When a mapper is declared with an iterator variable inside the map
clause, it results in unintended behavior due to the iterator being
implicitly created but left uninitialized.
Testcase:
```
typedef struct myvec{
size_t len;
double *data;
} myvec_t;
#pragma omp declare mapper(id:myvec_t v) map( iterator( iterator_variable=0:v.len), tofrom: v.data[iterator_variable])
int main()
{
int errors = 0;
myvec_t s;
#pragma omp target map(mapper(id), to:s)
{
}
return 0;
}
```
The error we get while compiling this is:
```
/usr/lib64/gcc/x86_64-suse-linux/14/../../../../x86_64-suse-linux/bin/ld: /tmp/test-f70647.o: in function `.omp_mapper._ZTS5myvec.id':
test.cpp:(.text+0x21a): undefined reference to `iterator_variable'
/llvm-project/install/bin/clang-linker-wrapper: error: 'ld' failed
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
```
This patch tries to fix this by initializing the iterator variable to a
null constant.
---------
Co-authored-by: Shashwathi N <nshashwa@pe31.hpc.amslabs.hpecorp.net>
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)
OpenMP 6.0 12.1.2 specifies the behavior of the strict modifier for the
num_threads clause on parallel directives, along with the message and
severity clauses. This commit implements necessary codegen changes.
OpenMP 6.0 12.1.2 specifies the behavior of the strict modifier for the
num_threads clause on parallel directives, along with the message and
severity clauses. This commit implements necessary codegen changes.
This is a major change on how we represent nested name qualifications in
the AST.
* The nested name specifier itself and how it's stored is changed. The
prefixes for types are handled within the type hierarchy, which makes
canonicalization for them super cheap, no memory allocation required.
Also translating a type into nested name specifier form becomes a no-op.
An identifier is stored as a DependentNameType. The nested name
specifier gains a lightweight handle class, to be used instead of
passing around pointers, which is similar to what is implemented for
TemplateName. There is still one free bit available, and this handle can
be used within a PointerUnion and PointerIntPair, which should keep
bit-packing aficionados happy.
* The ElaboratedType node is removed, all type nodes in which it could
previously apply to can now store the elaborated keyword and name
qualifier, tail allocating when present.
* TagTypes can now point to the exact declaration found when producing
these, as opposed to the previous situation of there only existing one
TagType per entity. This increases the amount of type sugar retained,
and can have several applications, for example in tracking module
ownership, and other tools which care about source file origins, such as
IWYU. These TagTypes are lazily allocated, in order to limit the
increase in AST size.
This patch offers a great performance benefit.
It greatly improves compilation time for
[stdexec](https://github.com/NVIDIA/stdexec). For one datapoint, for
`test_on2.cpp` in that project, which is the slowest compiling test,
this patch improves `-c` compilation time by about 7.2%, with the
`-fsyntax-only` improvement being at ~12%.
This has great results on compile-time-tracker as well:
This patch also further enables other optimziations in the future, and
will reduce the performance impact of template specialization resugaring
when that lands.
It has some other miscelaneous drive-by fixes.
About the review: Yes the patch is huge, sorry about that. Part of the
reason is that I started by the nested name specifier part, before the
ElaboratedType part, but that had a huge performance downside, as
ElaboratedType is a big performance hog. I didn't have the steam to go
back and change the patch after the fact.
There is also a lot of internal API changes, and it made sense to remove
ElaboratedType in one go, versus removing it from one type at a time, as
that would present much more churn to the users. Also, the nested name
specifier having a different API avoids missing changes related to how
prefixes work now, which could make existing code compile but not work.
How to review: The important changes are all in
`clang/include/clang/AST` and `clang/lib/AST`, with also important
changes in `clang/lib/Sema/TreeTransform.h`.
The rest and bulk of the changes are mostly consequences of the changes
in API.
PS: TagType::getDecl is renamed to `getOriginalDecl` in this patch, just
for easier to rebasing. I plan to rename it back after this lands.
Fixes#136624
Fixes https://github.com/llvm/llvm-project/issues/43179
Fixes https://github.com/llvm/llvm-project/issues/68670
Fixes https://github.com/llvm/llvm-project/issues/92757
In OpenMP 6.0 specification, section 5.2.5 Array Sections, page 166,
lines 28-28:
When the length is absent and the size of the dimension is not known,
the array section is an assumed-size array.
Testing
- Updated LIT test
- check-all
- OpenMP_VV (formerly sollve) test case
tests/6.0/target/test_target_assumed_array_size.c
If the need_device_addr adjust-op modifier is present, each list item
that appears in the clause must refer to an argument in the declaration
of the function variant that has a reference type.
Reference:
OpenMP 6.0 [Sec 9.6.2, page 332, line 31-33, adjust_args clause,
Restrictions]
Implement parsing and semantic analysis support for the message and
severity clauses that have been added to the parallel directive in
OpenMP 6.0, 12.1.
Implement parsing and semantic analysis support for the optional
'strict' modifier of the num_threads clause. This modifier has been
introduced in OpenMP 6.0, section 12.1.2.
Note: this is basically 1:1 https://reviews.llvm.org/D138328.
This patch is closely related to #139293 and addresses an existing issue
in the loop transformation codebase. Specifically, it corrects the
handling of the `NumGeneratedLoops` variable in
`OMPLoopTransformationDirective` AST nodes and its inheritors (such as
OMPUnrollDirective, OMPTileDirective, etc.).
Previously, this variable was inaccurately set for certain
transformations like reverse or tile. While this did not lead to
functional bugs, since the value was only checked to determine whether
it was greater than zero or equal to zero, the inconsistency could
introduce problems when supporting more complex directives in the
future.
This builds upon #101101 from @jyu2-git, which used compiler-generated
mappers when mapping an array-section of structs with members that have
user-defined default mappers.
Now we do the same when mapping arrays of structs.
Codegen support for reduction over private variable with reduction
clause. Section 7.6.10 in in OpenMP 6.0 spec.
- An internal shared copy is initialized with an initializer value.
- The shared copy is updated by combining its value with the values from
the private copies created by the clause.
- Once an encountering thread verifies that all updates are complete,
its original list item is updated by merging its value with that of the
shared copy and then broadcast to all threads.
Sample Test Case from OpenMP 6.0 Example
```
#include <assert.h>
#include <omp.h>
#define N 10
void do_red(int n, int *v, int &sum_v)
{
sum_v = 0; // sum_v is private
#pragma omp for reduction(original(private),+: sum_v)
for (int i = 0; i < n; i++)
{
sum_v += v[i];
}
}
int main(void)
{
int v[N];
for (int i = 0; i < N; i++)
v[i] = i;
#pragma omp parallel num_threads(4)
{
int s_v; // s_v is private
do_red(N, v, s_v);
assert(s_v == 45);
}
return 0;
}
```
Expected Codegen:
```
// A shared global/static variable is introduced for the reduction result.
// This variable is initialized (e.g., using memset or a UDR initializer)
// e.g., .omp.reduction.internal_private_var
// Barrier before any thread performs combination
call void @__kmpc_barrier(...)
// Initialization block (executed by thread 0)
// e.g., call void @llvm.memset.p0.i64(...) or call @udr_initializer(...)
call void @__kmpc_critical(...)
// Inside critical section:
// Load the current value from the shared variable
// Load the thread-local private variable's value
// Perform the reduction operation
// Store the result back to the shared variable
call void @__kmpc_end_critical(...)
// Barrier after all threads complete their combinations
call void @__kmpc_barrier(...)
// Broadcast phase:
// Load the final result from the shared variable)
// Store the final result to the original private variable in each thread
// Final barrier after broadcast
call void @__kmpc_barrier(...)
```
---------
Co-authored-by: Chandra Ghale <ghale@pe31.hpc.amslabs.hpecorp.net>
Summary:
When there are overloaded C++ operators in the global namespace the AST
node for these is not a `BinaryExpr` but a `CXXOperatorCallExpr`. Modify
the uses to handle this case, basically just treating it as a binary
expression with two arguments.
Fixes https://github.com/llvm/llvm-project/issues/141085
We weren't correctly handling size expressions with errors before trying
to get the type of the size expression.
No release note needed because support for 'stripe' was added to the
current release.
Fixes#139433
We were failing to pass a required argument when emitting the
diagnostic, so the source range was being used in place of an index.
This caused a failed assertion due to the incorrect index.
Fixes#139266
We were trying to get type information out of an expression node which
contained errors. That causes the type of the expression to be
dependent, which the code was not expecting. Now we handle error
conditions with an early return.
Fixes#139073
The "alternativeName" was introduced ~5 years ago in D82405, and at the
moment it has only one use, the one that the original change introduced.
OpenMP 6.0 spec has introduced different spellings of some directives,
but the "alternativeName" is not an adequate mechanism to implement it.
For those reasons remove the "alternativeName" member from both Clause
and Directive in DirectiveBase.td.
Since the alternativeName text appeared in a number of clang OpenMP
tests, implement `getOpenMPClauseNameForDiag` in SemaOpenMP.cpp to
preserve the text of the diagnostics.
OpenMP has restrictions on directives allowed to be strictly nested
inside a
construct with the order(concurrent) clause specified.
- OpenMP 5.0, 5.1, and 5.2 allows: 'loop', 'parallel', 'simd', and
combined directives starting with 'parallel'.
- OpenMP 6.0 allows: the above directives plus 'atomic' and
all loop-transformation directives.
Furthermore, a region that corresponds to a construct with
order(concurrent)
specified may not contain calls to the OpenMP runtime API.
This PR fixes the following issues in the current implementation:
With -fopenmp-version=50: none of the nesting restrictions above were
enforced
With -fopenmp-version=60:
1. Clang did not reject OpenMP runtime APIs encountered in the region.
2. Clang erroneously rejected combined directives starting with
parallel.
---------
Co-authored-by: Zahira Ammarguellat <zahira.ammarguellat@intel.com>
Original PR: #130537
Originally reverted due to revert of dependent commit. Relanding with no
changes.
This changes the MemberPointerType representation to use a
NestedNameSpecifier instead of a Type to represent the base class.
Since the qualifiers are always parsed as nested names, there was an
impedance mismatch when converting these back and forth into types, and
this led to issues in preserving sugar.
The nested names are indeed a better match for these, as the differences
which a QualType can represent cannot be expressed syntatically, and
they represent the use case more exactly, being either dependent or
referring to a CXXRecord, unqualified.
This patch also makes the MemberPointerType able to represent sugar for
a {up/downcast}cast conversion of the base class, although for now the
underlying type is canonical, as preserving the sugar up to that point
requires further work.
As usual, includes a few drive-by fixes in order to make use of the
improvements.
Initial Parse/Sema support for reduction over private variable with
reduction clause.
Section 7.6.10 in in OpenMP 6.0 spec.
- list item in a reduction clause can now be private in the enclosing
context.
- Added support for _original-sharing-modifier_ with reduction clause.
---------
Co-authored-by: Chandra Ghale <ghale@pe31.hpc.amslabs.hpecorp.net>
Original PR: #130537
Reland after updating lldb too.
This changes the MemberPointerType representation to use a
NestedNameSpecifier instead of a Type to represent the base class.
Since the qualifiers are always parsed as nested names, there was an
impedance mismatch when converting these back and forth into types, and
this led to issues in preserving sugar.
The nested names are indeed a better match for these, as the differences
which a QualType can represent cannot be expressed syntatically, and
they represent the use case more exactly, being either dependent or
referring to a CXXRecord, unqualified.
This patch also makes the MemberPointerType able to represent sugar for
a {up/downcast}cast conversion of the base class, although for now the
underlying type is canonical, as preserving the sugar up to that point
requires further work.
As usual, includes a few drive-by fixes in order to make use of the
improvements.
This changes the MemberPointerType representation to use a
NestedNameSpecifier instead of a Type to represent the class.
Since the qualifiers are always parsed as nested names, there was an
impedance mismatch when converting these back and forth into types, and
this led to issues in preserving sugar.
The nested names are indeed a better match for these, as the differences
which a QualType can represent cannot be expressed syntactically, and it
also represents the use case more exactly, being either dependent or
referring to a CXXRecord, unqualified.
This patch also makes the MemberPointerType able to represent sugar for
a {up/downcast}cast conversion of the base class, although for now the
underlying type is canonical, as preserving the sugar up to that point
requires further work.
As usual, includes a few drive-by fixes in order to make use of the
improvements, and removing some duplications, for example
CheckBaseClassAccess is deduplicated from across SemaAccess and
SemaCast.
Summary:
If the user tried to initialize a gobal declare target variable with
itself the compiler will hang forever. Add a visited set to make sure
this stops.
Fixes: https://github.com/llvm/llvm-project/issues/69194
