Re: PATCH [mainline] Fix for long double (TARGET_LONG_DOUBLE_128) on ppc-darwin

[Fariborz Jahanian <fjahanian at apple dot com>]

On Jul 30, 2004, at 2:17 PM, Geoffrey Keating wrote:

> Fariborz Jahanian <fjahanian@apple.com> writes:
>
> > 7e.com)
>
> I think the second part of this patch won't work.  If you get into
> rs6000_split_multireg_move with a non-offsettable address, there's no
> code you can generate.  I'll look into this a bit more and come up
> with a patch.

Second part was added after change in the first part. In the following 
test case:

static long long foo()
{
  static long long rat;
  return rat;
}

Following pattern is now being generated:

(insn 9 8 10 (set:SI (reg:SI 121)
        (plus:SI (reg:SI 31 r31)
            (high:SI (const:SI (minus:SI (symbol_ref:SI ("!D__*rat.0") 
[flags 0x2] <var_decl 0x41757380 rat>)
                        (symbol_ref:SI ("<pic base>"))))))) -1 (nil)
    (nil))

(insn 10 9 11 (set:SI (reg/f:SI 120)
        (lo_sum:SI (reg:SI 121)
            (const:SI (minus:SI (symbol_ref:SI ("!D__*rat.0") [flags 
0x2] <var_decl 0x41757380 rat>)
                    (symbol_ref:SI ("<pic base>")))))) -1 (nil)
    (expr_list:REG_EQUAL (symbol_ref:SI ("!D__*rat.0") [flags 0x2] 
<var_decl 0x41757380 rat>)
        (nil)))

And following code is generated which looks correct to me and works in 
test case (and bootstrap of gcc):

       addis r2,r10,ha16(rat.0-"L00000000001$pb")
        la r2,lo16(rat.0-"L00000000001$pb")(r2)
        lfd f0,0(r2)

	...


- Fariborz

> > ChangeLog:
> >
> > 2004-07-24 Fariborz Jahanian <fjahanian@apple.com>
> >         * config/rs6000/rs6000.c (legitimate_lo_sum_address_p):
> >         DImode is legit.  mode with lo_sum pic address and when
> >         long double is 128 bits.
> >         (rs6000_split_multireg_move): Added case of LO_SUM when
> >         register node is being obtained.
> >
> > Patch:
> >
> > Index: rs6000.c
> > ===================================================================
> > RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v
> > retrieving revision 1.671
> > diff -c -p -r1.671 rs6000.c
> > *** rs6000.c 23 Jul 2004 04:35:17 -0000 1.671
> > --- rs6000.c 24 Jul 2004 18:32:19 -0000
> > *************** legitimate_lo_sum_address_p (enum machin
> > *** 3162,3168 ****
> >         if (GET_MODE_NUNITS (mode) != 1)
> >         return false;
> >         if (GET_MODE_BITSIZE (mode) > 32
> > !  && !(TARGET_HARD_FLOAT && TARGET_FPRS && mode == DFmode))
> >         return false;
> >
> >         return CONSTANT_P (x);
> > --- 3162,3170 ----
> >         if (GET_MODE_NUNITS (mode) != 1)
> >         return false;
> >         if (GET_MODE_BITSIZE (mode) > 32
> > !  && !(TARGET_HARD_FLOAT && TARGET_FPRS
> > !  && (mode == DFmode ||
> > !  (TARGET_LONG_DOUBLE_128 && mode == DImode))))
> >         return false;
> >
> >         return CONSTANT_P (x);
> > *************** rs6000_split_multireg_move (rtx dst, rtx
> > *** 11077,11084 ****
> >              we have change that register last.  */
> >
> >           breg = (GET_CODE (XEXP (src, 0)) == PLUS
> >                   ? XEXP (XEXP (src, 0), 0)
> > !  : XEXP (src, 0));
> >
> >           if (!REG_P (breg))
> >               abort();
> > --- 11079,11087 ----
> >              we have change that register last.  */
> >
> >           breg = (GET_CODE (XEXP (src, 0)) == PLUS
> > + || GET_CODE (XEXP (src, 0)) == LO_SUM)
> >                   ? XEXP (XEXP (src, 0), 0)
> > !  : XEXP (src, 0);
> >
> >           if (!REG_P (breg))
> >               abort();