By the rational of making everything multiplication I add the entry at the end of the list
clc; clear all;
V = rand(1024*1024*32,1);
N = 10;
tic; for i=1:N, V1 = V/norm(V); end; toc % 4.5 s
tic; for i=1:N, V2 = V/sqrt(sum(V.*V)); end; toc % 7.5 s
tic; for i=1:N, V3 = V/sqrt(V'*V); end; toc % 4.9 s
tic; for i=1:N, V4 = V/sqrt(sum(V.^2)); end; toc % 6.8 s
tic; for i=1:N, V1 = V/norm(V); end; toc % 4.7 s
tic; for i=1:N, d = 1/norm(V); V1 = V*d;end; toc % 4.9 s
tic; for i=1:N, d = norm(V)^-1; V1 = V*d;end;toc % 4.4 s