Re: [PATCH] Add -funconstrained-commons to work around PR/69368 (and others) in SPEC2006

2016-03-11 Thread Jakub Jelinek 
On Fri, Mar 11, 2016 at 12:11:42PM +, Alan Lawrence wrote:
> On 10/03/16 16:18, Dominique d'Humières wrote:
> 
> > The test gfortran.dg/unconstrained_commons.f fails in the 32 bit mode. It
> > needs some regexp
> 
> Indeed, confirmed on ARM, sorry for not spotting this earlier.
> 
> I believe the variable, if there is one, should always be called 'j', as it is
> in the source. So how about this, tested on ARM, AArch64, x86_64?
> 
> gcc/testsuite/ChangeLog:
> 
>   * gfortran.dg/unconstrained_commons.f: Widen regexp to match j_

Ok.

>  gcc/testsuite/gfortran.dg/unconstrained_commons.f | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gcc/testsuite/gfortran.dg/unconstrained_commons.f 
> b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
> index f9fc471..bee67ab 100644
> --- a/gcc/testsuite/gfortran.dg/unconstrained_commons.f
> +++ b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
> @@ -17,4 +17,4 @@
>  ! { dg-final { scan-tree-dump-not "FIND" "dom2" } }
>  ! We should retain both a read and write of mycommon.x.
>  ! { dg-final { scan-tree-dump-times "  _\[0-9\]+ = 
> mycommon\\.x\\\[_\[0-9\]+\\\];" 1 "dom2" } }
> -! { dg-final { scan-tree-dump-times "  mycommon\\.x\\\[_\[0-9\]+\\\] = 
> _\[0-9\]+;" 1 "dom2" } }
> +! { dg-final { scan-tree-dump-times "  mycommon\\.x\\\[j?_\[0-9\]+\\\] = 
> _\[0-9\]+;" 1 "dom2" } }

Jakub

Re: [PATCH] Add -funconstrained-commons to work around PR/69368 (and others) in SPEC2006

2016-03-11 Thread Alan Lawrence 
On 10/03/16 16:18, Dominique d'Humières wrote:

> The test gfortran.dg/unconstrained_commons.f fails in the 32 bit mode. It
> needs some regexp

Indeed, confirmed on ARM, sorry for not spotting this earlier.

I believe the variable, if there is one, should always be called 'j', as it is
in the source. So how about this, tested on ARM, AArch64, x86_64?

gcc/testsuite/ChangeLog:

* gfortran.dg/unconstrained_commons.f: Widen regexp to match j_
---
 gcc/testsuite/gfortran.dg/unconstrained_commons.f | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/testsuite/gfortran.dg/unconstrained_commons.f 
b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
index f9fc471..bee67ab 100644
--- a/gcc/testsuite/gfortran.dg/unconstrained_commons.f
+++ b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
@@ -17,4 +17,4 @@
 ! { dg-final { scan-tree-dump-not "FIND" "dom2" } }
 ! We should retain both a read and write of mycommon.x.
 ! { dg-final { scan-tree-dump-times "  _\[0-9\]+ = 
mycommon\\.x\\\[_\[0-9\]+\\\];" 1 "dom2" } }
-! { dg-final { scan-tree-dump-times "  mycommon\\.x\\\[_\[0-9\]+\\\] = 
_\[0-9\]+;" 1 "dom2" } }
+! { dg-final { scan-tree-dump-times "  mycommon\\.x\\\[j?_\[0-9\]+\\\] = 
_\[0-9\]+;" 1 "dom2" } }
-- 
1.9.1

Re: [PATCH] Add -funconstrained-commons to work around PR/69368 (and others) in SPEC2006

2016-03-10 Thread Dominique d'Humières 
Alan,

The test gfortran.dg/unconstrained_commons.f fails in the 32 bit mode. It needs 
some regexp capturing

  mycommon.x[j_1] = _5;

as in "  mycommon\.x\[.?_[0-9]+\] = _[0-9]+;"

TIA

Dominique

Re: [PATCH] Add -funconstrained-commons to work around PR/69368 (and others) in SPEC2006

2016-03-10 Thread Richard Biener 
On Wed, Mar 9, 2016 at 6:54 PM, Alan Lawrence
 wrote:
> On 07/03/16 11:02, Alan Lawrence wrote:
>>
>> On 04/03/16 13:27, Richard Biener wrote:
>>>
>>> I think to make it work with LTO you need to mark it 'Optimization'.
>>> Also it's about
>>> arrays so maybe
>>>
>>> 'Assume common declarations may be overridden with ones with a larger
>>> trailing array'
>>>
>>> also if we document it here we should eventually document it in
>>> invoke.texi.
>>>
>>> Not sure if "unknown commons" is a good term, maybe "unconstrained
>>> commons" instead?
>>
>>
>> All done; I doubt there is really a good word, unconstrained seems as good
>> as
>> any. I've reused much the same wording in invoke.texi, unless you think
>> there
>> is more to add.
>>
>> On 04/03/16 13:33, Jakub Jelinek wrote:
>>>
>>> Also, isn't the *.opt description line supposed to end with a full stop?
>>
>>
>> Ah, yes, thanks.
>>
>> Is this version OK for trunk?
>>
>> gcc/ChangeLog:
>>
>> DATE  Alan Lawrence  
>>Jakub Jelinek  
>>
>>  * common.opt (funconstrained-commons,
>> flag_unconstrained_commons): New.
>>  * tree.c (array_at_struct_end_p): Do not limit to size of decl
>> for
>>  DECL_COMMONS if flag_unconstrained_commons is set.
>>  * tree-dfa.c (get_ref_base_and_extent): Likewise.
>
>
> And add to that
> * doc/invoke.texi (Optimize Options): Add -funconstrained-commons.
> (funconstrained-commons): Document.

Ok.

Richard.

> Thanks,
> Alan
>
>>
>> gcc/testsuite/ChangeLog:
>>
>>  * gfortran.dg/unconstrained_commons.f: New.
>> ---
>>   gcc/common.opt|  5 +
>>   gcc/doc/invoke.texi   |  8 +++-
>>   gcc/testsuite/gfortran.dg/unconstrained_commons.f | 20
>> 
>>   gcc/tree-dfa.c| 15 ++-
>>   gcc/tree.c|  6 --
>>   5 files changed, 50 insertions(+), 4 deletions(-)
>>   create mode 100644 gcc/testsuite/gfortran.dg/unconstrained_commons.f
>>
>> diff --git a/gcc/common.opt b/gcc/common.opt
>> index 520fa9c..bbf79ef 100644
>> --- a/gcc/common.opt
>> +++ b/gcc/common.opt
>> @@ -2451,6 +2451,11 @@ fsplit-paths
>>   Common Report Var(flag_split_paths) Init(0) Optimization
>>   Split paths leading to loop backedges.
>>
>> +funconstrained-commons
>> +Common Var(flag_unconstrained_commons) Optimization
>> +Assume common declarations may be overridden with ones with a larger
>> +trailing array.
>> +
>>   funit-at-a-time
>>   Common Report Var(flag_unit_at_a_time) Init(1)
>>   Compile whole compilation unit at a time.
>> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
>> index 0a2a6f4..68933a1 100644
>> --- a/gcc/doc/invoke.texi
>> +++ b/gcc/doc/invoke.texi
>> @@ -407,7 +407,7 @@ Objective-C and Objective-C++ Dialects}.
>>   -ftree-parallelize-loops=@var{n} -ftree-pre -ftree-partial-pre
>> -ftree-pta @gol
>>   -ftree-reassoc -ftree-sink -ftree-slsr -ftree-sra @gol
>>   -ftree-switch-conversion -ftree-tail-merge -ftree-ter @gol
>> --ftree-vectorize -ftree-vrp @gol
>> +-ftree-vectorize -ftree-vrp -funconstrained-commons @gol
>>   -funit-at-a-time -funroll-all-loops -funroll-loops @gol
>>   -funsafe-loop-optimizations -funsafe-math-optimizations -funswitch-loops
>> @gol
>>   -fipa-ra -fvariable-expansion-in-unroller -fvect-cost-model -fvpt @gol
>> @@ -6659,6 +6659,12 @@ the loop optimizer itself cannot prove that these
>> assumptions are valid.
>>   If you use @option{-Wunsafe-loop-optimizations}, the compiler warns you
>>   if it finds this kind of loop.
>>
>> +@item -funconstrained-commons
>> +@opindex funconstrained-commons
>> +This option tells the compiler that variables declared in common blocks
>> +(e.g. Fortran) may later be overridden with longer trailing arrays. This
>> +prevents certain optimizations that depend on knowing the array bounds.
>> +
>>   @item -fcrossjumping
>>   @opindex fcrossjumping
>>   Perform cross-jumping transformation.
>> diff --git a/gcc/testsuite/gfortran.dg/unconstrained_commons.f
>> b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
>> new file mode 100644
>> index 000..f9fc471
>> --- /dev/null
>> +++ b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
>> @@ -0,0 +1,20 @@
>> +! { dg-do compile }
>> +! { dg-options "-O3 -funconstrained-commons -fdump-tree-dom2-details" }
>> +
>> +! Test for PR69368: a single-element array in a common block, which will
>> be
>> +! overridden with a larger size at link time (contrary to language spec).
>> +! Dominator opts considers accesses to differently-computed elements of X
>> as
>> +! equivalent, unless -funconstrained-commons is passed in.
>> +  SUBROUTINE FOO
>> +  IMPLICIT DOUBLE PRECISION (X)
>> +  INTEGER J
>> +  COMMON /MYCOMMON / X(1)
>> +  DO 10 J=1,1024
>> + X(J+1)=X(J+7)
>> +  10  CONTINUE
>> +  RETURN
>> +  END
>> +! { dg-final

Re: [PATCH] Add -funconstrained-commons to work around PR/69368 (and others) in SPEC2006

2016-03-09 Thread Alan Lawrence 

On 07/03/16 11:02, Alan Lawrence wrote:

On 04/03/16 13:27, Richard Biener wrote:

I think to make it work with LTO you need to mark it 'Optimization'.
Also it's about
arrays so maybe

'Assume common declarations may be overridden with ones with a larger
trailing array'

also if we document it here we should eventually document it in invoke.texi.

Not sure if "unknown commons" is a good term, maybe "unconstrained
commons" instead?


All done; I doubt there is really a good word, unconstrained seems as good as
any. I've reused much the same wording in invoke.texi, unless you think there
is more to add.

On 04/03/16 13:33, Jakub Jelinek wrote:

Also, isn't the *.opt description line supposed to end with a full stop?


Ah, yes, thanks.

Is this version OK for trunk?

gcc/ChangeLog:

DATE  Alan Lawrence  
   Jakub Jelinek  

 * common.opt (funconstrained-commons, flag_unconstrained_commons): New.
 * tree.c (array_at_struct_end_p): Do not limit to size of decl for
 DECL_COMMONS if flag_unconstrained_commons is set.
 * tree-dfa.c (get_ref_base_and_extent): Likewise.


And add to that
* doc/invoke.texi (Optimize Options): Add -funconstrained-commons.
(funconstrained-commons): Document.

Thanks,
Alan



gcc/testsuite/ChangeLog:

 * gfortran.dg/unconstrained_commons.f: New.
---
  gcc/common.opt|  5 +
  gcc/doc/invoke.texi   |  8 +++-
  gcc/testsuite/gfortran.dg/unconstrained_commons.f | 20 
  gcc/tree-dfa.c| 15 ++-
  gcc/tree.c|  6 --
  5 files changed, 50 insertions(+), 4 deletions(-)
  create mode 100644 gcc/testsuite/gfortran.dg/unconstrained_commons.f

diff --git a/gcc/common.opt b/gcc/common.opt
index 520fa9c..bbf79ef 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2451,6 +2451,11 @@ fsplit-paths
  Common Report Var(flag_split_paths) Init(0) Optimization
  Split paths leading to loop backedges.

+funconstrained-commons
+Common Var(flag_unconstrained_commons) Optimization
+Assume common declarations may be overridden with ones with a larger
+trailing array.
+
  funit-at-a-time
  Common Report Var(flag_unit_at_a_time) Init(1)
  Compile whole compilation unit at a time.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 0a2a6f4..68933a1 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -407,7 +407,7 @@ Objective-C and Objective-C++ Dialects}.
  -ftree-parallelize-loops=@var{n} -ftree-pre -ftree-partial-pre -ftree-pta @gol
  -ftree-reassoc -ftree-sink -ftree-slsr -ftree-sra @gol
  -ftree-switch-conversion -ftree-tail-merge -ftree-ter @gol
--ftree-vectorize -ftree-vrp @gol
+-ftree-vectorize -ftree-vrp -funconstrained-commons @gol
  -funit-at-a-time -funroll-all-loops -funroll-loops @gol
  -funsafe-loop-optimizations -funsafe-math-optimizations -funswitch-loops @gol
  -fipa-ra -fvariable-expansion-in-unroller -fvect-cost-model -fvpt @gol
@@ -6659,6 +6659,12 @@ the loop optimizer itself cannot prove that these 
assumptions are valid.
  If you use @option{-Wunsafe-loop-optimizations}, the compiler warns you
  if it finds this kind of loop.

+@item -funconstrained-commons
+@opindex funconstrained-commons
+This option tells the compiler that variables declared in common blocks
+(e.g. Fortran) may later be overridden with longer trailing arrays. This
+prevents certain optimizations that depend on knowing the array bounds.
+
  @item -fcrossjumping
  @opindex fcrossjumping
  Perform cross-jumping transformation.
diff --git a/gcc/testsuite/gfortran.dg/unconstrained_commons.f 
b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
new file mode 100644
index 000..f9fc471
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/unconstrained_commons.f
@@ -0,0 +1,20 @@
+! { dg-do compile }
+! { dg-options "-O3 -funconstrained-commons -fdump-tree-dom2-details" }
+
+! Test for PR69368: a single-element array in a common block, which will be
+! overridden with a larger size at link time (contrary to language spec).
+! Dominator opts considers accesses to differently-computed elements of X as
+! equivalent, unless -funconstrained-commons is passed in.
+  SUBROUTINE FOO
+  IMPLICIT DOUBLE PRECISION (X)
+  INTEGER J
+  COMMON /MYCOMMON / X(1)
+  DO 10 J=1,1024
+ X(J+1)=X(J+7)
+  10  CONTINUE
+  RETURN
+  END
+! { dg-final { scan-tree-dump-not "FIND" "dom2" } }
+! We should retain both a read and write of mycommon.x.
+! { dg-final { scan-tree-dump-times "  _\[0-9\]+ = mycommon\\.x\\\[_\[0-9\]+\\\];" 1 
"dom2" } }
+! { dg-final { scan-tree-dump-times "  mycommon\\.x\\\[_\[0-9\]+\\\] = _\[0-9\]+;" 1 
"dom2" } }
diff --git a/gcc/tree-dfa.c b/gcc/tree-dfa.c
index 0e98056..f133abc 100644
--- a/gcc/tree-dfa.c
+++ b/gcc/tree-dfa.c
@@ -612,9 +612,22 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT