Hello,
While reading alias.c, it seemed to me that some comments could use
some cleanups.
OK for trunk?
Thanks.
gcc/
* alias.c: Cleanup comments.
---
gcc/alias.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/gcc/alias.c b/gcc/alias.c
index 0c6a744..09aef11 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -60,14 +60,13 @@ along with GCC; see the file COPYING3. If not see
struct Z z2, *pz;
- py = &px1.y1;
+ py = &x1.y1;
px2 = &x1;
Consider the four questions:
Can a store to x1 interfere with px2->y1?
Can a store to x1 interfere with px2->z2?
- (*px2).z2
Can a store to x1 change the value pointed to by with py?
Can a store to x1 change the value pointed to by with pz?
@@ -78,24 +77,24 @@ along with GCC; see the file COPYING3. If not see
a store through a pointer to an X can overwrite any field that is
contained (recursively) in an X (unless we know that px1 != px2).
- The last two of the questions can be solved in the same way as the
- first two questions but this is too conservative. The observation
- is that in some cases analysis we can know if which (if any) fields
- are addressed and if those addresses are used in bad ways. This
- analysis may be language specific. In C, arbitrary operations may
- be applied to pointers. However, there is some indication that
- this may be too conservative for some C++ types.
+ The last two questions can be solved in the same way as the first
+ two questions but this is too conservative. The observation is
+ that in some cases we can know which (if any) fields are addressed
+ and if those addresses are used in bad ways. This analysis may be
+ language specific. In C, arbitrary operations may be applied to
+ pointers. However, there is some indication that this may be too
+ conservative for some C++ types.
The pass ipa-type-escape does this analysis for the types whose
instances do not escape across the compilation boundary.
Historically in GCC, these two problems were combined and a single
- data structure was used to represent the solution to these
+ data structure that was used to represent the solution to these
problems. We now have two similar but different data structures,
- The data structure to solve the last two question is similar to the
- first, but does not contain have the fields in it whose address are
- never taken. For types that do escape the compilation unit, the
- data structures will have identical information.
+ The data structure to solve the last two questions is similar to
+ the first, but does not contain the fields whose address are never
+ taken. For types that do escape the compilation unit, the data
+ structures will have identical information.
*/
/* The alias sets assigned to MEMs assist the back-end in determining
--
Dodji
