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tree-vrp.c (extract_range_from_assert): Remove special handling for types with super-types.

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* tree-vrp.c (extract_range_from_assert): Remove special
	handling for types with super-types.

From-SVN: r111600
This commit is contained in:
Diego Novillo 2006-03-01 12:44:57 +00:00 committed by Diego Novillo
parent c1fa1ae9be
commit 6578c101b5
2 changed files with 5 additions and 60 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2006-03-01 Diego Novillo <dnovillo@redhat.com>
* tree-vrp.c (extract_range_from_assert): Remove special
handling for types with super-types.
2006-03-01 Ben Elliston <bje@au.ibm.com>
* config.gcc: Add t-dfprules to $tmake_file for powerpc-*-linux*

60
gcc/tree-vrp.c
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@ -826,66 +826,6 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
|| symbolic_range_p (limit_vr)))
limit_vr = NULL;
/* Special handling for integral types with super-types. Some FEs
construct integral types derived from other types and restrict
the range of values these new types may take.
It may happen that LIMIT is actually smaller than TYPE's minimum
value. For instance, the Ada FE is generating code like this
during bootstrap:
D.1480_32 = nam_30 - 300000361;
if (D.1480_32 <= 1) goto <L112>; else goto <L52>;
<L112>:;
D.1480_94 = ASSERT_EXPR <D.1480_32, D.1480_32 <= 1>;
All the names are of type types__name_id___XDLU_300000000__399999999
which has min == 300000000 and max == 399999999. This means that
the ASSERT_EXPR would try to create the range [3000000, 1] which
is invalid.
The fact that the type specifies MIN and MAX values does not
automatically mean that every variable of that type will always
be within that range, so the predicate may well be true at run
time. If we had symbolic -INF and +INF values, we could
represent this range, but we currently represent -INF and +INF
using the type's min and max values.
So, the only sensible thing we can do for now is set the
resulting range to VR_VARYING. TODO, would having symbolic -INF
and +INF values be worth the trouble? */
if (TREE_CODE (limit) != SSA_NAME
&& INTEGRAL_TYPE_P (type)
&& TREE_TYPE (type))
{
if (cond_code == LE_EXPR || cond_code == LT_EXPR)
{
tree type_min = TYPE_MIN_VALUE (type);
int cmp = compare_values (limit, type_min);
/* For < or <= comparisons, if LIMIT is smaller than
TYPE_MIN, set the range to VR_VARYING. */
if (cmp == -1 || cmp == 0)
{
set_value_range_to_varying (vr_p);
return;
}
}
else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
{
tree type_max = TYPE_MIN_VALUE (type);
int cmp = compare_values (limit, type_max);
/* For > or >= comparisons, if LIMIT is bigger than
TYPE_MAX, set the range to VR_VARYING. */
if (cmp == 1 || cmp == 0)
{
set_value_range_to_varying (vr_p);
return;
}
}
}
/* Initially, the new range has the same set of equivalences of
VAR's range. This will be revised before returning the final
value. Since assertions may be chained via mutually exclusive