pub unsafe fn dtgexc(
wantq: &[i32],
wantz: &[i32],
n: i32,
a: &mut [f64],
lda: i32,
b: &mut [f64],
ldb: i32,
q: &mut [f64],
ldq: i32,
z: &mut [f64],
ldz: i32,
ifst: &mut [i32],
ilst: &mut [i32],
work: &mut [f64],
lwork: i32,
info: &mut i32,
)