Re: [committed] PR testsuite/86540, twiddle for aarch64

["Richard Earnshaw (lists)" <Richard.Earnshaw@arm.com>]

On 06/12/2018 15:36, Jeff Law wrote:
> 
> As outlined in the PR, the aarch64 has a non-default value for
> CASE_VALUES_THRESHOLD which changes decisions in switch lowering.  Those
> changes in switch lowering can expose additional jump threads later in
> the pipeline which cause heartburn for a couple tests.
> 
> I looked at all the other ports with a non-default value of
> CASE_VALUES_THRESHOLD and only aarch64 is high enough to trigger these
> changes in behavior on the two relevant tests.  So I'm just skipping the
> tests that run after switch lowering on aarch64.
> 
> Verified with a cross that these tests now pass.
> 
> Committing to the trunk,
> 

Can't we use a param to force the value back to (near) the default?
That would then work even if other targets start changing the default here.

R.


> Jeff
> 
> 
> P
> 
> diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
> index 1adb751cd34..0272bbe0605 100644
> --- a/gcc/testsuite/ChangeLog
> +++ b/gcc/testsuite/ChangeLog
> @@ -1,3 +1,10 @@
> +2018-12-06  Jeff Law  <law@redhat.com>
> +
> +	PR testsuite/86540
> +	* gcc.dg/tree-ssa/ssa-dom-thread-7.c: Skip the post switch conversion
> +	tests on aarch64.
> +	* gcc.dg/tree-ssa/pr77445-2.c: Similarly.
> + 
>  2018-12-06  David Malcolm  <dmalcolm@redhat.com>
>  
>  	PR c++/85110
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr77445-2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr77445-2.c
> index eecfc4b195a..c5d567dabdc 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/pr77445-2.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr77445-2.c
> @@ -118,10 +118,14 @@ enum STATES FMS( u8 **in , u32 *transitions) {
>  
>  /* The profile is not updated perfectly because it is inconsitent from
>     profile estimation stage. But the number of inconsistencies should not
> -   increase much.  */
> +   increase much. 
> +
> +   aarch64 has the highest CASE_VALUES_THRESHOLD in GCC.  It's high enough
> +   to change decisions in switch expansion which in turn can expose new
> +   jump threading opportunities.  Skip the later tests on aarch64.  */
>  /* { dg-final { scan-tree-dump "Jumps threaded: 1\[1-9\]" "thread1" } } */
>  /* { dg-final { scan-tree-dump-times "Invalid sum" 3 "thread1" } } */
>  /* { dg-final { scan-tree-dump-not "not considered" "thread1" } } */
>  /* { dg-final { scan-tree-dump-not "not considered" "thread2" } } */
> -/* { dg-final { scan-tree-dump-not "not considered" "thread3" } } */
> -/* { dg-final { scan-tree-dump-not "not considered" "thread4" } } */
> +/* { dg-final { scan-tree-dump-not "not considered" "thread3" { target { ! aarch64*-*-* } } } } */
> +/* { dg-final { scan-tree-dump-not "not considered" "thread4" { target { ! aarch64*-*-* } } } } */ 
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c
> index e395de26ec0..f833aa4351d 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c
> @@ -3,8 +3,11 @@
>  /* { dg-final { scan-tree-dump "Jumps threaded: 16"  "thread1" } } */
>  /* { dg-final { scan-tree-dump "Jumps threaded: 9" "thread2" } } */
>  /* { dg-final { scan-tree-dump "Jumps threaded: 1"  "dom2" } } */
> -/* { dg-final { scan-tree-dump-not "Jumps threaded"  "dom3" } } */
> -/* { dg-final { scan-tree-dump-not "Jumps threaded"  "vrp2" } } */
> +/* aarch64 has the highest CASE_VALUES_THRESHOLD in GCC.  It's high enough
> +   to change decisions in switch expansion which in turn can expose new
> +   jump threading opportunities.  Skip the later tests on aarch64.  */
> +/* { dg-final { scan-tree-dump-not "Jumps threaded"  "dom3" { target { ! aarch64*-*-* } } } } */
> +/* { dg-final { scan-tree-dump-not "Jumps threaded"  "vrp2" { target { ! aarch64*-*-* } } } } */
>  
>  /* Most architectures get 3 threadable paths here, whereas aarch64 and
>     possibly others get 5.  We really should rewrite threading tests to
>