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| author | Diego Novillo <dnovillo@redhat.com> | 2005-04-11 22:06:46 +0000 |
|---|---|---|
| committer | Diego Novillo <dnovillo@gcc.gnu.org> | 2005-04-11 18:06:46 -0400 |
| commit | f8d66d34f711e94a48b1eb28ab0fa25c6e1404c9 (patch) | |
| tree | ea3a6eedbf40f8febad0a55f21fd8d5f0af2123d /gcc/tree-ssa-alias.c | |
| parent | 9f32d037484306f1045b661d9bf29e893d846ede (diff) | |
| download | gcc-f8d66d34f711e94a48b1eb28ab0fa25c6e1404c9.zip gcc-f8d66d34f711e94a48b1eb28ab0fa25c6e1404c9.tar.gz gcc-f8d66d34f711e94a48b1eb28ab0fa25c6e1404c9.tar.bz2 | |
re PR middle-end/20933 (gcc can no longer bootstrap itself)
PR tree-optimization/20933
* tree-ssa-alias.c (compute_flow_insensitive_aliasing): Move
logic to reject aliases between read-only and writable
variables ...
(may_alias_p): ... here.
(get_tmt_for): Do not associate read-only tags to pointers
whose pointed-to type is not read-only.
* tree-ssa.c (verify_ssa): Check that memory stores have at
least one V_MAY_DEF or V_MUST_DEF.
testsuite/ChangeLog
PR tree-optimization/20933
* gcc.dg/tree-ssa/pr20933.c: New test.
From-SVN: r97988
Diffstat (limited to 'gcc/tree-ssa-alias.c')
| -rw-r--r-- | gcc/tree-ssa-alias.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 7d8e783..c0bce92 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -1001,10 +1001,6 @@ compute_flow_insensitive_aliasing (struct alias_info *ai) if (!tag_stored_p && !var_stored_p) continue; - if ((unmodifiable_var_p (tag) && !unmodifiable_var_p (var)) - || (unmodifiable_var_p (var) && !unmodifiable_var_p (tag))) - continue; - if (may_alias_p (p_map->var, p_map->set, var, v_map->set)) { subvar_t svars; @@ -1719,6 +1715,16 @@ may_alias_p (tree ptr, HOST_WIDE_INT mem_alias_set, return false; } + /* If either MEM or VAR is a read-only global and the other one + isn't, then PTR cannot point to VAR. */ + if ((unmodifiable_var_p (mem) && !unmodifiable_var_p (var)) + || (unmodifiable_var_p (var) && !unmodifiable_var_p (mem))) + { + alias_stats.alias_noalias++; + alias_stats.simple_resolved++; + return false; + } + m_ann = var_ann (mem); gcc_assert (m_ann->mem_tag_kind == TYPE_TAG); @@ -2319,9 +2325,11 @@ get_tmt_for (tree ptr, struct alias_info *ai) for (i = 0, tag = NULL_TREE; i < ai->num_pointers; i++) { struct alias_map_d *curr = ai->pointers[i]; - if (tag_set == curr->set) + tree curr_tag = var_ann (curr->var)->type_mem_tag; + if (tag_set == curr->set + && TYPE_READONLY (tag_type) == TYPE_READONLY (TREE_TYPE (curr_tag))) { - tag = var_ann (curr->var)->type_mem_tag; + tag = curr_tag; break; } } @@ -2356,6 +2364,10 @@ get_tmt_for (tree ptr, struct alias_info *ai) pointed-to type. */ gcc_assert (tag_set == get_alias_set (tag)); + /* If PTR's pointed-to type is read-only, then TAG's type must also + be read-only. */ + gcc_assert (TYPE_READONLY (tag_type) == TYPE_READONLY (TREE_TYPE (tag))); + return tag; } |