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Re: Excess registers pushed - regs_ever_live not right way?
You can use DF_REG_DEF_COUNT() - if this is indeed a parameter register,
there should be only one def (artificial def) or no def at all.
Or if you want to see all defs for the reg,
On Wed, Feb 27, 2008 at 6:03 PM, Andrew Hutchinson
> Register contains parameter that is passed to function. This register
> is not part of call used set.
> If this type of register were modified by function, then it would be
> saved by function.
> If this register is not modified by function, it should not be saved.
> This is true even if function is not a leaf function (as same register
> would be preserved by deeper calls)
> Seongbae Park (박성배, 朴成培) wrote:
> > On Wed, Feb 27, 2008 at 5:16 PM, Andrew Hutchinson
> > <firstname.lastname@example.org> wrote:
> >> Register saves by prolog (pushes) are typically made with reference to
> >> "df_regs_ever_live_p()" or "regs_ever_live. "||
> >> If my understanding is correct, these calls reflect register USEs and
> >> not register DEFs. So if register is used in a function, but not
> >> otherwise changed, it will get pushed unnecessarily on stack by prolog.
> > This implies that the register is either a global register
> > or a parameter register, in either case it won't be saved/restored
> > as callee save.
> > What kind of a register is it and how com there's only use of it in a function
> > but it's not a global ?
> > Seongbae
#pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com"