ISPC

Since CMake 3.19, ISPC is straightforward to use :

• make sure to install ISPC and add its executable to path,
• .ispc files can be added as regular sources files to a target, e.g. for tests/ispc/ :

project(TEST_Ispc 
        LANGUAGES
            C CXX
            ISPC    # REQUIRED 
)
add_library(ispc_lib STATIC simple.ispc)

Following properties are overridable:

• ISPC_HEADER_DIRECTORY per target, or CMAKE_ISPC_HEADER_DIRECTORY globally (default CMAKE_CURRENT_BINARY).
• ISPC_HEADER_SUFFIX per target, or CMAKE_ISPC_HEADER_SUFFIX globally (default _ispc.h).
• ISPC_INSTRUCTION_SETS per target, or CMAKE_ISPC_INSTRUCTION_SETS globally (default should be the most capable one if we follow ispc's documentation).

There are nothing else to do for executable targets. However, by default, a library with .ispc files doesn't include ISPC_HEADER_DIRECTORY, so the following is needed:

target_include_directories(ispc_lib PUBLIC $<TARGET_PROPERTY:ISPC_HEADER_DIRECTORY>)

If you want to change a property, use

set_target_property(ispc_lib PROPERTIES ISPC_HEADER_DIRECTORY ...)

TCM provide a single convenience function to set these for a target through function's parameters.

tcm_target_setup_ispc(your_target 
        [ISPC_HEADER_DIRECTORY $<TARGET_PROPERTY:ISPC_HEADER_DIRECTORY>]
        [ISPC_HEADER_SUFFIX "_ispc.h"]
        [ISPC_INSTRUCTION_SETS "most capable one by default"] 
)