Backend port: Minimizing register usage in favor of memory accesses

[Jim Wilson]

xyzzy@hotpop.com wrote:
> Can you point me in the right place to look in the i386 target so I don't mess 
> this up?  Is what Joem said about "lowering MEMORY_MOVE_COST" the only thing 
> to do? Is there other black magic involved?

If your target has patterns that allow MEMs, then gcc will use them. 
Since some gcc optimizations (like combine) try to reduce the total 
number of instructions, you will naturally get code that uses MEM in 
preference to REG.

You shouldn't really need to do anything else to get started.  There are 
other things that you can do to fine tune the result and address 
specific problems, such as setting MEMORY_MOVE_COST.  However, since you 
haven't reported any specific problems, I can't offer any specific 
suggestions.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com