Instead of generating llvm.mem.parallel_loop_access metadata, generate
llvm.access.group on instructions and llvm.loop.parallel_accesses on
loops. There is one access group per generated loop.
This is clang part of D52116/r349725.
Differential Revision: https://reviews.llvm.org/D52117
llvm-svn: 349823
Summary:
For the following code:
```
int i;
#pragma omp taskloop
for (i = 0; i < 100; ++i)
{}
#pragma omp taskloop nogroup
for (i = 0; i < 100; ++i)
{}
```
Clang emits the following LLVM IR:
```
...
call void @__kmpc_taskgroup(%struct.ident_t* @0, i32 %0)
%2 = call i8* @__kmpc_omp_task_alloc(%struct.ident_t* @0, i32 %0, i32 1, i64 80, i64 8, i32 (i32, i8*)* bitcast (i32 (i32, %struct.kmp_task_t_with_privates*)* @.omp_task_entry. to i32 (i32, i8*)*))
...
call void @__kmpc_taskloop(%struct.ident_t* @0, i32 %0, i8* %2, i32 1, i64* %8, i64* %9, i64 %13, i32 0, i32 0, i64 0, i8* null)
call void @__kmpc_end_taskgroup(%struct.ident_t* @0, i32 %0)
...
%15 = call i8* @__kmpc_omp_task_alloc(%struct.ident_t* @0, i32 %0, i32 1, i64 80, i64 8, i32 (i32, i8*)* bitcast (i32 (i32, %struct.kmp_task_t_with_privates.1*)* @.omp_task_entry..2 to i32 (i32, i8*)*))
...
call void @__kmpc_taskloop(%struct.ident_t* @0, i32 %0, i8* %15, i32 1, i64* %21, i64* %22, i64 %26, i32 0, i32 0, i64 0, i8* null)
```
The first set of instructions corresponds to the first taskloop construct. It is important to note that the implicit taskgroup region associated with the taskloop construct has been materialized in our IR: the `__kmpc_taskloop` occurs inside a taskgroup region. Note also that this taskgroup region does not exist in our second taskloop because we are using the `nogroup` clause.
The issue here is the 4th argument of the kmpc_taskloop call, starting from the end, is always a zero. Checking the LLVM OpenMP RT implementation, we see that this argument corresponds to the nogroup parameter:
```
void __kmpc_taskloop(ident_t *loc, int gtid, kmp_task_t *task, int if_val,
kmp_uint64 *lb, kmp_uint64 *ub, kmp_int64 st, int nogroup,
int sched, kmp_uint64 grainsize, void *task_dup);
```
So basically we always tell to the RT to do another taskgroup region. For the first taskloop, this means that we create two taskgroup regions. For the second example, it means that despite the fact we had a nogroup clause we are going to have a taskgroup region, so we unnecessary wait until all descendant tasks have been executed.
Reviewers: ABataev
Reviewed By: ABataev
Subscribers: rogfer01, cfe-commits
Differential Revision: https://reviews.llvm.org/D53636
llvm-svn: 345180
only.
Added support for -fopenmp-simd option that allows compilation of
simd-based constructs without emission of OpenMP runtime calls.
llvm-svn: 321560
If taskloop directive has no associated nogroup clause, it must emitted
inside implicit taskgroup block. Runtime supports it, but we need to
generate implicit taskgroup block explicitly to support future
reductions codegen.
llvm-svn: 307822
directives.
'kmp_task_t' record type added a new field for 'priority' clause and
changed the representation of pointer to destructors for privates used
within loop-based directives.
Old representation:
typedef struct kmp_task { /* GEH: Shouldn't this be
aligned somehow? */
void *shareds; /**< pointer to block of
pointers to shared vars */
kmp_routine_entry_t routine; /**< pointer to routine
to call for executing task */
kmp_int32 part_id; /**< part id for the
task */
kmp_routine_entry_t destructors; /* pointer to function to
invoke deconstructors of firstprivate C++ objects */
/* private vars */
} kmp_task_t;
New representation:
typedef struct kmp_task { /* GEH: Shouldn't this be
aligned somehow? */
void *shareds; /**< pointer to block of
pointers to shared vars */
kmp_routine_entry_t routine; /**< pointer to routine
to call for executing task */
kmp_int32 part_id; /**< part id for the
task */
kmp_cmplrdata_t data1; /* Two known
optional additions: destructors and priority */
kmp_cmplrdata_t data2; /* Process
destructors first, priority second */
/* future data */
/* private vars */
} kmp_task_t;
Also excessive initialization of 'destructors' fields to 'null' was
removed from codegen if it is known that no destructors shal be used.
Currently a special bit is used in 'kmp_tasking_flags_t' bitfields
('destructors_thunk' bitfield).
llvm-svn: 271201
directives.
OpenMP 4.5 supports clause 'priority' in task-based directives. Patch
adds initial codegen support for this clause in codegen.
llvm-svn: 269050
If private variables require destructors call at the deletion of the
task, additional flag in task flags must be set. Patch fixes this
problem.
llvm-svn: 269039
OpenMP 4.5 defines 'taskloop simd' directive, which is combined
directive for 'taskloop' and 'simd' directives. Patch adds initial
codegen support for this directive and its 2 basic clauses 'safelen' and
'simdlen'.
llvm-svn: 267872
Michael Kruse