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Re: copyprop_hardreg_forward removes division


Lars Brinkhoff <lars.spam@nocrew.org> writes:
> Jan Hubicka <jh@suse.cz> writes:
> > Lars Brinkhoff wrote:
> > > I have a problem with a dissapearing division instruction.
> > It looks like you are having same problem as I had. copyprop_hardreg misses
> > the stores to subregs.  I've commited fix to that so hope it is OK in the
> > tree (see kill_value).
> No.  I'm using the trunk of the tree, updated yesterday, and your
> patch seems to be there

kill_set_value is called with the SUBREGs, so I need something like
this, or else kill_set_value will never call kill_value.  However,
this duplicates what your patch did to kill_value, so maybe we can
just change "REG_P(x)" to "(REG_P (x) || GET_CODE (x) == SUBREG)"
or something.

What do you think?  I'll make a fully tested patch when I know what
the best solution is.

*************** kill_set_value (x, set, data)
*** 1186,1191 ****
--- 1186,1195 ----
       void *data;
  {
    struct value_data *vd = data;
+ 
+   if (GET_CODE (x) == SUBREG)
+     x = simplify_subreg (GET_MODE (x), SUBREG_REG (x),
+ 			 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
    if (GET_CODE (set) != CLOBBER && REG_P (x))
      {
        kill_value (x, vd);


-- 
Lars Brinkhoff          http://lars.nocrew.org/     Linux, GCC, PDP-10,
Brinkhoff Consulting    http://www.brinkhoff.se/    HTTP programming


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