Hi,
On Thu, Jan 09 2020, Christophe Lyon wrote:
> On Tue, 7 Jan 2020 at 14:18, Martin Jambor <mjam...@suse.cz> wrote:
>>
>> Hi,
>>
>> On Fri, Jan 03 2020, Feng Xue OS wrote:
>> > When checking a self-recursively generated value for aggregate jump
>> > function, wrong aggregate lattice was used, which will cause infinite
>> > constant propagation. This patch is composed to fix this issue.
>> >
>> > 2020-01-03 Feng Xue <f...@os.amperecomputing.com>
>> >
>> > PR ipa/93084
>> > * ipa-cp.c (self_recursively_generated_p): Find matched aggregate
>> > lattice for a value to check.
>> > (propagate_vals_across_arith_jfunc): Add an assertion to ensure
>> > finite propagation in self-recursive scc.
>>
>> as far as I am concerned, the patch looks good.
>
> Hi,
> The new test introduced by this patch (gcc.dg/ipa/ipa-clone-3.c) fails
> on arm, powerpc and mips according to gcc-testresults.
> FAIL: gcc.dg/ipa/ipa-clone-3.c scan-ipa-dump-times cp "Creating a
> specialized node of recur_fn/[0-9]*\\." 8
>
> Can you have a look?
>
thank you, next time please also consider filing a bug with the exact
architecture triplets/quadruplets where it fails. I started with a look
at aarch64-suse-linux and then at ppc64le-redhat-linux but apparently
those were not the arms and powerpcs I was looking for.
After building a cross-compiler for armv8l-unknown-linux-gnueabihf I can
see the failure, aggregate jump functions do not get built for:
main ()
{
struct V v;
<bb 2> [local count: 1073741824]:
v = *.LC0;
_4 = recur_fn (&v);
return _4;
}
which is how the release_ssa dump looks like for this target, even
though it might actually be simpler than for the supported and more
common form:
main ()
{
struct V v;
<bb 2> [local count: 1073741824]:
v.f0 = 1;
v.f1 = 3;
_5 = recur_fn (&v);
return _5;
}
The different form stems from the fact that can_move_by_pieces returns
false in gimplify_init_constructor. I'll put this on my TODO list.
Meanwhile, I' about to commit this which should fix the testcase for now
after lightly testing it with make -k check-gcc RUNTESTFLAGS="ipa.exp".
Thanks,
Martin
2020-01-10 Martin Jambor <mjam...@suse.cz>
* gcc.dg/ipa/ipa-clone-3.c: Replace struct initializer with
piecemeal initialization.
---
gcc/testsuite/gcc.dg/ipa/ipa-clone-3.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-clone-3.c
b/gcc/testsuite/gcc.dg/ipa/ipa-clone-3.c
index 18d29bdd0b3..a73cb8b63fc 100644
--- a/gcc/testsuite/gcc.dg/ipa/ipa-clone-3.c
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-clone-3.c
@@ -34,8 +34,10 @@ int recur_fn (struct V * __restrict v)
int main ()
{
- struct V v = {1, 3};
+ struct V v;
+ v.f0 = 1;
+ v.f1 = 3;
return recur_fn (&v);
}
--
2.24.1
