BPF (eBPF) is an independent instruction set architecture which is
introduced in Linux a few years ago. Originally, eBPF execute
environment was only inside Linux kernel. However, recent years there
are some user space implementation (https://github.com/iovisor/ubpf,
https://doc.dpdk.org/guides/prog_guide/bpf_lib.html) and kernel space
implementation for FreeBSD is going on
(https://github.com/YutaroHayakawa/generic-ebpf).
The BPF target support can be enabled using WITH_LLVM_TARGET_BPF, as it
is not built by default.
Submitted by: Yutaro Hayakawa <yhayakawa3720@gmail.com>
Reviewed by: dim, bdrewery
Differential Revision: https://reviews.freebsd.org/D16033
This makes it possible, through src.conf(5) settings, to select which
LLVM targets you want to build during buildworld. The current list is:
* (WITH|WITHOUT)_LLVM_TARGET_AARCH64
* (WITH|WITHOUT)_LLVM_TARGET_ARM
* (WITH|WITHOUT)_LLVM_TARGET_MIPS
* (WITH|WITHOUT)_LLVM_TARGET_POWERPC
* (WITH|WITHOUT)_LLVM_TARGET_SPARC
* (WITH|WITHOUT)_LLVM_TARGET_X86
To not influence anything right now, all of these are on by default, in
situations where clang is enabled.
Selectively turning a few targets off manually should work. Turning on
only one target should work too, even if that target does not correspond
to the build architecture. (In that case, LLVM_NATIVE_ARCH will not be
defined, and you can only use the resulting clang executable for
cross-compiling.)
I performed a few measurements on one of the FreeBSD.org reference
machines, building clang from scratch, with all targets enabled, and
with only the x86 target enabled. The latter was ~12% faster in real
time (on a 32-core box), and ~14% faster in user time. For a full
buildworld the difference will probably be less pronounced, though.
Reviewed by: bdrewery
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D11077
to ease any rework of how clang is built to take arm64 in to account.
Submitted by: andrew
Reviewed by: andrew, emaste
Differential Revision: https://reviews.freebsd.org/D1446
This commit merges the latest LLVM sources from the vendor space. It
also updates the build glue to match the new sources. Clang's version
number is changed to match LLVM's, which means /usr/include/clang/2.0
has been renamed to /usr/include/clang/2.8.
Obtained from: projects/clangbsd
