create less temporary rtl

[Richard Henderson]

On Tue, Aug 13, 2002 at 07:50:01AM +0200, Segher Boessenkool wrote:
> I'm sure I got all the details wrong (and the indenting, too); but it
> bootstraps fine (on gnu-linux-powerpc), and is a full minute faster on
> bootstrap, too.  On some files (expr.c), it saves more than 10% compilation
> time.

You need to look on gcc mainline, in which this has already been fixed.

> ! 		/* We do not want REG_UNUSED notes for these registers.  */
> ! 		mark_set_1 (pbi, CLOBBER, gen_rtx_REG (reg_raw_mode[i], i),
> ! 			    cond, insn,
> ! 			    pbi->flags & ~(PROP_DEATH_NOTES | PROP_REG_INFO));

Mainline looks like 

                mark_set_1 (pbi, CLOBBER, regno_reg_rtx[i], cond, insn,
                            pbi->flags & ~(PROP_DEATH_NOTES | PROP_REG_INFO));

r~