diff mbox series

Fix DR_GROUP_GAP for strided accesses (PR 92677)

Message ID mpt1rtrymv7.fsf@arm.com
State New
Headers show
Series Fix DR_GROUP_GAP for strided accesses (PR 92677) | expand

Commit Message

Richard Sandiford Nov. 29, 2019, 10:53 a.m. UTC 
When dissolving an SLP-only group of accesses, we should only set
the gap to group_size - 1 for normal non-strided groups.

Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?

Richard


2019-11-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	PR tree-optimization/92677
	* tree-vect-loop.c (vect_dissolve_slp_only_groups): Set the gap
	to zero when dissolving a group of strided accesses.

gcc/testsuite/
	PR tree-optimization/92677
	* gcc.dg/vect/pr92677.c: New test.

Comments

Richard Biener Nov. 29, 2019, 12:22 p.m. UTC | #1 
On Fri, Nov 29, 2019 at 11:53 AM Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> When dissolving an SLP-only group of accesses, we should only set
> the gap to group_size - 1 for normal non-strided groups.
>
> Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?

OK.  Probably also broken on branch(es).

Richard.

> Richard
>
>
> 2019-11-29  Richard Sandiford  <richard.sandiford@arm.com>
>
> gcc/
>         PR tree-optimization/92677
>         * tree-vect-loop.c (vect_dissolve_slp_only_groups): Set the gap
>         to zero when dissolving a group of strided accesses.
>
> gcc/testsuite/
>         PR tree-optimization/92677
>         * gcc.dg/vect/pr92677.c: New test.
>
> Index: gcc/tree-vect-loop.c
> ===================================================================
> --- gcc/tree-vect-loop.c        2019-11-29 09:13:43.764143091 +0000
> +++ gcc/tree-vect-loop.c        2019-11-29 10:52:30.475476141 +0000
> @@ -1829,7 +1829,10 @@ vect_dissolve_slp_only_groups (loop_vec_
>                   DR_GROUP_FIRST_ELEMENT (vinfo) = vinfo;
>                   DR_GROUP_NEXT_ELEMENT (vinfo) = NULL;
>                   DR_GROUP_SIZE (vinfo) = 1;
> -                 DR_GROUP_GAP (vinfo) = group_size - 1;
> +                 if (STMT_VINFO_STRIDED_P (first_element))
> +                   DR_GROUP_GAP (vinfo) = 0;
> +                 else
> +                   DR_GROUP_GAP (vinfo) = group_size - 1;
>                   vinfo = next;
>                 }
>             }
> Index: gcc/testsuite/gcc.dg/vect/pr92677.c
> ===================================================================
> --- /dev/null   2019-09-17 11:41:18.176664108 +0100
> +++ gcc/testsuite/gcc.dg/vect/pr92677.c 2019-11-29 10:52:30.475476141 +0000
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-O3" } */
> +
> +int a, c;
> +int *b;
> +long d;
> +double *e;
> +
> +void fn1() {
> +  long f;
> +  double g, h;
> +  while (c) {
> +    if (d) {
> +      g = *e;
> +      *(b + 4) = g;
> +    }
> +    if (f) {
> +      h = *(e + 2);
> +      *(b + 6) = h;
> +    }
> +    e += a;
> +    b += 8;
> +    c--;
> +    d += 2;
> +  }
> +}
Richard Sandiford Nov. 29, 2019, 2:56 p.m. UTC | #2 
Richard Biener <richard.guenther@gmail.com> writes:
> On Fri, Nov 29, 2019 at 11:53 AM Richard Sandiford
> <richard.sandiford@arm.com> wrote:
>>
>> When dissolving an SLP-only group of accesses, we should only set
>> the gap to group_size - 1 for normal non-strided groups.
>>
>> Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?
>
> OK.  Probably also broken on branch(es).

It looks like it's trunk only -- we didn't dissolve DR groups here
until the support for SLP masked loads (r271704).

Thanks,
Richard

>
> Richard.
>
>> Richard
>>
>>
>> 2019-11-29  Richard Sandiford  <richard.sandiford@arm.com>
>>
>> gcc/
>>         PR tree-optimization/92677
>>         * tree-vect-loop.c (vect_dissolve_slp_only_groups): Set the gap
>>         to zero when dissolving a group of strided accesses.
>>
>> gcc/testsuite/
>>         PR tree-optimization/92677
>>         * gcc.dg/vect/pr92677.c: New test.
>>
>> Index: gcc/tree-vect-loop.c
>> ===================================================================
>> --- gcc/tree-vect-loop.c        2019-11-29 09:13:43.764143091 +0000
>> +++ gcc/tree-vect-loop.c        2019-11-29 10:52:30.475476141 +0000
>> @@ -1829,7 +1829,10 @@ vect_dissolve_slp_only_groups (loop_vec_
>>                   DR_GROUP_FIRST_ELEMENT (vinfo) = vinfo;
>>                   DR_GROUP_NEXT_ELEMENT (vinfo) = NULL;
>>                   DR_GROUP_SIZE (vinfo) = 1;
>> -                 DR_GROUP_GAP (vinfo) = group_size - 1;
>> +                 if (STMT_VINFO_STRIDED_P (first_element))
>> +                   DR_GROUP_GAP (vinfo) = 0;
>> +                 else
>> +                   DR_GROUP_GAP (vinfo) = group_size - 1;
>>                   vinfo = next;
>>                 }
>>             }
>> Index: gcc/testsuite/gcc.dg/vect/pr92677.c
>> ===================================================================
>> --- /dev/null   2019-09-17 11:41:18.176664108 +0100
>> +++ gcc/testsuite/gcc.dg/vect/pr92677.c 2019-11-29 10:52:30.475476141 +0000
>> @@ -0,0 +1,26 @@
>> +/* { dg-do compile } */
>> +/* { dg-additional-options "-O3" } */
>> +
>> +int a, c;
>> +int *b;
>> +long d;
>> +double *e;
>> +
>> +void fn1() {
>> +  long f;
>> +  double g, h;
>> +  while (c) {
>> +    if (d) {
>> +      g = *e;
>> +      *(b + 4) = g;
>> +    }
>> +    if (f) {
>> +      h = *(e + 2);
>> +      *(b + 6) = h;
>> +    }
>> +    e += a;
>> +    b += 8;
>> +    c--;
>> +    d += 2;
>> +  }
>> +}
diff mbox series

Patch

Index: gcc/tree-vect-loop.c
===================================================================
--- gcc/tree-vect-loop.c	2019-11-29 09:13:43.764143091 +0000
+++ gcc/tree-vect-loop.c	2019-11-29 10:52:30.475476141 +0000
@@ -1829,7 +1829,10 @@  vect_dissolve_slp_only_groups (loop_vec_
 		  DR_GROUP_FIRST_ELEMENT (vinfo) = vinfo;
 		  DR_GROUP_NEXT_ELEMENT (vinfo) = NULL;
 		  DR_GROUP_SIZE (vinfo) = 1;
-		  DR_GROUP_GAP (vinfo) = group_size - 1;
+		  if (STMT_VINFO_STRIDED_P (first_element))
+		    DR_GROUP_GAP (vinfo) = 0;
+		  else
+		    DR_GROUP_GAP (vinfo) = group_size - 1;
 		  vinfo = next;
 		}
 	    }
Index: gcc/testsuite/gcc.dg/vect/pr92677.c
===================================================================
--- /dev/null	2019-09-17 11:41:18.176664108 +0100
+++ gcc/testsuite/gcc.dg/vect/pr92677.c	2019-11-29 10:52:30.475476141 +0000
@@ -0,0 +1,26 @@ 
+/* { dg-do compile } */
+/* { dg-additional-options "-O3" } */
+
+int a, c;
+int *b;
+long d;
+double *e;
+
+void fn1() {
+  long f;
+  double g, h;
+  while (c) {
+    if (d) {
+      g = *e;
+      *(b + 4) = g;
+    }
+    if (f) {
+      h = *(e + 2);
+      *(b + 6) = h;
+    }
+    e += a;
+    b += 8;
+    c--;
+    d += 2;
+  }
+}