Fixup svd pullback

Author: Katharine Hyatt

src/pullbacks/svd.jl

@@ -89,18 +89,18 @@ function svd_pullback!(
         length(indS) == pS || throw(DimensionMismatch("length of selected S diagonals ($(length(indS))) does not match length of ΔS diagonal ($(length(ΔS)))"))
         view(diagview(UdΔAV), indS) .+= real.(ΔS)
     end
-    ΔA .+= Ur * UdΔAV * Vᴴr # add the contribution to ΔA
+    ΔA = mul!(ΔA, Ur, UdΔAV * Vᴴr, 1, 1) # add the contribution to ΔA
 
     # Add the remaining contributions
     if m > r && !iszerotangent(ΔU) # remaining ΔU is already orthogonal to Ur
         Sp = view(S, indU)
         Vᴴp = view(Vᴴ, indU, :)
-        ΔA .+= (ΔU ./ Sp') * Vᴴp
+        ΔA = mul!(ΔA, ΔU ./ Sp', Vᴴp, 1, 1)
     end
     if n > r && !iszerotangent(ΔVᴴ) # remaining ΔV is already orthogonal to Vᴴr
         Sp = view(S, indV)
         Up = view(U, :, indV)
-        ΔA .+= Up * (Sp .\ ΔVᴴ)
+        ΔA = mul!(ΔA, Up, Sp .\ ΔVᴴ, 1, 1)
     end
     return ΔA
 end
@@ -174,7 +174,7 @@ function svd_trunc_pullback!(
     aVΔV = project_antihermitian!(VΔV)
 
     # check whether cotangents arise from gauge-invariance objective function
-    check_svd_cotangents(aUΔU, Sr, aVΔV; degeneracy_atol, gauge_atol)
+    check_svd_cotangents(aUΔU, S, aVΔV; degeneracy_atol, gauge_atol)
 
     UdΔAV = (aUΔU .+ aVΔV) .* inv_safe.(S' .- S, degeneracy_atol) .+
         (aUΔU .- aVΔV) .* inv_safe.(S' .+ S, degeneracy_atol)