[llvm] [LV] Add epilogue minimum iteration check in VPlan as well. (PR #189372)

[via llvm-commits]

github-actions[bot] wrote:

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

* 132859 tests passed
* 3037 tests skipped
* 1 test failed

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

### LLVM
<details>
<summary>LLVM.Transforms/LoopVectorize/VPlan/dissolve-replicate-regions.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 3
c:\_work\llvm-project\llvm-project\build\bin\opt.exe -passes=loop-vectorize -force-vector-interleave=2 -force-vector-width=1 -vplan-print-after="VPlanTransforms::replicateByVF$" -disable-output C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LoopVectorize\VPlan\dissolve-replicate-regions.ll 2>&1 | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe --check-prefix=SCALAR C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LoopVectorize\VPlan\dissolve-replicate-regions.ll
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\opt.exe' -passes=loop-vectorize -force-vector-interleave=2 -force-vector-width=1 '-vplan-print-after=VPlanTransforms::replicateByVF$' -disable-output 'C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LoopVectorize\VPlan\dissolve-replicate-regions.ll'
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' --check-prefix=SCALAR 'C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LoopVectorize\VPlan\dissolve-replicate-regions.ll'
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LoopVectorize\VPlan\dissolve-replicate-regions.ll:16:16: error: SCALAR-NEXT: is not on the line after the previous match
# | ; SCALAR-NEXT: Successor(s): scalar.ph, vector.ph
# |                ^
# | <stdin>:16:1: note: 'next' match was here
# | Successor(s): scalar.ph, vector.ph
# | ^
# | <stdin>:9:31: note: previous match ended here
# |  EMIT branch-on-cond ir<false>
# |                               ^
# | <stdin>:10:1: note: non-matching line after previous match is here
# | Successor(s): scalar.ph, ir-bb<vector.memcheck>
# | ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LoopVectorize\VPlan\dissolve-replicate-regions.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |          .
# |          .
# |          .
# |         11:  
# |         12: ir-bb<vector.memcheck>: 
# |         13:  IR %0 = sub i64 %dst1, %ptr2 
# |         14:  IR %diff.check = icmp ult i64 %0, 2 
# |         15:  EMIT branch-on-cond ir<%diff.check> 
# |         16: Successor(s): scalar.ph, vector.ph 
# | next:16     !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  error: match on wrong line
# |         17:  
# |         18: vector.ph: 
# |         19: Successor(s): vector loop 
# |         20:  
# |         21: <x1> vector loop: { 
# |          .
# |          .
# |          .
# | >>>>>>
# `-----------------------------
# 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/189372