On Mon, 4 Apr 2016, Jakub Jelinek wrote:
> On Mon, Apr 04, 2016 at 02:56:51PM +0200, Richard Biener wrote:
> > The testcase gcc.target/i386/pr37870.c will already ICE with that
> > patch, so no additional testcase.
>
> In theory you could validate_subreg first and use that code if validation
> went ok, otherwise go through memory.
> But I admit I don't have anything in particular in mind where it would
> trigger this code and the subreg would successfully validate.
Not sure if it would help as that has
/* ??? Similarly, e.g. with (subreg:DF (reg:TI)). Though
store_bit_field
is the culprit here, and not the backends. */
else if (osize >= UNITS_PER_WORD && isize >= osize)
;
and thus we'd return true anyway for (subreg:XF (reg:TI) 0)
Richard.
> > 2016-04-04 Richard Biener <rguent...@suse.de>
> >
> > PR middle-end/37870
> > * expmed.c (extract_bit_field_1): Remove broken case
> > using a wider MODE_INT mode.
> >
> > Index: gcc/expmed.c
> > ===================================================================
> > --- gcc/expmed.c (revision 234708)
> > +++ gcc/expmed.c (working copy)
> > @@ -1647,17 +1647,6 @@ extract_bit_field_1 (rtx str_rtx, unsign
> > if (GET_CODE (op0) == SUBREG)
> > op0 = force_reg (imode, op0);
> > }
> > - else if (REG_P (op0))
> > - {
> > - rtx reg, subreg;
> > - imode = smallest_mode_for_size (GET_MODE_BITSIZE (GET_MODE (op0)),
> > - MODE_INT);
> > - reg = gen_reg_rtx (imode);
> > - subreg = gen_lowpart_SUBREG (GET_MODE (op0), reg);
> > - emit_move_insn (subreg, op0);
> > - op0 = reg;
> > - bitnum += SUBREG_BYTE (subreg) * BITS_PER_UNIT;
> > - }
> > else
> > {
> > HOST_WIDE_INT size = GET_MODE_SIZE (GET_MODE (op0));
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
