Re: [PATCH] tree-optimization/111779 - Handle some BIT_FIELD_REFs in SRA
Hi Richard,
being the one who wrote the surrounding code:
The fortran part looks good to me.
Ok for merge from the fortran side.
- Andre
On Thu, 12 Oct 2023 11:44:01 + (UTC)
Richard Biener wrote:
> On Thu, 12 Oct 2023, Richard Biener wrote:
>
> > The following handles byte-aligned, power-of-two and byte-multiple
> > sized BIT_FIELD_REF reads in SRA. In particular this should cover
> > BIT_FIELD_REFs created by optimize_bit_field_compare.
> >
> > For gcc.dg/tree-ssa/ssa-dse-26.c we now SRA the BIT_FIELD_REF
> > appearing there leading to more DSE, fully eliding the aggregates.
> >
> > This results in the same false positive -Wuninitialized as the
> > older attempt to remove the folding from optimize_bit_field_compare,
> > fixed by initializing part of the aggregate unconditionally.
> >
> > Bootstrapped and tested on x86_64-unknown-linux-gnu for all languages.
> >
> > Martin is on leave so I'll push this tomorrow unless the Fortran
> > folks have objections.
>
> Err, and I forgot that hunk. It's
>
> diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
> index 7beefa2e69c..1b8be081a17 100644
> --- a/gcc/fortran/trans-expr.cc
> +++ b/gcc/fortran/trans-expr.cc
> @@ -12015,7 +12015,10 @@ gfc_trans_assignment_1 (gfc_expr * expr1, gfc_expr *
> expr2, bool init_flag, && !is_runtime_conformable (expr1, expr2);
>
>/* Only analyze the expressions for coarray properties, when in coarray-lib
> - mode. */
> + mode. Avoid false-positive uninitialized diagnostics with initializing
> + the codimension flag unconditionally. */
> + lhs_caf_attr.codimension = false;
> + rhs_caf_attr.codimension = false;
>if (flag_coarray == GFC_FCOARRAY_LIB)
> {
>lhs_caf_attr = gfc_caf_attr (expr1, false, &lhs_refs_comp);
>
>
> > Thanks,
> > Richard.
> >
> > PR tree-optimization/111779
> > gcc/
> > * tree-sra.cc (sra_handled_bf_read_p): New function.
> > (build_access_from_expr_1): Handle some BIT_FIELD_REFs.
> > (sra_modify_expr): Likewise.
> > (make_fancy_name_1): Skip over BIT_FIELD_REF.
> >
> > gcc/fortran/
> > * trans-expr.cc (gfc_trans_assignment_1): Initialize
> > lhs_caf_attr and rhs_caf_attr codimension flag to avoid
> > false positive -Wuninitialized.
> >
> > gcc/testsuite/
> > * gcc.dg/tree-ssa/ssa-dse-26.c: Adjust for more DSE.
> > * gcc.dg/vect/vect-pr111779.c: New testcase.
> > ---
> > gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c | 4 +-
> > gcc/testsuite/gcc.dg/vect/vect-pr111779.c | 56 ++
> > gcc/tree-sra.cc| 24 --
> > 3 files changed, 79 insertions(+), 5 deletions(-)
> > create mode 100644 gcc/testsuite/gcc.dg/vect/vect-pr111779.c
> >
> > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
> > b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c index e3c33f49ef6..43152de5616
> > 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
> > +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
> > @@ -31,5 +31,5 @@ constraint_equal (struct constraint a, struct constraint
> > b) && constraint_expr_equal (a.rhs, b.rhs);
> > }
> >
> > -/* { dg-final { scan-tree-dump-times "Deleted dead store: x = " 1 "dse1" }
> > } */ -/* { dg-final { scan-tree-dump-times "Deleted dead store: y = " 1
> > "dse1" } } */ +/* { dg-final { scan-tree-dump-times "Deleted dead store: x
> > = " 2 "dse1" } } */ +/* { dg-final { scan-tree-dump-times "Deleted dead
> > store: y = " 2 "dse1" } } */ diff --git
> > a/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
> > b/gcc/testsuite/gcc.dg/vect/vect-pr111779.c new file mode 100644 index
> > 000..79b72aebc78 --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
> > @@ -0,0 +1,56 @@
> > +#include
> > +#include "tree-vect.h"
> > +
> > +struct C
> > +{
> > +int c;
> > +int d;
> > +bool f :1;
> > +float e;
> > +};
> > +
> > +struct A
> > +{
> > + unsigned int a;
> > + unsigned char c1, c2;
> > + bool b1 : 1;
> > + bool b2 : 1;
> > + bool b3 : 1;
> > + struct C b4;
> > +};
> > +
> > +void __attribute__((noipa))
> > +foo (const struct A * __restrict x, int y)
> > +{
> > + int s = 0, i = 0;
> > + for (i = 0; i < y; ++i)
> > +{
> > + const struct A a = x[i];
> > + s += a.b4.f ? 1 : 0;
> > +}
> > + if (s != 0)
> > +__builtin_abort ();
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + struct A x[100];
> > + int i;
> > +
> > + check_vect ();
> > +
> > + __builtin_memset (x, -1, sizeof (x));
> > +#pragma GCC novect
> > + for (i = 0; i < 100; i++)
> > +{
> > + x[i].b1 = false;
> > + x[i].b2 = false;
> > + x[i].b3 = false;
> > + x[i].b4.f = false;
> > +}
> > + foo (x, 100);
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" { target vect_int
> > } } } */ diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
> > index 56a8ba26135..24d0c20da6a 100644
> > --- a/gcc/tree-sra.cc
> > +++ b/gcc/tree-sra.cc
> > @@ -1113,6 +1113,21 @@ disqualify_base_of_expr
Re: [PATCH] tree-optimization/111779 - Handle some BIT_FIELD_REFs in SRA
On Thu, 12 Oct 2023, Richard Biener wrote:
> The following handles byte-aligned, power-of-two and byte-multiple
> sized BIT_FIELD_REF reads in SRA. In particular this should cover
> BIT_FIELD_REFs created by optimize_bit_field_compare.
>
> For gcc.dg/tree-ssa/ssa-dse-26.c we now SRA the BIT_FIELD_REF
> appearing there leading to more DSE, fully eliding the aggregates.
>
> This results in the same false positive -Wuninitialized as the
> older attempt to remove the folding from optimize_bit_field_compare,
> fixed by initializing part of the aggregate unconditionally.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu for all languages.
>
> Martin is on leave so I'll push this tomorrow unless the Fortran
> folks have objections.
Err, and I forgot that hunk. It's
diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 7beefa2e69c..1b8be081a17 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -12015,7 +12015,10 @@ gfc_trans_assignment_1 (gfc_expr * expr1, gfc_expr *
expr2, bool init_flag,
&& !is_runtime_conformable (expr1, expr2);
/* Only analyze the expressions for coarray properties, when in coarray-lib
- mode. */
+ mode. Avoid false-positive uninitialized diagnostics with initializing
+ the codimension flag unconditionally. */
+ lhs_caf_attr.codimension = false;
+ rhs_caf_attr.codimension = false;
if (flag_coarray == GFC_FCOARRAY_LIB)
{
lhs_caf_attr = gfc_caf_attr (expr1, false, &lhs_refs_comp);
> Thanks,
> Richard.
>
> PR tree-optimization/111779
> gcc/
> * tree-sra.cc (sra_handled_bf_read_p): New function.
> (build_access_from_expr_1): Handle some BIT_FIELD_REFs.
> (sra_modify_expr): Likewise.
> (make_fancy_name_1): Skip over BIT_FIELD_REF.
>
> gcc/fortran/
> * trans-expr.cc (gfc_trans_assignment_1): Initialize
> lhs_caf_attr and rhs_caf_attr codimension flag to avoid
> false positive -Wuninitialized.
>
> gcc/testsuite/
> * gcc.dg/tree-ssa/ssa-dse-26.c: Adjust for more DSE.
> * gcc.dg/vect/vect-pr111779.c: New testcase.
> ---
> gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c | 4 +-
> gcc/testsuite/gcc.dg/vect/vect-pr111779.c | 56 ++
> gcc/tree-sra.cc| 24 --
> 3 files changed, 79 insertions(+), 5 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/vect/vect-pr111779.c
>
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
> b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
> index e3c33f49ef6..43152de5616 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
> @@ -31,5 +31,5 @@ constraint_equal (struct constraint a, struct constraint b)
> && constraint_expr_equal (a.rhs, b.rhs);
> }
>
> -/* { dg-final { scan-tree-dump-times "Deleted dead store: x = " 1 "dse1" } }
> */
> -/* { dg-final { scan-tree-dump-times "Deleted dead store: y = " 1 "dse1" } }
> */
> +/* { dg-final { scan-tree-dump-times "Deleted dead store: x = " 2 "dse1" } }
> */
> +/* { dg-final { scan-tree-dump-times "Deleted dead store: y = " 2 "dse1" } }
> */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
> b/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
> new file mode 100644
> index 000..79b72aebc78
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
> @@ -0,0 +1,56 @@
> +#include
> +#include "tree-vect.h"
> +
> +struct C
> +{
> +int c;
> +int d;
> +bool f :1;
> +float e;
> +};
> +
> +struct A
> +{
> + unsigned int a;
> + unsigned char c1, c2;
> + bool b1 : 1;
> + bool b2 : 1;
> + bool b3 : 1;
> + struct C b4;
> +};
> +
> +void __attribute__((noipa))
> +foo (const struct A * __restrict x, int y)
> +{
> + int s = 0, i = 0;
> + for (i = 0; i < y; ++i)
> +{
> + const struct A a = x[i];
> + s += a.b4.f ? 1 : 0;
> +}
> + if (s != 0)
> +__builtin_abort ();
> +}
> +
> +int
> +main ()
> +{
> + struct A x[100];
> + int i;
> +
> + check_vect ();
> +
> + __builtin_memset (x, -1, sizeof (x));
> +#pragma GCC novect
> + for (i = 0; i < 100; i++)
> +{
> + x[i].b1 = false;
> + x[i].b2 = false;
> + x[i].b3 = false;
> + x[i].b4.f = false;
> +}
> + foo (x, 100);
> + return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" { target vect_int }
> } } */
> diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
> index 56a8ba26135..24d0c20da6a 100644
> --- a/gcc/tree-sra.cc
> +++ b/gcc/tree-sra.cc
> @@ -1113,6 +1113,21 @@ disqualify_base_of_expr (tree t, const char *reason)
> disqualify_candidate (t, reason);
> }
>
> +/* Return true if the BIT_FIELD_REF read EXPR is handled by SRA. */
> +
> +static bool
> +sra_handled_bf_read_p (tree expr)
> +{
> + uint64_t size, offset;
> + if (bit_field_size (expr).is_constant (&size)
> + && bit_field_offset (expr).is_constant (&offset)
> + && size % BITS_PER_UNIT == 0
> + && offset % B
[PATCH] tree-optimization/111779 - Handle some BIT_FIELD_REFs in SRA
The following handles byte-aligned, power-of-two and byte-multiple
sized BIT_FIELD_REF reads in SRA. In particular this should cover
BIT_FIELD_REFs created by optimize_bit_field_compare.
For gcc.dg/tree-ssa/ssa-dse-26.c we now SRA the BIT_FIELD_REF
appearing there leading to more DSE, fully eliding the aggregates.
This results in the same false positive -Wuninitialized as the
older attempt to remove the folding from optimize_bit_field_compare,
fixed by initializing part of the aggregate unconditionally.
Bootstrapped and tested on x86_64-unknown-linux-gnu for all languages.
Martin is on leave so I'll push this tomorrow unless the Fortran
folks have objections.
Thanks,
Richard.
PR tree-optimization/111779
gcc/
* tree-sra.cc (sra_handled_bf_read_p): New function.
(build_access_from_expr_1): Handle some BIT_FIELD_REFs.
(sra_modify_expr): Likewise.
(make_fancy_name_1): Skip over BIT_FIELD_REF.
gcc/fortran/
* trans-expr.cc (gfc_trans_assignment_1): Initialize
lhs_caf_attr and rhs_caf_attr codimension flag to avoid
false positive -Wuninitialized.
gcc/testsuite/
* gcc.dg/tree-ssa/ssa-dse-26.c: Adjust for more DSE.
* gcc.dg/vect/vect-pr111779.c: New testcase.
---
gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c | 4 +-
gcc/testsuite/gcc.dg/vect/vect-pr111779.c | 56 ++
gcc/tree-sra.cc| 24 --
3 files changed, 79 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/vect/vect-pr111779.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
index e3c33f49ef6..43152de5616 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c
@@ -31,5 +31,5 @@ constraint_equal (struct constraint a, struct constraint b)
&& constraint_expr_equal (a.rhs, b.rhs);
}
-/* { dg-final { scan-tree-dump-times "Deleted dead store: x = " 1 "dse1" } } */
-/* { dg-final { scan-tree-dump-times "Deleted dead store: y = " 1 "dse1" } } */
+/* { dg-final { scan-tree-dump-times "Deleted dead store: x = " 2 "dse1" } } */
+/* { dg-final { scan-tree-dump-times "Deleted dead store: y = " 2 "dse1" } } */
diff --git a/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
b/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
new file mode 100644
index 000..79b72aebc78
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-pr111779.c
@@ -0,0 +1,56 @@
+#include
+#include "tree-vect.h"
+
+struct C
+{
+int c;
+int d;
+bool f :1;
+float e;
+};
+
+struct A
+{
+ unsigned int a;
+ unsigned char c1, c2;
+ bool b1 : 1;
+ bool b2 : 1;
+ bool b3 : 1;
+ struct C b4;
+};
+
+void __attribute__((noipa))
+foo (const struct A * __restrict x, int y)
+{
+ int s = 0, i = 0;
+ for (i = 0; i < y; ++i)
+{
+ const struct A a = x[i];
+ s += a.b4.f ? 1 : 0;
+}
+ if (s != 0)
+__builtin_abort ();
+}
+
+int
+main ()
+{
+ struct A x[100];
+ int i;
+
+ check_vect ();
+
+ __builtin_memset (x, -1, sizeof (x));
+#pragma GCC novect
+ for (i = 0; i < 100; i++)
+{
+ x[i].b1 = false;
+ x[i].b2 = false;
+ x[i].b3 = false;
+ x[i].b4.f = false;
+}
+ foo (x, 100);
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" { target vect_int } }
} */
diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
index 56a8ba26135..24d0c20da6a 100644
--- a/gcc/tree-sra.cc
+++ b/gcc/tree-sra.cc
@@ -1113,6 +1113,21 @@ disqualify_base_of_expr (tree t, const char *reason)
disqualify_candidate (t, reason);
}
+/* Return true if the BIT_FIELD_REF read EXPR is handled by SRA. */
+
+static bool
+sra_handled_bf_read_p (tree expr)
+{
+ uint64_t size, offset;
+ if (bit_field_size (expr).is_constant (&size)
+ && bit_field_offset (expr).is_constant (&offset)
+ && size % BITS_PER_UNIT == 0
+ && offset % BITS_PER_UNIT == 0
+ && pow2p_hwi (size))
+return true;
+ return false;
+}
+
/* Scan expression EXPR and create access structures for all accesses to
candidates for scalarization. Return the created access or NULL if none is
created. */
@@ -1123,7 +1138,8 @@ build_access_from_expr_1 (tree expr, gimple *stmt, bool
write)
struct access *ret = NULL;
bool partial_ref;
- if (TREE_CODE (expr) == BIT_FIELD_REF
+ if ((TREE_CODE (expr) == BIT_FIELD_REF
+ && (write || !sra_handled_bf_read_p (expr)))
|| TREE_CODE (expr) == IMAGPART_EXPR
|| TREE_CODE (expr) == REALPART_EXPR)
{
@@ -1170,6 +1186,7 @@ build_access_from_expr_1 (tree expr, gimple *stmt, bool
write)
case COMPONENT_REF:
case ARRAY_REF:
case ARRAY_RANGE_REF:
+case BIT_FIELD_REF:
ret = create_access (expr, stmt, write);
break;
@@ -1549,6 +1566,7 @@ make_fancy_name_1 (tree expr)
obstack_grow (&name_obstack, buffer, strlen (buffer));
break;
+case BIT_FIELD_REF:
case ADDR_EXPR:
make_fancy_name_1 (TREE_OPER
