Public bug reported: On s390x, the type float_t has historically been defined as double for no good reason, yet with unexpected and unnecessary impact on performance in some scenarios. The upcoming glibc release 2.33 will be a first step towards cleaning that up, which will change float_t to become float on s390x when compiling C++ code, such as in clucene-core. That would break the ABI of clucene-core on s390x for existing binaries.
Today, clucene-core uses float_t for some parameters in its API; that type is defined as double on s390x today. Together with gcc's default behavior, that contradicts the C standard. To get to a more sane combination, the upcoming glibc release 2.33 will change float_t to become float on s390x (with some exceptions when compiling C code, which do not apply for clucene-core). To my knowledge, glibc 2.33 is a candidate for inclusion in Ubuntu 21.04. To avoid breaking the API of clucene-core in the process, I have prepared a trivial patch that fixes clucene-core's API to always use double instead of float_t on s390x. That patch effectively persists the current de-facto API on s390x, without changes for other architectures. Note that using float_t in an API is generally "not a great idea", because that type can have different definitions even with the same compiler and glibc version on the same system (e.g., on 32-bit x86, when switching between SSE and x87 FP ops). Patch submitted in https://sourceforge.net/p/clucene/bugs/233/ and https://sourceforge.net/p/clucene/mailman/message/37153930/ yet upstream clucene is effectively unmaintained. If Ubuntu 21.04 adopts glibc 2.33, please consider pulling in this patch in clucene-core. Related request for ImageMagick: https://bugs.launchpad.net/ubuntu/+source/imagemagick/+bug/1913268 ** Affects: linux (Ubuntu) Importance: Undecided Assignee: Skipper Bug Screeners (skipper-screen-team) Status: New ** Tags: architecture-s3903164 bugnameltc-191033 severity-medium targetmilestone-inin2104 ** Tags added: architecture-s3903164 bugnameltc-191033 severity-medium targetmilestone-inin2104 ** Changed in: ubuntu Assignee: (unassigned) => Skipper Bug Screeners (skipper-screen-team) ** Package changed: ubuntu => linux (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1913388 Title: clucene-core: please pull in patch to stabilize API on s390x during upgrade to glibc 2.33 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1913388/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
