Dead store elimination patch for switch statements

[Geoff Keating]

> Date: Tue, 26 Oct 1999 21:34:44 -0700
> From: Richard Henderson <rth@cygnus.com>
> Cc: gcc-patches@gcc.gnu.org
> 
> On Wed, Oct 27, 1999 at 02:22:55PM +1000, Geoff Keating wrote:
> > +	      for (inote = REG_NOTES (insn); inote; inote = XEXP (inote, 1))
> > +		{
> > +		  if (REG_NOTE_KIND (inote) == REG_LABEL)
> 
> Any reason not to use find_reg_note?

What if there was more than one label referenced?

I'm particularly thinking of

(set x (const (minus (code_label ".L1") (code_label ".LC0"))))

which is the sort of thing you can get when you have incomplete
constant propagation on switch statements; 'L1' is the real branch
target and 'LC0' is the address of the switch, and later 'LC0' will be
added back in.

-- 
Geoffrey Keating <geoffk@cygnus.com>