[llvm] [LV] Bundle sub reductions into VPExpressionRecipe (PR #147255)

[Sander de Smalen via llvm-commits]

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@@ -2797,6 +2797,10 @@ class VPExpressionRecipe : public VPSingleDefRecipe {
     /// vector operands, performing a reduction.add on the result, and adding
     /// the scalar result to a chain.
     MulAccReduction,
+    /// Represent an inloop multiply-accumulate reduction, multiplying the
+    /// extended vector operands, negating the multiplication, performing a
+    /// reduction.add on the result, and adding the scalar result to a chain.
+    ExtNegatedMulAccReduction,
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sdesmalen-arm wrote:

Should there also be `NegatedMulAccReduction` ?

https://github.com/llvm/llvm-project/pull/147255