Re: [PATCH] Simple fix to enhance outer-loop vectorization.
On Thu, May 28, 2015 at 5:51 PM, Yuri Rumyantsev ysrum...@gmail.com wrote:
Richard,
First of all, I don't think that it is possible to write out test for
outer-loop vectorization with zero-step reference because of possible
loop-carried dependencies and run-time aliasing is not supported for
outer-loop. If there are no such dependencies pre or pdse does
hoisting (sinking) of such invariant references. So I add a check on
it to accept zero-step references for outer loop marked with
forc-vectorize flag to guarantee absence of loop-carried dependencies
between inner-loop iterations.
I included run-time test that checks vectorization correctness.
Update patch is attached.
Please don't use fprintf from testcases but just call abort () when
you detect an error. gcc.dg/vect testcases shouldn't have an
explicit dg-do run, just drop it, it is implicit.
Ok with that changes.
Thanks,
Richard.
Yuri..
2015-05-28 14:39 GMT+03:00 Richard Biener richard.guent...@gmail.com:
On Thu, May 28, 2015 at 1:00 PM, Yuri Rumyantsev ysrum...@gmail.com wrote:
Hi All,
Here is a simple patch which removes restriction on outer-loop
vectorization - allow references in inner-loop with zero step. This
case was found in one important benchmark.
Bootstrap and regression testing did not show any new failures.
Is it OK for trunk.
ChangeLog:
2015-05-28 Yuri Rumyantsev ysrum...@gmail.com
* tree-vect-data-refs.c (vect_analyze_data_ref_access): Allow
consecutive accesses within outer-loop vectorization for references
with zero step in inner-loop.
gcc/testsuite/ChangeLog:
* gcc.dg/vect/fast-math-vect-outer-1.c: New test.
Can you please add a non-omp-simd testcase that triggers this as well and
that
is a runtime testcase verifying the transform is correct?
Also please don't add to the strange testcase-name machinery but just
use { dg-additional-options -ffast-math }
Index: tree-vect-data-refs.c
===
--- tree-vect-data-refs.c (revision 223653)
+++ tree-vect-data-refs.c (working copy)
@@ -2261,7 +2261,6 @@
return true;
}
-
/* Analyze the access pattern of the data-reference DR.
In case of non-consecutive accesses call vect_analyze_group_access() to
analyze groups of accesses. */
spurious white-space change
@@ -2291,14 +2290,8 @@
if (loop_vinfo integer_zerop (step))
Surely the comment before this needs updating now.
{
GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) = NULL;
- if (nested_in_vect_loop_p (loop, stmt))
- {
- if (dump_enabled_p ())
- dump_printf_loc (MSG_NOTE, vect_location,
-zero step in inner loop of nest\n);
- return false;
- }
- return DR_IS_READ (dr);
+ if (!nested_in_vect_loop_p (loop, stmt))
+ return DR_IS_READ (dr);
}
if (loop nested_in_vect_loop_p (loop, stmt))
so what happens after the patch? It would be nice to have a comment
explaining what happens in the nested_in_vect_loop_p case for
the case when the outer-loop step is zero and when it is not zero.
In particular as you don't need any code generation changes - this hints
at that you may miss something ;)
Otherwise of course the patch is ok - lifting restrictions is good.
Thanks,
Richard.
[PATCH] Simple fix to enhance outer-loop vectorization.
Hi All, Here is a simple patch which removes restriction on outer-loop vectorization - allow references in inner-loop with zero step. This case was found in one important benchmark. Bootstrap and regression testing did not show any new failures. Is it OK for trunk. ChangeLog: 2015-05-28 Yuri Rumyantsev ysrum...@gmail.com * tree-vect-data-refs.c (vect_analyze_data_ref_access): Allow consecutive accesses within outer-loop vectorization for references with zero step in inner-loop. gcc/testsuite/ChangeLog: * gcc.dg/vect/fast-math-vect-outer-1.c: New test. patch Description: Binary data
Re: [PATCH] Simple fix to enhance outer-loop vectorization.
On Thu, May 28, 2015 at 1:00 PM, Yuri Rumyantsev ysrum...@gmail.com wrote:
Hi All,
Here is a simple patch which removes restriction on outer-loop
vectorization - allow references in inner-loop with zero step. This
case was found in one important benchmark.
Bootstrap and regression testing did not show any new failures.
Is it OK for trunk.
ChangeLog:
2015-05-28 Yuri Rumyantsev ysrum...@gmail.com
* tree-vect-data-refs.c (vect_analyze_data_ref_access): Allow
consecutive accesses within outer-loop vectorization for references
with zero step in inner-loop.
gcc/testsuite/ChangeLog:
* gcc.dg/vect/fast-math-vect-outer-1.c: New test.
Can you please add a non-omp-simd testcase that triggers this as well and that
is a runtime testcase verifying the transform is correct?
Also please don't add to the strange testcase-name machinery but just
use { dg-additional-options -ffast-math }
Index: tree-vect-data-refs.c
===
--- tree-vect-data-refs.c (revision 223653)
+++ tree-vect-data-refs.c (working copy)
@@ -2261,7 +2261,6 @@
return true;
}
-
/* Analyze the access pattern of the data-reference DR.
In case of non-consecutive accesses call vect_analyze_group_access() to
analyze groups of accesses. */
spurious white-space change
@@ -2291,14 +2290,8 @@
if (loop_vinfo integer_zerop (step))
Surely the comment before this needs updating now.
{
GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) = NULL;
- if (nested_in_vect_loop_p (loop, stmt))
- {
- if (dump_enabled_p ())
- dump_printf_loc (MSG_NOTE, vect_location,
-zero step in inner loop of nest\n);
- return false;
- }
- return DR_IS_READ (dr);
+ if (!nested_in_vect_loop_p (loop, stmt))
+ return DR_IS_READ (dr);
}
if (loop nested_in_vect_loop_p (loop, stmt))
so what happens after the patch? It would be nice to have a comment
explaining what happens in the nested_in_vect_loop_p case for
the case when the outer-loop step is zero and when it is not zero.
In particular as you don't need any code generation changes - this hints
at that you may miss something ;)
Otherwise of course the patch is ok - lifting restrictions is good.
Thanks,
Richard.
Re: [PATCH] Simple fix to enhance outer-loop vectorization.
Richard,
First of all, I don't think that it is possible to write out test for
outer-loop vectorization with zero-step reference because of possible
loop-carried dependencies and run-time aliasing is not supported for
outer-loop. If there are no such dependencies pre or pdse does
hoisting (sinking) of such invariant references. So I add a check on
it to accept zero-step references for outer loop marked with
forc-vectorize flag to guarantee absence of loop-carried dependencies
between inner-loop iterations.
I included run-time test that checks vectorization correctness.
Update patch is attached.
Yuri..
2015-05-28 14:39 GMT+03:00 Richard Biener richard.guent...@gmail.com:
On Thu, May 28, 2015 at 1:00 PM, Yuri Rumyantsev ysrum...@gmail.com wrote:
Hi All,
Here is a simple patch which removes restriction on outer-loop
vectorization - allow references in inner-loop with zero step. This
case was found in one important benchmark.
Bootstrap and regression testing did not show any new failures.
Is it OK for trunk.
ChangeLog:
2015-05-28 Yuri Rumyantsev ysrum...@gmail.com
* tree-vect-data-refs.c (vect_analyze_data_ref_access): Allow
consecutive accesses within outer-loop vectorization for references
with zero step in inner-loop.
gcc/testsuite/ChangeLog:
* gcc.dg/vect/fast-math-vect-outer-1.c: New test.
Can you please add a non-omp-simd testcase that triggers this as well and that
is a runtime testcase verifying the transform is correct?
Also please don't add to the strange testcase-name machinery but just
use { dg-additional-options -ffast-math }
Index: tree-vect-data-refs.c
===
--- tree-vect-data-refs.c (revision 223653)
+++ tree-vect-data-refs.c (working copy)
@@ -2261,7 +2261,6 @@
return true;
}
-
/* Analyze the access pattern of the data-reference DR.
In case of non-consecutive accesses call vect_analyze_group_access() to
analyze groups of accesses. */
spurious white-space change
@@ -2291,14 +2290,8 @@
if (loop_vinfo integer_zerop (step))
Surely the comment before this needs updating now.
{
GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) = NULL;
- if (nested_in_vect_loop_p (loop, stmt))
- {
- if (dump_enabled_p ())
- dump_printf_loc (MSG_NOTE, vect_location,
-zero step in inner loop of nest\n);
- return false;
- }
- return DR_IS_READ (dr);
+ if (!nested_in_vect_loop_p (loop, stmt))
+ return DR_IS_READ (dr);
}
if (loop nested_in_vect_loop_p (loop, stmt))
so what happens after the patch? It would be nice to have a comment
explaining what happens in the nested_in_vect_loop_p case for
the case when the outer-loop step is zero and when it is not zero.
In particular as you don't need any code generation changes - this hints
at that you may miss something ;)
Otherwise of course the patch is ok - lifting restrictions is good.
Thanks,
Richard.
patch.1
Description: Binary data
