[libclc] Pass -fapprox-func when compiling 'native' builtins (#133119)

The libclc build system isn't well set up to pass arbitrary options to
arbitrary source files in a non-intrusive way. There isn't currently any
other motivating example to warrant rewriting the build system just to
satisfy this requirement. So this commit uses a filename-based approach
to inserting this option into the list of compile flags.

Author: frasercrmck

libclc/CMakeLists.txt

@@ -262,6 +262,28 @@ if ( clspv-- IN_LIST LIBCLC_TARGETS_TO_BUILD OR clspv64-- IN_LIST LIBCLC_TARGETS
   set_target_properties( generate-clspv-convert.cl PROPERTIES FOLDER "libclc/Sourcegenning" )
 endif()
 
+set_source_files_properties(
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_cos.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_divide.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_exp.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_exp10.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_exp2.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_log.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_log10.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_log2.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_powr.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_recip.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_rsqrt.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_sin.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_sqrt.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/generic/lib/math/native_tan.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/amdgpu/lib/math/native_exp.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/amdgpu/lib/math/native_log.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/amdgpu/lib/math/native_log10.cl
+  ${CMAKE_CURRENT_SOURCE_DIR}/r600/lib/math/native_rsqrt.cl
+  PROPERTIES COMPILE_OPTIONS -fapprox-func
+)
+
 enable_testing()
 
 foreach( t ${LIBCLC_TARGETS_TO_BUILD} )

libclc/cmake/modules/AddLibclc.cmake

@@ -261,11 +261,17 @@ function(add_libclc_builtin_set)
 
     get_filename_component( file_dir ${file} DIRECTORY )
 
+    set( file_specific_compile_options )
+    get_source_file_property( compile_opts ${file} COMPILE_OPTIONS)
+    if( compile_opts )
+      set( file_specific_compile_options "${compile_opts}" )
+    endif()
+
     compile_to_bc(
       TRIPLE ${ARG_TRIPLE}
       INPUT ${input_file}
       OUTPUT ${output_file}
-      EXTRA_OPTS -fno-builtin -nostdlib
+      EXTRA_OPTS -fno-builtin -nostdlib "${file_specific_compile_options}"
         "${ARG_COMPILE_FLAGS}" -I${CMAKE_CURRENT_SOURCE_DIR}/${file_dir}
       DEPENDENCIES ${input_file_dep}
     )