Include limits.h for LONG_{MAX,MIN}.

[libfirm] / ir / opt / opt_confirms.c

diff --git a/ir/opt/opt_confirms.c b/ir/opt/opt_confirms.c
index 861051e..28e0ef7 100644 (file)
--- a/ir/opt/opt_confirms.c
+++ b/ir/opt/opt_confirms.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -107,7 +107,15 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
        *confirm = NULL;
 
        /* there might be several Confirms one after other that form an interval */
-       for (; is_Confirm(n); n = get_Confirm_value(n)) {
+       for (;;) {
+               if (is_Minus(n) || is_Abs(n)) {
+                       /* we can safely skip Minus and Abs when checking for != 0 */
+                       n = get_unop_op(n);
+                       continue;
+               }
+               if (! is_Confirm(n))
+                       break;
+
                /*
                 * Note: A Confirm is never after a Const. So,
                 * we simply can check the bound for being a Const
@@ -143,6 +151,7 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
                default:
                        break;
                }
+               n = get_Confirm_value(n);
        }
        tv = value_of(n);
 
@@ -181,12 +190,17 @@ int value_not_null(ir_node *n, ir_node **confirm) {
                        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;
-       if (op == op_Const) {
-               if (!is_Const_null(n))
-                       return 1;
+       } else if (n == get_irg_frame(current_ir_graph)) {
+               /* local references are never NULL */
+               return 1;
+       } else if (op == op_Const) {
+               /* explicit non-NULL addresses */
+               return !is_Const_null(n);
        } else {
+               /* check for more Confirms */
                for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) {
                        if (get_Confirm_cmp(n) != pn_Cmp_Lg) {
                                ir_node *bound = get_Confirm_bound(n);
@@ -209,7 +223,23 @@ value_classify_sign classify_value_sign(ir_node *n) {
        tarval *tv, *c;
        ir_mode *mode;
        pn_Cmp cmp, ncmp;
+       int negate = 1;
+
+       for (;;) {
+               ir_opcode code = get_irn_opcode(n);
 
+               switch (code) {
+               case iro_Minus:
+                       negate *= -1;
+                       n = get_Minus_op(n);
+                       continue;
+               case iro_Confirm:
+                       break;
+               default:
+                       return value_classified_unknown;
+               }
+               break;
+       }
        if (get_irn_op(n) != op_Confirm)
                return value_classified_unknown;
 
@@ -252,7 +282,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
                        return value_classified_unknown;
 
                /* yep, negative */
-               return value_classified_negative;
+               return value_classified_negative * negate;
 
        case pn_Cmp_Ge:
                /*
@@ -283,7 +313,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
                }
 
                /* yep, positive */
-               return value_classified_positive;
+               return value_classified_positive * negate;
 
        default:
                return value_classified_unknown;
@@ -597,8 +627,9 @@ 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 */
@@ -731,6 +762,24 @@ 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);
+                       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)