Re: [PATCH v2] RISC-V: Add riscv_vector_cc function attribute
LGTM, thanks :)
On Fri, Mar 1, 2024 at 5:10 PM Li Xu wrote:
>
> From: xuli
>
> Standard vector calling convention variant will only enabled when function
> has vector argument or returning value by default, however user may also
> want to invoke function without that during a vectorized loop at some
> situation,
> but it will cause a huge performance penalty due to vector register
> store/restore.
>
> So user can declare function with this riscv_vector_cc attribute like below,
> that could enforce
> function will use standard vector calling convention variant.
>
> void foo() __attribute__((riscv_vector_cc));
> [[riscv::vector_cc]] void foo(); // For C++11 and C23
>
> For more details please reference the below link.
> https://github.com/riscv-non-isa/riscv-c-api-doc/pull/67
>
> gcc/ChangeLog:
>
> * config/riscv/riscv.cc (TARGET_GNU_ATTRIBUTES): Add riscv_vector_cc
> attribute to riscv_attribute_table.
> (riscv_vector_cc_function_p): Return true if FUNC is a
> riscv_vector_cc function.
> (riscv_fntype_abi): Add riscv_vector_cc attribute check.
> * doc/extend.texi: Add riscv_vector_cc attribute description.
>
> gcc/testsuite/ChangeLog:
>
> * g++.target/riscv/rvv/base/attribute-riscv_vector_cc-error.C: New
> test.
> * gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-callee-saved.c:
> New test.
> * gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-error.c: New
> test.
> ---
> gcc/config/riscv/riscv.cc | 55 ---
> gcc/doc/extend.texi | 10
> .../base/attribute-riscv_vector_cc-error.C| 21 +++
> .../attribute-riscv_vector_cc-callee-saved.c | 30 ++
> .../base/attribute-riscv_vector_cc-error.c| 11
> 5 files changed, 119 insertions(+), 8 deletions(-)
> create mode 100644
> gcc/testsuite/g++.target/riscv/rvv/base/attribute-riscv_vector_cc-error.C
> create mode 100644
> gcc/testsuite/gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-callee-saved.c
> create mode 100644
> gcc/testsuite/gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-error.c
>
> diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
> index 4100abc9dd1..7f37f231796 100644
> --- a/gcc/config/riscv/riscv.cc
> +++ b/gcc/config/riscv/riscv.cc
> @@ -537,24 +537,52 @@ static tree riscv_handle_fndecl_attribute (tree *,
> tree, tree, int, bool *);
> static tree riscv_handle_type_attribute (tree *, tree, tree, int, bool *);
>
> /* Defining target-specific uses of __attribute__. */
> -TARGET_GNU_ATTRIBUTES (riscv_attribute_table,
> +static const attribute_spec riscv_gnu_attributes[] =
> {
>/* Syntax: { name, min_len, max_len, decl_required, type_required,
>function_type_required, affects_type_identity, handler,
>exclude } */
>
>/* The attribute telling no prologue/epilogue. */
> - { "naked", 0, 0, true, false, false, false,
> -riscv_handle_fndecl_attribute, NULL },
> + {"naked", 0, 0, true, false, false, false, riscv_handle_fndecl_attribute,
> + NULL},
>/* This attribute generates prologue/epilogue for interrupt handlers. */
> - { "interrupt", 0, 1, false, true, true, false,
> -riscv_handle_type_attribute, NULL },
> + {"interrupt", 0, 1, false, true, true, false, riscv_handle_type_attribute,
> + NULL},
>
>/* The following two are used for the built-in properties of the Vector
> type
> and are not used externally */
>{"RVV sizeless type", 4, 4, false, true, false, true, NULL, NULL},
> - {"RVV type", 0, 0, false, true, false, true, NULL, NULL}
> -});
> + {"RVV type", 0, 0, false, true, false, true, NULL, NULL},
> + /* This attribute is used to declare a function, forcing it to use the
> +standard vector calling convention variant. Syntax:
> +__attribute__((riscv_vector_cc)). */
> + {"riscv_vector_cc", 0, 0, false, true, true, true, NULL, NULL}
> +};
> +
> +static const scoped_attribute_specs riscv_gnu_attribute_table =
> +{
> + "gnu", {riscv_gnu_attributes}
> +};
> +
> +static const attribute_spec riscv_attributes[] =
> +{
> + /* This attribute is used to declare a function, forcing it to use the
> + standard vector calling convention variant. Syntax:
> + [[riscv::vector_cc]]. */
> + {"vector_cc", 0, 0, false, true, true, true, NULL, NULL}
> +};
> +
> +static const scoped_attribute_specs riscv_nongnu_attribute_table =
> +{
> + "riscv", {riscv_attributes}
> +};
> +
> +static const scoped_attribute_specs *const riscv_attribute_table[] =
> +{
> + &riscv_gnu_attribute_table,
> + &riscv_nongnu_attribute_table
> +};
>
> /* Order for the CLOBBERs/USEs of gpr_save. */
> static const unsigned gpr_save_reg_order[] = {
> @@ -5425,6 +5453,16 @@ riscv_arguments_is_vector_type_p (const_tree fntype)
>return false;
> }
>
> +/* Return true if FUNC is a riscv_vector_cc function.
> + For more details please reference the below link.
> + https://github.com/riscv-non-i
[PATCH v2] RISC-V: Add riscv_vector_cc function attribute
From: xuli
Standard vector calling convention variant will only enabled when function
has vector argument or returning value by default, however user may also
want to invoke function without that during a vectorized loop at some situation,
but it will cause a huge performance penalty due to vector register
store/restore.
So user can declare function with this riscv_vector_cc attribute like below,
that could enforce
function will use standard vector calling convention variant.
void foo() __attribute__((riscv_vector_cc));
[[riscv::vector_cc]] void foo(); // For C++11 and C23
For more details please reference the below link.
https://github.com/riscv-non-isa/riscv-c-api-doc/pull/67
gcc/ChangeLog:
* config/riscv/riscv.cc (TARGET_GNU_ATTRIBUTES): Add riscv_vector_cc
attribute to riscv_attribute_table.
(riscv_vector_cc_function_p): Return true if FUNC is a riscv_vector_cc
function.
(riscv_fntype_abi): Add riscv_vector_cc attribute check.
* doc/extend.texi: Add riscv_vector_cc attribute description.
gcc/testsuite/ChangeLog:
* g++.target/riscv/rvv/base/attribute-riscv_vector_cc-error.C: New test.
* gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-callee-saved.c:
New test.
* gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-error.c: New test.
---
gcc/config/riscv/riscv.cc | 55 ---
gcc/doc/extend.texi | 10
.../base/attribute-riscv_vector_cc-error.C| 21 +++
.../attribute-riscv_vector_cc-callee-saved.c | 30 ++
.../base/attribute-riscv_vector_cc-error.c| 11
5 files changed, 119 insertions(+), 8 deletions(-)
create mode 100644
gcc/testsuite/g++.target/riscv/rvv/base/attribute-riscv_vector_cc-error.C
create mode 100644
gcc/testsuite/gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-callee-saved.c
create mode 100644
gcc/testsuite/gcc.target/riscv/rvv/base/attribute-riscv_vector_cc-error.c
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 4100abc9dd1..7f37f231796 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -537,24 +537,52 @@ static tree riscv_handle_fndecl_attribute (tree *, tree,
tree, int, bool *);
static tree riscv_handle_type_attribute (tree *, tree, tree, int, bool *);
/* Defining target-specific uses of __attribute__. */
-TARGET_GNU_ATTRIBUTES (riscv_attribute_table,
+static const attribute_spec riscv_gnu_attributes[] =
{
/* Syntax: { name, min_len, max_len, decl_required, type_required,
function_type_required, affects_type_identity, handler,
exclude } */
/* The attribute telling no prologue/epilogue. */
- { "naked", 0, 0, true, false, false, false,
-riscv_handle_fndecl_attribute, NULL },
+ {"naked", 0, 0, true, false, false, false, riscv_handle_fndecl_attribute,
+ NULL},
/* This attribute generates prologue/epilogue for interrupt handlers. */
- { "interrupt", 0, 1, false, true, true, false,
-riscv_handle_type_attribute, NULL },
+ {"interrupt", 0, 1, false, true, true, false, riscv_handle_type_attribute,
+ NULL},
/* The following two are used for the built-in properties of the Vector type
and are not used externally */
{"RVV sizeless type", 4, 4, false, true, false, true, NULL, NULL},
- {"RVV type", 0, 0, false, true, false, true, NULL, NULL}
-});
+ {"RVV type", 0, 0, false, true, false, true, NULL, NULL},
+ /* This attribute is used to declare a function, forcing it to use the
+standard vector calling convention variant. Syntax:
+__attribute__((riscv_vector_cc)). */
+ {"riscv_vector_cc", 0, 0, false, true, true, true, NULL, NULL}
+};
+
+static const scoped_attribute_specs riscv_gnu_attribute_table =
+{
+ "gnu", {riscv_gnu_attributes}
+};
+
+static const attribute_spec riscv_attributes[] =
+{
+ /* This attribute is used to declare a function, forcing it to use the
+ standard vector calling convention variant. Syntax:
+ [[riscv::vector_cc]]. */
+ {"vector_cc", 0, 0, false, true, true, true, NULL, NULL}
+};
+
+static const scoped_attribute_specs riscv_nongnu_attribute_table =
+{
+ "riscv", {riscv_attributes}
+};
+
+static const scoped_attribute_specs *const riscv_attribute_table[] =
+{
+ &riscv_gnu_attribute_table,
+ &riscv_nongnu_attribute_table
+};
/* Order for the CLOBBERs/USEs of gpr_save. */
static const unsigned gpr_save_reg_order[] = {
@@ -5425,6 +5453,16 @@ riscv_arguments_is_vector_type_p (const_tree fntype)
return false;
}
+/* Return true if FUNC is a riscv_vector_cc function.
+ For more details please reference the below link.
+ https://github.com/riscv-non-isa/riscv-c-api-doc/pull/67 */
+static bool
+riscv_vector_cc_function_p (const_tree fntype)
+{
+ return lookup_attribute ("vector_cc", TYPE_ATTRIBUTES (fntype)) != NULL_TREE
+|| lookup_attribute ("riscv_vector_cc", TYPE_ATTRIBUTES (fntype)) !=
NULL_TREE;
+}
+
/* Implement TARGET_FNTYP
