subtarget features for indirect calls and indirect branches.
This is in preparation for enabling *only* the call retpolines when
using speculative load hardening.
I've continued to use subtarget features for now as they continue to
seem the best fit given the lack of other retpoline like constructs so
far.
The LLVM side is pretty simple. I'd like to eventually get rid of the
old feature, but not sure what backwards compatibility issues that will
cause.
This does remove the "implies" from requesting an external thunk. This
always seemed somewhat questionable and is now clearly not desirable --
you specify a thunk the same way no matter which set of things are
getting retpolines.
I really want to keep this nicely isolated from end users and just an
LLVM implementation detail, so I've moved the `-mretpoline` flag in
Clang to no longer rely on a specific subtarget feature by that name and
instead to be directly handled. In some ways this is simpler, but in
order to preserve existing behavior I've had to add some fallback code
so that users who relied on merely passing -mretpoline-external-thunk
continue to get the same behavior. We should eventually remove this
I suspect (we have never tested that it works!) but I've not done that
in this patch.
Differential Revision: https://reviews.llvm.org/D51150
llvm-svn: 340515
For /arch:AVX512F:
clang-cl and cl.exe both defines __AVX512F__ __AVX512CD__.
clang-cl also defines __AVX512ER__ __AVX512PF__.
64-bit cl.exe also defines (according to /Bz) _NO_PREFETCHW.
For /arch:AVX512:
clang-cl and cl.exe both define
__AVX512F__ __AVX512CD__ __AVX512BW__ __AVX512DQ__ __AVX512VL__.
64-bit cl.exe also defines _NO_PREFETCHW.
So not 100% identical, but pretty close.
Also refactor the existing AVX / AVX2 code to not repeat itself in both the
32-bit and 64-bit cases.
https://reviews.llvm.org/D42538
llvm-svn: 323433
r213083 initially implemented /arch: support by mapping it to CPU features.
Then r241077 additionally mapped it to CPU, which made the feature flags
redundant (if harmless). This change here removes the redundant mapping to
feature flags, and rewrites test/Driver/cl-x86-flags.c to be a bit more of an
integration test that checks for preprocessor defines like AVX (like documented
on MSDN) instead of for driver flags.
To keep emitting warn_drv_unused_argument, use getLastArgNoClaim() followed by an explicit claim() if needed.
This is in preparation for adding support for /arch:AVX512(F).
No intended behavior change.
https://reviews.llvm.org/D42497
llvm-svn: 323426
Summary:
(This is a move-only refactoring patch. There are no functionality changes.)
This patch splits apart the Clang driver's tool and toolchain implementation
files. Each target platform toolchain is moved to its own file, along with the
closest-related tools. Each target platform toolchain has separate headers and
implementation files, so the hierarchy of classes is unchanged.
There are some remaining shared free functions, mostly from Tools.cpp. Several
of these move to their own architecture-specific files, similar to r296056. Some
of them are only used by a single target platform; since the tools and
toolchains are now together, some helpers now live in a platform-specific file.
The balance are helpers related to manipulating argument lists, so they are now
in a new file pair, CommonArgs.h and .cpp.
I've tried to cluster the code logically, which is fairly straightforward for
most of the target platforms and shared architectures. I think I've made
reasonable choices for these, as well as the various shared helpers; but of
course, I'm happy to hear feedback in the review.
There are some particular things I don't like about this patch, but haven't been
able to find a better overall solution. The first is the proliferation of files:
there are several files that are tiny because the toolchain is not very
different from its base (usually the Gnu tools/toolchain). I think this is
mostly a reflection of the true complexity, though, so it may not be "fixable"
in any reasonable sense. The second thing I don't like are the includes like
"../Something.h". I've avoided this largely by clustering into the current file
structure. However, a few of these includes remain, and in those cases it
doesn't make sense to me to sink an existing file any deeper.
Reviewers: rsmith, mehdi_amini, compnerd, rnk, javed.absar
Subscribers: emaste, jfb, danalbert, srhines, dschuff, jyknight, nemanjai, nhaehnle, mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D30372
llvm-svn: 297250
Chandler Carruth