Remove broadcast in MINRES-QLP (#929)

JuliaSmoothOptimizers · Nov 5, 2024 · 039acbe · 039acbe
1 parent 2d225a1
commit 039acbe
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/minres_qlp.jl b/src/minres_qlp.jl
@@ -353,7 +353,10 @@ kwargs_minres_qlp = (:M, :ldiv, :λ, :atol, :rtol, :Artol, :itmax, :timemax, :ve
         # [w̅ₖ₋₁ vₖ] [cpₖ  spₖ] = [ẘₖ₋₁ w̅ₖ] ⟷ ẘₖ₋₁ = cpₖ * w̅ₖ₋₁ + spₖ * vₖ
         #           [spₖ -cpₖ]             ⟷ w̅ₖ   = spₖ * w̅ₖ₋₁ - cpₖ * vₖ
         @kswap!(wₖ₋₁, wₖ)
-        wₖ .= spₖ .* wₖ₋₁ .- cpₖ .* vₖ
+        # Compute w̅ₖ
+        kcopy!(n, wₖ, wₖ₋₁)
+        kaxpby!(n, -cpₖ, vₖ, spₖ, wₖ)
+        # Compute ẘₖ₋₁
         kaxpby!(n, spₖ, vₖ, cpₖ, wₖ₋₁)
       else
         # [ẘₖ₋₂ w̄ₖ₋₁ vₖ] [cpₖ  0   spₖ] [1   0    0 ] = [wₖ₋₂ ẘₖ₋₁ w̄ₖ] ⟷ wₖ₋₂ = cpₖ * ẘₖ₋₂ + spₖ * vₖ