lock/lock_free decisions in compiled time
Summary:
Enables atomic.c in compiler_rt and forces clang to not emit a call for runtime
decision about lock/lock_free. At compiling time, if clang can't decide if
atomic operation can be lock free, it emits calls to external functions like
`__atomic_is_lock_free`, `__c11_atomic_is_lock_free` and
`__atomic_always_lock_free`, postponing decision to a runtime check. According
to LLVM code documentation, the mechanism exists due to differences between
x86_64 processors that can't be decided at runtime.
On PowerPC and PowerPCSPE (32 bits), we already know in advance it can't be lock
free, so we force the decision at compile time and avoid having to implement it
in an external library.
This patch was made after 32 bit users testing the PowePC32 bit ISO reported
llvm could not be compiled with in-base llvm due to `__atomic_load8` not
implemented.
Submitted by: alfredo.junior_eldorado.org.br
Reviewed by: jhibbits, dim
Differential Revision: https://reviews.freebsd.org/D22549
This uses the new layout of the upstream repository, which was recently
migrated to GitHub, and converted into a "monorepo". That is, most of
the earlier separate sub-projects with their own branches and tags were
consolidated into one top-level directory, and are now branched and
tagged together.
Updating the vendor area to match this layout is next.
As with other archs the compiler may emit calls to the byte swap routines
under certain conditions.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Make armv7 as a new MACHINE_ARCH.
Copy all the places we do armv6 and add armv7 as basically an
alias. clang appears to generate code for armv7 by default. armv7 hard
float isn't supported by the the in-tree gcc, so it hasn't been
updated to have a new default.
Support armv7 as a new valid MACHINE_ARCH (and by extension
TARGET_ARCH).
Add armv7 to the universe build.
Differential Revision: https://reviews.freebsd.org/D12010
conversion functions use SSE2 instructions, but these are not guarded by
#ifdef __SSE2__, and there is no implementation using general purpose
registers. For these functions, use the generic C variants instead,
otherwise they will cause SIGILL on older processors.
Reported by: bsdpr@phoe.frmug.org
PR: 221733
MFC after: 1 week
These builtins were listed in the mips-specific Symbol.map for libc but
were not implemented. Compiling mips with recent clang requires these
symbols.
Sponsored by: DARPA / AFRL
This is required for mips gcc 6.3 userland to build/run.
Reviewed by: emaste, dim
Approved by: emaste
Differential Revision: https://reviews.freebsd.org/D10838
Newer versions of GCC include an __ffssi2() symbol in libgcc and the
compiler can emit calls to it in generated code. This is true for at
least GCC 6.2 when compiling world for mips and mips64.
Reviewed by: jmallett, dim
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D10086
Hardfloat is now default (use riscv64sf as TARGET_ARCH
for softfloat).
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D8529
Also switch to the style used in the clang390-import branch to reduce
future conflicts.
Reviewed by: dim
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8039
