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## 6.7 Optimization

GNU Pascal is a 32/64 bit compiler with excellent optimization algorithms (which are identically the same as those of GNU C). There are six optimization levels, specified by the command line options ``-O'`, ``-O2'`, ..., ``-O6'`.

One example:

    program OptimizationDemo;

    procedure Foo;
    var
      A, B: Integer;
    begin
      A := 3;
      B := 4;
      WriteLn (A + B)
    end;

    begin
      Foo
    end.

When GNU Pascal compiles this program with optimization (``-O3'`), it recognizes that the argument to `WriteLn' is the constant 7 -- and optimizes away the variables `A` and `B`. If the variables were global, they would not be optimized away because they might be accessed from other places, but the constant 7 would still be optimized.

For more about optimization, see the GNU C documentation.

This document was generated by Frank Heckenbach on May, 10 2002 using texi2html