commit d0b1aef6f64643ad5c47738f803ccccee0bfedc7
author Zhuo Zhang <imzhuo@foxmail.com> Thu Mar 03 15:53:40 2022 +0800
committer Zhuo Zhang <imzhuo@foxmail.com> Thu Mar 03 08:52:09 2022 +0000
tree aa28d5fc70f52c8861679f61b263833616990d50
parent 55c7400db5f43c60ae8f9b475a296e897c05ddb3

Speed lscg by using .noalias

Eigen/src/IterativeLinearSolvers/LeastSquareConjugateGradient.h

diff --git a/Eigen/src/IterativeLinearSolvers/LeastSquareConjugateGradient.h b/Eigen/src/IterativeLinearSolvers/LeastSquareConjugateGradient.h
index f9feb72..a76f3f8 100644
--- a/Eigen/src/IterativeLinearSolvers/LeastSquareConjugateGradient.h
+++ b/Eigen/src/IterativeLinearSolvers/LeastSquareConjugateGradient.h
@@ -75,7 +75,7 @@
     Scalar alpha = absNew / tmp.squaredNorm();      // the amount we travel on dir
     x += alpha * p;                                 // update solution
     residual -= alpha * tmp;                        // update residual
-    normal_residual = mat.adjoint() * residual;     // update residual of the normal equation
+    normal_residual.noalias() = mat.adjoint() * residual;     // update residual of the normal equation
     
     residualNorm2 = normal_residual.squaredNorm();
     if(residualNorm2 < threshold)