Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision | Last revision Both sides next revision | ||
|
sav08:introduction_to_pointer_analysis [2008/05/21 10:40] vkuncak |
sav08:introduction_to_pointer_analysis [2008/05/21 10:41] vkuncak |
||
|---|---|---|---|
| Line 48: | Line 48: | ||
| * Can compiler prove one branch is dead? | * Can compiler prove one branch is dead? | ||
| * Can it do common subexpression elimination? | * Can it do common subexpression elimination? | ||
| - | <code c> | + | <code> |
| x = sin(z); | x = sin(z); | ||
| *p = 4.0; | *p = 4.0; | ||
| Line 58: | Line 58: | ||
| Is | Is | ||
| - | <code c> | + | <code> |
| int* p1, p2; | int* p1, p2; | ||
| ...S... | ...S... | ||
| Line 65: | Line 65: | ||
| </code> | </code> | ||
| equivalent to | equivalent to | ||
| - | <code c> | + | |
| + | <code> | ||
| int* p1, p2; | int* p1, p2; | ||
| ...S... | ...S... | ||
| Line 73: | Line 74: | ||
| There are also corresponding examples in Java, ocaml. | There are also corresponding examples in Java, ocaml. | ||
| - | <code java> | + | |
| + | <code> | ||
| x.f = 3; | x.f = 3; | ||
| p.f = 4; | p.f = 4; | ||
| Line 82: | Line 84: | ||
| } | } | ||
| </code> | </code> | ||
| - | <code ocaml> | + | |
| + | <code> | ||
| let x = ref 3 in | let x = ref 3 in | ||
| let p = x in | let p = x in | ||
| Line 114: | Line 117: | ||
| * **pointer analysis:** represent (usually disjoint) sets of locations to which each variable points to. For example, if we can determine that a pointer p points to an abstract location 1, and q points to location 2. If location 1 and location 2 are disjoint, then we can be sure that p and q do not overlap. | * **pointer analysis:** represent (usually disjoint) sets of locations to which each variable points to. For example, if we can determine that a pointer p points to an abstract location 1, and q points to location 2. If location 1 and location 2 are disjoint, then we can be sure that p and q do not overlap. | ||
| - | * **alias analysis:** can two symbolic expressions be an 'alias' for the same physical location i.e. can they point to the same location. | + | * **alias analysis:** can two symbolic expressions be an 'alias' for the same physical location i.e. can they point to the same location. |