[llvm] [LoopVectorizer][AArch64] Add support for partial reduce subtraction (PR #123636)

[Sam Tebbs via llvm-commits]

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@@ -8761,20 +8762,23 @@ bool VPRecipeBuilder::getScaledReductions(
     return false;
 
   using namespace llvm::PatternMatch;
+  BinaryOperator *ExtendedBinOp = BinOp;
+  match(BinOp, m_Neg(m_BinOp(ExtendedBinOp)));
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SamTebbs33 wrote:

Could this just set `BinOp` inside the match instead of creating a new variable?

https://github.com/llvm/llvm-project/pull/123636