Date: Sun, 26 Aug 2018 10:44:30 +0000 From: bugzilla-noreply@freebsd.org To: toolchain@FreeBSD.org Subject: [Bug 230888] Missing 64 bit atomic functions for i386 Message-ID: <bug-230888-29464-Ijck95nnuq@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-230888-29464@https.bugs.freebsd.org/bugzilla/> References: <bug-230888-29464@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D230888 David Chisnall <theraven@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |theraven@FreeBSD.org --- Comment #3 from David Chisnall <theraven@FreeBSD.org> --- Is there a reason, given that LLVM's atomic.c is in contrib, that we don't = just connect it to the libgcc_s build? Note that the problem is not just 64-bit. An increasing amount of x86-64 c= ode depends on 128-bit atomics (which are single instructions if compiling with -mcx16, libcalls otherwise). C11 allows arbitrary sized atomics. It's all= owed to write _Atomic(struct X) for any arbitrary X. The code in atomic.c handl= es this, though not for atomic types in shared memory (which can't be supported without changing the ABI - something that WG21 thought through by making std::atomic a library feature and allowing larger atomic types to be implemented with an inline lock, and which WG14 completely messed up). --=20 You are receiving this mail because: You are the assignee for the bug.=
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