This patch series implements __is_const, __is_volatile, __is_pointer, and __is_unbounded_array built-in traits, which were isolated from my previous patch series "Optimize type traits compilation performance" because they contained performance regression. I confirmed that this patch series does not cause any performance regression. The main reason of the performance regression were the exhaustiveness of the benchmarks and the instability of the benchmark results. Here are new benchmark results:
is_const: https://github.com/ken-matsui/gcc-bench/blob/main/is_const.md#sat-dec-23-090605-am-pst-2023 time: -4.36603%, peak memory: -0.300891%, total memory: -0.247934% is_volatile_v: https://github.com/ken-matsui/gcc-bench/blob/main/is_volatile_v.md#sat-dec-23-091518-am-pst-2023 time: -4.06816%, peak memory: -0.609298%, total memory: -0.659134% is_pointer: https://github.com/ken-matsui/gcc-bench/blob/main/is_pointer.md#sat-dec-23-124903-pm-pst-2023 time: -2.47124%, peak memory: -2.98207%, total memory: -4.0811% is_unbounded_array_v: https://github.com/ken-matsui/gcc-bench/blob/main/is_unbounded_array_v.md#sat-dec-23-010046-pm-pst-2023 time: -1.50025%, peak memory: -1.07386%, total memory: -2.32394% Ken Matsui (8): c++: Implement __is_const built-in trait libstdc++: Optimize std::is_const compilation performance c++: Implement __is_volatile built-in trait libstdc++: Optimize std::is_volatile compilation performance c++: Implement __is_pointer built-in trait libstdc++: Optimize std::is_pointer compilation performance c++: Implement __is_unbounded_array built-in trait libstdc++: Optimize std::is_unbounded_array compilation performance gcc/cp/constraint.cc | 12 +++ gcc/cp/cp-trait.def | 4 + gcc/cp/semantics.cc | 16 ++++ gcc/testsuite/g++.dg/ext/has-builtin-1.C | 12 +++ gcc/testsuite/g++.dg/ext/is_const.C | 19 +++++ gcc/testsuite/g++.dg/ext/is_pointer.C | 51 +++++++++++++ gcc/testsuite/g++.dg/ext/is_unbounded_array.C | 37 ++++++++++ gcc/testsuite/g++.dg/ext/is_volatile.C | 19 +++++ libstdc++-v3/include/bits/cpp_type_traits.h | 29 ++++++++ libstdc++-v3/include/std/type_traits | 73 +++++++++++++++++-- 10 files changed, 264 insertions(+), 8 deletions(-) create mode 100644 gcc/testsuite/g++.dg/ext/is_const.C create mode 100644 gcc/testsuite/g++.dg/ext/is_pointer.C create mode 100644 gcc/testsuite/g++.dg/ext/is_unbounded_array.C create mode 100644 gcc/testsuite/g++.dg/ext/is_volatile.C -- 2.43.0
