+2004-10-12 Fariborz Jahanian <fjahanian@apple.com>
+
+ PR 17892
+ * tree-ssa-dom.c (unsafe_associative_fp_binop): New function.
+ (simplify_rhs_and_lookup_avail_expr): Disallow associativity
+ and constant folding of floating point MULT_EXPR/PLUS_EXPR
+ expressions.
+
2004-10-12 Ulrich Weigand <uweigand@de.ibm.com>
* config/s390/s390.c (s390_va_start): Use build_va_arg_indirect_ref.
var_map map = tab->map;
value_expr_p p;
ssa_op_iter iter;
+ bitmap_iterator bi;
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
stmt = bsi_stmt (bsi);
ann = stmt_ann (stmt);
+ if (TREE_CODE (stmt) == ASM_EXPR && ASM_VOLATILE_P (stmt))
+ {
+ /* Volatile ASM_EXPRs kill all current expressions. */
+ EXECUTE_IF_SET_IN_BITMAP ((tab->partition_in_use), 0, partition, bi)
+ kill_expr (tab, partition, false);
+ continue;
+ }
/* Determine if this stmt finishes an existing expression. */
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_USE)
{
static void register_definitions_for_stmt (tree);
static edge single_incoming_edge_ignoring_loop_edges (basic_block);
static void restore_nonzero_vars_to_original_value (void);
+static inline bool unsafe_associative_fp_binop (tree);
/* Local version of fold that doesn't introduce cruft. */
record_const_or_copy_1 (x, y, prev_x);
}
+/* Return true, if it is ok to do folding of an associative expression.
+ EXP is the tree for the associative expression. */
+
+static inline bool
+unsafe_associative_fp_binop (tree exp)
+{
+ enum tree_code code = TREE_CODE (exp);
+ return !(!flag_unsafe_math_optimizations
+ && (code == MULT_EXPR || code == PLUS_EXPR)
+ && FLOAT_TYPE_P (TREE_TYPE (exp)));
+}
+
/* STMT is a MODIFY_EXPR for which we were unable to find RHS in the
hash tables. Try to simplify the RHS using whatever equivalences
we may have recorded.
tree rhs_def_rhs = TREE_OPERAND (rhs_def_stmt, 1);
enum tree_code rhs_def_code = TREE_CODE (rhs_def_rhs);
- if (rhs_code == rhs_def_code
+ if ((rhs_code == rhs_def_code && unsafe_associative_fp_binop (rhs))
|| (rhs_code == PLUS_EXPR && rhs_def_code == MINUS_EXPR)
|| (rhs_code == MINUS_EXPR && rhs_def_code == PLUS_EXPR))
{