[llvm] [LV] Create in-loop sub reductions (PR #147026)

[Sander de Smalen via llvm-commits]

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@@ -5151,6 +5151,8 @@ bool AArch64TTIImpl::isLegalToVectorizeReduction(
     return false;
 
   switch (RdxDesc.getRecurrenceKind()) {
+  case RecurKind::Sub:
+  case RecurKind::AddChainWithSubs:
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sdesmalen-arm wrote:

>From what I can see only AArch64 and RISC-V targets have this target hook implemented.

https://github.com/llvm/llvm-project/pull/147026