Re: [PATCH][GCC 10] aarch64: Fix SVE ACLE builtins with LTO [PR99216]
Alex Coplan writes:
> Hi,
>
> Here is a backport of my fix for PR99216. The only change w.r.t the
> original patch is a bump of lto-streamer.h:LTO_minor_version.
>
> Bootstrapped and regtested on aarch64-linux-gnu, no issues.
>
> OK for GCC 10 branch?
OK, thanks.
Richard
> As discussed in the PR, we currently have two different numbering
> schemes for SVE builtins: one for C, and one for C++. This is
> problematic for LTO, where we end up getting confused about which
> intrinsic we're talking about. This patch inserts placeholders into the
> registered_functions vector to ensure that there is a consistent
> numbering scheme for both C and C++.
>
> This version uses integer_zero_node as a placeholder node instead of
> building a function decl. This is safe because the node is only returned
> by the TARGET_BUILTIN_DECL hook, which (on AArch64) is only used for
> validation when builtin decls are streamed into lto1.
>
> gcc/ChangeLog:
>
> PR target/99216
> * config/aarch64/aarch64-sve-builtins.cc
> (function_builder::add_function): Add placeholder_p argument, use
> placeholder decls if this is set.
> (function_builder::add_unique_function): Instead of conditionally adding
> direct overloads, unconditionally add either a direct overload or a
> placeholder.
> (function_builder::add_overloaded_function): Set placeholder_p if we're
> using C++ overloads. Use the obstack for string storage instead
> of relying on the tree nodes.
> (function_builder::add_overloaded_functions): Don't return early for
> m_direct_overloads: we need to add placeholders.
> * config/aarch64/aarch64-sve-builtins.h
> (function_builder::add_function): Add placeholder_p argument.
> * lto-streamer.h (LTO_minor_version): Bump.
>
> gcc/testsuite/ChangeLog:
>
> PR target/99216
> * g++.target/aarch64/sve/pr99216.C: New test.
>
> diff --git a/gcc/config/aarch64/aarch64-sve-builtins.cc
> b/gcc/config/aarch64/aarch64-sve-builtins.cc
> index d534ca923d9..336a1db662b 100644
> --- a/gcc/config/aarch64/aarch64-sve-builtins.cc
> +++ b/gcc/config/aarch64/aarch64-sve-builtins.cc
> @@ -995,12 +995,29 @@ registered_function &
> function_builder::add_function (const function_instance ,
> const char *name, tree fntype, tree attrs,
> uint64_t required_extensions,
> - bool overloaded_p)
> + bool overloaded_p,
> + bool placeholder_p)
> {
>unsigned int code = vec_safe_length (registered_functions);
>code = (code << AARCH64_BUILTIN_SHIFT) | AARCH64_BUILTIN_SVE;
> - tree decl = simulate_builtin_function_decl (input_location, name, fntype,
> - code, NULL, attrs);
> +
> + /* We need to be able to generate placeholders to enusre that we have a
> + consistent numbering scheme for function codes between the C and C++
> + frontends, so that everything ties up in LTO.
> +
> + Currently, tree-streamer-in.c:unpack_ts_function_decl_value_fields
> + validates that tree nodes returned by TARGET_BUILTIN_DECL are non-NULL
> and
> + some node other than error_mark_node. This is a holdover from when
> builtin
> + decls were streamed by code rather than by value.
> +
> + Ultimately, we should be able to remove this validation of BUILT_IN_MD
> + nodes and remove the target hook. For now, however, we need to appease
> the
> + validation and return a non-NULL, non-error_mark_node node, so we
> + arbitrarily choose integer_zero_node. */
> + tree decl = placeholder_p
> +? integer_zero_node
> +: simulate_builtin_function_decl (input_location, name, fntype,
> + code, NULL, attrs);
>
>registered_function = *ggc_alloc ();
>rfn.instance = instance;
> @@ -1032,7 +1049,7 @@ function_builder::add_unique_function (const
> function_instance ,
> argument_types.address ());
>tree attrs = get_attributes (instance);
>registered_function = add_function (instance, name, fntype, attrs,
> -required_extensions, false);
> +required_extensions, false, false);
>
>/* Enter the function into the hash table. */
>hashval_t hash = instance.hash ();
> @@ -1043,16 +1060,14 @@ function_builder::add_unique_function (const
> function_instance ,
>
>/* Also add the function under its overloaded alias, if we want
> a separate decl for each instance of an overloaded function. */
> - if (m_direct_overloads || force_direct_overloads)
> + char *overload_name = get_name (instance, true);
> + if (strcmp (name, overload_name) != 0)
> {
> - char *overload_name = get_name (instance, true);
> - if (strcmp (name, overload_name) != 0)
> - {
> - /*
[PATCH][GCC 10] aarch64: Fix SVE ACLE builtins with LTO [PR99216]
Hi,
Here is a backport of my fix for PR99216. The only change w.r.t the
original patch is a bump of lto-streamer.h:LTO_minor_version.
Bootstrapped and regtested on aarch64-linux-gnu, no issues.
OK for GCC 10 branch?
Thanks,
Alex
---
As discussed in the PR, we currently have two different numbering
schemes for SVE builtins: one for C, and one for C++. This is
problematic for LTO, where we end up getting confused about which
intrinsic we're talking about. This patch inserts placeholders into the
registered_functions vector to ensure that there is a consistent
numbering scheme for both C and C++.
This version uses integer_zero_node as a placeholder node instead of
building a function decl. This is safe because the node is only returned
by the TARGET_BUILTIN_DECL hook, which (on AArch64) is only used for
validation when builtin decls are streamed into lto1.
gcc/ChangeLog:
PR target/99216
* config/aarch64/aarch64-sve-builtins.cc
(function_builder::add_function): Add placeholder_p argument, use
placeholder decls if this is set.
(function_builder::add_unique_function): Instead of conditionally adding
direct overloads, unconditionally add either a direct overload or a
placeholder.
(function_builder::add_overloaded_function): Set placeholder_p if we're
using C++ overloads. Use the obstack for string storage instead
of relying on the tree nodes.
(function_builder::add_overloaded_functions): Don't return early for
m_direct_overloads: we need to add placeholders.
* config/aarch64/aarch64-sve-builtins.h
(function_builder::add_function): Add placeholder_p argument.
* lto-streamer.h (LTO_minor_version): Bump.
gcc/testsuite/ChangeLog:
PR target/99216
* g++.target/aarch64/sve/pr99216.C: New test.
diff --git a/gcc/config/aarch64/aarch64-sve-builtins.cc b/gcc/config/aarch64/aarch64-sve-builtins.cc
index d534ca923d9..336a1db662b 100644
--- a/gcc/config/aarch64/aarch64-sve-builtins.cc
+++ b/gcc/config/aarch64/aarch64-sve-builtins.cc
@@ -995,12 +995,29 @@ registered_function &
function_builder::add_function (const function_instance ,
const char *name, tree fntype, tree attrs,
uint64_t required_extensions,
-bool overloaded_p)
+bool overloaded_p,
+bool placeholder_p)
{
unsigned int code = vec_safe_length (registered_functions);
code = (code << AARCH64_BUILTIN_SHIFT) | AARCH64_BUILTIN_SVE;
- tree decl = simulate_builtin_function_decl (input_location, name, fntype,
- code, NULL, attrs);
+
+ /* We need to be able to generate placeholders to enusre that we have a
+ consistent numbering scheme for function codes between the C and C++
+ frontends, so that everything ties up in LTO.
+
+ Currently, tree-streamer-in.c:unpack_ts_function_decl_value_fields
+ validates that tree nodes returned by TARGET_BUILTIN_DECL are non-NULL and
+ some node other than error_mark_node. This is a holdover from when builtin
+ decls were streamed by code rather than by value.
+
+ Ultimately, we should be able to remove this validation of BUILT_IN_MD
+ nodes and remove the target hook. For now, however, we need to appease the
+ validation and return a non-NULL, non-error_mark_node node, so we
+ arbitrarily choose integer_zero_node. */
+ tree decl = placeholder_p
+? integer_zero_node
+: simulate_builtin_function_decl (input_location, name, fntype,
+ code, NULL, attrs);
registered_function = *ggc_alloc ();
rfn.instance = instance;
@@ -1032,7 +1049,7 @@ function_builder::add_unique_function (const function_instance ,
argument_types.address ());
tree attrs = get_attributes (instance);
registered_function = add_function (instance, name, fntype, attrs,
- required_extensions, false);
+ required_extensions, false, false);
/* Enter the function into the hash table. */
hashval_t hash = instance.hash ();
@@ -1043,16 +1060,14 @@ function_builder::add_unique_function (const function_instance ,
/* Also add the function under its overloaded alias, if we want
a separate decl for each instance of an overloaded function. */
- if (m_direct_overloads || force_direct_overloads)
+ char *overload_name = get_name (instance, true);
+ if (strcmp (name, overload_name) != 0)
{
- char *overload_name = get_name (instance, true);
- if (strcmp (name, overload_name) != 0)
- {
- /* Attribute lists shouldn't be shared. */
- tree attrs = get_attributes (instance);
- add_function (instance, overload_name, fntype, attrs,
- required_extensions, false);
- }
+ /* Attribute lists shouldn't be shared. */
+ tree attrs = get_attributes (instance);
+ bool placeholder_p = !(m_direct_overloads || force_direct_overloads);
+ add_function (instance, overload_name, fntype, attrs,
+ required_extensions, false, placeholder_p);
}
obstack_free
