Try to pretty up JET changes a little

Author: Katharine Hyatt

src/implementations/polar.jl

@@ -117,13 +117,14 @@ end
 function _left_polarnewton!(A::AbstractMatrix, W, P = similar(A, (0, 0)); tol = defaulttol(A), maxiter = 10)
     m, n = size(A) # we must have m >= n
     Rᴴinv = isempty(P) ? similar(P, (n, n)) : P # use P as workspace when available
-    Q = similar(A, (0, 0))
-    if m > n # initial QR
+    istall = m > n
+    if istall # initial QR
         Q, R = qr_compact!(A)
         Rc = view(A, 1:n, 1:n)
         Rc .= R
         Rᴴinv = ldiv!(UpperTriangular(Rc)', one!(Rᴴinv))
     else # m == n
+        Q = similar(A, (0, 0)) # needed for JET
         R = A
         Rc = view(W, 1:n, 1:n)
         Rc .= R
@@ -149,7 +150,7 @@ function _left_polarnewton!(A::AbstractMatrix, W, P = similar(A, (0, 0)); tol =
     if conv > tol
         @warn "`left_polar!` via Newton iteration did not converge within $maxiter iterations (final residual: $conv)"
     end
-    if m > n
+    if istall 
         return mul!(W, Q, Rc)
     end
     return W
@@ -158,13 +159,14 @@ end
 function _right_polarnewton!(A::AbstractMatrix, Wᴴ, P = similar(A, (0, 0)); tol = defaulttol(A), maxiter = 10)
     m, n = size(A) # we must have m <= n
     Lᴴinv = isempty(P) ? similar(P, (m, m)) : P # use P as workspace when available
-    Q = similar(A, (0, 0))
-    if m < n # initial QR
+    isshort = m < n 
+    if isshort # initial QR
         L, Q = lq_compact!(A)
         Lc = view(A, 1:m, 1:m)
         copy!(Lc, L)
         Lᴴinv = ldiv!(LowerTriangular(Lc)', one!(Lᴴinv))
     else # m == n
+        Q = similar(A, (0, 0)) # needed for JET
         L = A
         Lc = view(Wᴴ, 1:m, 1:m)
         Lc .= L
@@ -190,7 +192,7 @@ function _right_polarnewton!(A::AbstractMatrix, Wᴴ, P = similar(A, (0, 0)); to
     if conv > tol
         @warn "`right_polar!` via Newton iteration did not converge within $maxiter iterations (final residual: $conv)"
     end
-    if m < n
+    if isshort
         return mul!(Wᴴ, Lc, Q)
     end
     return Wᴴ

src/pullbacks/eig.jl

@@ -137,6 +137,7 @@ function eig_trunc_pullback!(
         ΔVperp = ΔV - V * inv(G) * VᴴΔV
         VᴴΔV .*= conj.(inv_safe.(transpose(D) .- D, degeneracy_atol))
     else
+        ΔVperp = similar(G, (0, 0)) # needed for JET
         VᴴΔV = zero(G)
     end