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 <l...@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 <dmalc...@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
>
