From 25e53b59ef1cc60ff2b8a5bf5a3403389b9105ac Mon Sep 17 00:00:00 2001
From: Lukas Devos <ldevos98@gmail.com>
Date: Fri, 16 Jan 2026 12:38:30 +0100
Subject: [PATCH 1/3] naively specialize diagonal pullback

---
 src/pullbacks/eigh.jl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/pullbacks/eigh.jl b/src/pullbacks/eigh.jl
index 195539cf..11171685 100644
--- a/src/pullbacks/eigh.jl
+++ b/src/pullbacks/eigh.jl
@@ -68,6 +68,16 @@ function eigh_pullback!(
     end
     return ΔA
 end
+function eigh_pullback!(
+        ΔA::Diagonal, A, DV, ΔDV, ind = Colon();
+        degeneracy_atol::Real = default_pullback_rank_atol(DV[1]),
+        gauge_atol::Real = default_pullback_gauge_atol(ΔDV[2])
+    )
+    ΔA_full = zero!(similar(ΔA, size(ΔA)))
+    ΔA_full = eigh_pullback!(ΔA_full, A, DV, ΔDV, ind; degeneracy_atol, gauge_atol)
+    diagview(ΔA) .+= diagview(ΔA_full)
+    return ΔA
+end
 
 """
     eigh_trunc_pullback!(
@@ -141,6 +151,16 @@ function eigh_trunc_pullback!(
     end
     return ΔA
 end
+function eigh_trunc_pullback!(
+        ΔA::Diagonal, A, DV, ΔDV;
+        degeneracy_atol::Real = default_pullback_rank_atol(DV[1]),
+        gauge_atol::Real = default_pullback_gauge_atol(ΔDV[2])
+    )
+    ΔA_full = zero!(similar(ΔA, size(ΔA)))
+    ΔA_full = eigh_trunc_pullback!(ΔA_full, A, DV, ΔDV; degeneracy_atol, gauge_atol)
+    diagview(ΔA) .+= diagview(ΔA_full)
+    return ΔA
+end
 
 """
     eigh_vals_pullback!(

From 519675524eb9d3d786a68205ecf6efb6e1baf876 Mon Sep 17 00:00:00 2001
From: Lukas Devos <ldevos98@gmail.com>
Date: Fri, 16 Jan 2026 14:01:43 +0100
Subject: [PATCH 2/3] add eig diagonal pullback

---
 src/pullbacks/eig.jl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/pullbacks/eig.jl b/src/pullbacks/eig.jl
index 4a203f64..6b89b64f 100644
--- a/src/pullbacks/eig.jl
+++ b/src/pullbacks/eig.jl
@@ -78,6 +78,16 @@ function eig_pullback!(
     end
     return ΔA
 end
+function eig_pullback!(
+        ΔA::Diagonal, A, DV, ΔDV, ind = Colon();
+        degeneracy_atol::Real = default_pullback_rank_atol(DV[1]),
+        gauge_atol::Real = default_pullback_gauge_atol(ΔDV[2])
+    )
+    ΔA_full = zero!(similar(ΔA, size(ΔA)))
+    ΔA_full = eig_pullback!(ΔA_full, A, DV, ΔDV, ind; degeneracy_atol, gauge_atol)
+    diagview(ΔA) .+= diagview(ΔA_full)
+    return ΔA
+end
 
 """
     eig_trunc_pullback!(
@@ -151,6 +161,16 @@ function eig_trunc_pullback!(
     end
     return ΔA
 end
+function eig_trunc_pullback!(
+        ΔA::Diagonal, A, DV, ΔDV;
+        degeneracy_atol::Real = default_pullback_rank_atol(DV[1]),
+        gauge_atol::Real = default_pullback_gauge_atol(ΔDV[2])
+    )
+    ΔA_full = zero!(similar(ΔA, size(ΔA)))
+    ΔA_full = eig_trunc_pullback!(ΔA_full, A, DV, ΔDV; degeneracy_atol, gauge_atol)
+    diagview(ΔA) .+= diagview(ΔA_full)
+    return ΔA
+end
 
 """
     eig_vals_pullback!(

From 48fe1a9f17abb87263c1614eb45e5b219ed1a5b8 Mon Sep 17 00:00:00 2001
From: Lukas Devos <ldevos98@gmail.com>
Date: Sun, 18 Jan 2026 07:44:01 -0500
Subject: [PATCH 3/3] add svd diagonal pullback

---
 src/pullbacks/svd.jl | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/pullbacks/svd.jl b/src/pullbacks/svd.jl
index a8f8b70c..1608343e 100644
--- a/src/pullbacks/svd.jl
+++ b/src/pullbacks/svd.jl
@@ -99,6 +99,17 @@ function svd_pullback!(
     end
     return ΔA
 end
+function svd_pullback!(
+        ΔA::Diagonal, A, USVᴴ, ΔUSVᴴ, ind = Colon();
+        rank_atol::Real = default_pullback_rank_atol(USVᴴ[2]),
+        degeneracy_atol::Real = default_pullback_rank_atol(USVᴴ[2]),
+        gauge_atol::Real = default_pullback_gauge_atol(ΔUSVᴴ[1], ΔUSVᴴ[3])
+    )
+    ΔA_full = zero!(similar(ΔA, size(ΔA)))
+    ΔA_full = svd_pullback!(ΔA_full, A, USVᴴ, ΔUSVᴴ, ind; rank_atol, degeneracy_atol, gauge_atol)
+    diagview(ΔA) .+= diagview(ΔA_full)
+    return ΔA
+end
 
 """
     svd_trunc_pullback!(
@@ -201,6 +212,17 @@ function svd_trunc_pullback!(
     ΔA = mul!(ΔA, U, Y' * Ṽᴴ, 1, 1)
     return ΔA
 end
+function svd_trunc_pullback!(
+        ΔA::Diagonal, A, USVᴴ, ΔUSVᴴ;
+        rank_atol::Real = 0,
+        degeneracy_atol::Real = default_pullback_rank_atol(USVᴴ[2]),
+        gauge_atol::Real = default_pullback_gauge_atol(ΔUSVᴴ[1], ΔUSVᴴ[3])
+    )
+    ΔA_full = zero!(similar(ΔA, size(ΔA)))
+    ΔA_full = svd_trunc_pullback!(ΔA_full, A, USVᴴ, ΔUSVᴴ; rank_atol, degeneracy_atol, gauge_atol)
+    diagview(ΔA) .+= diagview(ΔA_full)
+    return ΔA
+end
 
 """
     svd_vals_pullback!(