[PATCH] sra: Avoid verification failure (PR 93516)
Richard Biener
rguenther@suse.de
Fri Feb 14 11:47:00 GMT 2020
On Fri, 14 Feb 2020, Martin Jambor wrote:
> Hi,
>
> get_ref_base_and_extent can return different sizes for COMPONENT_REFs
> and DECLs of the same type, with the latter including (more?) padding.
> When in the IL there is an assignment between such a COMPONENT_REF and a
> DECL, SRA will try to propagate the access from the former as a child of
> the latter, creating an artificial reference that does not match the
> access's declared size, which triggers a verifier assert.
"both" use DECL_SIZE, but those can differ dependent on alignment
for example.
> Fixed by teaching the propagation functions about this special situation
> so that they don't do it. The condition is the same that
> build_user_friendly_ref_for_offset uses so the artificial reference
> causing the verifier is guaranteed not to be created.
>
> Bootstrapped and tested on x86_64-linux. OK for trunk?
OK.
Thanks,
Richard.
> Thanks,
>
> Martin
>
>
> 2020-02-10 Martin Jambor <mjambor@suse.cz>
> PR tree-optimization/93516
> * tree-sra.c (propagate_subaccesses_from_rhs): Do not create
> access of the same type as the parent.
> (propagate_subaccesses_from_lhs): Likewise.
>
> gcc/testsuite/
> * g++.dg/tree-ssa/pr93516.C: New test.
> ---
> gcc/ChangeLog | 7 ++++++
> gcc/testsuite/ChangeLog | 5 ++++
> gcc/testsuite/g++.dg/tree-ssa/pr93516.C | 24 +++++++++++++++++++
> gcc/tree-sra.c | 31 +++++++++++++++++++------
> 4 files changed, 60 insertions(+), 7 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/tree-ssa/pr93516.C
>
> diff --git a/gcc/ChangeLog b/gcc/ChangeLog
> index fa3cbb895e9..daba335cf79 100644
> --- a/gcc/ChangeLog
> +++ b/gcc/ChangeLog
> @@ -1,3 +1,10 @@
> +2020-02-10 Martin Jambor <mjambor@suse.cz>
> +
> + PR tree-optimization/93516
> + * tree-sra.c (propagate_subaccesses_from_rhs): Do not create
> + access of the same type as the parent.
> + (propagate_subaccesses_from_lhs): Likewise.
> +
> 2020-02-10 Feng Xue <fxue@os.amperecomputing.com>
>
> PR ipa/93203
> diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
> index 0ede9604611..eada2ebed63 100644
> --- a/gcc/testsuite/ChangeLog
> +++ b/gcc/testsuite/ChangeLog
> @@ -1,3 +1,8 @@
> +2020-02-10 Martin Jambor <mjambor@suse.cz>
> +
> + PR tree-optimization/93516
> + * g++.dg/tree-ssa/pr93516.C: New test.
> +
> 2020-02-10 Feng Xue <fxue@os.amperecomputing.com>
>
> PR ipa/93203
> diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr93516.C b/gcc/testsuite/g++.dg/tree-ssa/pr93516.C
> new file mode 100644
> index 00000000000..2bba37c1386
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/tree-ssa/pr93516.C
> @@ -0,0 +1,24 @@
> +// { dg-do compile }
> +// { dg-options "-O2" } */
> +
> +struct b;
> +struct c {
> + b *operator->();
> +};
> +class e {
> + void *f;
> + int d;
> +
> +public:
> + template <typename a> a g() { return *static_cast<a *>(this); }
> +};
> +struct h : e {};
> +struct b {
> + void i(e);
> + e j();
> +};
> +void m() {
> + c k;
> + h l = k->j().g<h>();
> + k->i(l);
> +}
> diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
> index ea8594db193..a3bcd5f3e03 100644
> --- a/gcc/tree-sra.c
> +++ b/gcc/tree-sra.c
> @@ -2785,9 +2785,17 @@ propagate_subaccesses_from_rhs (struct access *lacc, struct access *racc)
> }
>
> rchild->grp_hint = 1;
> - new_acc = create_artificial_child_access (lacc, rchild, norm_offset,
> - false, (lacc->grp_write
> - || rchild->grp_write));
> + /* Because get_ref_base_and_extent always includes padding in size for
> + accesses to DECLs but not necessarily for COMPONENT_REFs of the same
> + type, we might be actually attempting to here to create a child of the
> + same type as the parent. */
> + if (!types_compatible_p (lacc->type, rchild->type))
> + new_acc = create_artificial_child_access (lacc, rchild, norm_offset,
> + false,
> + (lacc->grp_write
> + || rchild->grp_write));
> + else
> + new_acc = lacc;
> gcc_checking_assert (new_acc);
> if (racc->first_child)
> propagate_subaccesses_from_rhs (new_acc, rchild);
> @@ -2834,10 +2842,19 @@ propagate_subaccesses_from_lhs (struct access *lacc, struct access *racc)
> continue;
> }
>
> - struct access *new_acc
> - = create_artificial_child_access (racc, lchild, norm_offset,
> - true, false);
> - propagate_subaccesses_from_lhs (lchild, new_acc);
> + /* Because get_ref_base_and_extent always includes padding in size for
> + accesses to DECLs but not necessarily for COMPONENT_REFs of the same
> + type, we might be actually attempting to here to create a child of the
> + same type as the parent. */
> + if (!types_compatible_p (racc->type, lchild->type))
> + {
> + struct access *new_acc
> + = create_artificial_child_access (racc, lchild, norm_offset,
> + true, false);
> + propagate_subaccesses_from_lhs (lchild, new_acc);
> + }
> + else
> + propagate_subaccesses_from_lhs (lchild, racc);
> ret = true;
> }
> return ret;
>
--
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
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