif()
endforeach()
Index: libc/cmake/modules/LLVMLibCHeaderRules.cmake
===================================================================
--- libc/cmake/modules/LLVMLibCHeaderRules.cmake
+++ libc/cmake/modules/LLVMLibCHeaderRules.cmake
@@ -131,6 +131,23 @@
${hdrgen_deps}
)
+ if(LIBC_TARGET_ARCHITECTURE_IS_GPU)
+ file(MAKE_DIRECTORY ${LIBC_INCLUDE_DIR}/llvm-libc-decls)
+ set(decl_out_file ${LIBC_INCLUDE_DIR}/llvm-libc-decls/${relative_path})
+ add_custom_command(
+ OUTPUT ${decl_out_file}
+ COMMAND ${hdrgen_exe} -o ${decl_out_file}
+ --header ${ADD_GEN_HDR_GEN_HDR} --def ${in_file} --export-decls
+ ${replacement_params} -I ${LIBC_SOURCE_DIR} ${ENTRYPOINT_NAME_LIST_ARG}
+ ${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/api.td
+
+ WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+ DEPENDS ${in_file} ${fq_data_files} ${td_includes}
+ ${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/api.td
+ ${hdrgen_deps}
+ )
+ endif()
+
if(ADD_GEN_HDR_DEPENDS)
get_fq_deps_list(fq_deps_list ${ADD_GEN_HDR_DEPENDS})
# Dependencies of a add_header target can only be another add_gen_header target
@@ -144,13 +161,14 @@
endif()
add_custom_target(
${fq_target_name}
- DEPENDS ${out_file} ${fq_deps_list}
+ DEPENDS ${out_file} ${fq_deps_list} ${decl_out_file}
)
set_target_properties(
${fq_target_name}
PROPERTIES
HEADER_FILE_PATH ${out_file}
+ DECLS_FILE_PATH ${decl_out_file}
DEPS "${fq_deps_list}"
)
endfunction(add_gen_header)
Index: clang/test/Driver/gpu-libc-headers.c
===================================================================
--- clang/test/Driver/gpu-libc-headers.c
+++ clang/test/Driver/gpu-libc-headers.c
@@ -1,6 +1,14 @@
// REQUIRES: nvptx-registered-target
// REQUIRES: amdgpu-registered-target
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fopenmp=libomp --sysroot=./ \
+// RUN: -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa --offload-arch=gfx908 \
+// RUN: -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fopenmp=libomp --sysroot=./ \
+// RUN: -fopenmp-targets=nvptx64-nvidia-cuda -Xopenmp-target=nvptx64-nvidia-cuda --offload-arch=sm_70 \
+// RUN: -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS
+// CHECK-HEADERS: "-cc1"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}llvm_libc_wrappers"{{.*}}"-isysroot" "./"
+
// RUN: %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
// RUN: -nogpuinc %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-DISABLED
// RUN: %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
Index: clang/lib/Headers/llvm_libc_wrappers/string.h
===================================================================
--- /dev/null
+++ clang/lib/Headers/llvm_libc_wrappers/string.h
@@ -0,0 +1,30 @@
+//===-- Wrapper for C standard string.h declarations on the GPU------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __CLANG_LLVM_LIBC_WRAPPERS_STRING_H__
+#define __CLANG_LLVM_LIBC_WRAPPERS_STRING_H__
+
+#include_next <string.h>
+
+#if !defined(_OPENMP) && defined(__HIP__) && defined(__CUDA__)
+#error "This file is for GPU offloading compilation only"
+#endif
+
+#if defined(__HIP__) || defined(__CUDA__)
+#define __LIBC_ATTRS __attribute__((device))
+#endif
+
+#pragma omp begin declare target
+
+#include <llvm-libc-decls/string.h>
+
+#pragma omp end declare target
+
+#undef __LIBC_ATTRS
+
+#endif
Index: clang/lib/Headers/llvm_libc_wrappers/stdlib.h
===================================================================
--- /dev/null
+++ clang/lib/Headers/llvm_libc_wrappers/stdlib.h
@@ -0,0 +1,33 @@
+//===-- Wrapper for C standard stdlib.h declarations on the GPU------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __CLANG_LLVM_LIBC_WRAPPERS_STDLIB_H__
+#define __CLANG_LLVM_LIBC_WRAPPERS_STDLIB_H__
+
+#include_next <stdlib.h>
+
+#if !defined(_OPENMP) && defined(__HIP__) && defined(__CUDA__)
+#error "This file is for GPU offloading compilation only"
+#endif
+
+#if defined(__HIP__) || defined(__CUDA__)
+#define __LIBC_ATTRS __attribute__((device))
+#endif
+
+#pragma omp begin declare target
+
+// The LLVM C library uses this type so we forward declare it.
+typedef void (*__atexithandler_t)(void);
+
+#include <llvm-libc-decls/stdlib.h>
+
+#pragma omp end declare target
+
+#undef __LIBC_ATTRS
+
+#endif
Index: clang/lib/Headers/llvm_libc_wrappers/stdio.h
===================================================================
--- /dev/null
+++ clang/lib/Headers/llvm_libc_wrappers/stdio.h
@@ -0,0 +1,30 @@
+//===-- Wrapper for C standard stdio.h declarations on the GPU ------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __CLANG_LLVM_LIBC_WRAPPERS_STDIO_H__
+#define __CLANG_LLVM_LIBC_WRAPPERS_STDIO_H__
+
+#include_next <stdio.h>
+
+#if !defined(_OPENMP) && defined(__HIP__) && defined(__CUDA__)
+#error "This file is for GPU offloading compilation only"
+#endif
+
+#if defined(__HIP__) || defined(__CUDA__)
+#define __LIBC_ATTRS __attribute__((device))
+#endif
+
+#pragma omp begin declare target
+
+#include <llvm-libc-decls/stdio.h>
+
+#pragma omp end declare target
+
+#undef __LIBC_ATTRS
+
+#endif
Index: clang/lib/Headers/llvm_libc_wrappers/llvm-libc-decls/README.txt
===================================================================
--- /dev/null
+++ clang/lib/Headers/llvm_libc_wrappers/llvm-libc-decls/README.txt
@@ -0,0 +1,6 @@
+LLVM libc declarations
+======================
+
+This directory will be filled by the `libc` project with declarations that are
+availible on the device. Each declaration will use the `__LIBC_ATTRS` attribute
+to control emission on the device side.
Index: clang/lib/Headers/llvm_libc_wrappers/ctype.h
===================================================================
--- /dev/null
+++ clang/lib/Headers/llvm_libc_wrappers/ctype.h
@@ -0,0 +1,30 @@
+//===-- Wrapper for C standard ctype.h declarations on the GPU ------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __CLANG_LLVM_LIBC_WRAPPERS_CTYPE_H__
+#define __CLANG_LLVM_LIBC_WRAPPERS_CTYPE_H__
+
+#include_next <ctype.h>
+
+#if !defined(_OPENMP) && defined(__HIP__) && defined(__CUDA__)
+#error "This file is for GPU offloading compilation only"
+#endif
+
+#if defined(__HIP__) || defined(__CUDA__)
+#define __LIBC_ATTRS __attribute__((device))
+#endif
+
+#pragma omp begin declare target
+
+#include <llvm-libc-decls/ctype.h>
+
+#pragma omp end declare target
+
+#undef __LIBC_ATTRS
+
+#endif
Index: clang/lib/Headers/CMakeLists.txt
===================================================================
--- clang/lib/Headers/CMakeLists.txt
+++ clang/lib/Headers/CMakeLists.txt
@@ -298,6 +298,13 @@
openmp_wrappers/new
)
+set(llvm_libc_wrapper_files
+ llvm_libc_wrappers/stdio.h
+ llvm_libc_wrappers/stdlib.h
+ llvm_libc_wrappers/string.h
+ llvm_libc_wrappers/ctype.h
+)
+
include(GetClangResourceDir)
get_clang_resource_dir(output_dir PREFIX ${LLVM_LIBRARY_OUTPUT_INTDIR}/.. SUBDIR include)
set(out_files)
@@ -333,7 +340,8 @@
# Copy header files from the source directory to the build directory
foreach( f ${files} ${cuda_wrapper_files} ${cuda_wrapper_bits_files}
- ${ppc_wrapper_files} ${openmp_wrapper_files} ${hlsl_files})
+ ${ppc_wrapper_files} ${openmp_wrapper_files} ${hlsl_files}
+ ${llvm_libc_wrapper_files})
copy_header_to_output_dir(${CMAKE_CURRENT_SOURCE_DIR} ${f})
endforeach( f )
@@ -427,6 +435,7 @@
"x86-resource-headers"
"opencl-resource-headers"
"openmp-resource-headers"
+ "llvm-libc-resource-headers"
"windows-resource-headers"
"utility-resource-headers")
@@ -453,6 +462,7 @@
# Other header groupings
add_header_target("hlsl-resource-headers" ${hlsl_files})
add_header_target("opencl-resource-headers" ${opencl_files})
+add_header_target("llvm-libc-resource-headers" ${llvm_libc_wrapper_files})
add_header_target("openmp-resource-headers" ${openmp_wrapper_files})
add_header_target("windows-resource-headers" ${windows_only_files})
add_header_target("utility-resource-headers" ${utility_files})
@@ -481,6 +491,11 @@
DESTINATION ${header_install_dir}/ppc_wrappers
COMPONENT clang-resource-headers)
+install(
+ FILES ${llvm_libc_wrapper_files}
+ DESTINATION ${header_install_dir}/llvm_libc_wrappers
+ COMPONENT clang-resource-headers)
+
install(
FILES ${openmp_wrapper_files}
DESTINATION ${header_install_dir}/openmp_wrappers
@@ -636,6 +651,12 @@
EXCLUDE_FROM_ALL
COMPONENT openmp-resource-headers)
+install(
+ FILES ${openmp_wrapper_files}
+ DESTINATION ${header_install_dir}/openmp_wrappers
+ EXCLUDE_FROM_ALL
+ COMPONENT openmp-resource-headers)
+
install(
FILES ${utility_files}
DESTINATION ${header_install_dir}
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -1181,23 +1181,28 @@
// If we are compiling for a GPU target we want to override the system headers
// with ones created by the 'libc' project if present.
- // FIXME: We need to find a way to make these headers compatible with the
- // host environment so they can be included from offloading languages. For now
- // these are only active when targeting the GPU with cross-compilation.
if (!Args.hasArg(options::OPT_nostdinc) &&
!Args.hasArg(options::OPT_nogpuinc) &&
!Args.hasArg(options::OPT_nobuiltininc) &&
- C.getActiveOffloadKinds() == Action::OFK_None &&
(getToolChain().getTriple().isNVPTX() ||
getToolChain().getTriple().isAMDGCN())) {
- // Add include/gpu-none-libc/* to our system include path. This lets us use
- // GPU-specific system headers first.
+ // Without an offloading language we will include these headers directly.
+ // Offloading languages will instead only use the declarations stored in
+ // the resource directory at clang/lib/Headers/llvm_libc_wrappers.
+ if (C.getActiveOffloadKinds() == Action::OFK_None) {
SmallString<128> P(llvm::sys::path::parent_path(D.InstalledDir));
llvm::sys::path::append(P, "include");
llvm::sys::path::append(P, "gpu-none-llvm");
CmdArgs.push_back("-c-isystem");
CmdArgs.push_back(Args.MakeArgString(P));
+ } else {
+ SmallString<128> P(D.ResourceDir);
+ llvm::sys::path::append(P, "include");
+ llvm::sys::path::append(P, "llvm_libc_wrappers");
+ CmdArgs.push_back("-internal-isystem");
+ CmdArgs.push_back(Args.MakeArgString(P));
+ }
}
// If we are offloading to a target via OpenMP we need to include the
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
