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Re: [PATCH] Improve lim for pulling loads from global variable out of loops
> > > > if (!is_gimple_reg (rhs))
> > > > cost += 20;
> > >
> > > This would cause us to count any operation except for simple reg = reg
> > > copy as expensive, which definitely is not what is wanted.
> > >
> > Huh? Absolutely not. Read the predicate again. If the RHS is a
> > register, we don't increase the cost.
> Never mind. I mis-read your paragraph, sorry.
> Yes, this would make reg = CST, expensive.
more importantly, for example
reg = reg + reg
would be considered expensive.
> So, if you only want to make
> memory stores and loads expensive, you can ask it directly with:
> if (NUM_VUSES (VUSE_OPS (ann)) > 0
> || NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann)) > 0
> || NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann)) > 0))
> cost += 20;
> (this whole expression should probably be implemented into a predicate).
This seems like a good idea. I will send the patch once it passes