OpenTTD-patches/cmake/FindBuiltins.cmake
Jonathan G Rennison e05fa5c1c3 CMake: Add builtins
2020-06-28 21:57:02 +01:00

35 lines
803 B
CMake

include(CheckCXXSourceCompiles)
check_cxx_source_compiles("
int main() {
return __builtin_popcountll(__builtin_popcountl(__builtin_popcount(__builtin_ctz(1))));
}"
BITMATH_BUILTINS_FOUND
)
if (BITMATH_BUILTINS_FOUND)
add_compile_options(
-DWITH_BITMATH_BUILTINS
)
endif (BITMATH_BUILTINS_FOUND)
check_cxx_source_compiles("
#include <cstdint>
int main() {
int64_t a = 0;
int64_t b = 0;
int64_t c = 0;
bool res1 = __builtin_add_overflow(a, b, &c);
bool res2 = __builtin_sub_overflow(a, b, &c);
bool res3 = __builtin_mul_overflow(a, b, &c);
return (res1 || res2 || res3) ? 1 : 0;
}"
OVERFLOW_BUILTINS_FOUND
)
if (OVERFLOW_BUILTINS_FOUND)
add_compile_options(
-DWITH_OVERFLOW_BUILTINS
)
endif (OVERFLOW_BUILTINS_FOUND)