diff options
Diffstat (limited to 'gcc/alias.c')
| -rw-r--r-- | gcc/alias.c | 45 |
1 files changed, 30 insertions, 15 deletions
diff --git a/gcc/alias.c b/gcc/alias.c index bf7c5e33e4f..37a8790c2ee 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -470,16 +470,32 @@ get_alias_set (t) return 0; /* We can be passed either an expression or a type. This and the - language-specific routine may make mutually-recursive calls to - each other to figure out what to do. At each juncture, we see if - this is a tree that the language may need to handle specially. - First handle things that aren't types and start by removing nops - since we care only about the actual object. */ + language-specific routine may make mutually-recursive calls to each other + to figure out what to do. At each juncture, we see if this is a tree + that the language may need to handle specially. First handle things that + aren't types and start by removing nops since we care only about the + actual object. Also replace PLACEHOLDER_EXPRs and pick up the outermost + object that we could have a pointer to. */ if (! TYPE_P (t)) { - while (TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR - || TREE_CODE (t) == NON_LVALUE_EXPR) - t = TREE_OPERAND (t, 0); + /* Remove any NOPs and see what any PLACEHOLD_EXPRs will expand to. */ + while (((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR) + && (TYPE_MODE (TREE_TYPE (t)) + == TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 0))))) + || TREE_CODE (t) == NON_LVALUE_EXPR + || TREE_CODE (t) == PLACEHOLDER_EXPR + || (handled_component_p (t) && ! can_address_p (t))) + { + /* Give the language a chance to do something with this tree + before we go inside it. */ + if ((set = lang_get_alias_set (t)) != -1) + return set; + + if (TREE_CODE (t) == PLACEHOLDER_EXPR) + t = find_placeholder (t, 0); + else + t = TREE_OPERAND (t, 0); + } /* Now give the language a chance to do something but record what we gave it this time. */ @@ -487,15 +503,9 @@ get_alias_set (t) if ((set = lang_get_alias_set (t)) != -1) return set; - /* Now loop the same way as get_inner_reference and get the alias - set to use. Pick up the outermost object that we could have - a pointer to. */ - while (handled_component_p (t) && ! can_address_p (t)) - t = TREE_OPERAND (t, 0); - + /* Check for accesses through restrict-qualified pointers. */ if (TREE_CODE (t) == INDIRECT_REF) { - /* Check for accesses through restrict-qualified pointers. */ tree decl = find_base_decl (TREE_OPERAND (t, 0)); if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl)) @@ -587,6 +597,11 @@ record_alias_subset (superset, subset) alias_set_entry superset_entry; alias_set_entry subset_entry; + /* It is possible in complex type situations for both sets to be the same, + in which case we can ignore this operation. */ + if (superset == subset) + return; + if (superset == 0) abort (); |