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

[Alexey Bataev via llvm-commits]

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@@ -836,8 +1103,7 @@ class InstructionsState {
   bool isAltShuffle() const { return getMainOp() != getAltOp(); }
 
   bool isOpcodeOrAlt(Instruction *I) const {
-    unsigned CheckedOpcode = I->getOpcode();
-    return getOpcode() == CheckedOpcode || getAltOpcode() == CheckedOpcode;
+    return isConvertible(I, MainOp, AltOp);
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alexey-bataev wrote:

Would be good to stop representing transformed nodes as nodes with the alternate InstructionsState. Instead, it should keep info that all instructions are homogeneous and build the correct operands for this, based on the the analysis, implemented here

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