Richard,
Thanks. I tried your patch and the -fno-tree-ter, and none works. The problem
is that
decl = find_base_decl (TREE_OPERAND (inner, 0)); <--- Cannot find the
base declaration, so decl = 0
if (decl <-- won't be checked
&& POINTER_TYPE_P (TREE_TYPE (decl))
&& TYPE_RESTRICT (TREE_TYPE (decl)))
The TREE_OPERAND (inner, 0) is:
<nop_expr 0xf7fc7400
type <pointer_type 0xf7fa6870
type <integer_type 0xf7f122f4 int sizes-gimplified public SI
size <integer_cst 0xf7f0f9d8 constant 32>
unit size <integer_cst 0xf7f0f7c4 constant 4>
align 32 symtab 0 alias set 2 canonical type 0xf7f122f4 precision
32 min <integer_cst 0xf7f0f984 -2147483648> max <integer_cst 0xf7f0f9a0
2147483647>
pointer_to_this <pointer_type 0xf7f18798>>
sizes-gimplified public unsigned restrict SI size <integer_cst
0xf7f0f9d8 32> unit size <integer_cst 0xf7f0f7c4 4>
align 32 symtab 0 alias set -1 canonical type 0xf7fa6870>
arg 0 <plus_expr 0xf7fc95e8
type <integer_type 0xf7f12438 long unsigned int public unsigned SI size
<integer_cst 0xf7f0f9d8 32> unit size <integer_cst 0xf7f0f7c4 4>
align 32 symtab 0 alias set -1 canonical type 0xf7f12438 precision
32 min <integer_cst 0xf7f0fa64 0> max <integer_cst 0xf7f0fa48 4294967295>>
arg 0 <var_decl 0xf7fc4a6c D.1768 type <integer_type 0xf7f12438 long
unsigned int>
used unsigned ignored SI file tst.c line 1 col 6 size <integer_cst
0xf7f0f9d8 32> unit size <integer_cst 0xf7f0f7c4 4>
align 32 context <function_decl 0xf7fa7080 foo>
(reg:SI 104 [ D.1768 ])>
arg 1 <integer_cst 0xf7fb7bec constant 4>
tst.c:7:5>
tst.c:7:5>
I added the following code. It seems to work for my example and others. Not
sure potential hazard with it.
...
else if(!decl
&& POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND(inner, 0)))
&& TYPE_RESTRICT (TREE_TYPE (TREE_OPERAND(inner, 0))))
{
return new_alias_set ();
}
....
Bingfeng
> -----Original Message-----
> From: Richard Guenther [mailto:richard.guent...@gmail.com]
> Sent: 03 June 2009 15:10
> To: Bingfeng Mei
> Cc: gcc@gcc.gnu.org
> Subject: Re: Restrict keyword doesn't work correctly in GCC 4.4
>
> On Wed, Jun 3, 2009 at 1:02 PM, Bingfeng Mei
> <b...@broadcom.com> wrote:
> > Richard,
> > Yes, my original code does have restrict qualified decl:
> >
> > void foo(int byte, char *a, char *b){
> > int * restrict dest = (int *)a;
> > int * restrict src = (int *)b;
> >
> > for(int i = 0; i < byte/8; i++){
> > *dest++ = *src++;
> > }
> > }
> >
> >
> > The code I shown is produced by tree level compilation.
> >
> > *(int * restrict) (D.1934 + 4) = *(int * restrict) (D.1936 + 4);
> > *(int * restrict) (D.1934 + 8) = *(int * restrict) (D.1936 + 8);
> > *(int * restrict) (D.1934 + 12) = *(int * restrict) (D.1936 + 12);
> > *(int * restrict) (D.1934 + 16) = *(int * restrict) (D.1936 + 16);
> > *(int * restrict) (D.1934 + 20) = *(int * restrict) (D.1936 + 20);
> > *(int * restrict) (D.1934 + 24) = *(int * restrict) (D.1936 + 24);
> > *(int * restrict) (D.1934 + 28) = *(int * restrict) (D.1936 + 28);
> > *(int * restrict) (D.1934 + 32) = *(int * restrict) (D.1936 + 32);
> > *(int * restrict) (D.1934 + 36) = *(int * restrict) (D.1936 + 36);
> > *(int * restrict) (D.1934 + 40) = *(int * restrict) (D.1936 + 40);
> > *(int * restrict) (D.1934 + 44) = *(int * restrict) (D.1936 + 44);
> > *(int * restrict) (D.1934 + 48) = *(int * restrict) (D.1936 + 48);
> > *(int * restrict) (D.1934 + 52) = *(int * restrict) (D.1936 + 52);
> > *(int * restrict) (D.1934 + 56) = *(int * restrict) (D.1936 + 56);
> > *(int * restrict) (D.1934 + 60) = *(int * restrict) (D.1936 + 60);
> >
> > If we agree these tree statements still preserve the
> meaning of restrict,
> > it should be RTL expansion going wrong. Am I right?
>
> No, it is TER that removes the temporary that is required to make
> restrict work. Try -fno-tree-ter or fixing TER to not TER
> to-restrict-pointer conversions.
>
> Richard.
>
> >
> > - Bingfeng
> >
> >
> >> -----Original Message-----
> >> From: Richard Guenther [mailto:richard.guent...@gmail.com]
> >> Sent: 03 June 2009 11:54
> >> To: Bingfeng Mei
> >> Cc: gcc@gcc.gnu.org
> >> Subject: Re: Restrict keyword doesn't work correctly in GCC 4.4
> >>
> >> On Wed, Jun 3, 2009 at 12:41 PM, Bingfeng Mei
> >> <b...@broadcom.com> wrote:
> >> > Hello,
> >> > I noticed that the restrict doesn't work fully on 4.4.0
> >> (used to work on
> >> > our port based on 4.3 branch). The problem is that tree
> >> optimizer can do a
> >> > lot of optimization regarding pointer, e.g., at -O3. The
> >> alias set property
> >> > is not propagated accordingly.
> >> >
> >> > Is the following RTL expansion correct? Both read and write
> >> address are
> >> > converted to a restrict pointer, but the both mem rtx have
> >> the same alias set (2).
> >> >
> >> > ;; *(int * restrict) (D.1768 + 4) = *(int * restrict)
> (D.1770 + 4);
> >>
> >> restrict only works if there is a restrict qualified
> pointer decl in
> >> your source.
> >>
> >> I will re-implement restrict support completely for 4.5.
> >>
> >> You can try the attached hack which might help (but also cause
> >> weird effects ...).
> >>
> >> Richard.
> >>
> >> > (insn 56 55 57 tst.c:7 (set (reg:SI 124)
> >> > (mem:SI (plus:SI (reg:SI 103 [ D.1770 ])
> >> > (const_int 4 [0x4])) [2 S4 A32])) -1 (nil))
> >> >
> >> > (insn 57 56 0 tst.c:7 (set (mem:SI (plus:SI (reg:SI 104
> [ D.1768 ])
> >> > (const_int 4 [0x4])) [2 S4 A32])
> >> > (reg:SI 124)) -1 (nil))
> >> >
> >> >
> >> > The alias set property is copied from tree node:
> >> > <indirect_ref 0xf7f09d40
> >> > type <integer_type 0xf7f122f4 int sizes-gimplified public SI
> >> > size <integer_cst 0xf7f0f9d8 constant 32>
> >> > unit size <integer_cst 0xf7f0f7c4 constant 4>
> >> > align 32 symtab 0 alias set 2 canonical type
> >> 0xf7f122f4 precision 32 min <integer_cst 0xf7f0f984
> >> -2147483648> max <integer_cst 0xf7f0f9a0 2147483647>
> >> > pointer_to_this <pointer_type 0xf7f18798>>
> >> >
> >> > arg 0 <nop_expr 0xf7fc7400
> >> > type <pointer_type 0xf7fa6870 type <integer_type
> >> 0xf7f122f4 int>
> >> > sizes-gimplified public unsigned restrict SI
> >> size <integer_cst 0xf7f0f9d8 32> unit size <integer_cst
> 0xf7f0f7c4 4>
> >> > align 32 symtab 0 alias set -1 canonical type
> 0xf7fa6870>
> >> >
> >> > arg 0 <plus_expr 0xf7fc95e8 type <integer_type
> >> 0xf7f12438 long unsigned int>
> >> > arg 0 <var_decl 0xf7fc4a6c D.1768>
> >> > arg 1 <integer_cst 0xf7fb7bec constant 4>
> >> > tst.c:7:5>
> >> > tst.c:7:5>
> >> > tst.c:7:5>
> >> >
> >> > Is the RTL expansion wrong or the orginal tree node is
> >> constructed incorrectly?
> >> >
> >> > Thanks,
> >> > Bingfeng Mei
> >> >
> >> > Broadcom UK
> >> >
> >>
> >
>
>
