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Re: aliasing_component_refs_p tweek
>
> No need for the else {} and thus indenting the rest since the if ()
> arm always returns from the function.
>
> OK with eliding this else { } wrapping.
Ah, right, I changed the function bit too many times :)
Here is updated patch I re-tested and comitted.
* tree-ssa-alias.c (aliasing_component_refs_p): Continue looking
for comparaible types in the second direction even if first one
hits incomparable type.
Index: tree-ssa-alias.c
===================================================================
--- tree-ssa-alias.c (revision 270877)
+++ tree-ssa-alias.c (working copy)
@@ -795,7 +795,7 @@ aliasing_component_refs_p (tree ref1,
tree base1, base2;
tree type1, type2;
tree *refp;
- int same_p;
+ int same_p, same_p2;
/* Choose bases and base types to search for. */
base1 = ref1;
@@ -814,10 +814,7 @@ aliasing_component_refs_p (tree ref1,
&& same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0)
refp = &TREE_OPERAND (*refp, 0);
same_p = same_type_for_tbaa (TREE_TYPE (*refp), type1);
- /* If we couldn't compare types we have to bail out. */
- if (same_p == -1)
- return true;
- else if (same_p == 1)
+ if (same_p == 1)
{
poly_int64 offadj, sztmp, msztmp;
bool reverse;
@@ -827,26 +824,31 @@ aliasing_component_refs_p (tree ref1,
offset1 -= offadj;
return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2);
}
+
/* If we didn't find a common base, try the other way around. */
refp = &ref1;
while (handled_component_p (*refp)
&& same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0)
refp = &TREE_OPERAND (*refp, 0);
- same_p = same_type_for_tbaa (TREE_TYPE (*refp), type2);
- /* If we couldn't compare types we have to bail out. */
- if (same_p == -1)
- return true;
- else if (same_p == 1)
+ same_p2 = same_type_for_tbaa (TREE_TYPE (*refp), type2);
+ if (same_p2 == 1)
{
poly_int64 offadj, sztmp, msztmp;
bool reverse;
get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp, &reverse);
offset1 -= offadj;
get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp, &reverse);
offset2 -= offadj;
- return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2);
+ return ranges_maybe_overlap_p (offset1, max_size1,
+ offset2, max_size2);
}
+ /* In the remaining test we assume that there is no overlapping type
+ at all. So if we are unsure, we need to give up. */
+ if (same_p == -1 || same_p2 == -1)
+ return true;
+
/* If we have two type access paths B1.path1 and B2.path2 they may
only alias if either B1 is in B2.path2 or B2 is in B1.path1.
But we can still have a path that goes B1.path1...B2.path2 with