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From: "Zahira.Ammarguellat at intel dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/106117] New: Use of option -fexcess-precision for operation-by-operation emulation for _Float16 arithmetics. Date: Tue, 28 Jun 2022 13:17:32 +0000 [thread overview] Message-ID: <bug-106117-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106117 Bug ID: 106117 Summary: Use of option -fexcess-precision for operation-by-operation emulation for _Float16 arithmetics. Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: Zahira.Ammarguellat at intel dot com Target Milestone: --- We are adding in Clang the support of '_Float16' on X86 targets with SSE2 enabled. When the target supports AVX512-FP16, Clang performs '_Float16' arithmetic using native support. Otherwise, '_Float16' arithmetic is performed by promoting to 'float', then performing the operation, and finally truncating to '_Float16'. This operation-by-operation emulation is the default in Clang, and is in line with the C standard's rules for excess precision arithmetic. We would like to adopt the option '-fexcess-precision' to request this operation-by-operation emulation by setting '-fexcess-precision=none'. First are there any objections in using this option to request operation-by-operation emulation for '_Float16' arithmetic? Second is 'none' the right value to use? Thanks.
next reply other threads:[~2022-06-28 13:17 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-28 13:17 Zahira.Ammarguellat at intel dot com [this message] 2022-06-28 15:04 ` [Bug c/106117] " rjmccall at gmail dot com 2022-06-28 21:14 ` joseph at codesourcery dot com 2022-06-28 23:44 ` crazylht at gmail dot com 2022-06-29 15:47 ` rjmccall at gmail dot com 2022-06-29 17:34 ` joseph at codesourcery dot com 2022-06-29 17:58 ` rjmccall at gmail dot com 2022-06-29 20:16 ` joseph at codesourcery dot com 2022-06-29 21:31 ` rjmccall at gmail dot com
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