Patch improves codegen for OpenMP constructs. If the OpenMP region does not have internal 'cancel' construct, a call to 'void __kmpc_barrier()' runtime function is generated for all implicit/explicit barriers. If the region has inner 'cancel' directive, then
```
if (__kmpc_cancel_barrier())
exit from outer construct;
```
code is generated.
Also, the code for 'canellation point' directive is not generated if parent directive does not have 'cancel' directive.
llvm-svn: 247681
Currently private copies of captured variables have default alignment. Patch makes private variables to have same alignment as original variables.
llvm-svn: 247260
Currently all variables used in OpenMP regions are captured into a record and passed to outlined functions in this record. It may result in some poor performance because of too complex analysis later in optimization passes. Patch makes to emit outlined functions for parallel-based regions with a list of captured variables. It reduces code for 2*n GEPs, stores and loads at least.
Codegen for task-based regions remains unchanged because runtime requires that all captured variables are passed in captured record.
llvm-svn: 247251
Fix processing of shared variables with reference types in OpenMP constructs. Previously, if the variable was not marked in one of the private clauses, the reference to this variable was emitted incorrectly and caused an assertion later.
llvm-svn: 246846
OpenMP 4.1 allows to use variables with reference types in all private clauses (private, firstprivate, lastprivate, linear etc.). Patch allows to use such variables and fixes codegen for linear variables with reference types.
llvm-svn: 245268
If the variable is marked as private in OpenMP construct, the reference to this variable should not keep type qualifiers for the original variable. Private copy is not volatile or constant, so we can use unqualified type for private copy.
llvm-svn: 242133
If loop control variable in a worksharing construct is marked as lastprivate, we should copy last calculated value of private counter back to original variable.
llvm-svn: 237879
-fopenmp turns on OpenMP support and links libiomp5 as OpenMP library. Also there is -fopenmp={libiomp5|libgomp} option that allows to override effect of -fopenmp and link libgomp library (if -fopenmp=libgomp is specified).
Differential Revision: http://reviews.llvm.org/D9736
llvm-svn: 237769
Patch fixes bugs in codegen for loops with unsigned counters and zero trip count. Previously preconditions for all loops were built using logic (Upper - Lower) > 0. But if the loop is a loop with zero trip count, then Upper - Lower is < 0 only for signed integer, for unsigned we're running into an underflow situation.
In this patch we're using original Lower<Upper condition to check that loop body can be executed at least once. Also this allows to skip code generation for loops, if it is known that preconditions for the loop are always false.
Differential Revision: http://reviews.llvm.org/D9103
llvm-svn: 235500
#pragma omp for lastprivate(<var>)
for (i = a; i < b; ++b)
<BODY>;
This construct is translated into something like:
<last_iter> = alloca i32
<lastprivate_var> = alloca <type>
<last_iter> = 0
; No initializer for simple variables or a default constructor is called for objects.
; For arrays perform element by element initialization by the call of the default constructor.
...
OMP_FOR_START(...,<last_iter>, ..); sets <last_iter> to 1 if this is the last iteration.
<BODY>
...
OMP_FOR_END
if (<last_iter> != 0) {
<var> = <lastprivate_var> ; Update original variable with the lastprivate value.
}
call __kmpc_cancel_barrier() ; an implicit barrier to avoid possible data race.
Differential Revision: http://reviews.llvm.org/D8658
llvm-svn: 235074
Alexey Bataev