Bug 1538817
| Summary: | g++ fails to compile libcxx on ppc64: error: ‘(9.223372036854775807e+18 / 1.0e+9)’ is not a constant expression | ||||||
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| Product: | [Fedora] Fedora | Reporter: | Tom Stellard <tstellar> | ||||
| Component: | gcc | Assignee: | Jakub Jelinek <jakub> | ||||
| Status: | CLOSED RAWHIDE | QA Contact: | Fedora Extras Quality Assurance <extras-qa> | ||||
| Severity: | unspecified | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 30 | CC: | bugproxy, dan, davejohansen, dcantrell, dxm480, fweimer, hannsj_uhl, itaru.kitayama, jakub, jwakely, law, mpolacek, noloader, normand, wschmidt | ||||
| Target Milestone: | --- | Keywords: | Reopened | ||||
| Target Release: | --- | ||||||
| Hardware: | ppc64le | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | gcc-9.2.1-1.fc32.3 | Doc Type: | If docs needed, set a value | ||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2020-01-16 02:25:05 UTC | Type: | Bug | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Bug Depends On: | |||||||
| Bug Blocks: | 1071880 | ||||||
| Attachments: |
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The IBM long double format is too weird and not everything in it is possible to be evaluated at compile time. So is my best option to modify the source to not use constexpr on ppc? I also should have mentioned that this compiles fine with clang. @Jakub - what about (9.223372036854775807e+18 / 1.0e+9) is not possible to evaluate at compile time in IBM long double format? I agree that it's an abomination but the unfortunate reality is there will be systems out there with IBM long-double ABI libraries for decades to come. :( @Tom: one potential workaround is to use IEEE754 standard long double format, e.g. build with "-mabi=ieeelongdouble", but now you're using a different ABI, which may or may not be what you want. It is probably easier to just avoid using constexpr when building with the GCC+PPC combination. same problem with gcc-8.1.1-5.fc28.ppc64le (In reply to Tom Stellard from comment #2) > So is my best option to modify the source to not use constexpr on ppc? Yes. Bill Schmidt, Ph.D. GCC Architect for Linux on Power IBM Linux Technology Center wschmidt.com Also see https://bugs.llvm.org/show_bug.cgi?id=39696 . This issue blocks LLVM from building on GCC112 on the compile farm. (There may be additional build problems). This message is a reminder that Fedora 27 is nearing its end of life. On 2018-Nov-30 Fedora will stop maintaining and issuing updates for Fedora 27. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '27'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 27 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. Fedora 27 changed to end-of-life (EOL) status on 2018-11-30. Fedora 27 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed. This bug appears to have been reported against 'rawhide' during the Fedora 30 development cycle. Changing version to '30. This is working now with gcc-9.2.1-1.fc32.3. (In reply to Tom Stellard from comment #11) > This is working now with gcc-9.2.1-1.fc32.3. Thanks Tom. |
Created attachment 1386322 [details] Preprocesed C++ File Description of problem: The attached reprocessed c++ file fails to compile on ppc64 and ppc64le, but it does compile successfully on x86_64. Version-Release number of selected component (if applicable): gcc-7.2.1-2.fc27 How reproducible: Always Steps to Reproduce: 1. c++ condition_variable.i Actual results: In file included from /root/libcxx/include/__mutex_base:15:0, from /root/libcxx/include/condition_variable:111, from ../src/condition_variable.cpp:14: /root/libcxx/include/chrono: In function ‘void std::__1::this_thread::sleep_for(const std::__1::chrono::duration<_Rep, _Period>&)’: /root/libcxx/include/thread:438:65: in constexpr expansion of ‘std::__1::chrono::duration<long double>(std::__1::chrono::duration<long long int, std::__1::ratio<1, 1000000000> >::max(), 0)’ /root/libcxx/include/chrono:563:67: in constexpr expansion of ‘std::__1::chrono::duration_cast<std::__1::chrono::duration<long double>, long long int, std::__1::ratio<1, 1000000000> >(__d)’ /root/libcxx/include/chrono:415:67: in constexpr expansion of ‘std::__1::chrono::__duration_cast<std::__1::chrono::duration<long long int, std::__1::ratio<1, 1000000000> >, std::__1::chrono::duration<long double>, std::__1::ratio<1, 1000000000>, true, false>().std::__1::chrono::__duration_cast<std::__1::chrono::duration<long long int, std::__1::ratio<1, 1000000000> >, std::__1::chrono::duration<long double>, std::__1::ratio<1, 1000000000>, true, false>::operator()(__fd)’ /root/libcxx/include/chrono:376:59: error: ‘(9.223372036854775807e+18 / 1.0e+9)’ is not a constant expression static_cast<_Ct>(__fd.count()) / static_cast<_Ct>(_Period::den))); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Expected results: File compiles successfully.