check_c_source_compiles("
    #include <stdio.h>
    int main(void) {
      double a = 0.0;
      __builtin_assume(a >= 0.0);
      a = a + 1.0;
      printf(\"a=%g\", a);
      return 0;
    }
  " SUNDIALS_C_COMPILER_HAS_BUILTIN_ASSUME)