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Re: fold_const.c/tree_swap_operands_p change from Oct 11 breaks m68k


On Mon, Oct 27, 2003 at 08:46:14AM -0800, Richard Henderson wrote:
> On Mon, Oct 27, 2003 at 04:40:50PM +0100, Gunther Nikl wrote:
> >   With VALUE >= 128 that doesn't happen and a 20031008 doesn't save the
> >   register either. I would like to know where I should look to findout
> >   why GCC saves %d2?
> 
> You need to study the debugging dumps.  I suspect that it was used in
> one dump, then eliminated.

  The DFI_greg dumps list it as a used hardreg and reload1.c/find_reg
  says it used reg 2 (%d2) for to reload a spilled instruction. Later
  in the dump the reload says it uses reload_reg_rtx of %d1 for the
  reload. %d2 is marked as a used spill register in used_spill_reg and
  thus regs_ever_live for it is set to 1 in finish_spills().
  I don't know what I am really looking for.

  Anyway, are you going to commit the proposed patch?

  Gunther


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