* Fix PR/46200 -- ivopt bug in test condition cost computation
@ 2010-10-29 23:10 Xinliang David Li
2010-10-31 9:22 ` Zdenek Dvorak
2010-11-05 20:40 ` H.J. Lu
0 siblings, 2 replies; 11+ messages in thread
From: Xinliang David Li @ 2010-10-29 23:10 UTC (permalink / raw)
To: GCC Patches; +Cc: Zdenek Dvorak
[-- Attachment #1: Type: text/plain, Size: 282 bytes --]
Hi, please review the patch attached. Regression and some performance
test is under going.
Thanks,
David
2010-10-29 Xinliang David Li <davidxl@google.com>
PR target/46200
* tree-ssa-loop-ivopts.c (get_computation_cost_at):
Adjust cbase if the use stmt is after iv update.
[-- Attachment #2: ivopt_46200.p --]
[-- Type: text/x-pascal, Size: 1702 bytes --]
Index: gcc/tree-ssa-loop-ivopts.c
===================================================================
--- gcc/tree-ssa-loop-ivopts.c (revision 166032)
+++ gcc/tree-ssa-loop-ivopts.c (working copy)
@@ -4027,6 +4027,8 @@ get_computation_cost_at (struct ivopts_d
STRIP_NOPS (cbase);
ctype = TREE_TYPE (cbase);
+ stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);
+
/* use = ubase + ratio * (var - cbase). If either cbase is a constant
or ratio == 1, it is better to handle this like
@@ -4045,8 +4047,24 @@ get_computation_cost_at (struct ivopts_d
}
else if (ratio == 1)
{
+ tree real_cbase = cbase;
+
+ /* Check to see if any adjustment is needed. */
+ if (cstepi == 0 && stmt_is_after_inc)
+ {
+ aff_tree real_cbase_aff;
+ aff_tree cstep_aff;
+
+ tree_to_aff_combination (cbase, TREE_TYPE (real_cbase),
+ &real_cbase_aff);
+ tree_to_aff_combination (cstep, TREE_TYPE (cstep), &cstep_aff);
+
+ aff_combination_add (&real_cbase_aff, &cstep_aff);
+ real_cbase = aff_combination_to_tree (&real_cbase_aff);
+ }
+
cost = difference_cost (data,
- ubase, cbase,
+ ubase, real_cbase,
&symbol_present, &var_present, &offset,
depends_on);
cost.cost /= avg_loop_niter (data->current_loop);
@@ -4088,7 +4106,6 @@ get_computation_cost_at (struct ivopts_d
/* If we are after the increment, the value of the candidate is higher by
one iteration. */
- stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);
if (stmt_is_after_inc)
offset -= ratio * cstepi;
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-10-29 23:10 Fix PR/46200 -- ivopt bug in test condition cost computation Xinliang David Li
@ 2010-10-31 9:22 ` Zdenek Dvorak
2010-11-01 6:59 ` Xinliang David Li
2010-11-05 20:40 ` H.J. Lu
1 sibling, 1 reply; 11+ messages in thread
From: Zdenek Dvorak @ 2010-10-31 9:22 UTC (permalink / raw)
To: Xinliang David Li; +Cc: GCC Patches
Hi,
> Hi, please review the patch attached. Regression and some performance
> test is under going.
it would be more consistent to either avoid using aff_combination functions
in get_computation_cost_at completely, or rewrite it to use aff_combination
instead of the current difference_cost/... functions (however, the latter
would probably lead to somewhat slower compilation time). The patch should
also include a testcase for the problem.
Thanks for working on this,
Zdenek
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-10-31 9:22 ` Zdenek Dvorak
@ 2010-11-01 6:59 ` Xinliang David Li
2010-11-02 17:15 ` Xinliang David Li
2010-11-03 10:28 ` Zdenek Dvorak
0 siblings, 2 replies; 11+ messages in thread
From: Xinliang David Li @ 2010-11-01 6:59 UTC (permalink / raw)
To: Zdenek Dvorak; +Cc: GCC Patches
[-- Attachment #1: Type: text/plain, Size: 1123 bytes --]
On Sat, Oct 30, 2010 at 12:30 PM, Zdenek Dvorak <rakdver@kam.mff.cuni.cz> wrote:
> Hi,
>
>> Hi, please review the patch attached. Regression and some performance
>> test is under going.
>
> it would be more consistent to either avoid using aff_combination functions
> in get_computation_cost_at completely, or rewrite it to use aff_combination
> instead of the current difference_cost/... functions (however, the latter
> would probably lead to somewhat slower compilation time). The patch should
> also include a testcase for the problem.
I agree -- the code for cost computation should match (or probably
share with) code in the rewrite functions -- however that is a much
larger task than is needed for this PR.
I added a test case (marked with x86 target as ivopt are very target
sensitive). Regression test and minimal perf testing went ok.
Ok to checkin?
Thanks,
David
(test case change log)
010-10-31 Xinliang David Li <davidxl@google.com>
PR target/46200
* g++.dg/tree-ssa/ivopts-2.C: New test.
>
> Thanks for working on this,
>
> Zdenek
>
[-- Attachment #2: ivopt_46200_2.p --]
[-- Type: application/octet-stream, Size: 2294 bytes --]
Index: gcc/testsuite/g++.dg/tree-ssa/ivopts-2.C
===================================================================
--- gcc/testsuite/g++.dg/tree-ssa/ivopts-2.C (revision 0)
+++ gcc/testsuite/g++.dg/tree-ssa/ivopts-2.C (revision 0)
@@ -0,0 +1,11 @@
+/* { dg-do compile { target { i?86-*-* x86_64-*-* } } } */
+/* { dg-options "-O2 -fdump-tree-ivopts-details" } */
+
+void test (int *b, int *e, int stride)
+ {
+ for (int *p = b; p != e; p += stride)
+ *p = 1;
+ }
+
+/* { dg-final { scan-tree-dump-times "PHI <p" 1 "ivopts"} } */
+/* { dg-final { cleanup-tree-dump "ivopts" } } */
Index: gcc/tree-ssa-loop-ivopts.c
===================================================================
--- gcc/tree-ssa-loop-ivopts.c (revision 166032)
+++ gcc/tree-ssa-loop-ivopts.c (working copy)
@@ -4027,6 +4027,8 @@ get_computation_cost_at (struct ivopts_d
STRIP_NOPS (cbase);
ctype = TREE_TYPE (cbase);
+ stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);
+
/* use = ubase + ratio * (var - cbase). If either cbase is a constant
or ratio == 1, it is better to handle this like
@@ -4045,8 +4047,24 @@ get_computation_cost_at (struct ivopts_d
}
else if (ratio == 1)
{
+ tree real_cbase = cbase;
+
+ /* Check to see if any adjustment is needed. */
+ if (cstepi == 0 && stmt_is_after_inc)
+ {
+ aff_tree real_cbase_aff;
+ aff_tree cstep_aff;
+
+ tree_to_aff_combination (cbase, TREE_TYPE (real_cbase),
+ &real_cbase_aff);
+ tree_to_aff_combination (cstep, TREE_TYPE (cstep), &cstep_aff);
+
+ aff_combination_add (&real_cbase_aff, &cstep_aff);
+ real_cbase = aff_combination_to_tree (&real_cbase_aff);
+ }
+
cost = difference_cost (data,
- ubase, cbase,
+ ubase, real_cbase,
&symbol_present, &var_present, &offset,
depends_on);
cost.cost /= avg_loop_niter (data->current_loop);
@@ -4088,7 +4106,6 @@ get_computation_cost_at (struct ivopts_d
/* If we are after the increment, the value of the candidate is higher by
one iteration. */
- stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);
if (stmt_is_after_inc)
offset -= ratio * cstepi;
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-11-01 6:59 ` Xinliang David Li
@ 2010-11-02 17:15 ` Xinliang David Li
2010-11-03 10:28 ` Zdenek Dvorak
1 sibling, 0 replies; 11+ messages in thread
From: Xinliang David Li @ 2010-11-02 17:15 UTC (permalink / raw)
To: Zdenek Dvorak; +Cc: GCC Patches
Can I get an explicit OK :) ?
Thanks,
David
On Sun, Oct 31, 2010 at 11:59 PM, Xinliang David Li <davidxl@google.com> wrote:
> On Sat, Oct 30, 2010 at 12:30 PM, Zdenek Dvorak <rakdver@kam.mff.cuni.cz> wrote:
>> Hi,
>>
>>> Hi, please review the patch attached. Regression and some performance
>>> test is under going.
>>
>> it would be more consistent to either avoid using aff_combination functions
>> in get_computation_cost_at completely, or rewrite it to use aff_combination
>> instead of the current difference_cost/... functions (however, the latter
>> would probably lead to somewhat slower compilation time). The patch should
>> also include a testcase for the problem.
>
> I agree -- the code for cost computation should match (or probably
> share with) code in the rewrite functions -- however that is a much
> larger task than is needed for this PR.
>
> I added a test case (marked with x86 target as ivopt are very target
> sensitive). Regression test and minimal perf testing went ok.
>
> Ok to checkin?
>
> Thanks,
>
> David
>
> (test case change log)
>
> 010-10-31 Xinliang David Li <davidxl@google.com>
>
> PR target/46200
> * g++.dg/tree-ssa/ivopts-2.C: New test.
>
>
>
>
>
>
>>
>> Thanks for working on this,
>>
>> Zdenek
>>
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-11-01 6:59 ` Xinliang David Li
2010-11-02 17:15 ` Xinliang David Li
@ 2010-11-03 10:28 ` Zdenek Dvorak
2010-11-03 23:10 ` Xinliang David Li
1 sibling, 1 reply; 11+ messages in thread
From: Zdenek Dvorak @ 2010-11-03 10:28 UTC (permalink / raw)
To: Xinliang David Li; +Cc: GCC Patches
Hi,
> >> Hi, please review the patch attached. Regression and some performance
> >> test is under going.
> >
> > it would be more consistent to either avoid using aff_combination functions
> > in get_computation_cost_at completely, or rewrite it to use aff_combination
> > instead of the current difference_cost/... functions (however, the latter
> > would probably lead to somewhat slower compilation time). Â The patch should
> > also include a testcase for the problem.
>
> I agree -- the code for cost computation should match (or probably
> share with) code in the rewrite functions -- however that is a much
> larger task than is needed for this PR.
>
> I added a test case (marked with x86 target as ivopt are very target
> sensitive). Regression test and minimal perf testing went ok.
OK,
Zdenek
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-11-03 10:28 ` Zdenek Dvorak
@ 2010-11-03 23:10 ` Xinliang David Li
0 siblings, 0 replies; 11+ messages in thread
From: Xinliang David Li @ 2010-11-03 23:10 UTC (permalink / raw)
To: Zdenek Dvorak; +Cc: GCC Patches
Submitted as r166280.
Thanks,
David
On Wed, Nov 3, 2010 at 3:27 AM, Zdenek Dvorak <rakdver@kam.mff.cuni.cz> wrote:
> Hi,
>
>> >> Hi, please review the patch attached. Regression and some performance
>> >> test is under going.
>> >
>> > it would be more consistent to either avoid using aff_combination functions
>> > in get_computation_cost_at completely, or rewrite it to use aff_combination
>> > instead of the current difference_cost/... functions (however, the latter
>> > would probably lead to somewhat slower compilation time). The patch should
>> > also include a testcase for the problem.
>>
>> I agree -- the code for cost computation should match (or probably
>> share with) code in the rewrite functions -- however that is a much
>> larger task than is needed for this PR.
>>
>> I added a test case (marked with x86 target as ivopt are very target
>> sensitive). Regression test and minimal perf testing went ok.
>
> OK,
>
> Zdenek
>
>
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-10-29 23:10 Fix PR/46200 -- ivopt bug in test condition cost computation Xinliang David Li
2010-10-31 9:22 ` Zdenek Dvorak
@ 2010-11-05 20:40 ` H.J. Lu
2010-11-05 20:42 ` H.J. Lu
` (2 more replies)
1 sibling, 3 replies; 11+ messages in thread
From: H.J. Lu @ 2010-11-05 20:40 UTC (permalink / raw)
To: Xinliang David Li; +Cc: GCC Patches, Zdenek Dvorak
On Fri, Oct 29, 2010 at 1:28 PM, Xinliang David Li <davidxl@google.com> wrote:
> Hi, please review the patch attached. Regression and some performance
> test is under going.
>
> Thanks,
>
> David
>
>
> 2010-10-29 Xinliang David Li <davidxl@google.com>
>
> PR target/46200
> * tree-ssa-loop-ivopts.c (get_computation_cost_at):
> Adjust cbase if the use stmt is after iv update.
>
This patch may have caused:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46316
You need to build a 32bit gcc to reproduce it. I am using
CC="gcc -m32" CXX="g++ -m32" configure i686-linux
on Fedora 16/Intel64 to build 32bit GCC.
--
H.J.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-11-05 20:40 ` H.J. Lu
@ 2010-11-05 20:42 ` H.J. Lu
2010-11-05 21:00 ` H.J. Lu
2010-11-06 11:08 ` Xinliang David Li
2010-11-07 21:29 ` Xinliang David Li
2 siblings, 1 reply; 11+ messages in thread
From: H.J. Lu @ 2010-11-05 20:42 UTC (permalink / raw)
To: Xinliang David Li; +Cc: GCC Patches, Zdenek Dvorak
On Fri, Nov 5, 2010 at 1:32 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Oct 29, 2010 at 1:28 PM, Xinliang David Li <davidxl@google.com> wrote:
>> Hi, please review the patch attached. Regression and some performance
>> test is under going.
>>
>> Thanks,
>>
>> David
>>
>>
>> 2010-10-29 Xinliang David Li <davidxl@google.com>
>>
>> PR target/46200
>> * tree-ssa-loop-ivopts.c (get_computation_cost_at):
>> Adjust cbase if the use stmt is after iv update.
>>
>
> This patch may have caused:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46316
>
I was wrong. Ignore it.
--
H.J.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-11-05 20:42 ` H.J. Lu
@ 2010-11-05 21:00 ` H.J. Lu
0 siblings, 0 replies; 11+ messages in thread
From: H.J. Lu @ 2010-11-05 21:00 UTC (permalink / raw)
To: Xinliang David Li; +Cc: GCC Patches, Zdenek Dvorak
On Fri, Nov 5, 2010 at 1:40 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Nov 5, 2010 at 1:32 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Fri, Oct 29, 2010 at 1:28 PM, Xinliang David Li <davidxl@google.com> wrote:
>>> Hi, please review the patch attached. Regression and some performance
>>> test is under going.
>>>
>>> Thanks,
>>>
>>> David
>>>
>>>
>>> 2010-10-29 Xinliang David Li <davidxl@google.com>
>>>
>>> PR target/46200
>>> * tree-ssa-loop-ivopts.c (get_computation_cost_at):
>>> Adjust cbase if the use stmt is after iv update.
>>>
>>
>> This patch may have caused:
>>
>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46316
>>
>
> I was wrong. Ignore it.
Ooops. I was right. This is the cause/
--
H.J.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-11-05 20:40 ` H.J. Lu
2010-11-05 20:42 ` H.J. Lu
@ 2010-11-06 11:08 ` Xinliang David Li
2010-11-07 21:29 ` Xinliang David Li
2 siblings, 0 replies; 11+ messages in thread
From: Xinliang David Li @ 2010-11-06 11:08 UTC (permalink / raw)
To: H.J. Lu; +Cc: GCC Patches, Zdenek Dvorak
Sorry for the late reply -- reproduced. It is likely some bug
triggered by this change. I will take a look.
David
On Fri, Nov 5, 2010 at 1:32 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Oct 29, 2010 at 1:28 PM, Xinliang David Li <davidxl@google.com> wrote:
>> Hi, please review the patch attached. Regression and some performance
>> test is under going.
>>
>> Thanks,
>>
>> David
>>
>>
>> 2010-10-29 Xinliang David Li <davidxl@google.com>
>>
>> PR target/46200
>> * tree-ssa-loop-ivopts.c (get_computation_cost_at):
>> Adjust cbase if the use stmt is after iv update.
>>
>
> This patch may have caused:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46316
>
> You need to build a 32bit gcc to reproduce it. I am using
>
> CC="gcc -m32" CXX="g++ -m32" configure i686-linux
>
> on Fedora 16/Intel64 to build 32bit GCC.
>
>
> --
> H.J.
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Fix PR/46200 -- ivopt bug in test condition cost computation
2010-11-05 20:40 ` H.J. Lu
2010-11-05 20:42 ` H.J. Lu
2010-11-06 11:08 ` Xinliang David Li
@ 2010-11-07 21:29 ` Xinliang David Li
2 siblings, 0 replies; 11+ messages in thread
From: Xinliang David Li @ 2010-11-07 21:29 UTC (permalink / raw)
To: H.J. Lu; +Cc: GCC Patches, Zdenek Dvorak
I have no idea why my patch would have affected it, but this seems to
be a problem in double_int overflow in tree-vrp. I will send out a
patch shortly.
David
On Fri, Nov 5, 2010 at 1:32 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Oct 29, 2010 at 1:28 PM, Xinliang David Li <davidxl@google.com> wrote:
>> Hi, please review the patch attached. Regression and some performance
>> test is under going.
>>
>> Thanks,
>>
>> David
>>
>>
>> 2010-10-29 Xinliang David Li <davidxl@google.com>
>>
>> PR target/46200
>> * tree-ssa-loop-ivopts.c (get_computation_cost_at):
>> Adjust cbase if the use stmt is after iv update.
>>
>
> This patch may have caused:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46316
>
> You need to build a 32bit gcc to reproduce it. I am using
>
> CC="gcc -m32" CXX="g++ -m32" configure i686-linux
>
> on Fedora 16/Intel64 to build 32bit GCC.
>
>
> --
> H.J.
>
^ permalink raw reply [flat|nested] 11+ messages in thread
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2010-10-29 23:10 Fix PR/46200 -- ivopt bug in test condition cost computation Xinliang David Li
2010-10-31 9:22 ` Zdenek Dvorak
2010-11-01 6:59 ` Xinliang David Li
2010-11-02 17:15 ` Xinliang David Li
2010-11-03 10:28 ` Zdenek Dvorak
2010-11-03 23:10 ` Xinliang David Li
2010-11-05 20:40 ` H.J. Lu
2010-11-05 20:42 ` H.J. Lu
2010-11-05 21:00 ` H.J. Lu
2010-11-06 11:08 ` Xinliang David Li
2010-11-07 21:29 ` Xinliang David Li
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