[llvm] [AArch64] Fix correctness of FORM_TRANSPOSED_REG_TUPLE expansions (PR #205528)

[via llvm-commits]

github-actions[bot] wrote:

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

* 176076 tests passed
* 3531 tests skipped
* 1 test failed

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

### LLVM
<details>
<summary>LLVM.CodeGen/AArch64/sme2-multivec-regalloc.mir</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -mtriple=aarch64-linux-gnu -mattr=+sme2 -force-streaming -verify-machineinstrs -enable-subreg-liveness -start-before=greedy /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AArch64/sme2-multivec-regalloc.mir -o - | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AArch64/sme2-multivec-regalloc.mir
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -mtriple=aarch64-linux-gnu -mattr=+sme2 -force-streaming -verify-machineinstrs -enable-subreg-liveness -start-before=greedy /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AArch64/sme2-multivec-regalloc.mir -o -
# 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/AArch64/sme2-multivec-regalloc.mir
# .---command stderr------------
# | /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AArch64/sme2-multivec-regalloc.mir:35:16: error: CHECK-NEXT: is not on the line after the previous match
# |  ; CHECK-NEXT: mov z8.d, z16.d
# |                ^
# | <stdin>:28:2: note: 'next' match was here
# |  mov z8.d, z16.d
# |  ^
# | <stdin>:26:40: note: previous match ended here
# |  ld1b { z4.b - z7.b }, pn8/z, [x0, x10]
# |                                        ^
# | <stdin>:27:1: note: non-matching line after previous match is here
# |  mov z9.d, z18.d
# | ^
# | 
# | Input file: <stdin>
# | Check file: /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AArch64/sme2-multivec-regalloc.mir
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |          .
# |          .
# |          .
# |         23:  ptrue p0.b 
# |         24:  add x10, x9, x1 
# |         25:  ld1b { z19.b, z23.b, z27.b, z31.b }, pn8/z, [x0, x9] 
# |         26:  ld1b { z4.b - z7.b }, pn8/z, [x0, x10] 
# |         27:  mov z9.d, z18.d 
# |         28:  mov z8.d, z16.d 
# | next:35      !~~~~~~~~~~~~~~  error: match on wrong line
# |         29:  mov z21.d, z22.d 
# |         30:  mov z10.d, z19.d 
# |         31:  mov z22.d, z23.d 
# |         32:  mov z25.d, z26.d 
# |         33:  mov z11.d, z4.d 
# |          .
# |          .
# |          .
# | >>>>>>
# `-----------------------------
# 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/205528