From a8cc0ce887fe236f2c44866f12ffe8be5a98d38b Mon Sep 17 00:00:00 2001
From: Toshiki Teramura <toshiki.teramura@gmail.com>
Date: Thu, 29 Sep 2022 20:54:44 +0900
Subject: [PATCH] WIP: InvWork

---
 lax/src/solve.rs | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/lax/src/solve.rs b/lax/src/solve.rs
index d0f764fd..2f251fb2 100644
--- a/lax/src/solve.rs
+++ b/lax/src/solve.rs
@@ -64,6 +64,50 @@ pub trait Solve_: Scalar + Sized {
     fn solve(l: MatrixLayout, t: Transpose, a: &[Self], p: &Pivot, b: &mut [Self]) -> Result<()>;
 }
 
+pub struct InvWork<T: Scalar> {
+    pub work: Vec<MaybeUninit<T>>,
+}
+
+pub trait InvWorkImpl: Sized {
+    type Elem: Scalar;
+    fn new(layout: MatrixLayout) -> Result<Self>;
+    fn calc(&mut self, a: &mut [Self::Elem], p: &Pivot) -> Result<()>;
+}
+
+macro_rules! impl_inv_work {
+    ($s:ty, $tri:path) => {
+        impl InvWorkImpl for InvWork<c64> {
+            type Elem = c64;
+            fn new(layout: MatrixLayout) -> Result<Self> {
+                let (n, _) = layout.size();
+                let mut info = 0;
+                let mut work_size = [Self::Elem::zero()];
+                unsafe {
+                    $tri(
+                        &n,
+                        std::ptr::null_mut(),
+                        &layout.lda(),
+                        std::ptr::null(),
+                        AsPtr::as_mut_ptr(&mut work_size),
+                        &(-1),
+                        &mut info,
+                    )
+                };
+                info.as_lapack_result()?;
+                let lwork = work_size[0].to_usize().unwrap();
+                let work = vec_uninit(lwork);
+                Ok(InvWork { work })
+            }
+
+            fn calc(&mut self, a: &mut [Self::Elem], p: &Pivot) -> Result<()> {
+                todo!()
+            }
+        }
+    };
+}
+
+impl_inv_work!(c64, lapack_sys::zgetri_);
+
 macro_rules! impl_solve {
     ($scalar:ty, $getrf:path, $getri:path, $getrs:path) => {
         impl Solve_ for $scalar {