PR tree-optimization/31034

	* tree-vrp.c (extract_range_from_assert): Don't try to handle a
	half-range if the other side is an overflow infinity.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@122562 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3c2a92e..a1a5e3c 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2007-03-05  Ian Lance Taylor  <iant@google.com>
+
+       PR tree-optimization/31034
+       * tree-vrp.c (extract_range_from_assert): Don't try to handle a
+       half-range if the other side is an overflow infinity.
+
 2007-03-05  Bernd Schmidt  <bernd.schmidt@analog.com>
 
        * config.gcc (bfin*-uclinux*): Use t-bfin-uclinux.

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index d3785a4..fd5ba64 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -1137,13 +1137,14 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
       /* If the maximum value forces us to be out of bounds, simply punt.
         It would be pointless to try and do anything more since this
         all should be optimized away above us.  */
-      if (cond_code == LT_EXPR && compare_values (max, min) == 0)
+      if ((cond_code == LT_EXPR
+          && compare_values (max, min) == 0)
+         || is_overflow_infinity (max))
        set_value_range_to_varying (vr_p);
       else
        {
          /* For LT_EXPR, we create the range [MIN, MAX - 1].  */
-         if (cond_code == LT_EXPR
-             && !is_positive_overflow_infinity (max))
+         if (cond_code == LT_EXPR)
            {
              tree one = build_int_cst (type, 1);
              max = fold_build2 (MINUS_EXPR, type, max, one);
@@ -1169,13 +1170,14 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
       /* If the minimum value forces us to be out of bounds, simply punt.
         It would be pointless to try and do anything more since this
         all should be optimized away above us.  */
-      if (cond_code == GT_EXPR && compare_values (min, max) == 0)
+      if ((cond_code == GT_EXPR
+          && compare_values (min, max) == 0)
+         || is_overflow_infinity (min))
        set_value_range_to_varying (vr_p);
       else
        {
          /* For GT_EXPR, we create the range [MIN + 1, MAX].  */
-         if (cond_code == GT_EXPR
-             && !is_negative_overflow_infinity (min))
+         if (cond_code == GT_EXPR)
            {
              tree one = build_int_cst (type, 1);
              min = fold_build2 (PLUS_EXPR, type, min, one);