[PATCH] [testsuite] [ppc] expect vectorization in gen-vect-11c.c

[PATCH] [testsuite] [ppc] expect vectorization in gen-vect-11c.c

[Alexandre Oliva]

The first loop in main gets stores "vectorized" on powerpc into
full-word stores, even without any vector instruction support, so the
test's expectation of no loop vectorization is not met.

Regstrapped on ppc64-linux-gnu.  Also tested with ppc64-vxworks7r2
(gcc-12).  Ok to install?


for  gcc/testsuite/ChangeLog

	* gcc.dg/tree-ssa/gen-vect-11c.c: xfail the test for no
	vectorization on powerpc*-*-*.
---
 gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c b/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c
index 22ff44cf66da9..116f6af233887 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c
@@ -39,4 +39,4 @@ int main ()
 }
 
 
-/* { dg-final { scan-tree-dump-times "vectorized 0 loops" 1 "vect" { xfail amdgcn*-*-* } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 0 loops" 1 "vect" { xfail amdgcn*-*-* powerpc*-*-* } } } */

-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts.  Ask me about <https://stallmansupport.org>

Re: [PATCH] [testsuite] [ppc] expect vectorization in gen-vect-11c.c

[Kewen.Lin]

Hi Alexandre,

on 2023/3/25 16:35, Alexandre Oliva wrote:
> 
> The first loop in main gets stores "vectorized" on powerpc into
> full-word stores, even without any vector instruction support, so the
> test's expectation of no loop vectorization is not met.
> 

I think this test issue has been gone since r13-5771-gdc87e1391c55c6.

Could you have a double check?

BR,
Kewen

> Regstrapped on ppc64-linux-gnu.  Also tested with ppc64-vxworks7r2
> (gcc-12).  Ok to install?
> 
> 
> for  gcc/testsuite/ChangeLog
> 
> 	* gcc.dg/tree-ssa/gen-vect-11c.c: xfail the test for no
> 	vectorization on powerpc*-*-*.
> ---
>  gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c b/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c
> index 22ff44cf66da9..116f6af233887 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/gen-vect-11c.c
> @@ -39,4 +39,4 @@ int main ()
>  }
> 
> 
> -/* { dg-final { scan-tree-dump-times "vectorized 0 loops" 1 "vect" { xfail amdgcn*-*-* } } } */
> +/* { dg-final { scan-tree-dump-times "vectorized 0 loops" 1 "vect" { xfail amdgcn*-*-* powerpc*-*-* } } } */
> 

Re: [PATCH] [testsuite] [ppc] expect vectorization in gen-vect-11c.c

[Alexandre Oliva]

Hello, Kewen,

On Mar 27, 2023, "Kewen.Lin" <linkw@linux.ibm.com> wrote:

> on 2023/3/25 16:35, Alexandre Oliva wrote:

>> The first loop in main gets stores "vectorized" on powerpc into
>> full-word stores, even without any vector instruction support, so the
>> test's expectation of no loop vectorization is not met.

> I think this test issue has been gone since r13-5771-gdc87e1391c55c6.

That patch has been backported to gcc-12 as r12-9258-g21e7145aaf582c.

> Could you have a double check?

I confirm I observe the problem with gcc-12 targeting ppc64-vx7r2,
containing the backported patch, and that the loop is vectorized,
failing the test.


It's unfortunately not viable for me to test GCC trunk with vxworks, so
my testing with it is limited to earlier GCC versions, that we (AdaCore)
have already ported or are in the process of porting.  I make up for
that by testing trunk with other target variants, to the best of my
abilities, to avoid regressions, but sometimes I just can't tell whether
my baseline for regression testing doesn't contain a failure because
there's another fix, or because it just doesn't fail on that target
variant.


In this case, the comments in the patch you mentioned don't seem to
match the situation at hand: the SImode stores vectorized into V2SImode
(DImode) seem profitable and are *not* split by vector lowering.

-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts.  Ask me about <https://stallmansupport.org>

Re: [PATCH] [testsuite] [ppc] expect vectorization in gen-vect-11c.c

[Kewen.Lin]

Hi Alexandre,

on 2023/4/6 13:20, Alexandre Oliva wrote:
> Hello, Kewen,
> 
> On Mar 27, 2023, "Kewen.Lin" <linkw@linux.ibm.com> wrote:
> 
>> on 2023/3/25 16:35, Alexandre Oliva wrote:
> 
>>> The first loop in main gets stores "vectorized" on powerpc into
>>> full-word stores, even without any vector instruction support, so the
>>> test's expectation of no loop vectorization is not met.
> 
>> I think this test issue has been gone since r13-5771-gdc87e1391c55c6.
> 
> That patch has been backported to gcc-12 as r12-9258-g21e7145aaf582c.
> 
>> Could you have a double check?
> 
> I confirm I observe the problem with gcc-12 targeting ppc64-vx7r2,
> containing the backported patch, and that the loop is vectorized,
> failing the test.

Thanks for confirming!  Sorry that I didn't have a vxworks env to
reproduce this locally, but I guessed that vxworks env doesn't have
its specific configurations on vectorization?, so I tried to reproduce
this on a env with powerpc64-linux-gnu, with the latest gcc-12 branch
(r12-9388), I still saw it passed with vect dumping:

gen-vect-11c.c:26:17: note:   ==> examining statement: _3 = _1 + _2;
gen-vect-11c.c:26:17: note:   vect_is_simple_use: operand ib[i_24], type of def: internal
gen-vect-11c.c:26:17: note:   vect_is_simple_use: vectype vector(2) int
gen-vect-11c.c:26:17: note:   vect_is_simple_use: operand ic[i_24], type of def: internal
gen-vect-11c.c:26:17: note:   vect_is_simple_use: vectype vector(2) int
not using word mode for +- and less than four vector elements
gen-vect-11c.c:28:21: missed:   not vectorized: relevant stmt not supported: _3 = _1 + _2;
gen-vect-11c.c:26:17: missed:  bad operation or unsupported loop bound.
gen-vect-11c.c:26:17: note:  ***** Analysis  failed with vector mode DI
gen-vect-11c.c:26:17: missed: couldn't vectorize loop
gen-vect-11c.c:18:5: note: vectorized 0 loops in function.

By reverting r12-9258-g21e7145aaf582c, I saw it failed with dumping:

gen-vect-11c.c:26:17: note:   ==> examining statement: _3 = _1 + _2;
gen-vect-11c.c:26:17: note:   vect_is_simple_use: operand ib[i_24], type of def: internal
gen-vect-11c.c:26:17: note:   vect_is_simple_use: vectype vector(2) int
gen-vect-11c.c:26:17: note:   vect_is_simple_use: operand ic[i_24], type of def: internal
gen-vect-11c.c:26:17: note:   vect_is_simple_use: vectype vector(2) int

...

gen-vect-11c.c:26:17: note:  ***** Analysis succeeded with vector mode DI
gen-vect-11c.c:26:17: note:  ***** Choosing vector mode DI
gen-vect-11c.c:26:17: optimized: loop vectorized using 8 byte vectors


> 
> 
> It's unfortunately not viable for me to test GCC trunk with vxworks, so
> my testing with it is limited to earlier GCC versions, that we (AdaCore)
> have already ported or are in the process of porting.  I make up for
> that by testing trunk with other target variants, to the best of my
> abilities, to avoid regressions, but sometimes I just can't tell whether
> my baseline for regression testing doesn't contain a failure because
> there's another fix, or because it just doesn't fail on that target
> variant.
> 
> 
> In this case, the comments in the patch you mentioned don't seem to
> match the situation at hand: the SImode stores vectorized into V2SImode
> (DImode) seem profitable and are *not* split by vector lowering.
> 

Yeah, but the case also have "+" (PLUS), it results in a unvectorized
decision as the above dumping, I'm not quite sure what's the difference
between our ENVs and something caused that you didn't see the above
analysis failure on your side, do you mind to have a further check?

BR,
Kewen

Re: [PATCH] [testsuite] [ppc] expect vectorization in gen-vect-11c.c

[Alexandre Oliva]

On Apr  6, 2023, "Kewen.Lin" <linkw@linux.ibm.com> wrote:

> on 2023/4/6 13:20, Alexandre Oliva wrote:
>> I confirm I observe the problem with gcc-12 targeting ppc64-vx7r2,
>> containing the backported patch, and that the loop is vectorized,
>> failing the test.

I take that back.  My notes indicate I looked into this failure on March
15th.  The patch you referenced was dated Feb 10, so I assumed it was
already in when I looked into it: my confirmation amounted to checking
what I had observed according to my notes, and when.

But now that you asked me to investigate it again, I used a far more
recent tree, and I failed to duplicate it.  Digging further, I found out
the patch, despite its commit date, was only merged into gcc-12 on March
16th.  What I was missing to get the intended effects of the fix was
just a fresher tree athat actually contained the fix.

I suppose this means we don't need the testsuite tweak, after all.
Patch withdrawn.

-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts.  Ask me about <https://stallmansupport.org>

Re: [PATCH] [testsuite] [ppc] expect vectorization in gen-vect-11c.c

[Kewen.Lin]

Hi Alexandre,

on 2023/4/7 12:37, Alexandre Oliva wrote:
> On Apr  6, 2023, "Kewen.Lin" <linkw@linux.ibm.com> wrote:
> 
>> on 2023/4/6 13:20, Alexandre Oliva wrote:
>>> I confirm I observe the problem with gcc-12 targeting ppc64-vx7r2,
>>> containing the backported patch, and that the loop is vectorized,
>>> failing the test.
> 
> I take that back.  My notes indicate I looked into this failure on March
> 15th.  The patch you referenced was dated Feb 10, so I assumed it was
> already in when I looked into it: my confirmation amounted to checking
> what I had observed according to my notes, and when.
> 
> But now that you asked me to investigate it again, I used a far more
> recent tree, and I failed to duplicate it.  Digging further, I found out
> the patch, despite its commit date, was only merged into gcc-12 on March
> 16th.  What I was missing to get the intended effects of the fix was
> just a fresher tree athat actually contained the fix.

aha, good to know it's not due to some differences between our ENVs or
some other mysteries. :) Thanks for checking.

> 
> I suppose this means we don't need the testsuite tweak, after all.

Yeah. :)

BR,
Kewen

> Patch withdrawn.
>