[OPENMP50]Codegen for inscan reductions in worksharing directives.
Summary:
Implemented codegen for reduction clauses with inscan modifiers in
worksharing constructs.
Emits the code for the directive with inscan reductions.
The code is the following:
```
size num_iters = <num_iters>;
<type> buffer[num_iters];
for (i: 0..<num_iters>) {
<input phase>;
buffer[i] = red;
}
for (int k = 0; k != ceil(log2(num_iters)); ++k)
for (size cnt = last_iter; cnt >= pow(2, k); --k)
buffer[i] op= buffer[i-pow(2,k)];
for (0..<num_iters>) {
red = InclusiveScan ? buffer[i] : buffer[i-1];
<scan phase>;
}
```
Reviewers: jdoerfert
Subscribers: yaxunl, guansong, arphaman, cfe-commits, caomhin
Tags: #clang
Differential Revision: https://reviews.llvm.org/D79948
13 files changed: