This patch implements Clang support for an original OpenMP extension
we have developed to support OpenACC: the `ompx_hold` map type
modifier. The next patch in this series, D106510, implements OpenMP
runtime support.
Consider the following example:
```
#pragma omp target data map(ompx_hold, tofrom: x) // holds onto mapping of x
{
foo(); // might have map(delete: x)
#pragma omp target map(present, alloc: x) // x is guaranteed to be present
printf("%d\n", x);
}
```
The `ompx_hold` map type modifier above specifies that the `target
data` directive holds onto the mapping for `x` throughout the
associated region regardless of any `target exit data` directives
executed during the call to `foo`. Thus, the presence assertion for
`x` at the enclosed `target` construct cannot fail. (As usual, the
standard OpenMP reference count for `x` must also reach zero before
the data is unmapped.)
Justification for inclusion in Clang and LLVM's OpenMP runtime:
* The `ompx_hold` modifier supports OpenACC functionality (structured
reference count) that cannot be achieved in standard OpenMP, as of
5.1.
* The runtime implementation for `ompx_hold` (next patch) will thus be
used by Flang's OpenACC support.
* The Clang implementation for `ompx_hold` (this patch) as well as the
runtime implementation are required for the Clang OpenACC support
being developed as part of the ECP Clacc project, which translates
OpenACC to OpenMP at the directive AST level. These patches are the
first step in upstreaming OpenACC functionality from Clacc.
* The Clang implementation for `ompx_hold` is also used by the tests
in the runtime implementation. That syntactic support makes the
tests more readable than low-level runtime calls can. Moreover,
upstream Flang and Clang do not yet support OpenACC syntax
sufficiently for writing the tests.
* More generally, the Clang implementation enables a clean separation
of concerns between OpenACC and OpenMP development in LLVM. That
is, LLVM's OpenMP developers can discuss, modify, and debug LLVM's
extended OpenMP implementation and test suite without directly
considering OpenACC's language and execution model, which can be
handled by LLVM's OpenACC developers.
* OpenMP users might find the `ompx_hold` modifier useful, as in the
above example.
See new documentation introduced by this patch in `openmp/docs` for
more detail on the functionality of this extension and its
relationship with OpenACC. For example, it explains how the runtime
must support two reference counts, as specified by OpenACC.
Clang recognizes `ompx_hold` unless `-fno-openmp-extensions`, a new
command-line option introduced by this patch, is specified.
Reviewed By: ABataev, jdoerfert, protze.joachim, grokos
Differential Revision: https://reviews.llvm.org/D106509
-fstack-clash-protection was added in Clang commit e67cbac812 but was
enabled only on Linux. Allow it on FreeBSD as well, as it works fine.
Reviewed By: serge-sans-paille
Differential Revision: https://reviews.llvm.org/D108571
Previoulsy debug-info-for-profiling and pseudo-probe-for-profiling are mutual exclusive because they compete the dwarf discrimnator for callsites on the IR. This changes allows to use the two switches together. The side effect is that callsite discriminators will be taken by pseudo probe, while discriminators for other instructions are still available for AutoFDO use. This is less than ideal, however, it still allows us a chance to smoothly transition from AutoFDO to CSSPGO, by collecting both profiles from a CSSPGO binary.
Reviewed By: wenlei, wmi
Differential Revision: https://reviews.llvm.org/D107876
Temporary files created by the offloading device toolchain are not removed
after compilation when using a two-step compilation. The offload-bundler uses a
different filename for the device binary than the `.o` file present in the
Job's input list. This is not listed as a temporary file so it is never
removed. This patch explicitly adds the device binary as a temporary file to
consume it. This fixes PR50336.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D107668
GCC supports multiple forms of -falign-loops=.
-falign-loops= is currently ignored in Clang.
This patch implements the simplest but the most useful form where N is a
power of 2.
The underlying implementation uses a `llvm::TargetOptions` option for now.
Bitcode generation ignores this option.
Differential Revision: https://reviews.llvm.org/D106701
The declaration for the global new function in C++ is generated in the compiler front-end. When examining exception propagation, we found that this is the largest root throw site propagator requiring unwind code to be generated for callers up the stack. Allowing this to be handled immediately with termination stops upward propagation and leads to significantly less landing pads generated. This in turns leads to a performance and .text size win.
With `-fnew-infallible` this annotates the declaration with `throw()` and `__attribute__((returns_nonnull))`. `throw()` allows the compiler to assume exceptions do not propagate out of new and eliminate it as a root throw site. Note that the definition of global new is user-replaceable so users should ensure that the one used follows these semantics.
Measuring internally, we're seeing at 0.5% CPU win in one of our large internal FB workload. Measuring on clang self-build (cd0a1226b5) we get:
thinlto/
"dwarfehprepare.NumCleanupLandingPadsRemaining": 153494,
"dwarfehprepare.NumNoUnwind": 26309,
thinlto_newinfallible/
"dwarfehprepare.NumCleanupLandingPadsRemaining": 143660,
"dwarfehprepare.NumNoUnwind": 28744,
a 1-143660/153494 = 6.4% reduction in landing pads and a 28744/26309 = 9.3% increase in the number of nounwind functions.
Testing:
ninja check-all
new test case to make sure these attributes are added correctly to global new.
Reviewed By: urnathan
Differential Revision: https://reviews.llvm.org/D105225
With this patch, OpenMP on AMDGCN will use the math functions
provided by ROCm ocml library. Linking device code to the ocml will be
done in the next patch.
Reviewed By: JonChesterfield, jdoerfert, scchan
Differential Revision: https://reviews.llvm.org/D104904
Definition of `__cpp_threadsafe_static_init` macro is controlled by
language option Opts.ThreadsafeStatics. This patch sets language
option to false by default in OpenCL mode, resulting in macro
`__cpp_threadsafe_static_init` being undefined. Default value can be
overridden using command line option -fthreadsafe-statics.
Change is supposed to address portability because not all OpenCL
vendors support thread safe implementation of static initialization.
Fixes llvm.org/PR48012
Differential Revision: https://reviews.llvm.org/D107163
With this patch, OpenMP on AMDGCN will use the math functions
provided by ROCm ocml library. Linking device code to the ocml will be
done in the next patch.
Reviewed By: JonChesterfield, jdoerfert, scchan
Differential Revision: https://reviews.llvm.org/D104904
The Intel compiler ICC supports the option "-fp-model=(source|double|extended)"
which causes the compiler to use a wider type for intermediate floating point
calculations. Also supported is a way to embed this effect in the source
program with #pragma float_control(source|double|extended).
This patch extends pragma float_control syntax, and also adds support
for a new floating point option "-ffp-eval-method=(source|double|extended)".
source: intermediate results use source precision
double: intermediate results use double precision
extended: intermediate results use extended precision
Reviewed By: Aaron Ballman
Differential Revision: https://reviews.llvm.org/D93769
Change the ffp-model=precise to enables -ffp-contract=on (previously
-ffp-model=precise enabled -ffp-contract=fast). This is a follow-up
to Andy Kaylor's comments in the llvm-dev discussion "Floating Point
semantic modes". From the same email thread, I put Andy's distillation
of floating point options and floating point modes into UsersManual.rst
Also fixes bugs.llvm.org/show_bug.cgi?id=50222
I had to revert this a few times because of failures on the x86-64
buildbot but I think we finally have that fixed by LNT/79f2b03c51.
Reviewed By: rjmccall, andrew.kaylor
Differential Revision: https://reviews.llvm.org/D74436
Moving `InputInfo.h` from `lib/Driver/` into `include/Driver` to be able to expose it in an API consumed from outside of `clangDriver`.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D106787
Constructor homing reduces the amount of class type info that is emitted
by emitting conmplete type info for a class only when a constructor for
that class is emitted.
This will mainly reduce the amount of duplicate debug info in object
files. In Chrome enabling ctor homing decreased total build directory sizes
by about 30%.
It's also expected that some class types (such as unused classes)
will no longer be emitted in the debug info. This is fine, since we wouldn't
expect to need these types when debugging.
In some cases (e.g. libc++, https://reviews.llvm.org/D98750), classes
are used without calling the constructor. Since this is technically
undefined behavior, enabling constructor homing should be fine.
However Clang now has an attribute
`__attribute__((standalone_debug))` that can be used on classes to
ignore ctor homing.
Bug: https://bugs.llvm.org/show_bug.cgi?id=46537
Differential Revision: https://reviews.llvm.org/D106084
This patch adds the -fminimize-whitespace with the following effects:
* If combined with -E, remove as much non-line-breaking whitespace as
possible.
* If combined with -E -P, removes as much whitespace as possible,
including line-breaks.
The motivation is to reduce the amount of insignificant changes in the
preprocessed output with source files where only whitespace has been
changed (add/remove comments, clang-format, etc.) which is in particular
useful with ccache.
A patch for ccache for using this flag has been proposed to ccache as well:
https://github.com/ccache/ccache/pull/815, which will use
-fnormalize-whitespace when clang-13 has been detected, and additionally
uses -P in "unify_mode". ccache already had a unify_mode in an older
version which was removed because of problems that using the
preprocessor itself does not have (such that the custom tokenizer did
not recognize C++11 raw strings).
This patch slightly reorganizes which part is responsible for adding
newlines that are required for semantics. It is now either
startNewLineIfNeeded() or MoveToLine() but never both; this avoids the
ShouldUpdateCurrentLine workaround and avoids redundant lines being
inserted in some cases. It also fixes a mandatory newline not inserted
after a _Pragma("...") that is expanded into a #pragma.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D104601
This patch makes the changes in the driver that converts the medium code
model to large.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D106371
Emit the unsupported option error until the Clang's library integration support for 128-bit long double is available for AIX.
Reviewed By: Whitney, cebowleratibm
Differential Revision: https://reviews.llvm.org/D106074
Change the ffp-model=precise to enables -ffp-contract=on (previously
-ffp-model=precise enabled -ffp-contract=fast). This is a follow-up
to Andy Kaylor's comments in the llvm-dev discussion "Floating Point
semantic modes". From the same email thread, I put Andy's distillation
of floating point options and floating point modes into UsersManual.rst
Also fixes bugs.llvm.org/show_bug.cgi?id=50222
Reviewed By: rjmccall, andrew.kaylor
Differential Revision: https://reviews.llvm.org/D74436
With this patch, OpenMP on AMDGCN will use the math functions
provided by ROCm ocml library. Linking device code to the ocml will be
done in the next patch.
Reviewed By: JonChesterfield, jdoerfert, scchan
Differential Revision: https://reviews.llvm.org/D104904
The Intel compiler ICC supports the option "-fp-model=(source|double|extended)"
which causes the compiler to use a wider type for intermediate floating point
calculations. Also supported is a way to embed this effect in the source
program with #pragma float_control(source|double|extended).
This patch extends pragma float_control syntax, and also adds support
for a new floating point option "-ffp-eval-method=(source|double|extended)".
source: intermediate results use source precision
double: intermediate results use double precision
extended: intermediate results use extended precision
Reviewed By: Aaron Ballman
Differential Revision: https://reviews.llvm.org/D93769
This diff changes llvm-ifs to use unified IFS file format
and perform other renaming changes in preparation for the
merging between elfabi/ifs.
Differential Revision: https://reviews.llvm.org/D99810
Turning on -funique-internal-linkage-names when -fpseudo-probe-for-profiling is on, unless -fno-unique-internal-linkage-names is specified.
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D106193
While GNU as only allows the directory form of the .file directive for DWARF v5,
the integrated assembler prefers the directory form on all DWARF versions
(-fdwarf-directory-asm).
We currently set CC1 -fno-dwarf-directory-asm for -fno-integrated-as -gdwarf-5
which may cause the directory entry 0 and the filename entry 0 to be incorrect
(see D105662 and the example below). This patch makes -fno-integrated-as -gdwarf-5 use
-fdwarf-directory-asm as well.
```
cd /tmp/c
before
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -S -o - | grep '\.file.*0'
.file 0 "/tmp/c/e/a.c" md5 0x97e31cee64b4e58a4af8787512d735b6
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -c
% llvm-dwarfdump a.o | grep include_directories
include_directories[ 0] = "/tmp/c/e"
after
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -S -o - | grep '\.file.*0'
.file 0 "/tmp/c" "e/a.c" md5 0x97e31cee64b4e58a4af8787512d735b6
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -c
% llvm-dwarfdump a.o | grep include_directories
include_directories[ 0] = "/tmp/c"
```
Reviewed By: #debug-info, dblaikie, osandov
Differential Revision: https://reviews.llvm.org/D105835
D105314 added the abibility choose to use AsmParser for parsing inline
asm. -no-intergrated-as will override this default if specified
explicitly.
If toolchain choose to use MCAsmParser for inline asm, don't pass
the option to disable integrated-as explictly unless set by user.
Reviewed By: #powerpc, shchenz
Differential Revision: https://reviews.llvm.org/D105512
We should not error out on non-x86 targets if `-fbasic-block-sections=none` is in effect.
Also, filter it out for GPU-side compilations, as we do with other options not
supported on the GPU.
Differential Revision: https://reviews.llvm.org/D105226
This patch adds a new clang builtin, __arithmetic_fence. The purpose of the
builtin is to provide the user fine control, at the expression level, over
floating point optimization when -ffast-math (-ffp-model=fast) is enabled.
The builtin prevents the optimizer from rearranging floating point expression
evaluation. The new option fprotect-parens has the same effect on
parenthesized expressions, forcing the optimizer to respect the parentheses.
Reviewed By: aaron.ballman, kpn
Differential Revision: https://reviews.llvm.org/D100118
This patch adds unbundling support of an archive file. It takes an
archive file along with a set of offload targets as input.
Output is a device specific archive for each given offload target.
Input archive contains bundled code objects bundled using
clang-offload-bundler. Each generated device specific archive contains
a set of device code object files which are named as
<Parent Bundle Name>-<CodeObject-GPUArch>.
Entries in input archive can be of any binary type which is
supported by clang-offload-bundler, like *.bc. Output archives will
contain files in same type.
Example Usuage:
clang-offload-bundler --unbundle --inputs=lib-generic.a -type=a
-targets=openmp-amdgcn-amdhsa--gfx906,openmp-amdgcn-amdhsa--gfx908
-outputs=devicelib-gfx906.a,deviceLib-gfx908.a
Reviewed By: jdoerfert, yaxunl
Differential Revision: https://reviews.llvm.org/D93525
Added the option `-altivec-src-compat=[mixed,gcc,xl]`. The default at this time is `mixed`.
The default behavior for clang is for all vector compares to return a scalar unless the vectors being
compared are vector bool or vector pixel. In that case the compare returns a
vector. With the gcc case all vector compares return vectors and in the xl case
all vector compares return scalars.
This patch does not change the default behavior of clang.
This option will be used in future patches to implement behaviour compatibility for the vector bool/pixel types.
Reviewed By: bmahjour
Differential Revision: https://reviews.llvm.org/D103615
This reverts commit c3fe847f9d.
Tests fail in non-asserts builds because they assume named IR, by the
looks of it (testing for the "entry" label, for instance). I don't know
enough about the update_cc_test_checks.py stuff to know how to manually
fix these tests, so reverting for now.
This patch adds a new clang builtin, __arithmetic_fence. The purpose of the
builtin is to provide the user fine control, at the expression level, over
floating point optimization when -ffast-math (-ffp-model=fast) is enabled.
The builtin prevents the optimizer from rearranging floating point expression
evaluation. The new option fprotect-parens has the same effect on
parenthesized expressions, forcing the optimizer to respect the parentheses.
Reviewed By: aaron.ballman, kpn
Differential Revision: https://reviews.llvm.org/D100118
Added the option `-altivec-src-compat=[mixed,gcc,xl]`. The default at this time is `mixed`.
The default behavior for clang is for all vector compares to return a scalar unless the vectors being
compared are vector bool or vector pixel. In that case the compare returns a
vector. With the gcc case all vector compares return vectors and in the xl case
all vector compares return scalars.
This patch does not change the default behavior of clang.
This option will be used in future patches to implement behaviour compatibility for the vector bool/pixel types.
Reviewed By: bmahjour
Differential Revision: https://reviews.llvm.org/D103615
When clang driver is used with -save-temps to compile OpenCL program,
clang driver first launches clang -cc1 -E to generate preprocessor expansion output,
then launches clang -cc1 with the generated preprocessor expansion output as input
to generate LLVM IR.
Currently clang by default passes "-finclude-default-header" "-fdeclare-opencl-builtins"
in both steps, which causes default header included again in the second step, which
causes error.
This patch let clang not to include default header when input type is preprocessor expansion
output, which fixes the issue.
Reviewed by: Anastasia Stulova
Differential Revision: https://reviews.llvm.org/D104800
This is mostly a mechanical change, but a testcase that contains
parts of the StringRef class (clang/test/Analysis/llvm-conventions.cpp)
isn't touched.
Only LLVM-based instrumentation profile is supported on AIX.
And it currently must be used with full LTO.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D104803
The default Altivec ABI was implemented but the clang error for specifying
its use still remains. Users could get around this but not specifying the
type of Altivec ABI but we need to remove the error.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D102094
Summary:
The changes introduced in D97680 turns this command line option into a no-op so
it can be removed entirely.
Reviewed By: tianshilei1992
Differential Revision: https://reviews.llvm.org/D102940
This reverts commit a1449a10db.
Seems like my changes to LNT had no effect -- puzzled.
The 21 tests pass on my sandbox with the clang patch but are
failing in exec time in the bot
This patch changes the ffp-model=precise to enables -ffp-contract=on
(previously -ffp-model=precise enabled -ffp-contract=fast). This is a
follow-up to Andy Kaylor's comments in the llvm-dev discussion
"Floating Point semantic modes". From the same email thread, I put
Andy's distillation of floating point options and floating point modes
into UsersManual.rst
Differential Revision: https://reviews.llvm.org/D74436
Support -Wno-frame-larger-than (with no =) and make it properly
interoperate with -Wframe-larger-than. Reject -Wframe-larger-than with
no argument.
We continue to support Clang's old spelling, -Wframe-larger-than=, for
compatibility with existing users of that facility.
In passing, stop the driver from accepting and ignoring
-fwarn-stack-size and make it a cc1-only flag as intended.
-Wframe-larger-than= is an interesting warning; we can't know the frame
size until PrologueEpilogueInsertion (PEI); very late in the compilation
pipeline.
-Wframe-larger-than= was propagated through CC1 as an -mllvm flag, then
was a cl::opt in LLVM's PEI pass; this meant it was dropped during LTO
and needed to be re-specified via -plugin-opt.
Instead, make it part of the IR proper as a module level attribute,
similar to D103048. Introduce -fwarn-stack-size CC1 option.
Reviewed By: rsmith, qcolombet
Differential Revision: https://reviews.llvm.org/D103928
Joel E. Denny