[llvm] [DAG] isKnownNeverZero - add ISD::OR DemandedElts handling (PR #183228)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 170494 tests passed
* 3088 tests skipped
* 1 test failed

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

### LLVM
<details>
<summary>LLVM.CodeGen/X86/known-never-zero.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc < /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/X86/known-never-zero.ll -mtriple=i686-unknown-unknown -mattr=+sse2 | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/X86/known-never-zero.ll --check-prefixes=X86
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -mtriple=i686-unknown-unknown -mattr=+sse2
# note: command had no output on stdout or stderr
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/X86/known-never-zero.ll --check-prefixes=X86
# .---command stderr------------
# | /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/X86/known-never-zero.ll:34:13: error: X86-NEXT: expected string not found in input
# | ; X86-NEXT: bsfl %eax, %ecx
# |             ^
# | <stdin>:35:18: note: scanning from here
# |  movd %xmm0, %eax
# |                  ^
# | <stdin>:36:6: note: possible intended match here
# |  rep bsfl %eax, %eax
# |      ^
# | 
# | Input file: <stdin>
# | Check file: /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/X86/known-never-zero.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |            .
# |            .
# |            .
# |           30:  .cfi_startproc 
# |           31: # %bb.0: 
# |           32:  movl 4(%esp), %eax 
# |           33:  por .LCPI1_0, %xmm0 
# |           34:  movdqa %xmm0, (%eax) 
# |           35:  movd %xmm0, %eax 
# | next:34'0                      X error: no match found
# |           36:  rep bsfl %eax, %eax 
# | next:34'0     ~~~~~~~~~~~~~~~~~~~~~
# | next:34'1          ?                possible intended match
# |           37:  retl 
# | next:34'0     ~~~~~~
# |           38: .Lfunc_end1: 
# | next:34'0     ~~~~~~~~~~~~~
# |           39:  .size or_known_nonzero_vec, .Lfunc_end1-or_known_nonzero_vec 
# | next:34'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |           40:  .cfi_endproc 
# | next:34'0     ~~~~~~~~~~~~~~
# |           41:  # -- End function 
# | next:34'0     ~~~~~~~~~~~~~~~~~~~
# |            .
# |            .
# |            .
# | >>>>>>
# `-----------------------------
# 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/183228