[llvm] [IA]: Construct (de)interleave4 out of (de)interleave2 (PR #89276)

[Paul Walker via llvm-commits]

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@@ -17168,13 +17167,17 @@ bool AArch64TargetLowering::lowerInterleaveIntrinsicToStore(
   const DataLayout &DL = II->getModule()->getDataLayout();
 
   bool UseScalable;
-  if (!isLegalInterleavedAccessType(VTy, DL, UseScalable))
+  if (!isLegalInterleavedAccessType(VTy, DL, UseScalable)) {
+    DeadInsts.clear();
     return false;
+  }
 
   // TODO: Add support for using SVE instructions with fixed types later, using
   // the code from lowerInterleavedStore to obtain the correct container type.
-  if (UseScalable && !VTy->isScalableTy())
+  if (UseScalable && !VTy->isScalableTy()) {
+    DeadInsts.clear();
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paulwalker-arm wrote:

As above, you cannot assume DeadInsts is empty on function entry.

https://github.com/llvm/llvm-project/pull/89276