[llvm] [LV] Add support for partial reductions without a binary op (PR #133922)

[David Sherwood via llvm-commits]

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@@ -8803,40 +8802,70 @@ bool VPRecipeBuilder::getScaledReductions(
   if (PhiOp != PHI)
     return false;
 
-  auto *BinOp = dyn_cast<BinaryOperator>(Op);
-  if (!BinOp || !BinOp->hasOneUse())
-    return false;
-
   using namespace llvm::PatternMatch;
-  // Use the side-effect of match to replace BinOp only if the pattern is
-  // matched, we don't care at this point whether it actually matched.
-  match(BinOp, m_Neg(m_BinOp(BinOp)));
 
-  Value *A, *B;
-  if (!match(BinOp->getOperand(0), m_ZExtOrSExt(m_Value(A))) ||
-      !match(BinOp->getOperand(1), m_ZExtOrSExt(m_Value(B))))
-    return false;
+  // If the update is a binary operator, check both of its operands to see if
+  // they are extends. Otherwise, see if the update comes directly from an
+  // extend.
+  Instruction *Exts[2] = {nullptr};
+  BinaryOperator *ExtendUser = dyn_cast<BinaryOperator>(Op);
+  std::optional<unsigned> BinOpc;
+  Type *ExtOpTypes[2] = {nullptr};
+
+  auto collectExtInfo = [&Exts,
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david-arm wrote:

Done

https://github.com/llvm/llvm-project/pull/133922