disable multiply by scalar long on x86

Author: saucecontrol

src/coreclr/jit/hwintrinsicxarch.cpp

@@ -3356,6 +3356,14 @@ GenTree* Compiler::impSpecialIntrinsic(NamedIntrinsic        intrinsic,
             argType = JITtype2varType(strip(info.compCompHnd->getArgType(sig, arg1, &argClass)));
             op1     = getArgForHWIntrinsic(argType, argClass);
 
+#if defined(TARGET_X86)
+            if (varTypeIsLong(op1->gtType) || varTypeIsLong(op2->gtType))
+            {
+                // We can only handle long in vectors on x86. If one of the operands is scalar, fall back to managed.
+                break;
+            }
+#endif // TARGET_X86
+
             retNode = gtNewSimdBinOpNode(GT_MUL, retType, op1, op2, simdBaseJitType, simdSize);
             break;
         }