one question: tree-ssa vs no tree-ssa? no such global optimization exists.

["J.C. Pizarro" <jcpiza at gmail dot com>]

* Was it useful the implementation of the complicated tree-ssa code
waited for long time (many years)?

* Was it better the optimization without tree-ssa code?

If doesn't exist a method for global optimization to use tree-ssa then
* why did not it implement the simplest trial-and-error method for
local optimization (e.g. minima/maxima local) following the K.I.S.S.
principle without tree-ssa code?

* why was it too complicated adding several optimization's features as
instruction scheduling using tree-ssa code?

* was not it too easy adding several optimization's features with
trial-and-error and without tree-ssa code?

* why both performance's measures will be different if both are
following the same principle of local optimization when none uses
global optimization?

IMHO,
A) with tree-ssa => many KLOCS.
B) without tree-ssa and with trial-and-error => few KLOCS + more
optimization's features + could outperfom better.

There are other methods of search of minima/maxima local as Hill
Climbing, Beam Search, Genetic Algorithms, Simulated Annealing, Tabu
Search, A*, Alfa-Beta, Min-Max, Branch-and-Bound, Greedy, etc.

The extension with more optimization's features is more easy without
tree-ssa code.

      Sincerely, J.C. Pizarro ;)