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how to specify instruction size for optimization
- From: cirrus75 <cirrus75 at uol dot com dot br>
- To: gcc at gcc dot gnu dot org
- Date: Fri, 15 Jan 2010 17:49:34 -0200
- Subject: how to specify instruction size for optimization
Hi,
I could not understand exactly how to specify instruction size to gcc (so it can really optimize the code size when -Os is used).
I would like to inform gcc that if some registers are used for certain operations, the instruction will be smaller. For example, an add which destination register is register 4 has lowest size if compared to all "add" forms.
What is the easiest way to give this information to gcc ? I took a long look at the internals documentation and other ports but I'm not sure.
thank you for the help,
Alex Prado