* [PATCH]middle-end: inspect all exits for additional annotations for loop.
@ 2024-02-14 13:09 Tamar Christina
2024-02-14 13:41 ` Richard Biener
0 siblings, 1 reply; 4+ messages in thread
From: Tamar Christina @ 2024-02-14 13:09 UTC (permalink / raw)
To: gcc-patches; +Cc: nd, rguenther, jlaw
[-- Attachment #1: Type: text/plain, Size: 2887 bytes --]
Hi All,
Attaching a pragma to a loop which has a complex condition often gets the pragma
dropped. e.g.
#pragma GCC novector
while (i < N && parse_tables_n--)
before lowering this is represented as:
if (ANNOTATE_EXPR <i <= 305 && parse_tables_n-- != 0, no-vector>) ...
But after lowering the condition is broken appart and attached to the final
component of the expression:
if (parse_tables_n.2_2 != 0) goto <D.4456>; else goto <D.4453>;
<D.4456>:
iftmp.1D.4452 = 1;
goto <D.4454>;
<D.4453>:
iftmp.1D.4452 = 0;
<D.4454>:
D.4451 = .ANNOTATE (iftmp.1D.4452, 2, 0);
if (D.4451 != 0) goto <D.4442>; else goto <D.4440>;
<D.4440>:
and it's never heard from again because during replace_loop_annotate we only
inspect the loop header and latch for annotations.
Since annotations were supposed to apply to the loop as a whole this fixes it
by also checking the loop exit src blocks for annotations.
Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
Ok for master?
Thanks,
Tamar
gcc/ChangeLog:
* tree-cfg.cc (replace_loop_annotate): Inspect loop edges for annotations.
gcc/testsuite/ChangeLog:
* gcc.dg/vect/vect-novect_gcond.c: New test.
--- inline copy of patch --
diff --git a/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
new file mode 100644
index 0000000000000000000000000000000000000000..01e69cbef9d51b234c08a400c78dc078d53252f1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
@@ -0,0 +1,39 @@
+/* { dg-add-options vect_early_break } */
+/* { dg-require-effective-target vect_early_break_hw } */
+/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "-O3" } */
+
+/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
+
+#include "tree-vect.h"
+
+#define N 306
+#define NEEDLE 136
+
+int table[N];
+
+__attribute__ ((noipa))
+int foo (int i, unsigned short parse_tables_n)
+{
+ parse_tables_n >>= 9;
+ parse_tables_n += 11;
+#pragma GCC novector
+ while (i < N && parse_tables_n--)
+ table[i++] = 0;
+
+ return table[NEEDLE];
+}
+
+int main ()
+{
+ check_vect ();
+
+#pragma GCC novector
+ for (int j = 0; j < N; j++)
+ table[j] = -1;
+
+ if (foo (0, 0xFFFF) != 0)
+ __builtin_abort ();
+
+ return 0;
+}
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index cdd439fe7506e7bc33654ffa027b493f23d278ac..a29681bffb902d2d05e3f18764ab519aacb3c5bc 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -327,6 +327,10 @@ replace_loop_annotate (void)
if (loop->latch)
replace_loop_annotate_in_block (loop->latch, loop);
+ /* Then also check all other exits. */
+ for (auto e : get_loop_exit_edges (loop))
+ replace_loop_annotate_in_block (e->src, loop);
+
/* Push the global flag_finite_loops state down to individual loops. */
loop->finite_p = flag_finite_loops;
}
--
[-- Attachment #2: rb18267.patch --]
[-- Type: text/plain, Size: 1659 bytes --]
diff --git a/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
new file mode 100644
index 0000000000000000000000000000000000000000..01e69cbef9d51b234c08a400c78dc078d53252f1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
@@ -0,0 +1,39 @@
+/* { dg-add-options vect_early_break } */
+/* { dg-require-effective-target vect_early_break_hw } */
+/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "-O3" } */
+
+/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
+
+#include "tree-vect.h"
+
+#define N 306
+#define NEEDLE 136
+
+int table[N];
+
+__attribute__ ((noipa))
+int foo (int i, unsigned short parse_tables_n)
+{
+ parse_tables_n >>= 9;
+ parse_tables_n += 11;
+#pragma GCC novector
+ while (i < N && parse_tables_n--)
+ table[i++] = 0;
+
+ return table[NEEDLE];
+}
+
+int main ()
+{
+ check_vect ();
+
+#pragma GCC novector
+ for (int j = 0; j < N; j++)
+ table[j] = -1;
+
+ if (foo (0, 0xFFFF) != 0)
+ __builtin_abort ();
+
+ return 0;
+}
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index cdd439fe7506e7bc33654ffa027b493f23d278ac..a29681bffb902d2d05e3f18764ab519aacb3c5bc 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -327,6 +327,10 @@ replace_loop_annotate (void)
if (loop->latch)
replace_loop_annotate_in_block (loop->latch, loop);
+ /* Then also check all other exits. */
+ for (auto e : get_loop_exit_edges (loop))
+ replace_loop_annotate_in_block (e->src, loop);
+
/* Push the global flag_finite_loops state down to individual loops. */
loop->finite_p = flag_finite_loops;
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH]middle-end: inspect all exits for additional annotations for loop.
2024-02-14 13:09 [PATCH]middle-end: inspect all exits for additional annotations for loop Tamar Christina
@ 2024-02-14 13:41 ` Richard Biener
2024-02-14 15:15 ` Tamar Christina
0 siblings, 1 reply; 4+ messages in thread
From: Richard Biener @ 2024-02-14 13:41 UTC (permalink / raw)
To: Tamar Christina; +Cc: gcc-patches, nd, jlaw
On Wed, 14 Feb 2024, Tamar Christina wrote:
> Hi All,
>
> Attaching a pragma to a loop which has a complex condition often gets the pragma
> dropped. e.g.
>
> #pragma GCC novector
> while (i < N && parse_tables_n--)
>
> before lowering this is represented as:
>
> if (ANNOTATE_EXPR <i <= 305 && parse_tables_n-- != 0, no-vector>) ...
>
> But after lowering the condition is broken appart and attached to the final
> component of the expression:
>
> if (parse_tables_n.2_2 != 0) goto <D.4456>; else goto <D.4453>;
> <D.4456>:
> iftmp.1D.4452 = 1;
> goto <D.4454>;
> <D.4453>:
> iftmp.1D.4452 = 0;
> <D.4454>:
> D.4451 = .ANNOTATE (iftmp.1D.4452, 2, 0);
> if (D.4451 != 0) goto <D.4442>; else goto <D.4440>;
> <D.4440>:
>
> and it's never heard from again because during replace_loop_annotate we only
> inspect the loop header and latch for annotations.
>
> Since annotations were supposed to apply to the loop as a whole this fixes it
> by also checking the loop exit src blocks for annotations.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
I think this isn't entirely good. For simple cases for
do {} while the condition ends up in the latch while for while () {}
loops it ends up in the header. In your case the latch isn't empty
so it doesn't end up with the conditional.
I think your patch is OK to the point of looking at all loop exit
sources but you should elide the special-casing of header and
latch since it's really only exit conditionals that matter.
Richard.
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> * tree-cfg.cc (replace_loop_annotate): Inspect loop edges for annotations.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/vect/vect-novect_gcond.c: New test.
>
> --- inline copy of patch --
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..01e69cbef9d51b234c08a400c78dc078d53252f1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
> @@ -0,0 +1,39 @@
> +/* { dg-add-options vect_early_break } */
> +/* { dg-require-effective-target vect_early_break_hw } */
> +/* { dg-require-effective-target vect_int } */
> +/* { dg-additional-options "-O3" } */
> +
> +/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
> +
> +#include "tree-vect.h"
> +
> +#define N 306
> +#define NEEDLE 136
> +
> +int table[N];
> +
> +__attribute__ ((noipa))
> +int foo (int i, unsigned short parse_tables_n)
> +{
> + parse_tables_n >>= 9;
> + parse_tables_n += 11;
> +#pragma GCC novector
> + while (i < N && parse_tables_n--)
> + table[i++] = 0;
> +
> + return table[NEEDLE];
> +}
> +
> +int main ()
> +{
> + check_vect ();
> +
> +#pragma GCC novector
> + for (int j = 0; j < N; j++)
> + table[j] = -1;
> +
> + if (foo (0, 0xFFFF) != 0)
> + __builtin_abort ();
> +
> + return 0;
> +}
> diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
> index cdd439fe7506e7bc33654ffa027b493f23d278ac..a29681bffb902d2d05e3f18764ab519aacb3c5bc 100644
> --- a/gcc/tree-cfg.cc
> +++ b/gcc/tree-cfg.cc
> @@ -327,6 +327,10 @@ replace_loop_annotate (void)
> if (loop->latch)
> replace_loop_annotate_in_block (loop->latch, loop);
>
> + /* Then also check all other exits. */
> + for (auto e : get_loop_exit_edges (loop))
> + replace_loop_annotate_in_block (e->src, loop);
> +
> /* Push the global flag_finite_loops state down to individual loops. */
> loop->finite_p = flag_finite_loops;
> }
>
>
>
>
>
--
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH]middle-end: inspect all exits for additional annotations for loop.
2024-02-14 13:41 ` Richard Biener
@ 2024-02-14 15:15 ` Tamar Christina
2024-02-14 15:18 ` Richard Biener
0 siblings, 1 reply; 4+ messages in thread
From: Tamar Christina @ 2024-02-14 15:15 UTC (permalink / raw)
To: Richard Biener; +Cc: gcc-patches, nd, jlaw
[-- Attachment #1: Type: text/plain, Size: 2840 bytes --]
>
> I think this isn't entirely good. For simple cases for
> do {} while the condition ends up in the latch while for while () {}
> loops it ends up in the header. In your case the latch isn't empty
> so it doesn't end up with the conditional.
>
> I think your patch is OK to the point of looking at all loop exit
> sources but you should elide the special-casing of header and
> latch since it's really only exit conditionals that matter.
>
That makes sense, since in both cases the edges are in the respective
blocks. Should have thought about it more.
So how about this one.
Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
Ok for master?
Thanks,
Tamar
gcc/ChangeLog:
* tree-cfg.cc (replace_loop_annotate): Inspect loop edges for annotations.
gcc/testsuite/ChangeLog:
* gcc.dg/vect/vect-novect_gcond.c: New test.
--- inline copy of patch ---
diff --git a/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
new file mode 100644
index 0000000000000000000000000000000000000000..01e69cbef9d51b234c08a400c78dc078d53252f1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
@@ -0,0 +1,39 @@
+/* { dg-add-options vect_early_break } */
+/* { dg-require-effective-target vect_early_break_hw } */
+/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "-O3" } */
+
+/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
+
+#include "tree-vect.h"
+
+#define N 306
+#define NEEDLE 136
+
+int table[N];
+
+__attribute__ ((noipa))
+int foo (int i, unsigned short parse_tables_n)
+{
+ parse_tables_n >>= 9;
+ parse_tables_n += 11;
+#pragma GCC novector
+ while (i < N && parse_tables_n--)
+ table[i++] = 0;
+
+ return table[NEEDLE];
+}
+
+int main ()
+{
+ check_vect ();
+
+#pragma GCC novector
+ for (int j = 0; j < N; j++)
+ table[j] = -1;
+
+ if (foo (0, 0xFFFF) != 0)
+ __builtin_abort ();
+
+ return 0;
+}
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index cdd439fe7506e7bc33654ffa027b493f23d278ac..bdffc3b4ed277724e81b7dd67fe7966e8ece0c13 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -320,12 +320,9 @@ replace_loop_annotate (void)
for (auto loop : loops_list (cfun, 0))
{
- /* First look into the header. */
- replace_loop_annotate_in_block (loop->header, loop);
-
- /* Then look into the latch, if any. */
- if (loop->latch)
- replace_loop_annotate_in_block (loop->latch, loop);
+ /* Check all exit source blocks for annotations. */
+ for (auto e : get_loop_exit_edges (loop))
+ replace_loop_annotate_in_block (e->src, loop);
/* Push the global flag_finite_loops state down to individual loops. */
loop->finite_p = flag_finite_loops;
[-- Attachment #2: rb18267.patch --]
[-- Type: application/octet-stream, Size: 1863 bytes --]
diff --git a/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
new file mode 100644
index 0000000000000000000000000000000000000000..01e69cbef9d51b234c08a400c78dc078d53252f1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
@@ -0,0 +1,39 @@
+/* { dg-add-options vect_early_break } */
+/* { dg-require-effective-target vect_early_break_hw } */
+/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "-O3" } */
+
+/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
+
+#include "tree-vect.h"
+
+#define N 306
+#define NEEDLE 136
+
+int table[N];
+
+__attribute__ ((noipa))
+int foo (int i, unsigned short parse_tables_n)
+{
+ parse_tables_n >>= 9;
+ parse_tables_n += 11;
+#pragma GCC novector
+ while (i < N && parse_tables_n--)
+ table[i++] = 0;
+
+ return table[NEEDLE];
+}
+
+int main ()
+{
+ check_vect ();
+
+#pragma GCC novector
+ for (int j = 0; j < N; j++)
+ table[j] = -1;
+
+ if (foo (0, 0xFFFF) != 0)
+ __builtin_abort ();
+
+ return 0;
+}
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index cdd439fe7506e7bc33654ffa027b493f23d278ac..bdffc3b4ed277724e81b7dd67fe7966e8ece0c13 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -320,12 +320,9 @@ replace_loop_annotate (void)
for (auto loop : loops_list (cfun, 0))
{
- /* First look into the header. */
- replace_loop_annotate_in_block (loop->header, loop);
-
- /* Then look into the latch, if any. */
- if (loop->latch)
- replace_loop_annotate_in_block (loop->latch, loop);
+ /* Check all exit source blocks for annotations. */
+ for (auto e : get_loop_exit_edges (loop))
+ replace_loop_annotate_in_block (e->src, loop);
/* Push the global flag_finite_loops state down to individual loops. */
loop->finite_p = flag_finite_loops;
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH]middle-end: inspect all exits for additional annotations for loop.
2024-02-14 15:15 ` Tamar Christina
@ 2024-02-14 15:18 ` Richard Biener
0 siblings, 0 replies; 4+ messages in thread
From: Richard Biener @ 2024-02-14 15:18 UTC (permalink / raw)
To: Tamar Christina; +Cc: gcc-patches, nd, jlaw
> Am 14.02.2024 um 16:16 schrieb Tamar Christina <tamar.christina@arm.com>:
>
>
>>
>>
>> I think this isn't entirely good. For simple cases for
>> do {} while the condition ends up in the latch while for while () {}
>> loops it ends up in the header. In your case the latch isn't empty
>> so it doesn't end up with the conditional.
>>
>> I think your patch is OK to the point of looking at all loop exit
>> sources but you should elide the special-casing of header and
>> latch since it's really only exit conditionals that matter.
>>
>
> That makes sense, since in both cases the edges are in the respective
> blocks. Should have thought about it more.
>
> So how about this one.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
Ok
Richard
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> * tree-cfg.cc (replace_loop_annotate): Inspect loop edges for annotations.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/vect/vect-novect_gcond.c: New test.
>
> --- inline copy of patch ---
>
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..01e69cbef9d51b234c08a400c78dc078d53252f1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c
> @@ -0,0 +1,39 @@
> +/* { dg-add-options vect_early_break } */
> +/* { dg-require-effective-target vect_early_break_hw } */
> +/* { dg-require-effective-target vect_int } */
> +/* { dg-additional-options "-O3" } */
> +
> +/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
> +
> +#include "tree-vect.h"
> +
> +#define N 306
> +#define NEEDLE 136
> +
> +int table[N];
> +
> +__attribute__ ((noipa))
> +int foo (int i, unsigned short parse_tables_n)
> +{
> + parse_tables_n >>= 9;
> + parse_tables_n += 11;
> +#pragma GCC novector
> + while (i < N && parse_tables_n--)
> + table[i++] = 0;
> +
> + return table[NEEDLE];
> +}
> +
> +int main ()
> +{
> + check_vect ();
> +
> +#pragma GCC novector
> + for (int j = 0; j < N; j++)
> + table[j] = -1;
> +
> + if (foo (0, 0xFFFF) != 0)
> + __builtin_abort ();
> +
> + return 0;
> +}
> diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
> index cdd439fe7506e7bc33654ffa027b493f23d278ac..bdffc3b4ed277724e81b7dd67fe7966e8ece0c13 100644
> --- a/gcc/tree-cfg.cc
> +++ b/gcc/tree-cfg.cc
> @@ -320,12 +320,9 @@ replace_loop_annotate (void)
>
> for (auto loop : loops_list (cfun, 0))
> {
> - /* First look into the header. */
> - replace_loop_annotate_in_block (loop->header, loop);
> -
> - /* Then look into the latch, if any. */
> - if (loop->latch)
> - replace_loop_annotate_in_block (loop->latch, loop);
> + /* Check all exit source blocks for annotations. */
> + for (auto e : get_loop_exit_edges (loop))
> + replace_loop_annotate_in_block (e->src, loop);
>
> /* Push the global flag_finite_loops state down to individual loops. */
> loop->finite_p = flag_finite_loops;
> <rb18267.patch>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2024-02-14 13:09 [PATCH]middle-end: inspect all exits for additional annotations for loop Tamar Christina
2024-02-14 13:41 ` Richard Biener
2024-02-14 15:15 ` Tamar Christina
2024-02-14 15:18 ` Richard Biener
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