[llvm] [llvm][LICM] Add flag to control re-association (PR #149829)

[Theodoros Theodoridis via llvm-commits]

================
@@ -2850,7 +2855,7 @@ static bool hoistBOAssociation(Instruction &I, Loop &L,
   bool LVInRHS = L.isLoopInvariant(BO->getOperand(0));
   auto *BO0 = dyn_cast<BinaryOperator>(BO->getOperand(LVInRHS));
   if (!BO0 || BO0->getOpcode() != Opcode || !BO0->isAssociative() ||
-      BO0->hasNUsesOrMore(3))
+      BO0->hasNUsesOrMore(BOAssociationUserLimit + 1))
----------------
thetheodor wrote:

In principle it makes sense to fix such RP issues in the backend. However, in our case, the the re-associated and hoisted instructions are further modified by other passes (LSR etc) and sinking them becomes non-trivial.


https://github.com/llvm/llvm-project/pull/149829