[llvm-branch-commits] [llvm] [AArch64] Let LoadStoreOptimizer handle renamable implicit-defs. (PR #174186)

[Sander de Smalen via llvm-branch-commits]

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sdesmalen-arm wrote:

That would introduce regressions because the implicit operands to ORRWrs/ADDWri, at least when generated by the VirtRegRewriter, don't have the `renamable` attribute, even when their sub-register does, e.g.:
```
renamable $w1 = ORRWrr $wzr, renamable $w0, implicit-def $x1
```
Here `$x1` should have been `renamable` as well, which seems like an existing bug.

It seems the check for the opcode here in `isRewritableImplicitDef` is to make sure they can safely be renamed (although it conservatively limits it to only two operations)

https://github.com/llvm/llvm-project/pull/174186