Here is the benchmark result for is_volatile:
https://github.com/ken-matsui/gcc-benches/blob/main/is_volatile.md#sat-jun-24-074036-am-pdt-2023
Time: -2.42335%
Peak Memory Usage: -1.07651%
Total Memory Usage: -1.62369%
On Sat, Jun 24, 2023 at 7:24 AM Ken Matsui <kmat...@cs.washington.edu> wrote:
>
> This patch implements built-in trait for std::is_volatile.
>
> gcc/cp/ChangeLog:
>
> * cp-trait.def: Define __is_volatile.
> * constraint.cc (diagnose_trait_expr): Handle CPTK_IS_VOLATILE.
> * semantics.cc (trait_expr_value): Likewise.
> (finish_trait_expr): Likewise.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/ext/has-builtin-1.C: Test existence of __is_volatile.
> * g++.dg/ext/is_volatile.C: New test.
>
> Signed-off-by: Ken Matsui <kmat...@cs.washington.edu>
> ---
> gcc/cp/constraint.cc | 3 +++
> gcc/cp/cp-trait.def | 1 +
> gcc/cp/semantics.cc | 4 ++++
> gcc/testsuite/g++.dg/ext/has-builtin-1.C | 3 +++
> gcc/testsuite/g++.dg/ext/is_volatile.C | 19 +++++++++++++++++++
> 5 files changed, 30 insertions(+)
> create mode 100644 gcc/testsuite/g++.dg/ext/is_volatile.C
>
> diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
> index 8cf0f2d0974..e971d67ee25 100644
> --- a/gcc/cp/constraint.cc
> +++ b/gcc/cp/constraint.cc
> @@ -3751,6 +3751,9 @@ diagnose_trait_expr (tree expr, tree args)
> case CPTK_IS_UNION:
> inform (loc, " %qT is not a union", t1);
> break;
> + case CPTK_IS_VOLATILE:
> + inform (loc, " %qT is not a volatile type", t1);
> + break;
> case CPTK_IS_AGGREGATE:
> inform (loc, " %qT is not an aggregate", t1);
> break;
> diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
> index 8b7fece0cc8..414b1065a11 100644
> --- a/gcc/cp/cp-trait.def
> +++ b/gcc/cp/cp-trait.def
> @@ -82,6 +82,7 @@ DEFTRAIT_EXPR (IS_TRIVIALLY_ASSIGNABLE,
> "__is_trivially_assignable", 2)
> DEFTRAIT_EXPR (IS_TRIVIALLY_CONSTRUCTIBLE, "__is_trivially_constructible",
> -1)
> DEFTRAIT_EXPR (IS_TRIVIALLY_COPYABLE, "__is_trivially_copyable", 1)
> DEFTRAIT_EXPR (IS_UNION, "__is_union", 1)
> +DEFTRAIT_EXPR (IS_VOLATILE, "__is_volatile", 1)
> DEFTRAIT_EXPR (REF_CONSTRUCTS_FROM_TEMPORARY,
> "__reference_constructs_from_temporary", 2)
> DEFTRAIT_EXPR (REF_CONVERTS_FROM_TEMPORARY,
> "__reference_converts_from_temporary", 2)
> /* FIXME Added space to avoid direct usage in GCC 13. */
> diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> index 8fb47fd179e..10934d01504 100644
> --- a/gcc/cp/semantics.cc
> +++ b/gcc/cp/semantics.cc
> @@ -12079,6 +12079,9 @@ trait_expr_value (cp_trait_kind kind, tree type1,
> tree type2)
> case CPTK_IS_ENUM:
> return type_code1 == ENUMERAL_TYPE;
>
> + case CPTK_IS_VOLATILE:
> + return CP_TYPE_VOLATILE_P (type1);
> +
> case CPTK_IS_FINAL:
> return CLASS_TYPE_P (type1) && CLASSTYPE_FINAL (type1);
>
> @@ -12296,6 +12299,7 @@ finish_trait_expr (location_t loc, cp_trait_kind
> kind, tree type1, tree type2)
> case CPTK_IS_ENUM:
> case CPTK_IS_UNION:
> case CPTK_IS_SAME:
> + case CPTK_IS_VOLATILE:
> break;
>
> case CPTK_IS_LAYOUT_COMPATIBLE:
> diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> index f343e153e56..7ad640f141b 100644
> --- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> +++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> @@ -146,3 +146,6 @@
> #if !__has_builtin (__remove_cvref)
> # error "__has_builtin (__remove_cvref) failed"
> #endif
> +#if !__has_builtin (__is_volatile)
> +# error "__has_builtin (__is_volatile) failed"
> +#endif
> diff --git a/gcc/testsuite/g++.dg/ext/is_volatile.C
> b/gcc/testsuite/g++.dg/ext/is_volatile.C
> new file mode 100644
> index 00000000000..004e397e5e7
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ext/is_volatile.C
> @@ -0,0 +1,19 @@
> +// { dg-do compile { target c++11 } }
> +
> +#include <testsuite_tr1.h>
> +
> +using namespace __gnu_test;
> +
> +#define SA(X) static_assert((X),#X)
> +
> +// Positive tests.
> +SA(__is_volatile(volatile int));
> +SA(__is_volatile(const volatile int));
> +SA(__is_volatile(vClassType));
> +SA(__is_volatile(cvClassType));
> +
> +// Negative tests.
> +SA(!__is_volatile(int));
> +SA(!__is_volatile(const int));
> +SA(!__is_volatile(ClassType));
> +SA(!__is_volatile(cClassType));
> --
> 2.41.0
>
