* c-common.h: Remove the prototype for yyparse.

[pf3gnuchains/gcc-fork.git] / gcc / tree-vrp.c

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 1734d44..3ac01fb 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -939,14 +939,22 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
          max = limit_vr->max;
        }
 
-      /* For LT_EXPR, we create the range [MIN, MAX - 1].  */
-      if (cond_code == LT_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)
+       set_value_range_to_varying (vr_p);
+      else
        {
-         tree one = build_int_cst (type, 1);
-         max = fold_build2 (MINUS_EXPR, type, max, one);
-       }
+         /* For LT_EXPR, we create the range [MIN, MAX - 1].  */
+         if (cond_code == LT_EXPR)
+           {
+             tree one = build_int_cst (type, 1);
+             max = fold_build2 (MINUS_EXPR, type, max, one);
+           }
 
-      set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
+         set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
+       }
     }
   else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
     {
@@ -962,14 +970,22 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
          min = limit_vr->min;
        }
 
-      /* For GT_EXPR, we create the range [MIN + 1, MAX].  */
-      if (cond_code == GT_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)
+       set_value_range_to_varying (vr_p);
+      else
        {
-         tree one = build_int_cst (type, 1);
-         min = fold_build2 (PLUS_EXPR, type, min, one);
-       }
+         /* For GT_EXPR, we create the range [MIN + 1, MAX].  */
+         if (cond_code == GT_EXPR)
+           {
+             tree one = build_int_cst (type, 1);
+             min = fold_build2 (PLUS_EXPR, type, min, one);
+           }
 
-      set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
+         set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
+       }
     }
   else
     gcc_unreachable ();
@@ -1975,7 +1991,7 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop, tree stmt,
                        tree var)
 {
   tree init, step, chrec;
-  bool init_is_max, unknown_max;
+  enum ev_direction dir;
 
   /* TODO.  Don't adjust anti-ranges.  An anti-range may provide
      better opportunities than a regular range, but I'm not sure.  */
@@ -1998,11 +2014,14 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop, tree stmt,
       || !valid_value_p (init))
     return;
 
-  /* Do not adjust ranges when chrec may wrap.  */
-  if (scev_probably_wraps_p (chrec_type (chrec), init, step, stmt,
-                            current_loops->parray[CHREC_VARIABLE (chrec)],
-                            &init_is_max, &unknown_max)
-      || unknown_max)
+  dir = scev_direction (chrec);
+  if (/* Do not adjust ranges if we do not know whether the iv increases
+        or decreases,  ... */
+      dir == EV_DIR_UNKNOWN
+      /* ... or if it may wrap.  */
+      || scev_probably_wraps_p (init, step, stmt,
+                               current_loops->parray[CHREC_VARIABLE (chrec)],
+                               true))
     return;
 
   if (!POINTER_TYPE_P (TREE_TYPE (init))
@@ -2013,7 +2032,7 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop, tree stmt,
       tree min = TYPE_MIN_VALUE (TREE_TYPE (init));
       tree max = TYPE_MAX_VALUE (TREE_TYPE (init));
 
-      if (init_is_max)
+      if (dir == EV_DIR_DECREASES)
        max = init;
       else
        min = init;
@@ -2031,7 +2050,7 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop, tree stmt,
       tree min = vr->min;
       tree max = vr->max;
 
-      if (init_is_max)
+      if (dir == EV_DIR_DECREASES)
        {
          /* INIT is the maximum value.  If INIT is lower than VR->MAX
             but no smaller than VR->MIN, set VR->MAX to INIT.  */