'Unreachable code' presentation slideshows

Recap from last time: live variables

453 views • 44 slides

From last lecture

435 views • 43 slides

Common Sub-expression Elim

Common Sub-expression Elim. Want to compute when an expression is available in a var Domain:. Common Sub-expression Elim. Want to compute when an expression is available in a var Domain:. Flow functions. in. F X := Y op Z (in) =. X := Y op Z. out. in. F X := Y (in) =. X := Y. out.

497 views • 41 slides

Common Sub-expression Elim

Common Sub-expression Elim. Want to compute when an expression is available in a var Domain:. Common Sub-expression Elim. Want to compute when an expression is available in a var Domain:. Flow functions. in. F X := Y op Z (in) =. X := Y op Z. out. in. F X := Y (in) =. X := Y. out.

420 views • 41 slides

Precision

Precision. Going back to constant prop, in what cases would we lose precision?. Precision. Going back to constant prop, in what cases would we lose precision?. if (...) { x := -1; } else x := 1; } y := x * x; ... y. if (p) { x := 5; } else x := 4; } ... if (p) {

387 views • 28 slides

From last lecture

From last lecture. in. F x := y op z (in) = in [ x ! in(y) op in(z) ] where a op b =. x := y op z. out. General approach to domain design. Simple lattices: boolean logic lattice powerset lattice incomparable set: set of incomparable values, plus top and bottom (eg const prop lattice)

255 views • 25 slides

Example

Example. x := read() v := a + b. w := x + 1 a := w v := a + b. x := x + 1 w := x + 1. z := x + 1 t := a + b. Direction of analysis. Although constraints are not directional, flow functions are All flow functions we have seen so far are in the forward direction

202 views • 20 slides

RiskRanker : Scalable and Accurate Zero-day Android Malware Detection

417 views • 10 slides

The Fine Points of Conditionals

The Fine Points of Conditionals.

211 views • 10 slides