function_exists    54 Zend/zend_builtin_functions.c static ZEND_FUNCTION(function_exists);
function_exists   265 Zend/zend_builtin_functions.c 	ZEND_FE(function_exists,	arginfo_function_exists)
function_exists  1359 Zend/zend_builtin_functions.c ZEND_FUNCTION(function_exists)