Re: Minor tweak to function.c:keep_stack_depressed

[Richard Henderson <rth at redhat dot com>]

On Wed, Dec 05, 2001 at 12:44:46PM -0800, Eric Christopher wrote:
> > This is used only by Ada and only on some targets.
> > 
> > Wed Dec  5 06:26:27 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
> > 
> > 	* function.c (keep_stack_depressed): Refine check for register
> > 	clobbered over call.
> > 
> 
> If you want to check that a function has been clobbered over a call you
> should, I believe, only check TEST_HARD_REG_BIT
> (regs_invalidated_by_call, no) and not check !fixed_regs[regno] as well.
> This will give you false positives. See propagate_one_insn for a similar
> check.

Actually, he's looking for an available temporary register.

There are a number of bugs here.  Not the least of which is
failing to honor EPILOGUE_USES or tracking which registers
are being used as temporaries by the epilogue itself.


r~