Hi All! I would like to create a small filter which eliminates unnecessary LIR_ld instructions. It seems that there are several unnecessary loads which can not be simply eliminated by the CSE filter due to its elimination is not as simple as the elimination of other CSE instructions like LIR_add. For example: class C { var x : int = 5; var y : int = 7; } var o : C = new C(); function f(o) { var j = 0; for (var i = 0; i < 20; i++) { j += o.x + o.y + (o.x + o.y) * (o.x + o.y); } return j; } The values of o.x and o.y are loaded every time when they are used but only one of them would be enough. Since the loads are done by different LIR instructions the add instructions will also be executed three times. If we could eliminate the loads the CSE filter would eliminate the second and third adds too. In the first implementation of the filter I check only the LIR_ld instructions created by the getslotvalue function of the Interpreter and all the store insertions. Between the first and the second loads of o.x all the possible stores, which can modify the value of o.x should be checked. If anything modified the o.x between the two loads than the second load could not be eliminated. It passes on almost all of the acceptance tests but fails in 28 cases. It seems that not only the store instructions but some IL primitive functions can also modify the objects so that is why it fails in test. If I handled this situation too conservatively and let the elimination of a load instruction only if there were no call instruction between the first and the second load than there would be almost nothing to eliminate. I think that it could work if I could decrease the number of possible primitive-function calls when the load must not be eliminated but unfortunately I am not yet familiar with the tamarin in detail to see everything. I would welcome any opinion, observation, comment or anything about this. :) Thanks, Peter Siket