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re PR tree-optimization/24670 (VRP ICE in compare_name_with_value)

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PR 24670
	* tree-vrp.c (fix_equivalence_set): New.
	(extract_range_from_assert): Call it.


testsuite/

	PR 24670
	* gcc.dg/tree-ssa/pr24670.c: New test.

From-SVN: r106562
This commit is contained in:
Diego Novillo 2005-11-06 14:51:16 +00:00 committed by Diego Novillo
parent 3a4983938c
commit db3d5328dd
4 changed files with 120 additions and 2 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2005-11-06 Diego Novillo <dnovillo@redhat.com>
PR 24670
* tree-vrp.c (fix_equivalence_set): New.
(extract_range_from_assert): Call it.
2005-11-05 Ian Lance Taylor <ian@airs.com>
PR target/22432

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2005-11-06 Diego Novillo <dnovillo@redhat.com>
PR 24670
* gcc.dg/tree-ssa/pr24670.c: New test.
2005-11-05 Ian Lance Taylor <ian@airs.com>
PR target/22432

23
gcc/testsuite/gcc.dg/tree-ssa/pr24670.c Normal file
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@ -0,0 +1,23 @@
/* { dg-do compile } */
/* { dg-options "-O2" } */
__inline__ void
shift128Right (int count, long long int *z1Ptr)
{
long long int z1;
if (count == 0);
else if (count < 64);
else
z1 = (count < 64) ? count : 0;
*z1Ptr = z1;
}
float128_rem ()
{
signed int expDiff;
long long int aSig1;
long long int sigMean1;
if (-64 < expDiff)
shift128Right (-expDiff, &aSig1);
add128 (&sigMean1);
}

88
gcc/tree-vrp.c
View File

@ -632,6 +632,81 @@ range_includes_zero_p (value_range_t *vr)
}
/* When extracting ranges from X_i = ASSERT_EXPR <Y_j, pred>, we will
initially consider X_i and Y_j equivalent, so the equivalence set
of Y_j is added to the equivalence set of X_i. However, it is
possible to have a chain of ASSERT_EXPRs whose predicates are
actually incompatible. This is usually the result of nesting of
contradictory if-then-else statements. For instance, in PR 24670:
count_4 has range [-INF, 63]
if (count_4 != 0)
{
count_19 = ASSERT_EXPR <count_4, count_4 != 0>
if (count_19 > 63)
{
count_18 = ASSERT_EXPR <count_19, count_19 > 63>
if (count_18 <= 63)
...
}
}
Notice that 'if (count_19 > 63)' is trivially false and will be
folded out at the end. However, during propagation, the flowgraph
is not cleaned up and so, VRP will evaluate predicates more
predicates than necessary, so it must support these
inconsistencies. The problem here is that because of the chaining
of ASSERT_EXPRs, the equivalency set for count_18 includes count_4.
Since count_4 has an incompatible range, we ICE when evaluating the
ranges in the equivalency set. So, we need to remove count_4 from
it. */
static void
fix_equivalence_set (value_range_t *vr_p)
{
bitmap_iterator bi;
unsigned i;
bitmap e = vr_p->equiv;
bitmap to_remove = BITMAP_ALLOC (NULL);
/* Only detect inconsistencies on numeric ranges. */
if (vr_p->type == VR_VARYING
|| vr_p->type == VR_UNDEFINED
|| symbolic_range_p (vr_p))
return;
EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
{
value_range_t *equiv_vr = vr_value[i];
if (equiv_vr->type == VR_VARYING
|| equiv_vr->type == VR_UNDEFINED
|| symbolic_range_p (equiv_vr))
continue;
if (equiv_vr->type == VR_RANGE
&& vr_p->type == VR_RANGE
&& !value_ranges_intersect_p (vr_p, equiv_vr))
bitmap_set_bit (to_remove, i);
else if ((equiv_vr->type == VR_RANGE && vr_p->type == VR_ANTI_RANGE)
|| (equiv_vr->type == VR_ANTI_RANGE && vr_p->type == VR_RANGE))
{
/* A range and an anti-range have an empty intersection if
their end points are the same. FIXME,
value_ranges_intersect_p should handle this
automatically. */
if (compare_values (equiv_vr->min, vr_p->min) == 0
&& compare_values (equiv_vr->max, vr_p->max) == 0)
bitmap_set_bit (to_remove, i);
}
}
bitmap_and_compl_into (vr_p->equiv, to_remove);
BITMAP_FREE (to_remove);
}
/* Extract value range information from an ASSERT_EXPR EXPR and store
it in *VR_P. */
@ -747,7 +822,11 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
}
}
/* The new range has the same set of equivalences of VAR's range. */
/* 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
predicates, we will need to trim the set of equivalences before
we are done. */
gcc_assert (vr_p->equiv == NULL);
vr_p->equiv = BITMAP_ALLOC (NULL);
add_equivalence (vr_p->equiv, var);
@ -924,7 +1003,7 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
|| var_vr->type == VR_UNDEFINED
|| symbolic_range_p (vr_p)
|| symbolic_range_p (var_vr))
return;
goto done;
if (var_vr->type == VR_RANGE && vr_p->type == VR_RANGE)
{
@ -968,6 +1047,11 @@ extract_range_from_assert (value_range_t *vr_p, tree expr)
&& compare_values (var_vr->max, vr_p->max) == 0)
set_value_range_to_varying (vr_p);
}
/* Remove names from the equivalence set that have ranges
incompatible with VR_P. */
done:
fix_equivalence_set (vr_p);
}