[OPENMP] Codegen for 'reduction' clause in 'parallel' directive.
Emit a code for reduction clause. Next code should be emitted for reductions:
static kmp_critical_name lock = { 0 };
void reduce_func(void *lhs[<n>], void *rhs[<n>]) {
...
*(Type<i> *)lhs[i] = RedOp<i>(*(Type<i> *)lhs[i], *(Type<i> *)rhs[i]);
...
}
... void *RedList[<n>] = {&<RHSExprs>[0], ..., &<RHSExprs>[<n> - 1]};
switch (__kmpc_reduce{_nowait}(<loc>, <gtid>, <n>, sizeof(RedList), RedList, reduce_func, &<lock>)) {
case 1:
...
<LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]);
...
__kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
break;
case 2:
...
Atomic(<LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]));
...
break;
default:
;
}
Reduction variables are a kind of a private variables, they have private copies, but initial values are chosen in accordance with the reduction operation.
Differential Revision: http://reviews.llvm.org/D8915
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234583
91177308-0d34-0410-b5e6-
96231b3b80d8