File pr34043-1.diff of Package gcc43
2008-02-29 Richard Guenther <rguenther@suse.de>
* tree-ssa-pre.c (get_sccvn_value): Create missing VNs via
vn_lookup_or_add.
* tree-ssa-sccnv.c (visit_reference_op_store): Use the rhs
value for comparing for a store match.
(simplify_unary_expression): Do nothing for SSA_NAMEs.
(try_to_simplify): Do not do a full-blown reference lookup.
Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c (revision 132767)
+++ gcc/tree-ssa-sccvn.c (revision 132768)
@@ -1231,6 +1231,8 @@ visit_reference_op_store (tree lhs, tree
{
if (TREE_CODE (result) == SSA_NAME)
result = SSA_VAL (result);
+ if (TREE_CODE (op) == SSA_NAME)
+ op = SSA_VAL (op);
resultsame = expressions_equal_p (result, op);
}
@@ -1527,13 +1529,10 @@ simplify_unary_expression (tree rhs)
static tree
try_to_simplify (tree stmt, tree rhs)
{
+ /* For stores we can end up simplifying a SSA_NAME rhs. Just return
+ in this case, there is no point in doing extra work. */
if (TREE_CODE (rhs) == SSA_NAME)
- {
- if (is_gimple_min_invariant (SSA_VAL (rhs)))
- return SSA_VAL (rhs);
- else if (VN_INFO (rhs)->has_constants)
- return VN_INFO (rhs)->expr;
- }
+ return rhs;
else
{
switch (TREE_CODE_CLASS (TREE_CODE (rhs)))
@@ -1550,13 +1549,11 @@ try_to_simplify (tree stmt, tree rhs)
/* Fallthrough. */
case tcc_reference:
- {
- tree result = vn_reference_lookup (rhs,
- shared_vuses_from_stmt (stmt));
- if (result)
- return result;
- }
- /* Fallthrough for some codes. */
+ /* Do not do full-blown reference lookup here.
+ ??? But like for tcc_declaration, we should simplify
+ from constant initializers. */
+
+ /* Fallthrough for some codes that can operate on registers. */
if (!(TREE_CODE (rhs) == REALPART_EXPR
|| TREE_CODE (rhs) == IMAGPART_EXPR))
break;
Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c (revision 132767)
+++ gcc/tree-ssa-pre.c (revision 132768)
@@ -3256,7 +3256,9 @@ get_sccvn_value (tree name)
!ZERO_SSA_OPERANDS (defstmt2, SSA_OP_ALL_VIRTUALS))
gcc_assert (defstmt);
}
- valvh = vn_lookup_or_add_with_stmt (val, defstmt);
+ /* We lookup with the LHS, so do not use vn_lookup_or_add_with_stmt
+ here, as that will result in useless reference lookups. */
+ valvh = vn_lookup_or_add (val);
}
if (dump_file && (dump_flags & TDF_DETAILS))