Multiply simplifier should ask CG before decomposition

compiler/codegen/OMRCodeGenerator.hpp

@@ -702,6 +702,19 @@ class OMR_EXTENSIBLE CodeGenerator
    bool opCodeIsNoOp(TR::ILOpCode &opCode);
    bool opCodeIsNoOpOnThisPlatform(TR::ILOpCode &opCode) {return false;}
 
+   /**
+    * @brief Determines whether integer multiplication decomposition should be deferred to the code generator.
+    *
+    * This function indicates if the decomposition of integer multiplication operations should
+    * be handled by the code generator instead of the optimizer (tree simplifier). Each architecture's
+    * code generator provides its own implementation of this function. By default, this function
+    * returns `false`, meaning that decomposition is not deferred to the code generator and the
+    * optimizer will attempt to simplify.
+    *
+    * @return true if integer multiplication decomposition should be deferred to the code generator, otherwise false.
+    */
+   bool doIntMulDecompositionInCG() { return false; };
+
    bool supportsSinglePrecisionSQRT() {return false;}
    bool supportsFusedMultiplyAdd() {return false;}
    bool supportsNegativeFusedMultiplyAdd() {return false;}

compiler/optimizer/OMRSimplifierHandlers.cpp

@@ -8194,6 +8194,7 @@ TR::Node *imulSimplifier(TR::Node * node, TR::Block * block, TR::Simplifier * s)
          }
       }
    else if (secondChildOp == TR::iconst &&
+            !s->comp()->cg()->doIntMulDecompositionInCG() &&
             !s->getLastRun() &&
             secondChild->getInt()!=0 && !isNonNegativePowerOf2(secondChild->getInt()) &&
             secondChild->getInt() != TR::getMinSigned<TR::Int32>())
@@ -8588,7 +8589,10 @@ TR::Node *lmulSimplifier(TR::Node * node, TR::Block * block, TR::Simplifier * s)
             }
          }
       }
-   else if (s->comp()->target().is64Bit() && secondChildOp==TR::lconst && !s->getLastRun() && secondChild->getLongInt()!=0 && !isNonNegativePowerOf2(secondChild->getLongInt()) && secondChild->getLongInt() != TR::getMinSigned<TR::Int64>())
+   else if (s->comp()->target().is64Bit() && !s->comp()->cg()->doIntMulDecompositionInCG() &&
+            secondChildOp == TR::lconst && !s->getLastRun() && secondChild->getLongInt() != 0 &&
+            !isNonNegativePowerOf2(secondChild->getLongInt()) &&
+            secondChild->getLongInt() != TR::getMinSigned<TR::Int64>())
       {
       decomposeMultiply(node, s, true);
       }

compiler/x/codegen/OMRCodeGenerator.hpp

@@ -533,6 +533,8 @@ class OMR_EXTENSIBLE CodeGenerator : public OMR::CodeGenerator
    bool supportsAddressRematerialization();
    bool supportsXMMRRematerialization();
 
+   bool doIntMulDecompositionInCG() { return true; };
+
    TR::Instruction *setLastCatchAppendInstruction(TR::Instruction *i) {return (_lastCatchAppendInstruction=i);}
    TR::Instruction *getLastCatchAppendInstruction()                  {return _lastCatchAppendInstruction;}