On 18/06/19 13:58 +0200, Christophe Lyon wrote:
On Mon, 17 Jun 2019 at 15:21, Jonathan Wakely <jwak...@redhat.com> wrote:
On 13/06/19 22:41 +0200, Christophe Lyon wrote:
>Hi,
>
>
>On Wed, 12 Jun 2019 at 16:54, Jonathan Wakely <jwak...@redhat.com> wrote:
>>
>> The std::to_chars functions from C++17 can be used to implement
>> std::to_string with much better performance than calling snprintf. Only
>> the __detail::__to_chars_len and __detail::__to_chars_10 functions are
>> needed for to_string, because it always outputs base 10 representations.
>>
>> The return type of __detail::__to_chars_10 should not be declared before
>> C++17, so the function body is extracted into a new function that can be
>> reused by to_string and __detail::__to_chars_10.
>>
>> The existing tests for to_chars rely on to_string to check for correct
>> answers. Now that they use the same code that doesn't actually ensure
>> correctness, so add new tests for std::to_string that compare against
>> printf output.
>>
>> * include/Makefile.am: Add new <bits/charconv.h> header.
>> * include/Makefile.in: Regenerate.
>> * include/bits/basic_string.h (to_string(int), to_string(unsigned))
>> (to_string(long), to_string(unsigned long), to_string(long long))
>> (to_string(unsigned long long)): Rewrite to use __to_chars_10_impl.
>> * include/bits/charconv.h: New header.
>> (__detail::__to_chars_len): Move here from <charconv>.
>> (__detail::__to_chars_10_impl): New function extracted from
>> __detail::__to_chars_10.
>> * include/std/charconv (__cpp_lib_to_chars): Add, but comment out.
>> (__to_chars_unsigned_type): New class template that reuses
>> __make_unsigned_selector_base::__select to pick a type.
>> (__unsigned_least_t): Redefine as __to_chars_unsigned_type<T>::type.
>> (__detail::__to_chars_len): Move to new header.
>> (__detail::__to_chars_10): Add inline specifier. Move code doing the
>> output to __detail::__to_chars_10_impl and call that.
>> * include/std/version (__cpp_lib_to_chars): Add, but comment out.
>> * testsuite/21_strings/basic_string/numeric_conversions/char/
>> to_string.cc: Fix reference in comment. Remove unused variable.
>> * testsuite/21_strings/basic_string/numeric_conversions/char/
>> to_string_int.cc: New test.
>>
>> Tested x86_64-linux, committed to trunk.
>>
>
>The new test to_string_int.cc fails on arm-none-eabi:
>PASS: 21_strings/basic_string/numeric_conversions/char/to_string_int.cc
>(test for excess errors)
>spawn
/aci-gcc-fsf/builds/gcc-fsf-gccsrc/obj-arm-none-eabi/gcc3/utils/bin/qemu-wrapper.sh
>./to_string_int.exe
>/libstdc++-v3/testsuite/21_strings/basic_string/numeric_conversions/char/to_string_int.cc:105:
>void check_value(T) [with T = long long int]: Assertion 's ==
>expected' failed.
>FAIL: 21_strings/basic_string/numeric_conversions/char/to_string_int.cc
>execution test
Does the target support "%lld" in printf?
Does the .sum file show UNSUPPORTED for the existing
21_strings/basic_string/numeric_conversions/char/to_string.cc test?
No, it PASSes.
Does the attached patch make the test show what fails?
I didn't try because I realized that it might be a problem with how I
configure newlib in my validation system.
After I added the same flags I use when I build&test manually,
to_string_int.cc now passes.
I added:
--enable-newlib-io-pos-args \
--enable-newlib-io-c99-formats \
--enable-newlib-io-long-long \
--enable-newlib-io-long-double \
to newlib's configure flags.
I assume it's io-c99-formats that makes "%lld" work.
However, this makes several other libstdc++ tests fail on aarch64:
22_locale/money_get/get/char/5.cc execution test
22_locale/money_get/get/wchar_t/5.cc execution test
22_locale/num_get/get/char/39168.cc execution test
22_locale/num_get/get/char/4.cc execution test
22_locale/num_get/get/wchar_t/39168.cc execution test
22_locale/num_get/get/wchar_t/4.cc execution test
26_numerics/complex/inserters_extractors/char/1.cc execution test
26_numerics/complex/inserters_extractors/wchar_t/1.cc execution test
27_io/basic_istream/extractors_arithmetic/char/01.cc execution test
27_io/basic_istream/extractors_arithmetic/char/12.cc execution test
27_io/basic_istream/extractors_arithmetic/wchar_t/01.cc execution test
27_io/basic_istream/extractors_arithmetic/wchar_t/12.cc execution test
but I guess that should be a separate bug report....
I'll add those flags to my automated tests.
Thanks.
