Handle @llvm.expect.with.probability in GlobalISel in the same way
@llvm.expect is handled, passing the value through as-is. This can be
encountered if the intrinsic is used without optimizations, which would
otherwise transform it out.
Fixes#115411 for GlobalISel
This adds the `llvm.sincos` intrinsic, legalization, and lowering.
The `llvm.sincos` intrinsic takes a floating-point value and returns
both the sine and cosine (as a struct).
```
declare { float, float } @llvm.sincos.f32(float %Val)
declare { double, double } @llvm.sincos.f64(double %Val)
declare { x86_fp80, x86_fp80 } @llvm.sincos.f80(x86_fp80 %Val)
declare { fp128, fp128 } @llvm.sincos.f128(fp128 %Val)
declare { ppc_fp128, ppc_fp128 } @llvm.sincos.ppcf128(ppc_fp128 %Val)
declare { <4 x float>, <4 x float> } @llvm.sincos.v4f32(<4 x float> %Val)
```
The lowering is built on top of the existing FSINCOS ISD node, with
additional type legalization to allow for f16, f128, and vector values.
Add support for using a thread-local variable with a specified offset
for holding the stack guard canary value. This supports both 32- and 64-
bit PowerPC targets.
This mirrors changes from #108942 but targeting PowerPC instead of
RISCV. Because both of these PRs modify the same driver functions, this
series is stack on top of the RISC-V one.
---------
Signed-off-by: Keith Packard <keithp@keithp.com>
Following the addition of the llvm.fake.use intrinsic and corresponding
MIR instruction, two further changes are planned: to add an
-fextend-lifetimes flag to Clang that emits these intrinsics, and to
have -Og enable this flag by default. Currently, some logic for handling
fake uses is gated by the optdebug attribute, which is intended to be
switched on by -fextend-lifetimes (and by extension -Og later on).
However, the decision was made that a general optdebug attribute should
be incompatible with other opt_ attributes (e.g. optsize, optnone),
since they all express different intents for how to optimize the
program. We would still like to allow -fextend-lifetimes with optsize
however (i.e. -Os -fextend-lifetimes should be legal), since it may be a
useful configuration and there is no technical reason to not allow it.
This patch resolves this by tracking MachineFunctions that have fake
uses, allowing us to run passes that interact with them and skip passes
that clash with them.
It is almost always simpler to use {} instead of std::nullopt to
initialize an empty ArrayRef. This patch changes all occurrences I could
find in LLVM itself. In future the ArrayRef(std::nullopt_t) constructor
could be deprecated or removed.
This is an implementation of the saturating fp to int conversions for
GlobalISel. On AArch64 the converstion instrctions work this way,
producing saturating results. LegalizerHelper::lowerFPTOINT_SAT is
ported from SDAG.
AArch64 has a lot of existing tests for fptosi_sat, covering a wide
range of types. I have tried to make most of them work all at once, but
a few fall back due to other missing features such as f128 handling for
min/max.
This patch is part of a set of patches that add an `-fextend-lifetimes`
flag to clang, which extends the lifetimes of local variables and
parameters for improved debuggability. In addition to that flag, the
patch series adds a pragma to selectively disable `-fextend-lifetimes`,
and an `-fextend-this-ptr` flag which functions as `-fextend-lifetimes`
for this pointers only. All changes and tests in these patches were
written by Wolfgang Pieb (@wolfy1961), while Stephen Tozer (@SLTozer)
has handled review and merging. The extend lifetimes flag is intended to
eventually be set on by `-Og`, as discussed in the RFC
here:
https://discourse.llvm.org/t/rfc-redefine-og-o1-and-add-a-new-level-of-og/72850
This patch implements a new intrinsic instruction in LLVM,
`llvm.fake.use` in IR and `FAKE_USE` in MIR, that takes a single operand
and has no effect other than "using" its operand, to ensure that its
operand remains live until after the fake use. This patch does not emit
fake uses anywhere; the next patch in this sequence causes them to be
emitted from the clang frontend, such that for each variable (or this) a
fake.use operand is inserted at the end of that variable's scope, using
that variable's value. This patch covers everything post-frontend, which
is largely just the basic plumbing for a new intrinsic/instruction,
along with a few steps to preserve the fake uses through optimizations
(such as moving them ahead of a tail call or translating them through
SROA).
Co-authored-by: Stephen Tozer <stephen.tozer@sony.com>
Similar to #102156.
runOnMachineFunction() installs the Observer correctly manually.
finishPendingPhis() doesn't install into the MF, but this currently
can't cause issues because DILocationVerifier doesn't care about changed
instructions.
Switch to RAIIMFObsDelInstaller in both places for consistency.
This reverts commit 740161a9b98c9920dedf1852b5f1c94d0a683af5.
I moved the `ISD` dependencies into the CodeGen portion of the handling,
it's a little awkward but it's the easiest solution I can think of for
now.
MachineFunction's probably should not include a backreference to
the owning MachineModuleInfo. Most of these references were used
just to query the MCContext, which MachineFunction already directly
stores. Other contexts are using it to query the LLVMContext, which
can already be accessed through the IR function reference.
This PR adds a new vector intrinsic `@llvm.experimental.vector.compress`
to "compress" data within a vector based on a selection mask, i.e., it
moves all selected values (i.e., where `mask[i] == 1`) to consecutive
lanes in the result vector. A `passthru` vector can be provided, from
which remaining lanes are filled.
The main reason for this is that the existing
`@llvm.masked.compressstore` has very strong constraints in that it can
only write values that were selected, resulting in guard branches for
all targets except AVX-512 (and even there the AMD implementation is
_very_ slow). More instruction sets support "compress" logic, but only
within registers. So to store the values, an additional store is needed.
But this combination is likely significantly faster on many target as it
avoids branches.
In follow up PRs, my plan is to add target-specific lowerings for x86,
SVE, and possibly RISCV. I also want to combine this with a store
instruction, as this is probably a common case and we can avoid some
memory writes in that case.
See [discussion in
forum](https://discourse.llvm.org/t/new-intrinsic-for-masked-vector-compress-without-store/78663)
for initial discussion on the design.
Summary:
The LTO pass and LLD linker have logic in them that forces extraction
and prevent internalization of needed runtime calls. However, these
currently take all RTLibcalls into account, even if the target does not
support them. The target opts-out of a libcall if it sets its name to
nullptr. This patch pulls this logic out into a class in the header so
that LTO / lld can use it to determine if a symbol actually needs to be
kept.
This is important for targets like AMDGPU that want to be able to use
`lld` to perform the final link step, but does not want the overhead of
uncalled functions. (This adds like a second to the link time trivially)
This tries to turn indirect ptrauth calls into direct calls, using
`ConstantPtrAuth::isKnownEquivalent` to compare the `ConstantPtrAuth`
target with the ptrauth call bundle.
This should be straightforward, other than the somewhat awkward GISel
handling, which has a handshake between CallLowering and IRTranslator to
elide the ptrauth when possible.
With `--trap-unreachable`, `clang` can emit double `TRAP` instructions
for code that contains a call to `__builtin_trap()`:
```
> cat test.c
void test() { __builtin_trap(); }
> clang test.c --target=x86_64 -mllvm --trap-unreachable -O1 -S -o -
...
test:
...
ud2
ud2
...
```
`SimplifyCFGPass` inserts `unreachable` after a call to a `noreturn`
function, and later this instruction causes `TRAP/G_TRAP` to be emitted
in `SelectionDAGBuilder::visitUnreachable()` or
`IRTranslator::translateUnreachable()` if
`TargetOptions.TrapUnreachable` is set.
The patch checks the instruction before `unreachable` and avoids
inserting an additional trap.
Since `raw_string_ostream` doesn't own the string buffer, it is
desirable (in terms of memory safety) for users to directly reference
the string buffer rather than use `raw_string_ostream::str()`.
Work towards TODO comment to remove `raw_string_ostream::str()`.
This re-applies #94241 after fixing buildbot failure, see
https://lab.llvm.org/buildbot/#/builders/51/builds/570
According to standard, `constexpr` variables and `const` variables
initialized with constant expressions can be used in lambdas w/o
capturing - see https://en.cppreference.com/w/cpp/language/lambda.
However, MSVC used on buildkite seems to ignore that rule and does not
allow using such uncaptured variables in lambdas: we have "error C3493:
'Mask16' cannot be implicitly captured because no default capture mode
has been specified" - see
https://buildkite.com/llvm-project/github-pull-requests/builds/73238
Explicitly capturing such a variable, however, makes buildbot fail with
"error: lambda capture 'Mask16' is not required to be captured for this
use [-Werror,-Wunused-lambda-capture]" - see
https://lab.llvm.org/buildbot/#/builders/51/builds/570.
Fix both cases by using `0xffff` value directly instead of giving a name
to it.
Original PR description below.
Depends on #94240.
Define the following pseudos for lowering ptrauth constants in code:
- non-`extern_weak`:
- no GOT load needed: `MOVaddrPAC` - similar to `MOVaddr`, with added
PAC;
- GOT load needed: `LOADgotPAC` - similar to `LOADgot`, with added PAC;
- `extern_weak`: `LOADauthptrstatic` - similar to `LOADgot`, but use a
special stub slot named `sym$auth_ptr$key$disc` filled by dynamic linker
during relocation resolving instead of a GOT slot.
---------
Co-authored-by: Ahmed Bougacha <ahmed@bougacha.org>
Depends on #94240.
Define the following pseudos for lowering ptrauth constants in code:
- non-`extern_weak`:
- no GOT load needed: `MOVaddrPAC` - similar to `MOVaddr`, with added
PAC;
- GOT load needed: `LOADgotPAC` - similar to `LOADgot`, with added PAC;
- `extern_weak`: `LOADauthptrstatic` - similar to `LOADgot`, but use a
special stub slot named `sym$auth_ptr$key$disc` filled by dynamic linker
during relocation resolving instead of a GOT slot.
---------
Co-authored-by: Ahmed Bougacha <ahmed@bougacha.org>
As far as I can tell, this pull request was not approved, and
did not go through an RFC on discourse.
This reverts commit 89881480030f48f83af668175b70a9798edca2fb.
This reverts commit 225d8fc8eb24fb797154c1ef6dcbe5ba033142da.
Currently, on different platform, the behaivor of llvm.minnum is
different if one operand is sNaN:
When we compare sNaN vs NUM:
ARM/AArch64/PowerPC: follow the IEEE754-2008's minNUM: return qNaN.
RISC-V/Hexagon follow the IEEE754-2019's minimumNumber: return NUM. X86:
Returns NUM but not same with IEEE754-2019's minimumNumber as
+0.0 is not always greater than -0.0.
MIPS/LoongArch/Generic: return NUM.
LIBCALL: returns qNaN.
So, let's introduce llvm.minmumnum/llvm.maximumnum, which always follow
IEEE754-2019's minimumNumber/maximumNumber.
Half-fix: #93033
Remove support for the icmp and fcmp constant expressions.
This is part of:
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179
As usual, many of the updated tests will no longer test what they were
originally intended to -- this is hard to preserve when constant
expressions get removed, and in many cases just impossible as the
existence of a specific kind of constant expression was the cause of the
issue in the first place.
This adds codegen support for the "ptrauth" operand bundles, which can
be used to augment indirect calls with the equivalent of an
`@llvm.ptrauth.auth` intrinsic call on the call target (possibly
preceded by an `@llvm.ptrauth.blend` on the auth discriminator if
applicable.)
This allows the generation of combined authenticating calls
on AArch64 (in the BLRA* PAuth instructions), while avoiding
the raw just-authenticated function pointer from being
exposed to attackers.
This is done by threading a PtrAuthInfo descriptor through
the call lowering infrastructure, eventually selecting a BLRA
pseudo. The pseudo encapsulates the safe discriminator
computation, which together with the real BLRA* call get emitted
in late pseudo expansion in AsmPrinter.
Note that this also applies to the other forms of indirect calls,
notably invokes, rvmarker, and tail calls. Tail-calls in particular
bring some additional complexity, with the intersecting register
constraints of BTI and PAC discriminator computation.
However this doesn't currently support PAuth_LR tail-call variants.
This also adopts an x8+ allocation order for GPR64noip, matching
GPR64.
This patch adds basic support for scalable vector types in load & store
instructions for AArch64 with GISel.
Only scalable vector types with a 128-bit base size are supported, e.g.
`<vscale x 4 x i32>`, `<vscale x 16 x i8>`.
This patch adapted some ideas from a similar abandoned patch
[https://github.com/llvm/llvm-project/pull/72976](https://github.com/llvm/llvm-project/pull/72976).
