- fixed some typos

[libfirm] / ir / opt / opt_confirms.c

diff --git a/ir/opt/opt_confirms.c b/ir/opt/opt_confirms.c
index 0e6ca9a..0908cb6 100644 (file)
--- a/ir/opt/opt_confirms.c
+++ b/ir/opt/opt_confirms.c
@@ -97,7 +97,7 @@ static tarval *compare_iv_dbg(const interval_t *l_iv, const interval_t *r_iv, pn
  * This is a often needed case, so we handle here Confirm
  * nodes too.
  */
-int value_not_zero(ir_node *n, ir_node **confirm) {
+int value_not_zero(const ir_node *n, ir_node_cnst_ptr *confirm) {
 #define RET_ON(x)  if (x) { *confirm = n; return 1; }; break
 
        tarval *tv;
@@ -175,31 +175,37 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
  * - A SymConst(entity) is NEVER a NULL pointer
  * - Confirms are evaluated
  */
-int value_not_null(ir_node *n, ir_node **confirm) {
-       ir_op *op;
+int value_not_null(const ir_node *n, ir_node_cnst_ptr *confirm) {
+       tarval *tv;
 
        *confirm = NULL;
-       n  = skip_Cast(n);
+       n  = skip_Cast_const(n);
+
+       tv = value_of(n);
+       if (tarval_is_constant(tv) && ! tarval_is_null(tv))
+               return 1;
 
-       op = get_irn_op(n);
        assert(mode_is_reference(get_irn_mode(n)));
        if (get_opt_sel_based_null_check_elim()) {
                /* skip all Sel nodes and Cast's */
-               while (op == op_Sel) {
+               while (is_Sel(n)) {
                        n = skip_Cast(get_Sel_ptr(n));
-                       op = get_irn_op(n);
                }
        }
-       if (op == op_SymConst && get_SymConst_kind(n) == symconst_addr_ent)
+       if (is_Global(n)) {
+               /* global references are never NULL */
+               return 1;
+       } else if (n == get_irg_frame(current_ir_graph)) {
+               /* local references are never NULL */
                return 1;
-       if (op == op_Const) {
-               if (!is_Const_null(n))
-                       return 1;
        } else {
+               /* check for more Confirms */
                for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) {
-                       if (get_Confirm_cmp(n) != pn_Cmp_Lg) {
+                       if (get_Confirm_cmp(n) == pn_Cmp_Lg) {
                                ir_node *bound = get_Confirm_bound(n);
-                               if (is_Const(bound) && is_Const_null(bound)) {
+                               tarval  *tv    = value_of(bound);
+
+                               if (tarval_is_null(tv)) {
                                        *confirm = n;
                                        return 1;
                                }
@@ -235,7 +241,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
                }
                break;
        }
-       if (get_irn_op(n) != op_Confirm)
+       if (!is_Confirm(n))
                return value_classified_unknown;
 
        tv  = value_of(get_Confirm_bound(n));
@@ -622,8 +628,9 @@ tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right,
 
                pnc = get_inversed_pnc(pnc);
        } else if (! is_Confirm(left)) {
-               /* no Confirm on either one side, finish */
-               return tarval_bad;
+               /* nothing more found */
+               tv = tarval_bad;
+               goto check_null_case;
        }
 
        /* ok, here at least left is a Confirm, right might be */
@@ -756,6 +763,24 @@ tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right,
                        get_interval(&l_iv, l_bound, l_pnc),
                        get_interval_from_tv(&r_iv, tv),
                        pnc);
+       } else {
+check_null_case:
+               /* check some other cases */
+               if ((pnc == pn_Cmp_Eq || pnc == pn_Cmp_Lg) &&
+                       is_Const(right) && is_Const_null(right)) {
+                       /* for == 0 or != 0 we have some special tools */
+                       ir_mode       *mode = get_irn_mode(left);
+                       const ir_node *dummy;
+                       if (mode_is_reference(mode)) {
+                               if (value_not_null(left, &dummy)) {
+                                       tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true;
+                               }
+                       } else {
+                               if (value_not_zero(left, &dummy)) {
+                                       tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true;
+                               }
+                       }
+               }
        }
 
        if (tv != tarval_bad)