For the language C++ the keyword __unaligned (a Microsoft extension) had no effect on pointers.
The reason, why there was a difference between C and C++ for the keyword __unaligned:
For C, the Method getAsCXXREcordDecl() returns nullptr. That guarantees that hasUnaligned() is called.
If the language is C++, it is not guaranteed, that hasUnaligend() is called and evaluated.
Here are some links:
The Bug: https://bugs.llvm.org/show_bug.cgi?id=47499
Thread on the cfe-dev mailing list: http://lists.llvm.org/pipermail/cfe-dev/2020-September/066783.html
Diff, that introduced the check hasUnaligned() in getNaturalTypeAlignment(): https://reviews.llvm.org/D30166
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D90630
415f7ee883 had a silly typo introduced when I inlined some
code into a loop from its own function.
Original commit message:
For PlayStation we offer source code compatibility with
Microsoft's dllimport/export annotations; however, our file
format is based on ELF.
To support this we translate from DLL storage class to ELF
visibility at the end of codegen in Clang.
Other toolchains have used similar strategies (e.g. see the
documentation for this ARM toolchain:
https://developer.arm.com/documentation/dui0530/i/migrating-from-rvct-v3-1-to-rvct-v4-0/changes-to-symbol-visibility-between-rvct-v3-1-and-rvct-v4-0)
This patch adds the ability to perform this translation. Options
are provided to support customizing the mapping behaviour.
Differential Revision: https://reviews.llvm.org/D89970
Currently for explicit template function instantiation in CUDA/HIP device
compilation clang emits instantiated kernel with external linkage
and instantiated device function with internal linkage.
This is fine for -fno-gpu-rdc since there is only one TU.
However this causes duplicate symbols for kernels for -fgpu-rdc if
the same instantiation happen in multiple TU. Or missing symbols
if a device function calls an explicitly instantiated template function
in a different TU.
To make explicit template function instantiation work for
-fgpu-rdc we need to follow the C++ linkage paradigm, i.e.
use weak_odr linkage.
Differential Revision: https://reviews.llvm.org/D90311
415f7ee883 had LIT test failures on any build where the clang executable
was not called "clang". I have adjusted the LIT CHECKs to remove the
binary name to fix this.
Original commit message:
For PlayStation we offer source code compatibility with
Microsoft's dllimport/export annotations; however, our file
format is based on ELF.
To support this we translate from DLL storage class to ELF
visibility at the end of codegen in Clang.
Other toolchains have used similar strategies (e.g. see the
documentation for this ARM toolchain:
https://developer.arm.com/documentation/dui0530/i/migrating-from-rvct-v3-1-to-rvct-v4-0/changes-to-symbol-visibility-between-rvct-v3-1-and-rvct-v4-0)
This patch adds the ability to perform this translation. Options
are provided to support customizing the mapping behaviour.
Differential Revision: https://reviews.llvm.org/D89970
Similar to -fprofile-generate=, add -fmemory-profile= which takes a
directory path. This is passed down to LLVM via a new module flag
metadata. LLVM in turn provides this name to the runtime via the new
__memprof_profile_filename variable.
Additionally, always pass a default filename (in $cwd if a directory
name is not specified vi the = form of the option). This is also
consistent with the behavior of the PGO instrumentation. Since the
memory profiles will generally be fairly large, it doesn't make sense to
dump them to stderr. Also, importantly, the memory profiles will
eventually be dumped in a compact binary format, which is another reason
why it does not make sense to send these to stderr by default.
Change the existing memprof tests to specify log_path=stderr when that
was being relied on.
Depends on D89086.
Differential Revision: https://reviews.llvm.org/D89087
This allows using annotation in a much more contexts than it currently has.
especially when annotation with template or constexpr.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D88645
It's currently ambiguous in IR whether the source language explicitly
did not want a stack a stack protector (in C, via function attribute
no_stack_protector) or doesn't care for any given function.
It's common for code that manipulates the stack via inline assembly or
that has to set up its own stack canary (such as the Linux kernel) would
like to avoid stack protectors in certain functions. In this case, we've
been bitten by numerous bugs where a callee with a stack protector is
inlined into an __attribute__((__no_stack_protector__)) caller, which
generally breaks the caller's assumptions about not having a stack
protector. LTO exacerbates the issue.
While developers can avoid this by putting all no_stack_protector
functions in one translation unit together and compiling those with
-fno-stack-protector, it's generally not very ergonomic or as
ergonomic as a function attribute, and still doesn't work for LTO. See also:
https://lore.kernel.org/linux-pm/20200915172658.1432732-1-rkir@google.com/https://lore.kernel.org/lkml/20200918201436.2932360-30-samitolvanen@google.com/T/#u
Typically, when inlining a callee into a caller, the caller will be
upgraded in its level of stack protection (see adjustCallerSSPLevel()).
By adding an explicit attribute in the IR when the function attribute is
used in the source language, we can now identify such cases and prevent
inlining. Block inlining when the callee and caller differ in the case that one
contains `nossp` when the other has `ssp`, `sspstrong`, or `sspreq`.
Fixes pr/47479.
Reviewed By: void
Differential Revision: https://reviews.llvm.org/D87956
non-type template parameters.
Create a unique TemplateParamObjectDecl instance for each such value,
representing the globally unique template parameter object to which the
template parameter refers.
No IR generation support yet; that will follow in a separate patch.
This broke Chromium's PGO build, it seems because hot-cold-splitting got turned
on unintentionally. See comment on the code review for repro etc.
> This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
> the splitting pass to be toggled on/off. The current method of passing
> `-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
> correctly (say, with `-O0` or `-Oz`).
>
> To implement the -fsplit-cold-code option, an attribute is applied to
> functions to indicate that they may be considered for splitting. This
> removes some complexity from the old/new PM pipeline builders, and
> behaves as expected when LTO is enabled.
>
> Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
> Differential Revision: https://reviews.llvm.org/D57265
> Reviewed By: Aditya Kumar, Vedant Kumar
> Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar
This reverts commit 273c299d5d.
This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
the splitting pass to be toggled on/off. The current method of passing
`-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
correctly (say, with `-O0` or `-Oz`).
To implement the -fsplit-cold-code option, an attribute is applied to
functions to indicate that they may be considered for splitting. This
removes some complexity from the old/new PM pipeline builders, and
behaves as expected when LTO is enabled.
Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
Differential Revision: https://reviews.llvm.org/D57265
Reviewed By: Aditya Kumar, Vedant Kumar
Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar
This reverts commits 683b308c07 and
8487bfd4e9.
We will go for a more restricted approach that does not give freedom to
everyone to change ABIs on whichever platform.
See the discussion on https://reviews.llvm.org/D85802.
This implements the flag proposed in RFC http://lists.llvm.org/pipermail/cfe-dev/2020-August/066437.html.
The goal is to add a way to override the default target C++ ABI through
a compiler flag. This makes it easier to test and transition between different
C++ ABIs through compile flags rather than build flags.
In this patch:
- Store `-fc++-abi=` in a LangOpt. This isn't stored in a
CodeGenOpt because there are instances outside of codegen where Clang
needs to know what the ABI is (particularly through
ASTContext::createCXXABI), and we should be able to override the
target default if the flag is provided at that point.
- Expose the existing ABIs in TargetCXXABI as values that can be passed
through this flag.
- Create a .def file for these ABIs to make it easier to check flag
values.
- Add an error for diagnosing bad ABI flag values.
Differential Revision: https://reviews.llvm.org/D85802
D17779: host-side shadow variables of external declarations of device-side
global variables have internal linkage and are referenced by
`__cuda_register_globals`.
nvcc from CUDA 11 does not allow `__device__ inline` or `__device__ constexpr`
(C++17 inline variables) but clang has incorrectly supported them for a while:
```
error: A __device__ variable cannot be marked constexpr
error: An inline __device__/__constant__/__managed__ variable must have internal linkage when the program is compiled in whole program mode (-rdc=false)
```
If such a variable (which has a comdat group) is discarded (a copy from another
translation unit is prevailing and selected), accessing the variable from
outside the section group (`__cuda_register_globals`) is a violation of the ELF
specification and will be rejected by linkers:
> A symbol table entry with STB_LOCAL binding that is defined relative to one of a group's sections, and that is contained in a symbol table section that is not part of the group, must be discarded if the group members are discarded. References to this symbol table entry from outside the group are not allowed.
As a workaround, don't register such inline variables for now.
(If we register the variables in all TUs, we will keep multiple instances of the shadow and break the C++ semantics for inline variables).
We should reject such variables in Sema but our internal users need some time to migrate.
Reviewed By: tra
Differential Revision: https://reviews.llvm.org/D88786
PAC/BTI-related codegen in the AArch64 backend is controlled by a set
of LLVM IR function attributes, added to the function by Clang, based
on command-line options and GCC-style function attributes. However,
functions, generated in the LLVM middle end (for example,
asan.module.ctor or __llvm_gcov_write_out) do not get any attributes
and the backend incorrectly does not do any PAC/BTI code generation.
This patch record the default state of PAC/BTI codegen in a set of
LLVM IR module-level attributes, based on command-line options:
* "sign-return-address", with non-zero value means generate code to
sign return addresses (PAC-RET), zero value means disable PAC-RET.
* "sign-return-address-all", with non-zero value means enable PAC-RET
for all functions, zero value means enable PAC-RET only for
functions, which spill LR.
* "sign-return-address-with-bkey", with non-zero value means use B-key
for signing, zero value mean use A-key.
This set of attributes are always added for AArch64 targets (as
opposed, for example, to interpreting a missing attribute as having a
value 0) in order to be able to check for conflicts when combining
module attributed during LTO.
Module-level attributes are overridden by function level attributes.
All the decision making about whether to not to generate PAC and/or
BTI code is factored out into AArch64FunctionInfo, there shouldn't be
any places left, other than AArch64FunctionInfo, which directly
examine PAC/BTI attributes, except AArch64AsmPrinter.cpp, which
is/will-be handled by a separate patch.
Differential Revision: https://reviews.llvm.org/D85649
A static device variable may be accessed in host code through
cudaMemCpyFromSymbol etc. Currently clang does not
emit the static device variable if it is only referenced by
host code, which causes host code to fail at run time.
This patch fixes that.
Differential Revision: https://reviews.llvm.org/D88115
This assert doesn't really make sense for functions in general, since they
start life as declarations, and there isn't really any reason to require them
to be defined before attributes are applied to them.
rdar://67895846
This adds parsing and codegen support for tune in target attribute.
I've implemented this so that arch in the target attribute implicitly disables tune from the command line. I'm not sure what gcc does here. But since -march implies -mtune. I assume 'arch' in the target attribute implies tune in the target attribute.
Differential Revision: https://reviews.llvm.org/D86187
Building on the backend support from D85165. This parses the command line option in the driver, passes it on to CC1 and adds a function attribute.
-Still need to support tune on the target attribute.
-Need to use "generic" as the tuning by default. But need to change generic in the backend first.
-Need to set tune if march is specified and mtune isn't.
-May need to disable getHostCPUName's ability to guess CPU name from features when it doesn't have a family/model match for mtune=native. That's what gcc appears to do.
Differential Revision: https://reviews.llvm.org/D85384
Adds the binary format goff and the operating system zos to the triple
class. goff is selected as default binary format if zos is choosen as
operating system. No further functionality is added.
Reviewers: efriedma, tahonermann, hubert.reinterpertcast, MaskRay
Reviewed By: efriedma, tahonermann, hubert.reinterpertcast
Differential Revision: https://reviews.llvm.org/D82081
Fixes pr/11710.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Resubmit after breaking Windows and OSX builds.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D80242
Provides AMDGCN and NVPTX specific specialization of getGPUWarpSize,
getGPUThreadID, and getGPUNumThreads methods. Adds tests for AMDGCN
codegen for these methods in generic and simd modes. Also changes the
precondition in InitTempAlloca to be slightly more permissive. Useful for
AMDGCN OpenMP codegen where allocas are created with a cast to an
address space.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D84260
This patch introduces 2 new address spaces in OpenCL: global_device and global_host
which are a subset of a global address space, so the address space scheme will be
looking like:
```
generic->global->host
->device
->private
->local
constant
```
Justification: USM allocations may be associated with both host and device memory. We
want to give users a way to tell the compiler the allocation type of a USM pointer for
optimization purposes. (Link to the Unified Shared Memory extension:
https://github.com/intel/llvm/blob/sycl/sycl/doc/extensions/USM/cl_intel_unified_shared_memory.asciidoc)
Before this patch USM pointer could be only in opencl_global
address space, hence a device backend can't tell if a particular pointer
points to host or device memory. On FPGAs at least we can generate more
efficient hardware code if the user tells us where the pointer can point -
being able to distinguish between these types of pointers at compile time
allows us to instantiate simpler load-store units to perform memory
transactions.
Patch by Dmitry Sidorov.
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D82174
On AIX, the semantic of global_dtors contains __sterm functions associated with C++
cleanup actions and user-declared __attribute__((destructor)) functions. We should
never merely register __sterm with atexit(), so currently
-fregister_global_dtors_with_atexit does not work well on AIX: It would cause
finalization actions to not occur when unloading shared libraries. We need to figure
out a way to handle that when we start supporting user-declared
__attribute__((destructor)) functions.
Currently we report_fatal_error on this option temporarily.
Differential Revision: https://reviews.llvm.org/D83974
Summary:
D82193 exposed a problem with global type definitions in
`OMPConstants.h`. This causes a race when running in thinLTO mode.
Types now live inside of OpenMPIRBuilder to prevent this from happening.
Reviewers: jdoerfert
Subscribers: yaxunl, hiraditya, guansong, dexonsmith, aaron.ballman, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D83176
EmitTargetMetadata passed to emitTargetMD a null pointer as returned
from GetGlobalValue, for an unused inline function which has been
removed from the module at that point.
A FIXME in CodeGenModule.cpp commented that the calling code in
EmitTargetMetadata should be moved into the one target that needs it
(XCore). A review comment agreed. So the calling loop has been moved
into the XCore subclass. The check for null is done in that loop.
Differential Revision: https://reviews.llvm.org/D77068
1. Provides no piroirity supoort && disables three priority related
attributes: init_priority, ctor attr, dtor attr;
2. '-qunique' in XL compiler equivalent behavior of emitting sinit
and sterm functions name using getUniqueModuleId() util function
in LLVM (currently no support for InternalLinkage and WeakODRLinkage
symbols);
3. Add testcases to emit IR sample with __sinit80000000, __dtor, and
__sterm80000000;
4. Temporarily side-steps the need to implement the functionality of
llvm.global_ctors and llvm.global_dtors arrays. The uses of that
functionality in this patch (with respect to the name of the functions
involved) are not representative of how the functionality will be used
once implemented.
Differential Revision: https://reviews.llvm.org/D74166
Prevent IR-gen from emitting consteval declarations
Summary: with this patch instead of emitting calls to consteval function. the IR-gen will emit a store of the already computed result.
Summary: with this patch instead of emitting calls to consteval function. the IR-gen will emit a store of the already computed result.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76420
Summary:
Add -ftrivial-auto-var-init-stop-after= to limit the number of times
stack variables are initialized when -ftrivial-auto-var-init= is used to
initialize stack variables to zero or a pattern. This flag can be used
to bisect uninitialized uses of a stack variable exposed by automatic
variable initialization, such as http://crrev.com/c/2020401.
Reviewers: jfb, vitalybuka, kcc, glider, rsmith, rjmccall, pcc, eugenis, vlad.tsyrklevich
Reviewed By: jfb
Subscribers: phosek, hubert.reinterpretcast, srhines, MaskRay, george.burgess.iv, dexonsmith, inglorion, gbiv, llozano, manojgupta, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77168
Summary:
This patch upstreams support for a new storage only bfloat16 C type.
This type is used to implement primitive support for bfloat16 data, in
line with the Bfloat16 extension of the Armv8.6-a architecture, as
detailed here:
https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
The bfloat type, and its properties are specified in the Arm Architecture
Reference Manual:
https://developer.arm.com/docs/ddi0487/latest/arm-architecture-reference-manual-armv8-for-armv8-a-architecture-profile
In detail this patch:
- introduces an opaque, storage-only C-type __bf16, which introduces a new bfloat IR type.
This is part of a patch series, starting with command-line and Bfloat16
assembly support. The subsequent patches will upstream intrinsics
support for BFloat16, followed by Matrix Multiplication and the
remaining Virtualization features of the armv8.6-a architecture.
The following people contributed to this patch:
- Luke Cheeseman
- Momchil Velikov
- Alexandros Lamprineas
- Luke Geeson
- Simon Tatham
- Ties Stuij
Reviewers: SjoerdMeijer, rjmccall, rsmith, liutianle, RKSimon, craig.topper, jfb, LukeGeeson, fpetrogalli
Reviewed By: SjoerdMeijer
Subscribers: labrinea, majnemer, asmith, dexonsmith, kristof.beyls, arphaman, danielkiss, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76077
Summary:
Forked from:
https://reviews.llvm.org/D80242
Use the getter for access to DebugInfo consistently.
Use break in switch in CodeGenModule::EmitTopLevelDecl consistently.
Reviewers: dblaikie
Reviewed By: dblaikie
Subscribers: cfe-commits, srhines
Tags: #clang
Differential Revision: https://reviews.llvm.org/D80840
Unlike other platforms using ItaniumCXXABI, Darwin does not allow the
creation of a thread-wrapper function for a variable in the TU of
users. Because of this, it can set the linkage of the thread-local
symbol to internal, with the assumption that no TUs other than the one
defining the variable will need it.
However, constinit thread_local variables do not require the use of
the thread-wrapper call, so users reference the variable
directly. Thus, it must not be converted to internal, or users will
get a link failure.
This was a regression introduced by the optimization in
00223827a9.
Differential Revision: https://reviews.llvm.org/D80417
-fno-semantic-interposition is currently the CC1 default. (The opposite
disables some interprocedural optimizations.) However, it does not infer
dso_local: on most targets accesses to ExternalLinkage functions/variables
defined in the current module still need PLT/GOT.
This patch makes explicit -fno-semantic-interposition infer dso_local,
so that PLT/GOT can be eliminated if targets implement local aliases
for AsmPrinter::getSymbolPreferLocal (currently only x86).
Currently we check whether the module flag "SemanticInterposition" is 0.
If yes, infer dso_local. In the future, we can infer dso_local unless
"SemanticInterposition" is 1: frontends other than clang will also
benefit from the optimization if they don't bother setting the flag.
(There will be risks if they do want ELF interposition: they need to set
"SemanticInterposition" to 1.)
If we're going to assume references are dereferenceable, we should also
assume they're aligned: otherwise, we can't actually dereference them.
See also D80072.
Differential Revision: https://reviews.llvm.org/D80166
In cases where we have multiple decls of an inline builtin, we may need
to go hunting for the one with a definition when setting function
attributes.
An additional test-case was provided on
https://github.com/ClangBuiltLinux/linux/issues/979
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.
With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.
This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.
This fixes a few bugs and issues:
* PR38490: we now support reading from GUID objects returned from
__uuidof during constant evaluation.
* Our Itanium mangling for a non-instantiation-dependent template
argument involving __uuidof no longer depends on which CXXUuidofExpr
template argument we happened to see first.
* We now predeclare ::_GUID, and permit use of __uuidof without
any header inclusion, better matching MSVC's behavior. We do not
predefine ::__s_GUID, though; that seems like a step too far.
* Our IR representation for GUID constants now uses the correct IR type
wherever possible. We will still fall back to using the
{i32, i16, i16, [8 x i8]}
layout if a definition of struct _GUID is not available. This is not
ideal: in principle the two layouts could have different padding.
Reviewers: rnk, jdoerfert
Subscribers: arphaman, cfe-commits, aeubanks
Tags: #clang
Differential Revision: https://reviews.llvm.org/D78171
There are some inline builtin definitions that we can't emit
(isTriviallyRecursive & callers go into why). Marking these
nobuiltin is only useful if we actually emit the body, so don't mark
these as such unless we _do_ plan on emitting that.
This suboptimality was encountered in Linux (see some discussion on
D71082, and https://github.com/ClangBuiltLinux/linux/issues/979).
Differential Revision: https://reviews.llvm.org/D78162
This fixes code like the following on AVR:
void foo(void) {
}
void bar(void) __attribute__((alias("foo")));
Code like this is present in compiler-rt, which I'm trying to build.
Differential Revision: https://reviews.llvm.org/D76182
Summary:
- Use `device_builtin_surface` and `device_builtin_texture` for
surface/texture reference support. So far, both the host and device
use the same reference type, which could be revised later when
interface/implementation is stablized.
Reviewers: yaxunl
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77583
This is the second part loosely extracted from D71179 and cleaned up.
This patch provides semantic analysis support for `omp begin/end declare
variant`, mostly as defined in OpenMP technical report 8 (TR8) [0].
The sema handling makes code generation obsolete as we generate "the
right" calls that can just be handled as usual. This handling also
applies to the existing, albeit problematic, `omp declare variant
support`. As a consequence a lot of unneeded code generation and
complexity is removed.
A major purpose of this patch is to provide proper `math.h`/`cmath`
support for OpenMP target offloading. See PR42061, PR42798, PR42799. The
current code was developed with this feature in mind, see [1].
The logic is as follows:
If we have seen a `#pragma omp begin declare variant match(<SELECTOR>)`
but not the corresponding `end declare variant`, and we find a function
definition we will:
1) Create a function declaration for the definition we were about to generate.
2) Create a function definition but with a mangled name (according to
`<SELECTOR>`).
3) Annotate the declaration with the `OMPDeclareVariantAttr`, the same
one used already for `omp declare variant`, using and the mangled
function definition as specialization for the context defined by
`<SELECTOR>`.
When a call is created we inspect it. If the target has an
`OMPDeclareVariantAttr` attribute we try to specialize the call. To this
end, all variants are checked, the best applicable one is picked and a
new call to the specialization is created. The new call is used instead
of the original one to the base function. To keep the AST printing and
tooling possible we utilize the PseudoObjectExpr. The original call is
the syntactic expression, the specialized call is the semantic
expression.
[0] https://www.openmp.org/wp-content/uploads/openmp-TR8.pdf
[1] https://reviews.llvm.org/D61399#change-496lQkg0mhRN
Reviewers: kiranchandramohan, ABataev, RaviNarayanaswamy, gtbercea, grokos, sdmitriev, JonChesterfield, hfinkel, fghanim, aaron.ballman
Subscribers: bollu, guansong, openmp-commits, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D75779
Summary:
- Even though the bindless surface/texture interfaces are promoted,
there are still code using surface/texture references. For example,
[PR#26400](https://bugs.llvm.org/show_bug.cgi?id=26400) reports the
compilation issue for code using `tex2D` with texture references. For
better compatibility, this patch proposes the support of
surface/texture references.
- Due to the absent documentation and magic headers, it's believed that
`nvcc` does use builtins for texture support. From the limited NVVM
documentation[^nvvm] and NVPTX backend texture/surface related
tests[^test], it's believed that surface/texture references are
supported by replacing their reference types, which are annotated with
`device_builtin_surface_type`/`device_builtin_texture_type`, with the
corresponding handle-like object types, `cudaSurfaceObject_t` or
`cudaTextureObject_t`, in the device-side compilation. On the host
side, that global handle variables are registered and will be
established and updated later when corresponding binding/unbinding
APIs are called[^bind]. Surface/texture references are most like
device global variables but represented in different types on the host
and device sides.
- In this patch, the following changes are proposed to support that
behavior:
+ Refine `device_builtin_surface_type` and
`device_builtin_texture_type` attributes to be applied on `Type`
decl only to check whether a variable is of the surface/texture
reference type.
+ Add hooks in code generation to replace that reference types with
the correponding object types as well as all accesses to them. In
particular, `nvvm.texsurf.handle.internal` should be used to load
object handles from global reference variables[^texsurf] as well as
metadata annotations.
+ Generate host-side registration with proper template argument
parsing.
---
[^nvvm]: https://docs.nvidia.com/cuda/pdf/NVVM_IR_Specification.pdf
[^test]: https://raw.githubusercontent.com/llvm/llvm-project/master/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
[^bind]: See section 3.2.11.1.2 ``Texture reference API` in [CUDA C Programming Guide](https://docs.nvidia.com/cuda/pdf/CUDA_C_Programming_Guide.pdf).
[^texsurf]: According to NVVM IR, `nvvm.texsurf.handle` should be used. But, the current backend doesn't have that supported. We may revise that later.
Reviewers: tra, rjmccall, yaxunl, a.sidorin
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76365
Passing small data limit to RISCVELFTargetObjectFile by module flag,
So the backend can set small data section threshold by the value.
The data will be put into the small data section if the data smaller than
the threshold.
Differential Revision: https://reviews.llvm.org/D57497
Summary:
- https://reviews.llvm.org/D68578 revises the `GlobalDecl` constructors
to ensure all GPU kernels have `ReferenceKenelKind` initialized
properly with an explicit constructor and static one. But, there are
lots of places using the implicit constructor triggering the assertion
on non-GPU kernels. That's found in compilation of many tests and
workloads.
- Fixing all of them may change more code and, more importantly, all of
them assumes the default kernel reference kind. This patch changes
that constructor to tell `CUDAGlobalAttr` and construct `GlobalDecl`
properly.
Reviewers: yaxunl
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76344
Summary:
[Clang] Attribute to allow defining undef global variables
Initializing global variables is very cheap on hosted implementations. The
C semantics of zero initializing globals work very well there. It is not
necessarily cheap on freestanding implementations. Where there is no loader
available, code must be emitted near the start point to write the appropriate
values into memory.
At present, external variables can be declared in C++ and definitions provided
in assembly (or IR) to achive this effect. This patch provides an attribute in
order to remove this reason for writing assembly for performance sensitive
freestanding implementations.
A close analogue in tree is LDS memory for amdgcn, where the kernel is
responsible for initializing the memory after it starts executing on the gpu.
Uninitalized variables in LDS are observably cheaper than zero initialized.
Patch is loosely based on the cuda __shared__ and opencl __local variable
implementation which also produces undef global variables.
Reviewers: kcc, rjmccall, rsmith, glider, vitalybuka, pcc, eugenis, vlad.tsyrklevich, jdoerfert, gregrodgers, jfb, aaron.ballman
Reviewed By: rjmccall, aaron.ballman
Subscribers: Anastasia, aaron.ballman, davidb, Quuxplusone, dexonsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74361
Most clients of SourceManager.h need to do things like turning source
locations into file & line number pairs, but this doesn't require
bringing in FileManager.h and LLVM's FS headers.
The main code change here is to sink SM::createFileID into the cpp file.
I reason that this is not performance critical because it doesn't happen
on the diagnostic path, it happens along the paths of macro expansion
(could be hot) and new includes (less hot).
Saves some includes:
309 - /usr/local/google/home/rnk/llvm-project/clang/include/clang/Basic/FileManager.h
272 - /usr/local/google/home/rnk/llvm-project/clang/include/clang/Basic/FileSystemOptions.h
271 - /usr/local/google/home/rnk/llvm-project/llvm/include/llvm/Support/VirtualFileSystem.h
267 - /usr/local/google/home/rnk/llvm-project/llvm/include/llvm/Support/FileSystem.h
266 - /usr/local/google/home/rnk/llvm-project/llvm/include/llvm/Support/Chrono.h
Differential Revision: https://reviews.llvm.org/D75406
HIP emits a device stub function for each kernel in host code.
The HIP debugger requires device stub function to have a different unmangled name as the kernel.
Currently the name of the device stub function is the mangled name with a postfix .stub. However,
this does not work with the HIP debugger since the unmangled name is the same as the kernel.
This patch adds prefix __device__stub__ to the unmangled name of the device stub before mangling,
therefore the device stub function has a valid mangled name which is different than the device kernel
name. The device side kernel name is kept unchanged. kernels with extern "C" also gets the prefix added
to the corresponding device stub function.
Differential Revision: https://reviews.llvm.org/D68578
The initial implementation only did 'first declaration renaming' when
a default version came after. This is insufficient in cases where a
default does not exist, so this patch makes sure that we do the renaming
in all cases.
This renaming is necessary because we emit the first declaration before
knowing that it IS a target multiversion function, which would change
its name. The second declaration (the one that caused the
multiversioning) then needs to make sure that the first one has its name
changed to be consistent with the resolver usage.
Summary:
hip-pinned-shadow global var should remain in the final code object irrespective
of whether it is used or not within the code. Add it to used list, so that it
will not get eliminated when it is unused.
Reviewers: yaxunl, tra, hliao
Reviewed By: yaxunl
Subscribers: hliao, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D75402
WebAssembly enforces a rule that caller and callee signatures must
match. This means that the traditional technique of passing `main`
`argc` and `argv` even when it doesn't need them doesn't work.
Currently the backend renames `main` to `__original_main`, however this
doesn't interact well with LTO'ing libc, and the name isn't intuitive.
This patch allows us to transition to `__main_argc_argv` instead.
This implements the proposal in
https://github.com/WebAssembly/tool-conventions/pull/134
with a flag to disable it when targeting Emscripten, though this is
expected to be temporary, as discussed in the proposal comments.
Differential Revision: https://reviews.llvm.org/D70700
Summary:
Right now we annotate C++'s `operator new` with `noalias` attribute,
which very much is healthy for optimizations.
However as per [[ http://eel.is/c++draft/basic.stc.dynamic.allocation | `[basic.stc.dynamic.allocation]` ]],
there are more promises on global `operator new`, namely:
* non-`std::nothrow_t` `operator new` *never* returns `nullptr`
* If `std::align_val_t align` parameter is taken, the pointer will also be `align`-aligned
* ~~global `operator new`-returned pointer is `__STDCPP_DEFAULT_NEW_ALIGNMENT__`-aligned ~~ It's more caveated than that.
Supplying this information may not cause immediate landslide effects
on any specific benchmarks, but it for sure will be healthy for optimizer
in the sense that the IR will better reflect the guarantees provided in the source code.
The caveat is `-fno-assume-sane-operator-new`, which currently prevents emitting `noalias`
attribute, and is automatically passed by Sanitizers ([[ https://bugs.llvm.org/show_bug.cgi?id=16386 | PR16386 ]]) - should it also cover these attributes?
The problem is that the flag is back-end-specific, as seen in `test/Modules/explicit-build-flags.cpp`.
But while it is okay to add `noalias` metadata in backend, we really should be adding at least
the alignment metadata to the AST, since that allows us to perform sema checks on it.
Reviewers: erichkeane, rjmccall, jdoerfert, eugenis, rsmith
Reviewed By: rsmith
Subscribers: xbolva00, jrtc27, atanasyan, nlopes, cfe-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D73380
This PR enables "XL" C++ ABI in frontend AST to IR codegen. And it is driven by
static init work. The current kind in Clang by default is Generic Itanium, which
has different behavior on static init with IBM xlclang compiler on AIX.
Differential Revision: https://reviews.llvm.org/D74015
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with proper LiveIn
declaration, better option handling and more portable testing.
Differential Revision: https://reviews.llvm.org/D68720
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with proper LiveIn
declaration, better option handling and more portable testing.
Differential Revision: https://reviews.llvm.org/D68720
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with better option
handling and more portable testing
Differential Revision: https://reviews.llvm.org/D68720
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with correct option
flags set.
Differential Revision: https://reviews.llvm.org/D68720
This reverts commit 39f50da2a3.
The -fstack-clash-protection is being passed to the linker too, which
is not intended.
Reverting and fixing that in a later commit.
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
Differential Revision: https://reviews.llvm.org/D68720
AMDGPU and x86 at least both have separate controls for whether
denormal results are flushed on output, and for whether denormals are
implicitly treated as 0 as an input. The current DAGCombiner use only
really cares about the input treatment of denormals.
Summary:
Clang -fpic defaults to -fno-semantic-interposition (GCC -fpic defaults
to -fsemantic-interposition).
Users need to specify -fsemantic-interposition to get semantic
interposition behavior.
Semantic interposition is currently a best-effort feature. There may
still be some cases where it is not handled well.
Reviewers: peter.smith, rnk, serge-sans-paille, sfertile, jfb, jdoerfert
Subscribers: dschuff, jyknight, dylanmckay, nemanjai, jvesely, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, arphaman, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73865
First attempt at implementing -fsemantic-interposition.
Rely on GlobalValue::isInterposable that already captures most of the expected
behavior.
Rely on a ModuleFlag to state whether we should respect SemanticInterposition or
not. The default remains no.
So this should be a no-op if -fsemantic-interposition isn't used, and if it is,
isInterposable being already used in most optimisation, they should honor it
properly.
Note that it only impacts architecture compiled with -fPIC and no pie.
Differential Revision: https://reviews.llvm.org/D72829
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
First patch to support Safe Whole Program Devirtualization Enablement,
see RFC here: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html
Always emit !vcall_visibility metadata under -fwhole-program-vtables,
and not just for -fvirtual-function-elimination. The vcall visibility
metadata will (in a subsequent patch) be used to communicate to WPD
which vtables are safe to devirtualize, and we will optionally convert
the metadata to hidden visibility at link time. Subsequent follow on
patches will help enable this by adding vcall_visibility metadata to the
ThinLTO summaries, and always emit type test intrinsics under
-fwhole-program-vtables (and not just for vtables with hidden
visibility).
In order to do this safely with VFE, since for VFE all vtable loads must
be type checked loads which will no longer be the case, this patch adds
a new "Virtual Function Elim" module flag to communicate to GlobalDCE
whether to perform VFE using the vcall_visibility metadata.
One additional advantage of using the vcall_visibility metadata to drive
more WPD at LTO link time is that we can use the same mechanism to
enable more aggressive VFE at LTO link time as well. The link time
option proposed in the RFC will convert vcall_visibility metadata to
hidden (aka linkage unit visibility), which combined with
-fvirtual-function-elimination will allow it to be done more
aggressively at LTO link time under the same conditions.
Reviewers: pcc, ostannard, evgeny777, steven_wu
Subscribers: mehdi_amini, Prazek, hiraditya, dexonsmith, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71907
Currently there are 4 different mechanisms for controlling denormal
flushing behavior, and about as many equivalent frontend controls.
- AMDGPU uses the fp32-denormals and fp64-f16-denormals subtarget features
- NVPTX uses the nvptx-f32ftz attribute
- ARM directly uses the denormal-fp-math attribute
- Other targets indirectly use denormal-fp-math in one DAGCombine
- cl-denorms-are-zero has a corresponding denorms-are-zero attribute
AMDGPU wants a distinct control for f32 flushing from f16/f64, and as
far as I can tell the same is true for NVPTX (based on the attribute
name).
Work on consolidating these into the denormal-fp-math attribute, and a
new type specific denormal-fp-math-f32 variant. Only ARM seems to
support the two different flush modes, so this is overkill for the
other use cases. Ideally we would error on the unsupported
positive-zero mode on other targets from somewhere.
Move the logic for selecting the flush mode into the compiler driver,
instead of handling it in cc1. denormal-fp-math/denormal-fp-math-f32
are now both cc1 flags, but denormal-fp-math-f32 is not yet exposed as
a user flag.
-cl-denorms-are-zero, -fcuda-flush-denormals-to-zero and
-fno-cuda-flush-denormals-to-zero will be mapped to
-fp-denormal-math-f32=ieee or preserve-sign rather than the old
attributes.
Stop emitting the denorms-are-zero attribute for the OpenCL flag. It
has no in-tree users. The meaning would also be target dependent, such
as the AMDGPU choice to treat this as only meaning allow flushing of
f32 and not f16 or f64. The naming is also potentially confusing,
since DAZ in other contexts refers to instructions implicitly treating
input denormals as zero, not necessarily flushing output denormals to
zero.
This also does not attempt to change the behavior for the current
attribute. The LangRef now states that the default is ieee behavior,
but this is inaccurate for the current implementation. The clang
handling is slightly hacky to avoid touching the existing
denormal-fp-math uses. Fixing this will be left for a future patch.
AMDGPU is still using the subtarget feature to control the denormal
mode, but the new attribute are now emitted. A future change will
switch this and remove the subtarget features.
The option will limit debug info by only emitting complete class
type information when its constructor is emitted.
This patch changes comparisons with LimitedDebugInfo to use the new
level instead.
Differential Revision: https://reviews.llvm.org/D72427
If a system header provides an (inline) implementation of some of their
function, clang still matches on the function name and generate the appropriate
llvm builtin, e.g. memcpy. This behavior is in line with glibc recommendation «
users may not provide their own version of symbols » but doesn't account for the
fact that glibc itself can provide inline version of some functions.
It is the case for the memcpy function when -D_FORTIFY_SOURCE=1 is on. In that
case an inline version of memcpy calls __memcpy_chk, a function that performs
extra runtime checks. Clang currently ignores the inline version and thus
provides no runtime check.
This code fixes the issue by detecting functions whose name is a builtin name
but also have an inline implementation.
Differential Revision: https://reviews.llvm.org/D71082
The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But this can be affected by the
target attribute so we need to factor that in.
This patch moves some of the code from CodeGen to create an
appropriate feature map that we can pass to the function.
Differential Revision: https://reviews.llvm.org/D68627
Commit d77ae1552f
("[DebugInfo] Support to emit debugInfo for extern variables")
added deebugInfo for extern variables for BPF target.
The commit is reverted by 891e25b02d
as the committed tests using %clang instead of %clang_cc1 causing
test failed in certain scenarios as reported by Reid Kleckner.
This patch fixed the tests by using %clang_cc1.
Differential Revision: https://reviews.llvm.org/D71818
This is a follow up patch to use the OpenMP-IR-Builder, as discussed on
the mailing list ([1] and later) and at the US Dev Meeting'19.
[1] http://lists.flang-compiler.org/pipermail/flang-dev_lists.flang-compiler.org/2019-May/000197.html
Reviewers: kiranchandramohan, ABataev, RaviNarayanaswamy, gtbercea, grokos, sdmitriev, JonChesterfield, hfinkel, fghanim
Subscribers: ppenzin, penzn, llvm-commits, cfe-commits, jfb, guansong, bollu, hiraditya, mgorny
Tags: #clang
Differential Revision: https://reviews.llvm.org/D69922
Summary:
Attribute annotations are recorded in a special global composite variable
that points to annotation strings and the annotated objects.
As a restriction of the LLVM IR type system, those pointers are all
pointers to address space 0, so let's insert an addrspacecast when the
annotated global is in a non-0 address space.
Since this addrspacecast is only reachable from the global annotations
object, this should allow us to represent annotations on all globals
regardless of which addrspacecasts are usually legal for the target.
Reviewers: rjmccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D71208
Extern variable usage in BPF is different from traditional
pure user space application. Recent discussion in linux bpf
mailing list has two use cases where debug info types are
required to use extern variables:
- extern types are required to have a suitable interface
in libbpf (bpf loader) to provide kernel config parameters
to bpf programs.
https://lore.kernel.org/bpf/CAEf4BzYCNo5GeVGMhp3fhysQ=_axAf=23PtwaZs-yAyafmXC9g@mail.gmail.com/T/#t
- extern types are required so kernel bpf verifier can
verify program which uses external functions more precisely.
This will make later link with actual external function no
need to reverify.
https://lore.kernel.org/bpf/87eez4odqp.fsf@toke.dk/T/#m8d5c3e87ffe7f2764e02d722cb0d8cbc136880ed
This patch added clang support to emit debuginfo for extern variables
with a TargetInfo hook to enable it. The debuginfo for the
extern variable is emitted only if that extern variable is
referenced in the current compilation unit.
Currently, only BPF target enables to generate debug info for
extern variables. The emission of such debuginfo is disabled for C++
at this moment since BPF only supports a subset of C language.
Emission with C++ can be enabled later if an appropriate use case
is identified.
-fstandalone-debug permits us to see more debuginfo with the cost
of bloated binary size. This patch did not add emission of extern
variable debug info with -fstandalone-debug. This can be
re-evaluated if there is a real need.
Differential Revision: https://reviews.llvm.org/D70696
The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But this can be affected by the
target attribute so we need to factor that in.
This patch copies some of the code from CodeGen to create an
appropriate feature map that we can pass to the function. Probably
need some refactoring here to share more code with Codegen. Is
there a good place to do that? Also need to support the cpu_specific
attribute as well.
Differential Revision: https://reviews.llvm.org/D68627
Jan Ole Hüser