[llvm] [SLP] Make getSameOpcode support interchangeable instructions. (PR #127450)

[Alexey Bataev via llvm-commits]

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@@ -1085,6 +1358,25 @@ static InstructionsState getSameOpcode(ArrayRef<Value *> VL,
     return InstructionsState::invalid();
   }
 
+  if (IsBinOp) {
+    auto FindOp =
+        [&](const InterchangeableBinOp &Converter) {
+          unsigned InterchangeableInstructionOpcode = Converter.getOpcode();
+          for (Value *V : VL) {
+            if (isa<PoisonValue>(V))
+              continue;
+            auto *Inst = cast<Instruction>(V);
+            if (Inst->getOpcode() == InterchangeableInstructionOpcode)
+              return Inst;
+          }
+          llvm_unreachable(
+              "Cannot find the candidate instruction for InstructionsState.");
+        };
+    MainOp = FindOp(InterchangeableConverter);
+    AltOp = AlternateInterchangeableConverter
+                ? FindOp(*AlternateInterchangeableConverter)
+                : MainOp;
+  }
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alexey-bataev wrote:

Maybe create a new function for it , separate from getSameOpcode?

https://github.com/llvm/llvm-project/pull/127450