[all-commits] [llvm/llvm-project] 132bb5: [NFC][Coroutines] Use a reverse post-order to guid...

[witstorm95 via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 132bb5cc5fd5f91e6a25e8004ac5d6516518f31a
      https://github.com/llvm/llvm-project/commit/132bb5cc5fd5f91e6a25e8004ac5d6516518f31a
  Author: witstorm95 <witstorm at 163.com>
  Date:   2023-08-09 (Wed, 09 Aug 2023)

  Changed paths:
    M llvm/lib/Transforms/Coroutines/CoroFrame.cpp

  Log Message:
  -----------
  [NFC][Coroutines] Use a reverse post-order to guide the computation about cross suspend infomation to reach a fixed point faster.

Fixed https://github.com/llvm/llvm-project/issues/62348

Propagate cross suspend point information along reverse post-order.
It does not modify the original function, just selects a better
traversal order.

Before the patch:

```
n: 20000
4.31user 0.11system 0:04.44elapsed 99%CPU (0avgtext+0avgdata
552352maxresident)k
0inputs+8848outputs (0major+126254minor)pagefaults 0swaps

n: 40000
11.24user 0.40system 0:11.66elapsed 99%CPU (0avgtext+0avgdata
1788404maxresident)k
0inputs+17600outputs (0major+431105minor)pagefaults 0swaps

n: 60000
21.65user 0.96system 0:22.62elapsed 99%CPU (0avgtext+0avgdata
3809836maxresident)k
0inputs+26352outputs (0major+934749minor)pagefaults 0swaps

n: 80000
37.05user 1.53system 0:38.58elapsed 99%CPU (0avgtext+0avgdata
6602396maxresident)k
0inputs+35096outputs (0major+1622584minor)pagefaults 0swaps

n: 100000
51.87user 2.67system 0:54.54elapsed 99%CPU (0avgtext+0avgdata
10210736maxresident)k
0inputs+43848outputs (0major+2518945minor)pagefaults 0swaps

```
After the patch:

```
n: 20000
3.08user 0.12system 0:03.21elapsed 99%CPU (0avgtext+0avgdata
551012maxresident)k
0inputs+8848outputs (0major+129349minor)pagefaults 0swaps

n: 40000
5.88user 0.33system 0:06.22elapsed 99%CPU (0avgtext+0avgdata
1789248maxresident)k
0inputs+17600outputs (0major+435096minor)pagefaults 0swaps

n: 60000
8.84user 0.77system 0:09.63elapsed 99%CPU (0avgtext+0avgdata
3807800maxresident)k
0inputs+26352outputs (0major+939119minor)pagefaults 0swaps

n: 80000
11.64user 1.58system 0:13.23elapsed 99%CPU (0avgtext+0avgdata
6604708maxresident)k
0inputs+35096outputs (0major+1629566minor)pagefaults 0swaps

n: 100000
15.21user 2.56system 0:17.79elapsed 99%CPU (0avgtext+0avgdata
10208828maxresident)k
8inputs+43848outputs (0major+2526611minor)pagefaults 0swaps

```

Reviewed By: MatzeB, ChuanqiXu

Differential Revision: https://reviews.llvm.org/D156850