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)
Andy
Seongbae Park (박성배, 朴成培) wrote:
On Wed, Feb 27, 2008 at 5:16 PM, Andrew Hutchinson
<[EMAIL PROTECTED]> 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
