> Hi,
>
> In IPA-SRA we use can_be_local_p () predicate rather than just plain
> local call graph flag in order to figure out whether the node is a
> part of an external API that we cannot change. Although there are
> cases where this can allow more transformations, it also means we can
> analyze functions which have no callers at all, which is pointless.
Do we also have some cost model that we do not privatize very large
comdats?
>
> Moreover, it makes an assert of hint propagation trigger, which checks
> that we have looked at callers before processing hints that come from
> them. This has been reported as PR 110276.
>
> This patch simply adds a check that a node has at least one caller
> into the early checks and makes the node a non-candidate for any
> transformation if it does not.
>
> Bootstrapped and tested on x86_64-linux, LTO bootstrap is still
> underway. OK if it passes too?
OK. (It is run during WPA, not during early compilation, right?)
Honza
>
> Thanks,
>
> Martin
>
>
> gcc/ChangeLog:
>
> 2023-06-16 Martin Jambor <mjam...@suse.cz>
>
> PR ipa/110276
> * ipa-sra.cc (struct caller_issues): New field there_is_one.
> (check_for_caller_issues): Set it.
> (check_all_callers_for_issues): Check it.
>
> gcc/testsuite/ChangeLog:
>
> 2023-06-16 Martin Jambor <mjam...@suse.cz>
>
> PR ipa/110276
> * gcc.dg/ipa/pr110276.c: New test.
> ---
> gcc/ipa-sra.cc | 11 +++++++++++
> gcc/testsuite/gcc.dg/ipa/pr110276.c | 15 +++++++++++++++
> 2 files changed, 26 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/ipa/pr110276.c
>
> diff --git a/gcc/ipa-sra.cc b/gcc/ipa-sra.cc
> index 3fee8fb22ce..21d281a9756 100644
> --- a/gcc/ipa-sra.cc
> +++ b/gcc/ipa-sra.cc
> @@ -3074,6 +3074,8 @@ struct caller_issues
> cgraph_node *candidate;
> /* There is a thunk among callers. */
> bool thunk;
> + /* Set if there is at least one caller that is OK. */
> + bool there_is_one;
> /* Call site with no available information. */
> bool unknown_callsite;
> /* Call from outside the candidate's comdat group. */
> @@ -3116,6 +3118,8 @@ check_for_caller_issues (struct cgraph_node *node, void
> *data)
>
> if (csum->m_bit_aligned_arg)
> issues->bit_aligned_aggregate_argument = true;
> +
> + issues->there_is_one = true;
> }
> return false;
> }
> @@ -3170,6 +3174,13 @@ check_all_callers_for_issues (cgraph_node *node)
> for (unsigned i = 0; i < param_count; i++)
> (*ifs->m_parameters)[i].split_candidate = false;
> }
> + if (!issues.there_is_one)
> + {
> + if (dump_file && (dump_flags & TDF_DETAILS))
> + fprintf (dump_file, "There is no call to %s that we can modify. "
> + "Disabling all modifications.\n", node->dump_name ());
> + return true;
> + }
> return false;
> }
>
> diff --git a/gcc/testsuite/gcc.dg/ipa/pr110276.c
> b/gcc/testsuite/gcc.dg/ipa/pr110276.c
> new file mode 100644
> index 00000000000..5a1e2f3fb1c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/ipa/pr110276.c
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +typedef long (*EFI_PCI_IO_PROTOCOL_CONFIG)();
> +typedef struct {
> + EFI_PCI_IO_PROTOCOL_CONFIG Read;
> +} EFI_PCI_IO_PROTOCOL_CONFIG_ACCESS;
> +typedef struct {
> + EFI_PCI_IO_PROTOCOL_CONFIG_ACCESS Pci;
> +} EFI_PCI_IO_PROTOCOL;
> +int init_regs_0;
> +static void __attribute__((constructor)) init(EFI_PCI_IO_PROTOCOL *pci_io) {
> + if (init_regs_0)
> + pci_io->Pci.Read();
> +}
> --
> 2.40.1
>
