re PR middle-end/18859 (ACATS ICE c37305a at -O0: in tree_low_cst, at tree.c:3839)

	PR middle-end/18859
	* gimplify.c (gimplify_switch_expr): Discard empty ranges.
	* stmt.c (expand_case): Likewise.

From-SVN: r112000

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ab470b709cda03594b3092dffb3025907fdb1611..b7a2f5d09ff45978dcd4af14fdadd9285fbdc309 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2006-03-13  Eric Botcazou  <ebotcazou@adacore.com>
+
+       PR middle-end/18859
+       * gimplify.c (gimplify_switch_expr): Discard empty ranges.
+       * stmt.c (expand_case): Likewise.
+
 2006-03-13  Zdenek Dvorak <dvorakz@suse.cz>
 
        PR rtl-optimization/26254

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index c9498eef95afa4524d7abe4d9313e4b158c62a1e..506ad18968423e8962ad897637a3f19dd0f70639 100644 (file)
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1327,20 +1327,34 @@ gimplify_switch_expr (tree *expr_p, tree *pre_p)
       labels = gimplify_ctxp->case_labels;
       gimplify_ctxp->case_labels = saved_labels;
 
-      len = VEC_length (tree, labels);
-
-      for (i = 0; i < len; ++i)
+      i = 0;
+      while (i < VEC_length (tree, labels))
        {
-         tree t = VEC_index (tree, labels, i);
-         if (!CASE_LOW (t))
+         tree elt = VEC_index (tree, labels, i);
+         tree low = CASE_LOW (elt);
+         bool remove_element = FALSE;
+
+         if (low)
+           {
+             /* Discard empty ranges.  */
+             tree high = CASE_HIGH (elt);
+             if (high && INT_CST_LT (high, low))
+               remove_element = TRUE;
+           }
+         else
            {
              /* The default case must be the last label in the list.  */
-             default_case = t;
-             VEC_replace (tree, labels, i, VEC_index (tree, labels, len - 1));
-             len--;
-             break;
+             gcc_assert (!default_case);
+             default_case = elt;
+             remove_element = TRUE;
            }
+
+         if (remove_element)
+           VEC_ordered_remove (tree, labels, i);
+         else
+           i++;
        }
+      len = i;
 
       label_vec = make_tree_vec (len + 1);
       SWITCH_LABELS (*expr_p) = label_vec;

diff --git a/gcc/stmt.c b/gcc/stmt.c
index 38a7f909e1b282bf028b05f91836d49cde80175c..d199398e55f65c7bc86b271c28cd43bade1cdb22 100644 (file)
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -2286,7 +2286,7 @@ emit_case_bit_tests (tree index_type, tree index_expr, tree minval,
 #define HAVE_tablejump 0
 #endif
 
-/* Terminate a case (Pascal) or switch (C) statement
+/* Terminate a case (Pascal/Ada) or switch (C) statement
    in which ORIG_INDEX is the expression to be tested.
    If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
    type as given in the source before any compiler conversions.
@@ -2348,10 +2348,18 @@ expand_case (tree exp)
 
       for (i = TREE_VEC_LENGTH (vec) - 1; --i >= 0; )
        {
+         tree low, high;
          elt = TREE_VEC_ELT (vec, i);
-         gcc_assert (CASE_LOW (elt));
-         case_list = add_case_node (case_list, index_type,
-                                    CASE_LOW (elt), CASE_HIGH (elt),
+
+         low = CASE_LOW (elt);
+         gcc_assert (low);
+         high = CASE_HIGH (elt);
+
+         /* Discard empty ranges.  */
+         if (high && INT_CST_LT (high, low))
+           continue;
+
+         case_list = add_case_node (case_list, index_type, low, high,
                                     CASE_LABEL (elt));
        }
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 553dba47913424c03a6e59a96272c8b381e3563a..6ae2bca1e9082570669e32007c01f7e2292f8f7c 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2006-03-13  Eric Botcazou  <ebotcazou@adacore.com>
+
+       * gcc.dg/switch-9.c: New test.
+
 2006-03-13  Richard Guenther  <rguenther@suse.de>
 
        PR middle-end/26630

diff --git a/gcc/testsuite/gcc.dg/switch-9.c b/gcc/testsuite/gcc.dg/switch-9.c
new file mode 100644 (file)
index 0000000..2ae89d0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/switch-9.c
@@ -0,0 +1,25 @@
+/* PR middle-end/18859 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void foo(int a)
+{
+  switch (a)
+  {
+    case 0 ... -1:  /* { dg-warning "empty range" } */
+      a = a+2;
+      break;
+
+    case 1 ... 2:
+      a = 0;
+      break;
+
+    case 3 ... 4:
+      a = 1;
+      break;
+
+    case 5 ... 6:
+      a = 0;
+      break;
+  }
+}