This introduces the new `--print-enabled-extensions` command line option
to AArch64, which prints the list of extensions that are enabled for the
target specified by the combination of `--target`/`-march`/`-mcpu`
values.
The goal of the this option is both to enable the manual inspection of
the enabled extensions by users and to enhance the testability of
architecture versions and CPU targets implemented in the compiler.
As part of this change, a new field for `FEAT_*` architecture feature
names was added to the TableGen entries. The output of the existing
`--print-supported-extensions` option was updated accordingly to show
these in a separate column.
This introduces the new `--print-enabled-extensions` command line option
to AArch64, which prints the list of extensions that are enabled for the
target specified by the combination of `--target`/`-march`/`-mcpu`
values.
The goal of the this option is both to enable the manual inspection of
the enabled extensions by users and to enhance the testability of
architecture versions and CPU targets implemented in the compiler.
As part of this change, a new field for `FEAT_*` architecture feature
names was added to the TableGen entries. The output of the existing
`--print-supported-extensions` option was updated accordingly to show
these in a separate column.
This is the second attempt. When parsing the target attribute
we should be letting cc1 features which don't correspond to
Extensions pass through to avoid errors like the following:
% cat neon.c
__attribute__((target("arch=armv8-a")))
uint64x2_t foo(uint64x2_t a, uint64x2_t b) { return veorq_u64(a, b); }
% clang --target=aarch64-linux-gnu -c neon.c
error: always_inline function 'veorq_u64' requires target feature
'outline-atomics', but would be inlined into function 'foo'
that is compiled without support for 'outline-atomics'
Co-authored-by: Tomas Matheson <Tomas.Matheson@arm.com>
This is a follow up to #92037, which moved the architecture information.
Generate the AArch64TargetParser CPUInfo from tablegen Processor defs using a
new tablegen emitter. Some basic error checking is added in the emitter to
ensure that duplicate features are not added to the Processor defs.
The generic CPU becomes an entry in tablegen.
Some CPU features which were present in the CPUInfo but absent from the tablegen
defs have been added to tablegen. FeatureCrypto is replaced with FeatureSHA2 and
FeatureAES. This changes a few of the tests.
This reverts commit 70510733af33c70ff7877eaf30d7718b9358a725.
The following code is now incorrectly rejected.
```
% cat neon.c
#include <arm_neon.h>
__attribute__((target("arch=armv8-a")))
uint64x2_t foo(uint64x2_t a, uint64x2_t b) {
return veorq_u64(a, b);
}
% newclang --target=aarch64-linux-gnu -c neon.c
neon.c:5:10: error: always_inline function 'veorq_u64' requires target feature 'outline-atomics', but would be inlined into function 'foo' that is compiled without support for 'outline-atomics'
5 | return veorq_u64(a, b);
| ^
1 error generated.
```
"+outline-atomics" seems misleading here.
My reverted attempt to decouple feature dependency expansion (see
#95056) made it evident that some features are still using the FMV
dependencies in the target attribute.
The original commit broke the llvm test suite. This was addressed here:
https://github.com/llvm/llvm-test-suite/pull/133. I am now relanding it.
This reverts commit 2cf14398c9341feddb419e7ff9c8c5623a3da3db since it
broke the llvm test suite:
SingleSource/UnitTests/AArch64/acle-fmv-features.c:59:9:
error: instruction requires: altnzcv
SingleSource/UnitTests/AArch64/acle-fmv-features.c:117:10:
error: instruction requires: aes
...
Looks like the FMV dependencies were used in the target attribute and
now features that are FMVOnly (have AEK_NONE) cannot be expanded in
parseTargetAttr using the ExtensionSet.
This suggests that either the tests are wrong (they are using an FMVOnly
feature in a target attribute), or that we need to turn the FMVOnly
features into Extensions (these two are tablegen classes).
The dependency expansion step which was introduced by FMV has been
erroneously used for non-FMV features, for example when parsing the
target attribute. The PR #93695 has rectified most of the tests which
were relying on dependency expansion of target features specified on the
-cc1 command line. In this patch I am decoupling the dependency
expansion of features specified on the target attribute from FMV.
To do that first I am expanding FMV dependencies before passing the list
of target features to initFeatureMap(). Similarly when parsing the
target attribute I am reconstructing an ExtensionSet from the list of
target features which was created during the command line option
parsing. The attribute parsing may toggle bits of that ExtensionSet and
at the end it is converted to a list of target features. Those are
passed to initFeatureMap(), which no longer requires an override.
A side effect of this refactoring is that features specified on the
target_version attribute now supersede the command line options, which
is what should be happening in the first place.
This patch generates ExtensionDependency pairs {Earlier, Later} inferred
by the 'Implies' field of every Extension defined in tablegen. Implied
Subtarget Features that are not Extensions are skipped.
Currently, LLVM enables `-mbranch-protection=standard` as `bti+pac-ret`.
To align LLVM with the behaviour in GNU, this has been updated to
`bti+pac-ret+pc` when FEAT_PAuth_LR is enabled as an optional feature
via the `-mcpu=` options. If this is not enabled, then this will revert
to the existing behaviour.
When `+sve` is passed in the command line, if the Architecture being
targeted is V8.6A/V9.1A or later, `+f32mm` is also added. This enables
FEAT_32MM, however at the time of writing no CPU's support this. This
leads to the FEAT_32MM instructions being compiled for CPU's that do not
support them.
This commit removes the automatic enablement, however the option is
still able to be used by passing `+f32mm`.
This patch allows using the name "rdma" as an alias for "rdm". The name
makes its way to target attributes as well as the command line via the
-march and -mcpu options. The motivation was originally to support this
in Function Multi Versioning but it also makes sense to align with GCC
on the command line.
llvm-project/llvm/lib/TargetParser/AArch64TargetParser.cpp:157:1:
error: non-void function does not return a value in all control paths [-Werror,-Wreturn-type]
}
^
1 error generated.
Currently there are several bits of code in the AArch64 driver which
attempt to enforce dependencies between optional features in the -march=
and -mcpu= options. However, these are based on the list of feature
names being enabled/disabled, so they have a lot of logic to consider
the order in which features were turned on and off, which doesn't scale
well as dependency chains get longer.
This patch moves the code handling these dependencies to TargetParser,
and changes them to use a Bitset of enabled features. This makes it easy
to check which features are enabled, and is converted back to a list of
LLVM feature names once all of the command-line options are parsed.
The motivating example for this was the -mcpu=cortex-r82+nofp option.
Previously, the code handling the dependency between the fp16 and
fp16fml extensions did not consider the nofp modifier, so it added
+fullfp16 to the feature list. This should have been disabled by the
+nofp modifier, and also the backend did follow the dependency between
fullfp16 and fp, resulting in fp being turned back on in the backend.
Most of the dependencies added to AArch64TargetParser.h weren't known
about by clang before, I built that list by checking what the backend
thinks the dependencies between SubtargetFeatures are.
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
This follows the RISC-V work done in
4b40ced4e5ba10b841516b3970e7699ba8ded572.
This uses AArch64's target parser instead. We just list the names,
without the "+" on them, which matches RISC-V's format.
```
$ ./bin/clang -target aarch64-linux-gnu --print-supported-extensions
clang version 18.0.0 (https://github.com/llvm/llvm-project.git 154da8aec20719c82235a6957aa6e461f5a5e030)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: <...>
All available -march extensions for AArch64
aes
b16b16
bf16
brbe
crc
crypto
cssc
<...>
```
Since our extensions don't have versions in the same way there's just
one column with the name in.
Any extension without a feature name (including the special "none") is
not listed as those cannot be passed to -march, they're just for the
backend. For example the MTE extension can be added with "+memtag" but
MTE2 and MTE3 do not have feature names so they cannot be added to
-march.
This does not attempt to tackle the fact that clang allows invalid
combinations of AArch64 extensions, it simply lists the possible
options. It's still up to the user to ask for something sensible.
Equally, this has no context of what CPU is being selected. Neither does
the RISC-V option, the user has to be aware of that.
I've added a target parser test, and a high level clang test that checks
RISC-V and AArch64 work and that Intel, that doesn't support this, shows
the correct error.
This updates the AArch64's Target Parser and its uses to capture
information about default features directly from ArchInfo and CpuInfo
objects, instead of relying on an API function to access them
indirectly.
Reviewed By: tmatheson
Differential Revision: https://reviews.llvm.org/D142540
This updates the parsing methods in AArch64's Target Parser to make use
of optional returns instead of "invalid" enum values, making the API's
behaviour clearer.
Reviewed By: lenary, tmatheson
Differential Revision: https://reviews.llvm.org/D142539
Reworked after several other major changes to the TargetParser since
this was reverted. Combined with several other changes.
Inline calls for the following macros and delete AArch64TargetParser.def:
AARCH64_ARCH, AARCH64_CPU_NAME, AARCH64_CPU_ALIAS, AARCH64_ARCH_EXT_NAME
Squashed changes from D139278 and D139102.
Differential Revision: https://reviews.llvm.org/D138792
This reverts commit e43924a75145d2f9e722f74b673145c3e62bfd07.
Reason: Patch broke the MSan buildbots. More information is available on
the original phabricator review: https://reviews.llvm.org/D127812
This is a fairly large changeset, but it can be broken into a few
pieces:
- `llvm/Support/*TargetParser*` are all moved from the LLVM Support
component into a new LLVM Component called "TargetParser". This
potentially enables using tablegen to maintain this information, as
is shown in https://reviews.llvm.org/D137517. This cannot currently
be done, as llvm-tblgen relies on LLVM's Support component.
- This also moves two files from Support which use and depend on
information in the TargetParser:
- `llvm/Support/Host.{h,cpp}` which contains functions for inspecting
the current Host machine for info about it, primarily to support
getting the host triple, but also for `-mcpu=native` support in e.g.
Clang. This is fairly tightly intertwined with the information in
`X86TargetParser.h`, so keeping them in the same component makes
sense.
- `llvm/ADT/Triple.h` and `llvm/Support/Triple.cpp`, which contains
the target triple parser and representation. This is very intertwined
with the Arm target parser, because the arm architecture version
appears in canonical triples on arm platforms.
- I moved the relevant unittests to their own directory.
And so, we end up with a single component that has all the information
about the following, which to me seems like a unified component:
- Triples that LLVM Knows about
- Architecture names and CPUs that LLVM knows about
- CPU detection logic for LLVM
Given this, I have also moved `RISCVISAInfo.h` into this component, as
it seems to me to be part of that same set of functionality.
If you get link errors in your components after this patch, you likely
need to add TargetParser into LLVM_LINK_COMPONENTS in CMake.
Differential Revision: https://reviews.llvm.org/D137838
