[llvm] [LoopVectorizer] Add support for partial reductions (PR #92418)

[Florian Hahn via llvm-commits]

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@@ -2067,6 +2085,12 @@ class TargetTransformInfo::Concept {
   /// \return if target want to issue a prefetch in address space \p AS.
   virtual bool shouldPrefetchAddressSpace(unsigned AS) const = 0;
 
+  virtual InstructionCost
+  getPartialReductionCost(unsigned Opcode, Type *InputType, Type *AccumType,
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fhahn wrote:

Please document, this should include the definition of what partial reduction means in this context (possibly tying to the definition of the intrinsic?)

https://github.com/llvm/llvm-project/pull/92418