Date: Sat, 10 Apr 2021 12:03:13 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: =?UTF-8?B?W0J1ZyAyNTQ5MTFdIGxpYi9tc3VuL2N0cmlnX3Rlc3QgZmFpbHMg?= =?UTF-8?B?aWYgY29tcGlsZWQgd2l0aCBBVljCoCgtbWF2eCkgb3IgYW55IENQVVNFVCBl?= =?UTF-8?B?bmFibGluZyBBVlg=?= Message-ID: <bug-254911-227-EgmyHOZZ0Z@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-254911-227@https.bugs.freebsd.org/bugzilla/> References: <bug-254911-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D254911 --- Comment #4 from commit-hook@FreeBSD.org --- A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=3D3b00222f156dca5700c839d73e36daf47= 9fa640c commit 3b00222f156dca5700c839d73e36daf479fa640c Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2021-04-09 23:07:54 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2021-04-10 11:59:57 +0000 Avoid raising unexpected floating point exceptions in libm When using clang with x86_64 CPUs that support AVX, some floating point transformations may raise exceptions that would not have been raised by the original code. To avoid this, use the -fp-exception-behavior=3Dmayt= rap flag, introduced in clang 10.0.0. In particular, this fixes a number of test failures with ctanhf(3) and ctanf(3), when libm is compiled with -mavx. An unexpected FE_INVALID exception is then raised, because clang emits vdivps instructions to perform certain divides. (The vdivps instruction operates on multiple single-precision float operands simultaneously, but the exceptions may be influenced by unused parts of the XMM registers. In this particular case, it was calculating 0 / 0, which results in FE_INVALID.) If -fp-exception-behavior=3Dmaytrap is specified however, clang uses vdivss instructions instead, which work on one operand, and should not raise unexpected exceptions. Reported by: olivier Reviewed by: arichardson PR: 254911 MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D29686 lib/msun/Makefile | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --=20 You are receiving this mail because: You are the assignee for the bug.=
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