diff options
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/compile/pr18291.c | 12 | ||||
| -rw-r--r-- | gcc/tree-ssa-copy.c | 48 |
4 files changed, 60 insertions, 13 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7a2aa56a0e4..dd853a66212 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2004-12-01 Diego Novillo <dnovillo@redhat.com> + + PR tree-optimization/18291 + * tree-ssa-copy.c (merge_alias_info): Fix merging of + flow-sensitive alias information. If the new pointer has no + name tag, copy it from the original pointer. Otherwise, make + sure that the pointed-to sets have a common intersection. + 2004-12-01 Richard Henderson <rth@redhat.com> PR rtl-opt/15289 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 3e61438b4c5..ce903c62d2b 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2004-12-01 Diego Novillo <dnovillo@redhat.com> + + PR tree-optimization/18291 + * testsuite/gcc.c-torture/compile/pr18291.c: New test. + 2004-12-01 Nathan Sidwell <nathan@codesourcery.com> PR C++/18729 diff --git a/gcc/testsuite/gcc.c-torture/compile/pr18291.c b/gcc/testsuite/gcc.c-torture/compile/pr18291.c new file mode 100644 index 00000000000..7d983696f7d --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr18291.c @@ -0,0 +1,12 @@ +int baz(int k2) +{ + int i, j, *p, k = 1, k1 = 0; + if (k2) + p = &j; + else + p = &i; + if (k1) + *p = 0 , p = &k; + *p = 1; + return k; +} diff --git a/gcc/tree-ssa-copy.c b/gcc/tree-ssa-copy.c index ff497a8ae0a..8a03c2435d1 100644 --- a/gcc/tree-ssa-copy.c +++ b/gcc/tree-ssa-copy.c @@ -178,7 +178,6 @@ merge_alias_info (tree orig, tree new) tree orig_sym = SSA_NAME_VAR (orig); var_ann_t new_ann = var_ann (new_sym); var_ann_t orig_ann = var_ann (orig_sym); - struct ptr_info_def *new_ptr_info; struct ptr_info_def *orig_ptr_info; gcc_assert (POINTER_TYPE_P (TREE_TYPE (orig))); @@ -203,18 +202,41 @@ merge_alias_info (tree orig, tree new) else gcc_assert (new_ann->type_mem_tag == orig_ann->type_mem_tag); - /* Synchronize flow sensitive alias information. If both pointers - had flow information and they are inconsistent, then something - has gone wrong. */ - new_ptr_info = get_ptr_info (new); - orig_ptr_info = get_ptr_info (orig); - - if (new_ptr_info->name_mem_tag == NULL_TREE) - memcpy (new_ptr_info, orig_ptr_info, sizeof (*new_ptr_info)); - else if (orig_ptr_info->name_mem_tag == NULL_TREE) - memcpy (orig_ptr_info, new_ptr_info, sizeof (*orig_ptr_info)); - else if (orig_ptr_info->name_mem_tag != new_ptr_info->name_mem_tag) - abort (); + orig_ptr_info = SSA_NAME_PTR_INFO (orig); + if (orig_ptr_info && orig_ptr_info->name_mem_tag) + { + struct ptr_info_def *new_ptr_info = get_ptr_info (new); + + if (new_ptr_info->name_mem_tag == NULL_TREE) + { + /* If ORIG had a name tag, it means that was dereferenced in + the code, and since pointer NEW will now replace every + occurrence of ORIG, we have to make sure that NEW has an + appropriate tag. If, NEW did not have a name tag, get it + from ORIG. */ + memcpy (new_ptr_info, orig_ptr_info, sizeof (*new_ptr_info)); + new_ptr_info->pt_vars = BITMAP_GGC_ALLOC (); + bitmap_copy (new_ptr_info->pt_vars, orig_ptr_info->pt_vars); + new_ptr_info->name_mem_tag = orig_ptr_info->name_mem_tag; + } + else + { + /* If NEW already had a name tag, nothing needs to be done. + Note that pointer NEW may actually have a different set of + pointed-to variables. + + However, since NEW is being copy-propagated into ORIG, it must + always be true that the pointed-to set for pointer NEW is the + same, or a subset, of the pointed-to set for pointer ORIG. If + this isn't the case, we shouldn't have been able to do the + propagation of NEW into ORIG. */ +#if defined ENABLE_CHECKING + if (orig_ptr_info->pt_vars && new_ptr_info->pt_vars) + gcc_assert (bitmap_intersect_p (new_ptr_info->pt_vars, + orig_ptr_info->pt_vars)); +#endif + } + } } |