[llvm] [SLP]Initial support for copyables in fmuladd intrinsic (PR #211245)

[Simon Pilgrim via llvm-commits]

================
@@ -12261,8 +12279,10 @@ class InstructionsCompatibilityAnalysis {
         }
       }
     }
-    // 2. Check, if operands can be vectorized.
-    if (count_if(Operands.back(), IsaPred<Instruction>) > 1)
+    // 2. Check if operands can be vectorized. fmuladd's addend may hold many
+    // instructions (e.g. a run of loads), so this check applies to the
+    // 2-operand ops only; fmuladd checks the addend column below instead.
+    if (!IsFMulAdd && count_if(Operands.back(), IsaPred<Instruction>) > 1)
----------------
RKSimon wrote:

`Operands.size() == 2` ?

https://github.com/llvm/llvm-project/pull/211245