[libclc] [libclc] Use custom CMake handling to overhaul libclc compilation (PR #185247)

[Wenju He via cfe-commits]

================
@@ -285,155 +262,147 @@ foreach( t ${LIBCLC_TARGETS_TO_BUILD} )
     set( OS nvidiacl )
   endif()
 
-  # Append a variety of target- and triple-based directories to search,
-  # increasing in specificity.
-  list( APPEND opencl_dirs ${DARCH} ${DARCH}-${OS} ${DARCH}-${VENDOR}-${OS} )
-
-  # The 'generic' directory contains all of the generic implementations of the
-  # builtins. It is included first so it has the lowest search priority,
-  # allowing targets to override builtins based on file names found later in
-  # the list of search directories.
-  # CLC builds all builtins for all targets, so unconditionally prepend the
-  # 'generic' directory.
-  set( clc_dirs generic ${opencl_dirs} )
-  # Some OpenCL targets don't build all builtins, in which case they don't want
-  # the 'generic' directory. Otherwise, prepend the 'generic' directory.
-  if ( NOT ARCH STREQUAL spirv AND NOT ARCH STREQUAL spirv64 AND
-       NOT ARCH STREQUAL clspv AND NOT ARCH STREQUAL clspv64)
-    list( PREPEND opencl_dirs generic )
+  # Collect CLC sources, target specific sources will override the generic ones
+  # if present in the list.
+  set(_clc_overrides)
+  if(ARCH STREQUAL amdgcn)
+    list(APPEND _clc_overrides ${CLC_AMDGPU_SOURCES} ${CLC_AMDGCN_SOURCES})
+  elseif(DARCH STREQUAL ptx AND OS STREQUAL nvidiacl)
+    list(APPEND _clc_overrides ${CLC_PTX_NVIDIACL_SOURCES})
+  elseif(DARCH STREQUAL spirv)
+    list(APPEND _clc_overrides ${CLC_SPIRV_SOURCES})
+  elseif(DARCH STREQUAL clspv)
+    list(APPEND _clc_overrides ${CLC_CLSPV_SOURCES})
+  endif()
+  libclc_merge_sources(clc_sources ${CLC_GENERIC_SOURCES} ${_clc_overrides})
+
+  # Collect OpenCL sources. SPIR-V and Clspv targets use self-contained
+  # subsets while others merge with target-specific overrides.
+  if(ARCH STREQUAL spirv OR ARCH STREQUAL spirv64)
+    set(opencl_sources ${OPENCL_SPIRV_SOURCES})
+  elseif(ARCH STREQUAL clspv OR ARCH STREQUAL clspv64)
+    set(opencl_sources ${OPENCL_CLSPV_SOURCES})
+  else()
+    set(_opencl_overrides)
+    if(ARCH STREQUAL amdgcn)
+      list(APPEND _opencl_overrides ${OPENCL_AMDGCN_SOURCES})
+    elseif(DARCH STREQUAL ptx AND OS STREQUAL nvidiacl)
+      list(APPEND _opencl_overrides ${OPENCL_PTX_NVIDIACL_SOURCES})
+    endif()
+    libclc_merge_sources(opencl_sources
+      ${OPENCL_GENERIC_SOURCES} ${_opencl_overrides})
   endif()
 
-  set( clc_lib_files )
-
-  libclc_configure_lib_source(
-    clc_lib_files
-    LIB_ROOT_DIR clc
-    DIRS ${clc_dirs}
+  # Common compile options shared by CLC and OpenCL libraries.
+  set(compile_flags
+    -flto
+    --target=${clang_triple}
+    -nostdlib
+    -nostdlibinc
+    -cl-no-stdinc
+    -cl-std=CL3.0
+    -include opencl-c-base.h
+    -Werror=undef
+    -Wall
+    -Wextra
+    -fdiscard-value-names
+    -ffp-contract=fast-honor-pragmas
+    -fdenormal-fp-math=dynamic
+    ${target_compile_flags}
   )
 
-  set( opencl_lib_files )
+  set(_common_defs
+    ${target_define}
+    ${target_extra_defines}
+    __CLC_PRIVATE_ADDRSPACE_VAL=${private_addrspace_val}
+    __CLC_GENERIC_ADDRSPACE_VAL=${generic_addrspace_val}
+  )
 
-  libclc_configure_lib_source(
-    opencl_lib_files
-    LIB_ROOT_DIR opencl
-    DIRS ${opencl_dirs}
+  # Build the CLC internal builtins library.
+  string(REPLACE "-" "_" lib_suffix ${t})
+  set(clc_lib clc_builtins_${lib_suffix})
+  add_libclc_builtin_library(${clc_lib}
+    SOURCES ${clc_sources}
+    COMPILE_OPTIONS ${compile_flags}
+    INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/clc/include
+    COMPILE_DEFINITIONS ${_common_defs}
+    FOLDER "libclc/Device IR/CLC"
   )
 
-  foreach( d ${${t}_devices} )
-    get_libclc_device_info(
-      TRIPLE ${t}
-      DEVICE ${d}
-      CPU cpu
-      ARCH_SUFFIX arch_suffix
-      CLANG_TRIPLE clang_triple
-    )
+  # Build the OpenCL builtins library.
+  set(opencl_lib opencl_builtins_${lib_suffix})
+  add_libclc_builtin_library(${opencl_lib}
+    SOURCES ${opencl_sources}
+    COMPILE_OPTIONS ${compile_flags} "SHELL:-Xclang -fdeclare-opencl-builtins"
+    INCLUDE_DIRS
+      ${CMAKE_CURRENT_SOURCE_DIR}/clc/include
+      ${CMAKE_CURRENT_SOURCE_DIR}/opencl/include
+    COMPILE_DEFINITIONS ${_common_defs}
+    FOLDER "libclc/Device IR/OpenCL"
+  )
 
-    message( STATUS "  device: ${d} ( ${${d}_aliases} )" )
-
-    set( MACRO_ARCH ${ARCH} )
-    if ( ARCH STREQUAL spirv OR ARCH STREQUAL spirv64 )
-      set( build_flags -O0 -finline-hint-functions -DCLC_SPIRV )
-      set( opt_flags )
-      set( spvflags --spirv-max-version=1.1 )
-      set( MACRO_ARCH SPIRV32 )
-      if( ARCH STREQUAL spirv64 )
-        set( MACRO_ARCH SPIRV64 )
-      endif()
-    elseif( ARCH STREQUAL clspv OR ARCH STREQUAL clspv64 )
-      set( build_flags "-Wno-unknown-assumption" -DCLC_CLSPV )
-      set( opt_flags -O3 )
-      set( MACRO_ARCH CLSPV32 )
-      if( ARCH STREQUAL clspv64 )
-        set( MACRO_ARCH CLSPV64 )
-      endif()
-    elseif( ARCH STREQUAL amdgcn )
-      set( build_flags "-Xclang" "-mcode-object-version=none" )
-      set( opt_flags -O3 )
-    else()
-      set( build_flags )
-      set( opt_flags -O3 )
-    endif()
+  # Link the final library.
----------------
wenju-he wrote:

> So this isn't really related to the compilation of either library, it's just the final combining step that requires both of them.

Yes, but our downstream have multiple combined libraries and all of them links to the same CLC library. Putting the combination code into a cmake function will simplifies the creation of multiple combined libraries. Otherwise, the combination step will need to duplicated multiple times in the main CMakeLists.txt file.

https://github.com/llvm/llvm-project/pull/185247