[llvm] [LoopRotate] Use SCEV exit counts to improve rotation profitability (PR #187483)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 132471 tests passed
* 3018 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM
<details>
<summary>LLVM.Other/new-pm-print-pipeline.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 3
c:\_work\llvm-project\llvm-project\build\bin\opt.exe -disable-output -disable-verify -print-pipeline-passes -passes='function(adce),function(adce)' < C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll --match-full-lines --check-prefixes=CHECK-0
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\opt.exe' -disable-output -disable-verify -print-pipeline-passes '-passes=function(adce),function(adce)'
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll' --match-full-lines --check-prefixes=CHECK-0
# note: command had no output on stdout or stderr
# RUN: at line 6
c:\_work\llvm-project\llvm-project\build\bin\opt.exe -disable-output -disable-verify -print-pipeline-passes -passes='module(rpo-function-attrs,require<globals-aa>,function(float2int,lower-constant-intrinsics,loop(loop-rotate)),invalidate<globals-aa>)' < C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll --match-full-lines --check-prefixes=CHECK-1
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\opt.exe' -disable-output -disable-verify -print-pipeline-passes '-passes=module(rpo-function-attrs,require<globals-aa>,function(float2int,lower-constant-intrinsics,loop(loop-rotate)),invalidate<globals-aa>)'
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll' --match-full-lines --check-prefixes=CHECK-1
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll:7:12: error: CHECK-1: expected string not found in input
# | ; CHECK-1: rpo-function-attrs,require<globals-aa>,function(float2int,lower-constant-intrinsics,loop(loop-rotate<header-duplication;no-prepare-for-lto>)),invalidate<globals-aa>
# |            ^
# | <stdin>:1:1: note: scanning from here
# | rpo-function-attrs,require<globals-aa>,function(float2int,lower-constant-intrinsics,loop(loop-rotate<header-duplication;no-prepare-for-lto;no-check-exit-count>)),invalidate<globals-aa>
# | ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\llvm\test\Other\new-pm-print-pipeline.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |          1: rpo-function-attrs,require<globals-aa>,function(float2int,lower-constant-intrinsics,loop(loop-rotate<header-duplication;no-prepare-for-lto;no-check-exit-count>)),invalidate<globals-aa> 
# | check:7     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/187483