This adds support for using `ATTACH` map-type for proper
pointer-attachment when mapping list-items that have base-pointers.
For example, for the following:
```c
int *p;
#pragma omp target enter data map(p[1:10])
```
The following maps are now emitted by clang:
```
(A)
&p[0], &p[1], 10 * sizeof(p[1]), TO | FROM
&p, &p[1], sizeof(p), ATTACH
```
Previously, the two possible maps emitted by clang were:
```
(B)
&p[0], &p[1], 10 * sizeof(p[1]), TO | FROM
(C)
&p, &p[1], 10 * sizeof(p[1]), TO | FROM | PTR_AND_OBJ
````
(B) does not perform any pointer attachment, while (C) also maps the
pointer p, both of which are incorrect.
-----
With this change, we are using ATTACH-style maps, like `(A)`, for cases
where the expression has a base-pointer. For example:
```cpp
int *p, **pp;
S *ps, **pps;
... map(p[0])
... map(p[10:20])
... map(*p)
... map(([20])p)
... map(ps->a)
... map(pps->p->a)
... map(pp[0][0])
... map(*(pp + 10)[0])
```
#### Grouping of maps based on attach base-pointers
We also group mapping of clauses with the same base decl in the order of
the increasing complexity of their base-pointers, e.g. for something
like:
```
S **spp;
map(spp[0][0], spp[0][0].a), // attach-ptr: spp[0]
map(spp[0]), // attach-ptr: spp
map(spp), // attach-ptr: N/A
```
We first map `spp`, then `spp[0]` then `spp[0][0]` and `spp[0][0].a`.
This allows us to also group "struct" allocation based on their attach
pointers. This resolves the issues of us always mapping everything from
the beginning of the symbol `spp`. Each group is mapped independently,
and at the same level, like `spp[0][0]` and its member `spp[0][0].a`, we
still get map them together as part of the same contiguous struct
`spp[0][0]`. This resolves issue #141042.
#### use_device_ptr/addr fixes
The handling of `use_device_ptr/addr` was updated to use the attach-ptr
information, and works for many cases that were failing before. It has
to be done as part of this series because otherwise, the switch from
ptr_to_obj to attach-style mapping would have caused regressions in
existing use_device_ptr/addr tests.
#### Handling of attach-pointers that are members of implicitly mapped
structs:
* When a struct member-pointer, like `p` below, is a base-pointer in a
`map` clause on a target construct (like `map(p[0:1])`, and the base of
that struct is either the `this` pointer (implicitly or explicitly), or
a struct that is implicitly mapped on that construct, we add an implicit
`map(p)` so that we don't implicitly map the full struct.
```c
struct S { int *p;
void f1() {
#pragma omp target map(p[0:1]) // Implicitly map this->p, to ensure
// that the implicit map of `this[:]` does
// not map the full struct
printf("%p %p\n", &p, p);
}
```
#### Scope for improvement:
* We may be able to compute attach-ptr expr while collecting
component-lists in Sema.
* But we cache the computation results already, and `findAttachPtrExpr`
is fairly simple, and fast.
* There may be a better way to implement semantic expr comparison.
#### Needs future work:
* Attach-style maps not yet emitted for declare mappers.
* Mapping of class member references: We are still using PTR_AND_OBJ
maps for them. We will likely need to change that to handle
`ref_ptr/ref_ptee`, and `attach` map-type-modifier on them.
* Implicit capturing of "this" needs to map the full `this[0:1]` unless
there is an explicit map on one of the members, or a map with a member
as its base-pointer.
* Implicit map added for capturing a class member pointer needs to also
add a zero-length-array-section map.
* `use_device_addr` on array-sections-on-pointers need further
improvements (documented using FIXMEs)
#### Why a large PR
While it's unfortunate that this PR has gotten large and difficult to
review, the issue is that all the functional changes have to be made
together, to prevent regressions from partially implemented changes.
For example, the changes to capturing were previously done separately
(#145454), but they would still cause stability issues in absence of
full attach-mapping. And attach-mapping needs those changes to be able
to launch kernels.
We extracted the utilities and functions, like those for finding
attach-ptrs, or comparing exprs, out as a separate NFC PR that doesn't
call those functions, just adds them (#155625). Maybe the change that
adds a new error message for use_device_addr on array-sections with
non-var base-pointers could have been extracted out too (but that would
have had to be a follow-up change in that case, and we would get
comp-fails with this PR when the erroneous case was not
caught/diagnosed).
---------
Co-authored-by: Alex Duran <alejandro.duran@intel.com>
According to the OpenMP 6.0 specification, array sections with no length
and unknown size are considered assumed-size arrays. As of pull request
https://github.com/llvm/llvm-project/pull/148048
these types of array sections are allowed and can be specified in
clauses that allow array sections as list items. However, only two
clauses explicitly allow array sections that are assumed-size arrays:
- 'map' and 'use_device_addr'.
The other clauses that accept array sections do not explicitly accept
assumed-size arrays:
- inclusive, exclusive, has_device_addr, in_reduction, task_reduction,
reduction These cases should generate an error. See OpenMP 6.0
specification section 7.4 List Item Privatization, Restrictions, p. 222,
L15
Assumed-size arrays must not be privatized
For OpenMP 6.0, function getPrivateItem() now checks for array section
list items that are assumed-size arrays and generates an error if they
are not allowed for the clause.
Testing
- Updated LIT tests for assumed-size array sections to ensure these
clauses generate an error: inclusive, exclusive, has_device_addr,
in_reduction, task_reduction, reduction and that this clause is accepted
(codegen test): use_device_addr
- check-all
- OpenMP_VV (sollve_vv)
Add nuw attribute to inbounds GEPs where the expression used to form the
GEP is an addition of unsigned indices.
Relands #105496, which was reverted because it exposed a miscompilation
arising from #98608. This is now fixed by #106512.
Generate nuw GEPs for struct member accesses, as inbounds + non-negative
implies nuw.
Regression tests are updated using update scripts where possible, and by
find + replace where not.
Fix another runtime problem when explicit map both pointer and pointee
in target data region.
In #92210, problem is only addressed in target region, but missing for
target data region.
The change just passing AreBothBasePtrAndPteeMapped in
generateInfoForComponentList when processing target data.
---------
Co-authored-by: Alexey Bataev <a.bataev@gmx.com>
Currently we are missing set up-boundary address for FinalArraySection
as highests elements in partial struct data.
Currently for:
\#pragma omp target map(D.a) map(D.b[:2])
The size is:
%a = getelementptr inbounds %struct.DataTy, ptr %D, i32 0, i32 0
%b = getelementptr inbounds %struct.DataTy, ptr %D, i32 0, i32 1
%arrayidx = getelementptr inbounds [2 x float], ptr %b, i64 0, i64 0
%2 = getelementptr float, ptr %arrayidx, i32 1
%3 = ptrtoint ptr %2 to i64
%4 = ptrtoint ptr %a to i64
%5 = sub i64 %3, %4
%6 = sdiv exact i64 %5, ptrtoint (ptr getelementptr (i8, ptr null, i32
1) to i64)
Where %2 is wrong for (D.b[:2]) is pointer to first element of array
section. It should pointe to last element of array section.
The fix is to emit the pointer to the last element of array section and
use this pointer as the highest element in partial struct data.
After change IR:
%a = getelementptr inbounds %struct.DataTy, ptr %D, i32 0, i32 0
%b = getelementptr inbounds %struct.DataTy, ptr %D, i32 0, i32 1
%arrayidx = getelementptr inbounds [2 x float], ptr %b, i64 0, i64 0
%b1 = getelementptr inbounds %struct.DataTy, ptr %D, i32 0, i32 1
%arrayidx2 = getelementptr inbounds [2 x float], ptr %b1, i64 0, i64 1
%1 = getelementptr float, ptr %arrayidx2, i32 1
%2 = ptrtoint ptr %1 to i64
%3 = ptrtoint ptr %a to i64
%4 = sub i64 %2, %3
%5 = sdiv exact i64 %4, ptrtoint (ptr getelementptr (i8, ptr null, i32
1) to i64)
Reapplication of 7339c0f782d5c70e0928f8991b0c05338a90c84c with a fix
for a crash involving arrays without a size expression.
Clang supports VLAs in C++ as an extension, but we currently only warn
on their use when you pass -Wvla, -Wvla-extension, or -pedantic.
However, VLAs as they're expressed in C have been considered by WG21
and rejected, are easy to use accidentally to the surprise of users
(e.g., https://ddanilov.me/default-non-standard-features/), and they
have potential security implications beyond constant-size arrays
(https://wiki.sei.cmu.edu/confluence/display/c/ARR32-C.+Ensure+size+arguments+for+variable+length+arrays+are+in+a+valid+range).
C++ users should strongly consider using other functionality such as
std::vector instead.
This seems like sufficiently compelling evidence to warn users about
VLA use by default in C++ modes. This patch enables the -Wvla-extension
diagnostic group in C++ language modes by default, and adds the warning
group to -Wall in GNU++ language modes. The warning is still opt-in in
C language modes, where support for VLAs is somewhat less surprising to
users.
RFC: https://discourse.llvm.org/t/rfc-diagnosing-use-of-vlas-in-c/73109
Fixes https://github.com/llvm/llvm-project/issues/62836
Differential Revision: https://reviews.llvm.org/D156565
The default version of OpenMP is updated from 5.0 to 5.1 which means if -fopenmp is specified but -fopenmp-version is not specified with clang, the default version of OpenMP is taken to be 5.1. After modifying the Frontend for that, various LIT tests were updated. This patch contains all such changes. At a high level, these are the patterns of changes observed in LIT tests -
# RUN lines which mentioned `-fopenmp-version=50` need to kept only if the IR for version 5.0 and 5.1 are different. Otherwise only one RUN line with no version info(i.e. default version) needs to be there.
# Test cases of this sort already had the RUN lines with respect to the older default version 5.0 and the version 5.1. Only swapping the version specification flag `-fopenmp-version` from newer version RUN line to older version RUN line is required.
# Diagnostics: Remove the 5.0 version specific RUN lines if there was no difference in the Diagnostics messages with respect to the default 5.1.
# Diagnostics: In case there was any difference in diagnostics messages between 5.0 and 5.1, mention version specific messages in tests.
# If the test contained version specific ifdef's e.g. "#ifdef OMP5" but there were no RUN lines for any other version than 5.X, then bring the code guarded by ifdef's outside and remove the ifdef's.
# Some tests had RUN lines for both 5.0 and 5.1 versions, but it is found that the IR for 5.0 is not different from the 5.1, therefore such RUN lines are redundant. So, such duplicated lines are removed.
# To generate CHECK lines automatically, use the script llvm/utils/update_cc_test_checks.py
Reviewed By: saiislam, ABataev
Differential Revision: https://reviews.llvm.org/D129635
(cherry picked from commit 9dd2999907dc791136a75238a6000f69bf67cf4e)
As per the OpenMP Spec, "A list item in a use_device_addr clause
must have a corresponding list item in the device data environment"
. Therefore a `map` clause is added which will make sure that the
respective list items are mapped to the device data environment
before the `use_device_addr` clause is specified. The CHECK lines
are also modified based on this change.
Differential Revision: https://reviews.llvm.org/D134974
This adds -no-opaque-pointers to clang tests whose output will
change when opaque pointers are enabled by default. This is
intended to be part of the migration approach described in
https://discourse.llvm.org/t/enabling-opaque-pointers-by-default/61322/9.
The patch has been produced by replacing %clang_cc1 with
%clang_cc1 -no-opaque-pointers for tests that fail with opaque
pointers enabled. Worth noting that this doesn't cover all tests,
there's a remaining ~40 tests not using %clang_cc1 that will need
a followup change.
Differential Revision: https://reviews.llvm.org/D123115
Changed the we handle llvm::Constants in sizes arrays. ConstExprs and
GlobalValues cannot be used as initializers, need to put them at the
runtime, otherwise there wight be the compilation errors.
Differential Revision: https://reviews.llvm.org/D105297
Changed the we handle llvm::Constants in sizes arrays. ConstExprs and
GlobalValues cannot be used as initializers, need to put them at the
runtime, otherwise there wight be the compilation errors.
Differential Revision: https://reviews.llvm.org/D105297
OMP_MAP_TARGET_PARAM flag is used to mark the data that shoud be passed
as arguments to the target kernels, nothing else. But the compiler still
marks the data with OMP_MAP_TARGET_PARAM flags even if the data is
passed to the data movement directives, like target data, target update
etc. This flag is just ignored for this directives and the compiler does
not need to emit it.
Reviewed By: cchen
Differential Revision: https://reviews.llvm.org/D91261
Summary:
Add support for passing source locations to libomptarget runtime functions using the ident_t struct present in the rest of the libomp API. This will allow the runtime system to give much more insightful error messages and debugging values.
Reviewers: jdoerfert grokos
Differential Revision: https://reviews.llvm.org/D87946
Summary:
This patch adds support for passing in the original delcaration name in the source file to the libomptarget runtime. This will allow the runtime to provide more intelligent debugging messages. This patch takes the original expression parsed from the OpenMP map / update clause and provides a textual representation if it was explicitly mapped, otherwise it takes the name of the variable declaration as a fallback. The information in passed to the runtime in a global array of strings that matches the existing ident_t source location strings using ";name;filename;column;row;;"
Reviewers: jdoerfert
Differential Revision: https://reviews.llvm.org/D89802
Summary:
This patch adds support for passing in the original delcaration name in the
source file to the libomptarget runtime. This will allow the runtime to provide
more intelligent debugging messages. This patch takes the original expression
parsed from the OpenMP map / update clause and provides a textual
representation if it was explicitly mapped, otherwise it takes the name of the
variable declaration as a fallback. The information in passed to the runtime in
a global array of strings that matches the existing ident_t source location
strings using ";name;filename;column;row;;". See
clang/test/OpenMP/target_map_names.cpp for an example of the generated output
for a given map clause.
Reviewers: jdoervert
Differential Revision: https://reviews.llvm.org/D89802
This patch implements the code generation to use OpenMP 5.0 declare mapper (a.k.a. user-defined mapper) constructs.
Patch written by Lingda Li.
Differential Revision: https://reviews.llvm.org/D67833
Summary:
Added codegen for use_device_addr clause. The components of the list
items are mapped as a kind of RETURN components and then the returned
base address is used instead of the real address of the base declaration
used in the use_device_addr expressions.
Reviewers: jdoerfert
Subscribers: yaxunl, guansong, sstefan1, cfe-commits, caomhin
Tags: #clang
Differential Revision: https://reviews.llvm.org/D80730
