src/rp2_common/pico_float/CMakeLists.txt

 if (NOT TARGET pico_float)
    # library to be depended on - we make this depend on particular implementations using per target generator expressions
    pico_add_library(pico_float)

    # no custom implementation; falls thru to compiler
    pico_add_library(pico_float_compiler)

    target_include_directories(pico_float_headers SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)


    # add alias "default" which is just pico.
    add_library(pico_float_default INTERFACE)
    if (PICO_RISCV)
        target_link_libraries(pico_float_default INTERFACE pico_float_compiler)
    else()
        target_link_libraries(pico_float_default INTERFACE pico_float_pico)
    endif()

    set(PICO_DEFAULT_FLOAT_IMPL pico_float_default)

    target_link_libraries(pico_float INTERFACE
            $<IF:$<BOOL:$<TARGET_PROPERTY:PICO_TARGET_FLOAT_IMPL>>,$<TARGET_PROPERTY:PICO_TARGET_FLOAT_IMPL>,${PICO_DEFAULT_FLOAT_IMPL}>)

    function(wrap_float_functions TARGET)
        cmake_parse_arguments(WRAP_FLOAT "NO_WRAP_AEABI;NO_WRAP_SCI" "" "" ${ARGN} )
        if (NOT WRAP_FLOAT_NO_WRAP_AEABI)
            pico_wrap_function(${TARGET} __aeabi_fadd)
            pico_wrap_function(${TARGET} __aeabi_fdiv)
            pico_wrap_function(${TARGET} __aeabi_fmul)
            pico_wrap_function(${TARGET} __aeabi_frsub)
            pico_wrap_function(${TARGET} __aeabi_fsub)
            pico_wrap_function(${TARGET} __aeabi_cfcmpeq)
            pico_wrap_function(${TARGET} __aeabi_cfrcmple)
            pico_wrap_function(${TARGET} __aeabi_cfcmple)
            pico_wrap_function(${TARGET} __aeabi_fcmpeq)
            pico_wrap_function(${TARGET} __aeabi_fcmplt)
            pico_wrap_function(${TARGET} __aeabi_fcmple)
            pico_wrap_function(${TARGET} __aeabi_fcmpge)
            pico_wrap_function(${TARGET} __aeabi_fcmpgt)
            pico_wrap_function(${TARGET} __aeabi_fcmpun)
            pico_wrap_function(${TARGET} __aeabi_i2f)
            pico_wrap_function(${TARGET} __aeabi_l2f)
            pico_wrap_function(${TARGET} __aeabi_ui2f)
            pico_wrap_function(${TARGET} __aeabi_ul2f)
            pico_wrap_function(${TARGET} __aeabi_f2iz)
            pico_wrap_function(${TARGET} __aeabi_f2lz)
            pico_wrap_function(${TARGET} __aeabi_f2uiz)
            pico_wrap_function(${TARGET} __aeabi_f2ulz)
            pico_wrap_function(${TARGET} __aeabi_f2d)
            pico_wrap_function(${TARGET} sqrtf)
        endif()
        if (NOT WRAP_FLOAT_NO_WRAP_SCI)
            pico_wrap_function(${TARGET} cosf)
            pico_wrap_function(${TARGET} sinf)
            pico_wrap_function(${TARGET} tanf)
            pico_wrap_function(${TARGET} atan2f)
            pico_wrap_function(${TARGET} expf)
            pico_wrap_function(${TARGET} logf)

            pico_wrap_function(${TARGET} ldexpf)
            pico_wrap_function(${TARGET} copysignf)
            pico_wrap_function(${TARGET} truncf)
            pico_wrap_function(${TARGET} floorf)
            pico_wrap_function(${TARGET} ceilf)
            pico_wrap_function(${TARGET} roundf)
            pico_wrap_function(${TARGET} sincosf) # gnu
            pico_wrap_function(${TARGET} asinf)
            pico_wrap_function(${TARGET} acosf)
            pico_wrap_function(${TARGET} atanf)
            pico_wrap_function(${TARGET} sinhf)
            pico_wrap_function(${TARGET} coshf)
            pico_wrap_function(${TARGET} tanhf)
            pico_wrap_function(${TARGET} asinhf)
            pico_wrap_function(${TARGET} acoshf)
            pico_wrap_function(${TARGET} atanhf)
            pico_wrap_function(${TARGET} exp2f)
            pico_wrap_function(${TARGET} log2f)
            pico_wrap_function(${TARGET} exp10f)
            pico_wrap_function(${TARGET} log10f)
            pico_wrap_function(${TARGET} powf)
            pico_wrap_function(${TARGET} powintf) #gnu
            pico_wrap_function(${TARGET} hypotf)
            pico_wrap_function(${TARGET} cbrtf)
            pico_wrap_function(${TARGET} fmodf)
            pico_wrap_function(${TARGET} dremf)
            pico_wrap_function(${TARGET} remainderf)
            pico_wrap_function(${TARGET} remquof)
            pico_wrap_function(${TARGET} expm1f)
            pico_wrap_function(${TARGET} log1pf)
            pico_wrap_function(${TARGET} fmaf)
        endif()
    endfunction()

    pico_add_library(pico_float_none)
    target_sources(pico_float_none INTERFACE
            ${CMAKE_CURRENT_LIST_DIR}/float_none.S
    )

    target_link_libraries(pico_float_none INTERFACE pico_float_headers)
    wrap_float_functions(pico_float_none)

    pico_add_library(pico_float_pico)
    if (PICO_RP2040)
        target_sources(pico_float_pico INTERFACE
                ${CMAKE_CURRENT_LIST_DIR}/float_aeabi_rp2040.S
                ${CMAKE_CURRENT_LIST_DIR}/float_init_rom_rp2040.c
                ${CMAKE_CURRENT_LIST_DIR}/float_math.c
                ${CMAKE_CURRENT_LIST_DIR}/float_v1_rom_shim_rp2040.S
        )
        wrap_float_functions(pico_float_pico)
        target_link_libraries(pico_float_pico INTERFACE pico_bootrom pico_float_headers hardware_divider)
    elseif(NOT PICO_RISCV)
        pico_add_library(pico_float_pico_dcp)
        target_sources(pico_float_pico_dcp INTERFACE
                ${CMAKE_CURRENT_LIST_DIR}/float_math.c
                ${CMAKE_CURRENT_LIST_DIR}/float_aeabi_dcp.S
                ${CMAKE_CURRENT_LIST_DIR}/float_sci_m33.S
                ${CMAKE_CURRENT_LIST_DIR}/float_conv_m33.S
                )

        wrap_float_functions(pico_float_pico_dcp NO_WRAP_AEABI)
        pico_add_library(pico_float_pico_vfp)
        target_sources(pico_float_pico_vfp INTERFACE
                ${CMAKE_CURRENT_LIST_DIR}/float_math.c
                ${CMAKE_CURRENT_LIST_DIR}/float_sci_m33_vfp.S
                ${CMAKE_CURRENT_LIST_DIR}/float_conv_m33.S
        )
        wrap_float_functions(pico_float_pico_vfp NO_WRAP_AEABI)
        target_link_libraries(pico_float_pico INTERFACE
                pico_float_pico_vfp)
    endif()


    macro(pico_set_float_implementation TARGET IMPL)
        get_target_property(target_type ${TARGET} TYPE)
        if ("EXECUTABLE" STREQUAL "${target_type}")
            set_target_properties(${TARGET} PROPERTIES PICO_TARGET_FLOAT_IMPL "pico_float_${IMPL}")
        else()
            message(FATAL_ERROR "float implementation must be set on executable not library")
        endif()
    endmacro()
endif()