Re: Mark constant-sized objects as addressable if they have poly-int accesses
On Mon, Dec 2, 2019 at 5:30 PM Richard Sandiford
wrote:
>
> [finally getting back to this]
>
> Richard Biener writes:
> > On Fri, Nov 8, 2019 at 10:40 AM Richard Sandiford
> > wrote:
> >>
> >> If SVE code is written for a specific vector length, it might load from
> >> or store to fixed-sized objects. This needs to work even without
> >> -msve-vector-bits=N (which should never be needed for correctness).
> >>
> >> There's no way of handling a direct poly-int sized reference to a
> >> fixed-size register; it would have to go via memory. And in that
> >> case it's more efficient to mark the fixed-size object as
> >> addressable from the outset, like we do for array references
> >> with non-constant indices.
> >>
> >> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
> >
> > Hmm, shouldn't you somehow avoid walking subtrees again like
> > the array-ref cases? Do "intermediate" types really matter here?
> > Thus if you have BIT_FIELDREF > fixed-size-decl>,
> > select first element > do you really need it addressable?
> >
> > It seems to me you want to check it only on the actual reference type.
>
> Yeah, I guess it was overly general. I don't think it can happen
> for anything other than the MEM_REF/TARGET_MEM_REF itself.
>
> How about this version? Tested as before.
OK.
Thanks,
Richard.
> Richard
>
>
> 2019-12-02 Richard Sandiford
>
> gcc/
> * cfgexpand.c (discover_nonconstant_array_refs_r): If an access
> with POLY_INT_CST size is made to a fixed-size object, force the
> object to live in memory.
>
> gcc/testsuite/
> * gcc.target/aarch64/sve/acle/general/deref_1.c: New test.
>
> Index: gcc/cfgexpand.c
> ===
> --- gcc/cfgexpand.c 2019-11-13 08:42:44.901373255 +
> +++ gcc/cfgexpand.c 2019-12-02 16:27:45.157295080 +
> @@ -6133,6 +6133,21 @@ discover_nonconstant_array_refs_r (tree
>
>*walk_subtrees = 0;
> }
> + /* References of size POLY_INT_CST to a fixed-size object must go
> + through memory. It's more efficient to force that here than
> + to create temporary slots on the fly. */
> + else if ((TREE_CODE (t) == MEM_REF || TREE_CODE (t) == TARGET_MEM_REF)
> + && TYPE_SIZE (TREE_TYPE (t))
> + && POLY_INT_CST_P (TYPE_SIZE (TREE_TYPE (t
> +{
> + tree base = get_base_address (t);
> + if (base
> + && DECL_P (base)
> + && DECL_MODE (base) != BLKmode
> + && GET_MODE_SIZE (DECL_MODE (base)).is_constant ())
> + TREE_ADDRESSABLE (base) = 1;
> + *walk_subtrees = 0;
> +}
>
>return NULL_TREE;
> }
> Index: gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c
> ===
> --- /dev/null 2019-09-17 11:41:18.176664108 +0100
> +++ gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c 2019-12-02
> 16:27:45.165295026 +
> @@ -0,0 +1,25 @@
> +/* { dg-options "-O2" } */
> +
> +#include
> +
> +uint64_t
> +f1 (int32_t *x, int32_t *y)
> +{
> + union { uint64_t x; char c[8]; } u;
> + svbool_t pg = svptrue_b32 ();
> + *(svbool_t *)&u.c[0] = svcmpeq (pg, svld1 (pg, x), 0);
> + *(svbool_t *)&u.c[4] = svcmpeq (pg, svld1 (pg, y), 1);
> + return u.x;
> +}
> +
> +typedef unsigned int v4si __attribute__((vector_size(16)));
> +
> +/* The aliasing is somewhat dubious here, but it must compile. */
> +
> +v4si
> +f2 (void)
> +{
> + v4si res;
> + *(svuint32_t *) &res = svindex_u32 (0, 1);
> + return res;
> +}
Re: Mark constant-sized objects as addressable if they have poly-int accesses
[finally getting back to this]
Richard Biener writes:
> On Fri, Nov 8, 2019 at 10:40 AM Richard Sandiford
> wrote:
>>
>> If SVE code is written for a specific vector length, it might load from
>> or store to fixed-sized objects. This needs to work even without
>> -msve-vector-bits=N (which should never be needed for correctness).
>>
>> There's no way of handling a direct poly-int sized reference to a
>> fixed-size register; it would have to go via memory. And in that
>> case it's more efficient to mark the fixed-size object as
>> addressable from the outset, like we do for array references
>> with non-constant indices.
>>
>> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
>
> Hmm, shouldn't you somehow avoid walking subtrees again like
> the array-ref cases? Do "intermediate" types really matter here?
> Thus if you have BIT_FIELDREF fixed-size-decl>,
> select first element > do you really need it addressable?
>
> It seems to me you want to check it only on the actual reference type.
Yeah, I guess it was overly general. I don't think it can happen
for anything other than the MEM_REF/TARGET_MEM_REF itself.
How about this version? Tested as before.
Richard
2019-12-02 Richard Sandiford
gcc/
* cfgexpand.c (discover_nonconstant_array_refs_r): If an access
with POLY_INT_CST size is made to a fixed-size object, force the
object to live in memory.
gcc/testsuite/
* gcc.target/aarch64/sve/acle/general/deref_1.c: New test.
Index: gcc/cfgexpand.c
===
--- gcc/cfgexpand.c 2019-11-13 08:42:44.901373255 +
+++ gcc/cfgexpand.c 2019-12-02 16:27:45.157295080 +
@@ -6133,6 +6133,21 @@ discover_nonconstant_array_refs_r (tree
*walk_subtrees = 0;
}
+ /* References of size POLY_INT_CST to a fixed-size object must go
+ through memory. It's more efficient to force that here than
+ to create temporary slots on the fly. */
+ else if ((TREE_CODE (t) == MEM_REF || TREE_CODE (t) == TARGET_MEM_REF)
+ && TYPE_SIZE (TREE_TYPE (t))
+ && POLY_INT_CST_P (TYPE_SIZE (TREE_TYPE (t
+{
+ tree base = get_base_address (t);
+ if (base
+ && DECL_P (base)
+ && DECL_MODE (base) != BLKmode
+ && GET_MODE_SIZE (DECL_MODE (base)).is_constant ())
+ TREE_ADDRESSABLE (base) = 1;
+ *walk_subtrees = 0;
+}
return NULL_TREE;
}
Index: gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c
===
--- /dev/null 2019-09-17 11:41:18.176664108 +0100
+++ gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c 2019-12-02
16:27:45.165295026 +
@@ -0,0 +1,25 @@
+/* { dg-options "-O2" } */
+
+#include
+
+uint64_t
+f1 (int32_t *x, int32_t *y)
+{
+ union { uint64_t x; char c[8]; } u;
+ svbool_t pg = svptrue_b32 ();
+ *(svbool_t *)&u.c[0] = svcmpeq (pg, svld1 (pg, x), 0);
+ *(svbool_t *)&u.c[4] = svcmpeq (pg, svld1 (pg, y), 1);
+ return u.x;
+}
+
+typedef unsigned int v4si __attribute__((vector_size(16)));
+
+/* The aliasing is somewhat dubious here, but it must compile. */
+
+v4si
+f2 (void)
+{
+ v4si res;
+ *(svuint32_t *) &res = svindex_u32 (0, 1);
+ return res;
+}
Re: Mark constant-sized objects as addressable if they have poly-int accesses
On Fri, Nov 8, 2019 at 10:40 AM Richard Sandiford
wrote:
>
> If SVE code is written for a specific vector length, it might load from
> or store to fixed-sized objects. This needs to work even without
> -msve-vector-bits=N (which should never be needed for correctness).
>
> There's no way of handling a direct poly-int sized reference to a
> fixed-size register; it would have to go via memory. And in that
> case it's more efficient to mark the fixed-size object as
> addressable from the outset, like we do for array references
> with non-constant indices.
>
> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Hmm, shouldn't you somehow avoid walking subtrees again like
the array-ref cases? Do "intermediate" types really matter here?
Thus if you have BIT_FIELDREF ,
select first element > do you really need it addressable?
It seems to me you want to check it only on the actual reference type.
Richard.
> Richard
>
>
> 2019-11-08 Richard Sandiford
>
> gcc/
> * cfgexpand.c (discover_nonconstant_array_refs_r): If an access
> with POLY_INT_CST size is made to a fixed-size object, force the
> object to live in memory.
>
> gcc/testsuite/
> * gcc.target/aarch64/sve/acle/general/deref_1.c: New test.
>
> Index: gcc/cfgexpand.c
> ===
> --- gcc/cfgexpand.c 2019-10-01 09:55:35.062089236 +0100
> +++ gcc/cfgexpand.c 2019-11-08 09:39:13.105130902 +
> @@ -6106,6 +6106,20 @@ discover_nonconstant_array_refs_r (tree
> {
>tree t = *tp;
>
> + /* References of size POLY_INT_CST to a fixed-size object must go
> + through memory. It's more efficient to force that here than
> + to create temporary slots on the fly. */
> + if (TYPE_SIZE (TREE_TYPE (t))
> + && POLY_INT_CST_P (TYPE_SIZE (TREE_TYPE (t
> +{
> + t = get_base_address (t);
> + if (t
> + && DECL_P (t)
> + && DECL_MODE (t) != BLKmode
> + && GET_MODE_BITSIZE (DECL_MODE (t)).is_constant ())
> + TREE_ADDRESSABLE (t) = 1;
> +}
> +
>if (IS_TYPE_OR_DECL_P (t))
> *walk_subtrees = 0;
>else if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
> Index: gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c
> ===
> --- /dev/null 2019-09-17 11:41:18.176664108 +0100
> +++ gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c 2019-11-08
> 09:39:13.105130902 +
> @@ -0,0 +1,13 @@
> +/* { dg-options "-O2" } */
> +
> +#include
> +
> +uint64_t
> +f (int32_t *x, int32_t *y)
> +{
> + union { uint64_t x; char c[8]; } u;
> + svbool_t pg = svptrue_b32 ();
> + *(svbool_t *)&u.c[0] = svcmpeq (pg, svld1 (pg, x), 0);
> + *(svbool_t *)&u.c[4] = svcmpeq (pg, svld1 (pg, y), 1);
> + return u.x;
> +}
Mark constant-sized objects as addressable if they have poly-int accesses
If SVE code is written for a specific vector length, it might load from
or store to fixed-sized objects. This needs to work even without
-msve-vector-bits=N (which should never be needed for correctness).
There's no way of handling a direct poly-int sized reference to a
fixed-size register; it would have to go via memory. And in that
case it's more efficient to mark the fixed-size object as
addressable from the outset, like we do for array references
with non-constant indices.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Richard
2019-11-08 Richard Sandiford
gcc/
* cfgexpand.c (discover_nonconstant_array_refs_r): If an access
with POLY_INT_CST size is made to a fixed-size object, force the
object to live in memory.
gcc/testsuite/
* gcc.target/aarch64/sve/acle/general/deref_1.c: New test.
Index: gcc/cfgexpand.c
===
--- gcc/cfgexpand.c 2019-10-01 09:55:35.062089236 +0100
+++ gcc/cfgexpand.c 2019-11-08 09:39:13.105130902 +
@@ -6106,6 +6106,20 @@ discover_nonconstant_array_refs_r (tree
{
tree t = *tp;
+ /* References of size POLY_INT_CST to a fixed-size object must go
+ through memory. It's more efficient to force that here than
+ to create temporary slots on the fly. */
+ if (TYPE_SIZE (TREE_TYPE (t))
+ && POLY_INT_CST_P (TYPE_SIZE (TREE_TYPE (t
+{
+ t = get_base_address (t);
+ if (t
+ && DECL_P (t)
+ && DECL_MODE (t) != BLKmode
+ && GET_MODE_BITSIZE (DECL_MODE (t)).is_constant ())
+ TREE_ADDRESSABLE (t) = 1;
+}
+
if (IS_TYPE_OR_DECL_P (t))
*walk_subtrees = 0;
else if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
Index: gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c
===
--- /dev/null 2019-09-17 11:41:18.176664108 +0100
+++ gcc/testsuite/gcc.target/aarch64/sve/acle/general/deref_1.c 2019-11-08
09:39:13.105130902 +
@@ -0,0 +1,13 @@
+/* { dg-options "-O2" } */
+
+#include
+
+uint64_t
+f (int32_t *x, int32_t *y)
+{
+ union { uint64_t x; char c[8]; } u;
+ svbool_t pg = svptrue_b32 ();
+ *(svbool_t *)&u.c[0] = svcmpeq (pg, svld1 (pg, x), 0);
+ *(svbool_t *)&u.c[4] = svcmpeq (pg, svld1 (pg, y), 1);
+ return u.x;
+}
