1605 Commits

Author SHA1 Message Date
Chuanqi Xu
572cc8d38f Revert "[C++20] [Coroutines] Mark await_suspend as noinline if the awaiter is not empty"
This reverts commit 9d9c25f81456aace2bec4b58498a420e650007d9.
This reverts commit 19ab2664ad3182ffa8fe3a95bb19765e4ae84653.
This reverts commit c4672454743e942f148a1aff1e809dae73e464f6.

As the issue https://github.com/llvm/llvm-project/issues/65018 shows,
the previous fix introduce a regression actually. So this commit reverts
the fix by our policies.
2023-08-28 13:21:17 +08:00
Kazu Hirata
5ab7c285fb [CodeGen] Modernize PeepholeProtection (NFC) 2023-08-27 09:24:28 -07:00
Fangrui Song
7a41af8604 [X86] Support arch=x86-64{,-v2,-v3,-v4} for target_clones attribute
GCC 12 (https://gcc.gnu.org/PR101696) allows `arch=x86-64`
`arch=x86-64-v2` `arch=x86-64-v3` `arch=x86-64-v4` in the
target_clones function attribute. This patch ports the feature.

* Set KeyFeature to `x86-64{,-v2,-v3,-v4}` in `Processors[]`, to be used
  by X86TargetInfo::multiVersionSortPriority
* builtins: change `__cpu_features2` to an array like libgcc. Define
  `FEATURE_X86_64_{BASELINE,V2,V3,V4}` and depended ISA feature bits.
* CGBuiltin.cpp: update EmitX86CpuSupports to handle `arch=x86-64*`.

Close https://github.com/llvm/llvm-project/issues/55830

Reviewed By: pengfei

Differential Revision: https://reviews.llvm.org/D158329
2023-08-23 22:08:55 -07:00
Manna, Soumi
30c60ec52f [NFC][CLANG] Fix static analyzer bugs about large copy by values
Static Analyzer Tool complains about a large function call parameter which is is passed by value in CGBuiltin.cpp file.

1. In CodeGenFunction::EmitSMELdrStr(clang::SVETypeFlags, llvm::SmallVectorImpl<llvm::Value *> &, unsigned int): We are passing parameter TypeFlags of type clang::SVETypeFlags by value.

2. In CodeGenFunction::EmitSMEZero(clang::SVETypeFlags, llvm::SmallVectorImpl<llvm::Value *> &, unsigned int): We are passing parameter TypeFlags of type clang::SVETypeFlags by value.

3. In CodeGenFunction::EmitSMEReadWrite(clang::SVETypeFlags, llvm::SmallVectorImpl<llvm::Value *> &, unsigned int): We are passing parameter TypeFlags of type clang::SVETypeFlags by value.

4. In CodeGenFunction::EmitSMELd1St1(clang::SVETypeFlags, llvm::SmallVectorImpl<llvm::Value *> &, unsigned int): We are passing parameter TypeFlags of type clang::SVETypeFlags by value.

I see many places in CGBuiltin.cpp file, we are passing parameter TypeFlags of type clang::SVETypeFlags by reference.

clang::SVETypeFlags inherits several other types.

This patch passes parameter TypeFlags by reference instead of by value in the function.

Reviewed By: tahonermann, sdesmalen

Differential Revision: https://reviews.llvm.org/D158522
2023-08-23 07:57:04 -07:00
Chuanqi Xu
c467245474 [C++20] [Coroutines] Mark await_suspend as noinline if the awaiter is not empty
Close https://github.com/llvm/llvm-project/issues/56301
Close https://github.com/llvm/llvm-project/issues/64151

See the summary and the discussion of https://reviews.llvm.org/D157070
to get the full context.

As @rjmccall pointed out, the key point of the root cause is that
currently we didn't implement the semantics for '@llvm.coro.save' well
("after the await-ready returns false, the coroutine is considered to be
suspended ") well.
Since the semantics implies that we (the compiler) shouldn't write the
spills into the coroutine frame in the await_suspend. But now it is possible
due to some combinations of the optimizations so the semantics are
broken. And the inlining is the root optimization of such optimizations.
So in this patch, we tried to add the `noinline` attribute to the
await_suspend call.

Also as an optimization, we don't add the `noinline` attribute to the
await_suspend call if the awaiter is an empty class. This should be
correct since the programmers can't access the local variables in
await_suspend if the awaiter is empty. I think this is necessary for the
performance since it is pretty common.

Another potential optimization is:

    call @llvm.coro.await_suspend(ptr %awaiter, ptr %handle,
                                  ptr @awaitSuspendFn)

Then it is much easier to perform the safety analysis in the middle
end.
If it is safe to inline the call to awaitSuspend, we can replace it
in the CoroEarly pass. Otherwise we could replace it in the CoroSplit
pass.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D157833
2023-08-22 09:56:44 +08:00
wanglei
ea8d3b1f9f [Clang][LoongArch] Use the ClangBuiltin class to automatically generate support for CBE and CFE
Fixed the type modifier (L->W), removed redundant feature checking code
since the feature has already been checked in `EmitBuiltinExpr`. And
Cleaned up unused diagnostic information.

Reviewed By: SixWeining

Differential Revision: https://reviews.llvm.org/D156866
2023-08-09 16:04:09 +08:00
Amy Huang
27dab4d305 Reland "Try to implement lambdas with inalloca parameters by forwarding without use of inallocas."t
This reverts commit 8ed7aa59f489715d39d32e72a787b8e75cfda151.

Differential Revision: https://reviews.llvm.org/D154007
2023-07-26 16:13:36 -07:00
Bryan Chan
f225898a7c [Clang][AArch64][SME] Add intrinsics for ZA array load/store (LDR/STR)
This patch adds support for the following SME ACLE intrinsics (as defined
in https://arm-software.github.io/acle/main/acle.html):

  - svldr_vnum_za
  - svstr_vnum_za

Co-authored-by: Sagar Kulkarni <sagar.kulkarni1@huawei.com>

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D134678
2023-07-20 06:06:35 -04:00
Bryan Chan
578b0bd4e6 [Clang][AArch64][SME] Add ZA zeroing intrinsics
This patch adds support for the following SME ACLE intrinsics (as defined
 in https://arm-software.github.io/acle/main/acle.html):

   - svzero_mask_za
   - svzero_za

Co-authored-by: Sagar Kulkarni <sagar.kulkarni1@huawei.com>

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D134677
2023-07-20 06:06:34 -04:00
Bryan Chan
6dc94c54e5 [Clang][AArch64][SME] Add vector read/write (mova) intrinsics
This patch adds support for the following SME ACLE intrinsics (as defined
in https://arm-software.github.io/acle/main/acle.html):

  - svread_hor_za8[_s8]_m    // also for u8
  - svread_hor_za16[_s16]_m  // also for u16, f16, bf16
  - svread_hor_za32[_s32]_m  // also for u32, f32
  - svread_hor_za64[_s64]_m  // also for u64, f64
  - svread_hor_za128[_s8]_m  // also for s16, s32, s64, u8, u16, u32, u64, bf16, f16, f32, f64
  - svread_ver_za8[_s8]_m    // also for u8
  - svread_ver_za16[_s16]_m  // also for u16, f16, bf16
  - svread_ver_za32[_s32]_m  // also for u32, f32
  - svread_ver_za64[_s64]_m  // also for u64, f64
  - svread_ver_za128[_s8]_m  // also for s16, s32, s64, u8, u16, u32, u64, bf16, f16, f32, f64
  - svwrite_hor_za8[_s8]_m   // also for u8
  - svwrite_hor_za16[_s16]_m // also for u16, f16, bf16
  - svwrite_hor_za32[_s32]_m // also for u32, f32
  - svwrite_hor_za64[_s64]_m // also for u64, f64
  - svwrite_hor_za128[_s8]_m // also for s16, s32, s64, u8, u16, u32, u64, bf16, f16, f32, f64
  - svwrite_ver_za8[_s8]_m   // also for u8
  - svwrite_ver_za16[_s16]_m // also for u16, f16, bf16
  - svwrite_ver_za32[_s32]_m // also for u32, f32
  - svwrite_ver_za64[_s64]_m // also for u64, f64
  - svwrite_ver_za128[_s8]_m // also for s16, s32, s64, u8, u16, u32, u64, bf16, f16, f32, f64

Co-authored-by: Sagar Kulkarni <sagar.kulkarni1@huawei.com>

Reviewed By: sdesmalen, kmclaughlin

Differential Revision: https://reviews.llvm.org/D128648
2023-07-20 06:06:33 -04:00
Matt Arsenault
bac2a07540 clang: Attach !fpmath metadata to __builtin_sqrt based on language flags
OpenCL and HIP have -cl-fp32-correctly-rounded-divide-sqrt and
-fno-hip-correctly-rounded-divide-sqrt. The corresponding fpmath metadata
was only set on fdiv, and not sqrt. The backend is currently underutilizing
sqrt lowering options, and the responsibility is split between the libraries
and backend and this metadata is needed.

CUDA/NVCC has -prec-div and -prev-sqrt but clang doesn't appear to be
aiming for compatibility with those. Don't know if OpenMP has a similar
control.
2023-07-14 18:46:18 -04:00
Akash Banerjee
227012cbd7 [OpenMP] Migrate device code privatisation from Clang CodeGen to OMPIRBuilder
This patch migrates the UseDevicePtr and UseDeviceAddr clause related code for handling privatisation from Clang codegen to the OMPIRBuilder

Depends on D150860

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D152554
2023-07-12 12:03:28 +01:00
Sindhu Chittireddy
5942ae8681 [NFC] Initialize class member pointers to nullptr.
Reviewed here: https://reviews.llvm.org/D153926
2023-07-10 11:38:55 -07:00
Doru Bercea
13888870e5 Enable dynamic-sized VLAs for data sharing in OpenMP offloaded target regions.
Review: https://reviews.llvm.org/D153883
2023-07-06 10:57:10 -04:00
Dave Pagan
eb61bde829 [OpenMP][CodeGen] Add codegen for combined 'loop' directives.
The loop directive is a descriptive construct which allows the compiler
flexibility in how it generates code for the directive's associated
loop(s). See OpenMP specification 5.2 [257:8-9].

Codegen added in this patch for the combined 'loop' directives are:

'target teams loop'     -> 'target teams distribute parallel for'
'teams loop'            -> 'teams distribute parallel for'
'target parallel loop'  -> 'target parallel for'
'parallel loop'         -> 'parallel for'

NOTE: The implementation of the 'loop' directive itself is unchanged.

Differential Revision: https://reviews.llvm.org/D145823
2023-07-05 12:31:59 -05:00
Sergei Barannikov
2348902268 [clang][CodeGen] Remove no-op EmitCastToVoidPtr (NFC)
Reviewed By: JOE1994

Differential Revision: https://reviews.llvm.org/D153694
2023-06-29 20:29:38 +03:00
Amy Huang
8ed7aa59f4 Revert "Try to implement lambdas with inalloca parameters by forwarding without use of inallocas."
Causes a clang crash (see crbug.com/1457256).

This reverts commit 015049338d7e8e0e81f2ad2f94e5a43e2e3f5220.
2023-06-22 11:42:33 -07:00
Amy Huang
015049338d Try to implement lambdas with inalloca parameters by forwarding without use of inallocas.
Differential Revision: https://reviews.llvm.org/D137872
2023-06-20 17:30:20 -07:00
Bryan Chan
9f6250f591 [Clang][AArch64][SME] Add vector load/store (ld1/st1) intrinsics
This patch adds support for the following SME ACLE intrinsics (as defined
in https://arm-software.github.io/acle/main/acle.html):

  - svld1_hor_za8      // also for _za16, _za32, _za64 and _za128
  - svld1_hor_vnum_za8 // also for _za16, _za32, _za64 and _za128
  - svld1_ver_za8      // also for _za16, _za32, _za64 and _za128
  - svld1_ver_vnum_za8 // also for _za16, _za32, _za64 and _za128
  - svst1_hor_za8      // also for _za16, _za32, _za64 and _za128
  - svst1_hor_vnum_za8 // also for _za16, _za32, _za64 and _za128
  - svst1_ver_za8      // also for _za16, _za32, _za64 and _za128
  - svst1_ver_vnum_za8 // also for _za16, _za32, _za64 and _za128

SveEmitter.cpp is extended to generate arm_sme.h (currently named
arm_sme_draft_spec_subject_to_change.h) and other SME definitions from
arm_sme.td, which is modeled after arm_sve.td. Common TableGen definitions
are moved into arm_sve_sme_incl.td.

Co-authored-by: Sagar Kulkarni <sagar.kulkarni1@huawei.com>

Reviewed By: sdesmalen, kmclaughlin

Differential Revision: https://reviews.llvm.org/D127910
2023-05-28 21:08:13 -04:00
Fangrui Song
46f366494f -fsanitize=function: use type hashes instead of RTTI objects
Currently we use RTTI objects to check type compatibility. To support non-unique
RTTI objects, commit 5745eccef54ddd3caca278d1d292a88b2281528b added a
`checkTypeInfoEquality` string matching to the runtime.
The scheme is inefficient.

```
_Z1fv:
  .long   846595819                    # jmp
  .long   .L__llvm_rtti_proxy-_Z3funv
  ...

main:
  ...
  # Load the second word (pointer to the RTTI object) and dereference it.
  movslq  4(%rsi), %rax
  movq    (%rax,%rsi), %rdx
  # Is it the desired typeinfo object?
  leaq    _ZTIFvvE(%rip), %rax
  # If not, call __ubsan_handle_function_type_mismatch_v1, which may recover if checkTypeInfoEquality allows
  cmpq    %rax, %rdx
  jne     .LBB1_2
  ...

.section        .data.rel.ro,"aw",@progbits
  .p2align        3, 0x0
.L__llvm_rtti_proxy:
  .quad   _ZTIFvvE
```

Let's replace the indirect `_ZTI` pointer with a type hash similar to
`-fsanitize=kcfi`.

```
_Z1fv:
  .long   3238382334
  .long   2772461324  # type hash

main:
  ...
  # Load the second word (callee type hash) and check whether it is expected
  cmpl    $-1522505972, -4(%rax)
  # If not, fail: call __ubsan_handle_function_type_mismatch
  jne     .LBB2_2
```

The RTTI object derives its name from `clang::MangleContext::mangleCXXRTTI`,
which uses `mangleType`. `mangleTypeName` uses `mangleType` as well. So the
type compatibility change is high-fidelity.

Since we no longer need RTTI pointers in
`__ubsan::__ubsan_handle_function_type_mismatch_v1`, let's switch it back to
version 0, the original signature before
e215996a2932ed7c472f4e94dc4345b30fd0c373 (2019).
`__ubsan::__ubsan_handle_function_type_mismatch_abort` is not
recoverable, so we can revert some changes from
e215996a2932ed7c472f4e94dc4345b30fd0c373.

Reviewed By: samitolvanen

Differential Revision: https://reviews.llvm.org/D148785
2023-05-20 08:24:20 -07:00
Rafael A. Herrera Guaitero
64549f0903 [OpenMP][5.1] Fix parallel masked is ignored #59939
Code generation support for 'parallel masked' directive.

The `EmitOMPParallelMaskedDirective` was implemented.
In addition, the appropiate device functions were added.

Fix #59939.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D143527
2023-04-03 20:33:55 +00:00
Wei Wang
ce7eb2e055 [Coroutines] Avoid creating conditional cleanup markers in suspend block
We shouldn't access coro frame after returning from `await_suspend()` and before `llvm.coro.suspend()`.
Make sure we always hoist conditional cleanup markers when inside the `await.suspend` block.

Fix https://github.com/llvm/llvm-project/issues/59181

Reviewed By: ChuanqiXu

Differential Revision: https://reviews.llvm.org/D144680
2023-02-28 15:30:04 -08:00
Akira Hatanaka
57865bc5ad [CodeGen] Add a flag to Address and Lvalue that is used to keep
track of whether the pointer is known not to be null

The flag will be used for the arm64e work we plan to upstream in the
future (see https://lists.llvm.org/pipermail/llvm-dev/2019-October/136091.html).
Currently the flag has no effect on code generation.

Differential Revision: https://reviews.llvm.org/D142584
2023-02-15 10:15:13 -08:00
Kazu Hirata
6ad0788c33 [clang] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 12:31:01 -08:00
Kazu Hirata
a1580d7b59 [clang] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 11:07:21 -08:00
Guillaume Chatelet
bf5c17ed0f [clang][NFC] Remove dependency on DataLayout::getPrefTypeAlignment 2023-01-13 15:01:29 +00:00
Guillaume Chatelet
eaa1f46f11 [clang][NFC] Remove dependency on DataLayout::getPrefTypeAlignment 2023-01-13 13:19:19 +00:00
Pavel Iliin
fe5cf480ee Reland "[AArch64] FMV support and necessary target features dependencies."
This relands commits e43924a75145d2f9e722f74b673145c3e62bfd07,
a43f36142c501e2d3f4797ef938db4e0c5e0eeec,
bf94eac6a3f7c5cd8941956d44c15524fa3751bd with MSan buildbot
https://lab.llvm.org/buildbot/#/builders/5/builds/30139
use-of-uninitialized-value errors fixed.

Differential Revision: https://reviews.llvm.org/D127812
2022-12-27 19:18:07 +00:00
Mitch Phillips
744486ec21 Revert "[AArch64] FMV support and necessary target features dependencies."
This reverts commit e43924a75145d2f9e722f74b673145c3e62bfd07.

Reason: Patch broke the MSan buildbots. More information is available on
the original phabricator review: https://reviews.llvm.org/D127812
2022-12-20 17:16:32 -08:00
Pavel Iliin
e43924a751 [AArch64] FMV support and necessary target features dependencies.
This is Function Multi Versioning (FMV) implementation for AArch64 target in
accordance with Beta Arm C Language Extensions specification
https://github.com/ARM-software/acle/blob/main/main/acle.md#function-multi-versioning
It supports new "target_version" function attribute and extends existing
"target_clones" one. Also missing dependencies for target features were added.

Differential Revision: https://reviews.llvm.org/D127812
2022-12-20 15:42:25 +00:00
Kazu Hirata
bb666c6930 [CodeGen] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-03 11:13:43 -08:00
Eli Friedman
0fcb26c5b6 [clang] Fix __try/__finally blocks in C++ constructors.
We were crashing trying to convert a GlobalDecl from a
CXXConstructorDecl.  Instead of trying to do that conversion, just pass
down the original GlobalDecl.

I think we could actually compute the correct constructor/destructor
kind from the context, given the way Microsoft mangling works, but it's
simpler to just pass through the correct constructor/destructor kind.

Differential Revision: https://reviews.llvm.org/D136776
2022-11-16 15:13:33 -08:00
gonglingqin
85f08c4197 [Clang][LoongArch] Implement __builtin_loongarch_dbar builtin
Differential Revision: https://reviews.llvm.org/D136906
2022-11-10 17:27:44 +08:00
Matt Jacobson
dd9f7963e4 [ObjC] avoid crashing when emitting synthesized getter/setter and ptrdiff_t is smaller than long
On targets where ptrdiff_t is smaller than long, clang crashes when emitting
synthesized getters/setters that call objc_[gs]etProperty.  Explicitly emit a
zext/trunc of the ivar offset value (which is defined to long) to ptrdiff_t,
which objc_[gs]etProperty takes.

Add a test using the AVR target, where ptrdiff_t is smaller than long. Test
failed previously and passes now.

Differential Revision: https://reviews.llvm.org/D112049
2022-11-10 02:10:30 -05:00
Rageking8
94738a5ac3 Fix duplicate word typos; NFC
This revision fixes typos where there are 2 consecutive words which are
duplicated. There should be no code changes in this revision (only
changes to comments and docs). Do let me know if there are any
undesirable changes in this revision. Thanks.
2022-11-08 07:21:23 -05:00
Jennifer Yu
ea64e66f7b [OPENMP]Initial support for error directive.
Differential Revision: https://reviews.llvm.org/D137209
2022-11-02 14:25:28 -07:00
Aaron Ballman
9ced729c2c Repair a confusing standards reference; NFC
There is no 6.9 in C++11, the quote actually lives in
[intro.multithread] for that revision. However, the words moved in
C++17 to [intro.progress] so I added that information as well.
2022-10-10 14:10:39 -04:00
Dhruva Chakrabarti
839ac62c50 Revert "[OpenMP] Codegen aggregate for outlined function captures"
This reverts commit 7539e9cf811e590d9f12ae39673ca789e26386b4.
2022-09-15 03:08:46 +00:00
Giorgis Georgakoudis
7539e9cf81 [OpenMP] Codegen aggregate for outlined function captures
Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument list. That complicates the fork_call interface in the OpenMP runtime: (1) the fork_call is variadic since there is a variable number of arguments to forward to the outlined function, (2) wrapping/unwrapping arguments happens in the OpenMP runtime, which is sub-optimal, has been a source of ABI bugs, and has a hardcoded limit (16) in the number of arguments, (3)  forwarded arguments must cast to pointer types, which complicates debugging. This patch avoids those issues by aggregating captured arguments in a struct to pass to the fork_call.

Reviewed By: jdoerfert, jhuber6, ABataev

Differential Revision: https://reviews.llvm.org/D102107
2022-09-15 00:54:05 +00:00
Zahira Ammarguellat
5def954a5b Support of expression granularity for _Float16.
Differential Revision: https://reviews.llvm.org/D113107
2022-08-25 08:26:53 -04:00
Sami Tolvanen
cff5bef948 KCFI sanitizer
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.

Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.

KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.

A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:

```
.c:
  int f(void);
  int (*p)(void) = f;
  p();

.s:
  .4byte __kcfi_typeid_f
  .global f
  f:
    ...
```

Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.

As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.

Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.

Relands 67504c95494ff05be2a613129110c9bcf17f6c13 with a fix for
32-bit builds.

Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay

Differential Revision: https://reviews.llvm.org/D119296
2022-08-24 22:41:38 +00:00
Sami Tolvanen
a79060e275 Revert "KCFI sanitizer"
This reverts commit 67504c95494ff05be2a613129110c9bcf17f6c13 as using
PointerEmbeddedInt to store 32 bits breaks 32-bit arm builds.
2022-08-24 19:30:13 +00:00
Sami Tolvanen
67504c9549 KCFI sanitizer
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.

Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.

KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.

A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:

```
.c:
  int f(void);
  int (*p)(void) = f;
  p();

.s:
  .4byte __kcfi_typeid_f
  .global f
  f:
    ...
```

Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.

As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.

Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.

Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay

Differential Revision: https://reviews.llvm.org/D119296
2022-08-24 18:52:42 +00:00
Caroline Concatto
9f21d6e953 [Clang][AArch64] Use generic extract/insert vector for svget/svset/svcreate tuples
This patch replaces svget, svset and svcreate aarch64 intrinsics for tuple
types with the generic llvm-ir intrinsics extract/insert vector

Differential Revision: https://reviews.llvm.org/D131547
2022-08-19 12:58:59 +01:00
Shilei Tian
e21202dac1 [Clang][OpenMP] Fix the issue that llvm.lifetime.end is emitted too early for variables captured in linear clause
Currently if an OpenMP program uses `linear` clause, and is compiled with
optimization, `llvm.lifetime.end` for variables listed in `linear` clause are
emitted too early such that there could still be uses after that. Let's take the
following code as example:
```
// loop.c
int j;
int *u;

void loop(int n) {
  int i;
  for (i = 0; i < n; ++i) {
    ++j;
    u = &j;
  }
}
```
We compile using the command:
```
clang -cc1 -fopenmp-simd -O3 -x c -triple x86_64-apple-darwin10 -emit-llvm loop.c -o loop.ll
```
The following IR (simplified) will be generated:
```
@j = local_unnamed_addr global i32 0, align 4
@u = local_unnamed_addr global ptr null, align 8

define void @loop(i32 noundef %n) local_unnamed_addr {
entry:
  %j = alloca i32, align 4
  %cmp = icmp sgt i32 %n, 0
  br i1 %cmp, label %simd.if.then, label %simd.if.end

simd.if.then:                                     ; preds = %entry
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %j)
  store ptr %j, ptr @u, align 8
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %j)
  %0 = load i32, ptr %j, align 4
  store i32 %0, ptr @j, align 4
  br label %simd.if.end

simd.if.end:                                      ; preds = %simd.if.then, %entry
  ret void
}
```
The most important part is:
```
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %j)
  %0 = load i32, ptr %j, align 4
  store i32 %0, ptr @j, align 4
```
`%j` is still loaded after `@llvm.lifetime.end.p0(i64 4, ptr nonnull %j)`. This
could cause the backend incorrectly optimizes the code and further generates
incorrect code. The root cause is, when we emit a construct that could have
`linear` clause, it usually has the following pattern:
```
EmitOMPLinearClauseInit(S)
{
  OMPPrivateScope LoopScope(*this);
  ...
  EmitOMPLinearClause(S, LoopScope);
  ...
  (void)LoopScope.Privatize();
  ...
}
EmitOMPLinearClauseFinal(S, [](CodeGenFunction &) { return nullptr; });
```
Variables that need to be privatized are added into `LoopScope`, which also
serves as a RAII object. When `LoopScope` is destructed and if optimization is
enabled, a `@llvm.lifetime.end` is also emitted for each privatized variable.
However, the writing back to original variables in `linear` clause happens after
the scope in `EmitOMPLinearClauseFinal`, causing the issue we see above.

A quick "fix" seems to be, moving `EmitOMPLinearClauseFinal` inside the scope.
However, it doesn't work. That's because the local variable map has been updated
by `LoopScope` such that a variable declaration is mapped to the privatized
variable, instead of the actual one. In that way, the following code will be
generated:
```
  %0 = load i32, ptr %j, align 4
  store i32 %0, ptr %j, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %j)
```
Well, now the life time is correct, but apparently the writing back is broken.

In this patch, a new function `OMPPrivateScope::restoreMap` is added and called
before calling `EmitOMPLinearClauseFinal`. This can make sure that
`EmitOMPLinearClauseFinal` can find the orignal varaibls to write back.

Fixes #56913.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D131272
2022-08-06 16:50:37 -04:00
Matt Arsenault
c5b36ab1d6 AMDGPU/clang: Remove dead code
The order has to be a constant and should be enforced by the builtin
definition. The fallthrough behavior would have been broken anyway.

There's still an existing issue/assert if you try to use garbage for the
ordering. The IRGen should be broken, but we also hit another assert
before that.

Fixes issue 56832
2022-08-04 19:02:56 -04:00
Ellis Hoag
12e78ff881 [InstrProf] Add the skipprofile attribute
As discussed in [0], this diff adds the `skipprofile` attribute to
prevent the function from being profiled while allowing profiled
functions to be inlined into it. The `noprofile` attribute remains
unchanged.

The `noprofile` attribute is used for functions where it is
dangerous to add instrumentation to while the `skipprofile` attribute is
used to reduce code size or performance overhead.

[0] https://discourse.llvm.org/t/why-does-the-noprofile-attribute-restrict-inlining/64108

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D130807
2022-08-04 08:45:27 -07:00
Corentin Jabot
127bf44385 [Clang][C++20] Support capturing structured bindings in lambdas
This completes the implementation of P1091R3 and P1381R1.

This patch allow the capture of structured bindings
both for C++20+ and C++17, with extension/compat warning.

In addition, capturing an anonymous union member,
a bitfield, or a structured binding thereof now has a
better diagnostic.

We only support structured bindings - as opposed to other kinds
of structured statements/blocks. We still emit an error for those.

In addition, support for structured bindings capture is entirely disabled in
OpenMP mode as this needs more investigation - a specific diagnostic indicate the feature is not yet supported there.

Note that the rest of P1091R3 (static/thread_local structured bindings) was already implemented.

at the request of @shafik, i can confirm the correct behavior of lldb wit this change.

Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/52720

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122768
2022-08-04 10:12:53 +02:00
Corentin Jabot
a274219600 Revert "[Clang][C++20] Support capturing structured bindings in lambdas"
This reverts commit 44f2baa3804a62ca793f0ff3e43aa71cea91a795.

Breaks self builds and seems to have conformance issues.
2022-08-03 21:00:29 +02:00
Corentin Jabot
44f2baa380 [Clang][C++20] Support capturing structured bindings in lambdas
This completes the implementation of P1091R3 and P1381R1.

This patch allow the capture of structured bindings
both for C++20+ and C++17, with extension/compat warning.

In addition, capturing an anonymous union member,
a bitfield, or a structured binding thereof now has a
better diagnostic.

We only support structured bindings - as opposed to other kinds
of structured statements/blocks. We still emit an error for those.

In addition, support for structured bindings capture is entirely disabled in
OpenMP mode as this needs more investigation - a specific diagnostic indicate the feature is not yet supported there.

Note that the rest of P1091R3 (static/thread_local structured bindings) was already implemented.

at the request of @shafik, i can confirm the correct behavior of lldb wit this change.

Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/52720

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122768
2022-08-03 20:00:01 +02:00