On 08/23/2018 05:59 AM, Richard Biener wrote:
On Wed, Aug 22, 2018 at 11:31 AM Aldy Hernandez <al...@redhat.com> wrote:
On 08/21/2018 05:46 AM, Richard Biener wrote:
On Wed, Aug 15, 2018 at 3:33 AM Aldy Hernandez <al...@redhat.com> wrote:
Finally, my apologies for including a tiny change to the
POINTER_PLUS_EXPR handling code as well. It came about the same set of
auditing tests.
Bah, please split up things here ;) I've done a related change there
yesterday...
It turns out we can handle POINTER_PLUS_EXPR(~[0,0], [X,Y]) without
bailing as VR_VARYING in extract_range_from_binary_expr_1. In doing so,
I also noticed that ~[0,0] is not the only non-null. We could also have
~[0,2] and still know that the pointer is not zero. I have adjusted
range_is_nonnull accordingly.
But there are other consumers and it would have been better to
change range_includes_zero_p to do the natural thing (get a VR) and
then remove range_is_nonnull as redundant if possible.
Indeed. Cleaning up range_includes_zero_p makes VRP and friends a lot
cleaner. Thanks for the suggestion.
I lazily avoided cleaning up the division code affected in this patch
too much, since it's going to be superseded by my division changes in
the other patch.
OK pending tests?
-/* Return 1 if [MIN, MAX] includes the value zero, 0 if it does not
- include the value zero, -2 if we cannot tell. */
+/* Return 1 if *VR includes the value zero, 0 if it does not include
+ the value zero, or -2 if we cannot tell. */
int
-range_includes_zero_p (tree min, tree max)
+range_includes_zero_p (const value_range *vr)
{
- tree zero = build_int_cst (TREE_TYPE (min), 0);
- return value_inside_range (zero, min, max);
+ if (vr->type == VR_UNDEFINED || vr->type == VR_VARYING)
+ return -2;
+
+ tree zero = build_int_cst (TREE_TYPE (vr->min), 0);
+ if (vr->type == VR_RANGE)
+ return value_inside_range (zero, vr->min, vr->max);
+ else
+ return !value_inside_range (zero, vr->min, vr->max);
}
please make it return a bool. VR_VARYING means the range does
include zero. For VR_UNDEFINED we could say it doesn't or we choose
to not possibly optimize and thus return true (just do that for now).
That's because VR_VARYING is [-INF, INF] and VR_UNDEFINED is
an empty range.
Done.
I suppose the -2 for we cannot tell was for the case of symbolic
ranges where again we can conservatively return true
(and your return !value_inside_range for VR_ANTI_RANGE botched
the tri-state return value anyways...).
Bah! I sure botched up the anti range return. That was the last
bootstrap failure I was investigating. You'd be amazed how many things
mysteriously fail when things like ~[SYMBOL, SYMBOL] are assumed to be
non-zero.
Thanks for spotting this. Bootstrap is happy now :-P.
So, can you please rework that?
Sure can!
Attached.
gcc/
* gimple-ssa-evrp-analyze.c (set_ssa_range_info): Pass value_range
to range_includes_zero_p. Do not special case VR_ANTI_RANGE.
* tree-vrp.c (range_is_nonnull): Remove.
(range_includes_zero_p): Accept value_range instead of min/max.
(extract_range_from_binary_expr_1): Do not early bail on
POINTER_PLUS_EXPR.
Use range_includes_zero_p instead of range_is_nonnull.
(extract_range_from_unary_expr): Use range_includes_zero_p instead
of range_is_nonnull.
(vrp_meet_1): Pass value_range to range_includes_zero_p. Do not
special case VR_ANTI_RANGE.
(vrp_finalize): Same.
* tree-vrp.h (range_includes_zero_p): Pass value_range as argument
instead of min/max.
(range_is_nonnull): Remove.
* vr-values.c (vrp_stmt_computes_nonzero): Use
range_includes_zero_p instead of range_is_nonnull.
(extract_range_basic): Pass value_range to range_includes_zero_p
instead of range_is_nonnull.
diff --git a/gcc/gimple-ssa-evrp-analyze.c b/gcc/gimple-ssa-evrp-analyze.c
index b9dcf906ff7..e9afa80e191 100644
--- a/gcc/gimple-ssa-evrp-analyze.c
+++ b/gcc/gimple-ssa-evrp-analyze.c
@@ -119,12 +119,7 @@ evrp_range_analyzer::set_ssa_range_info (tree lhs, value_range *vr)
wi::to_wide (vr->max));
}
else if (POINTER_TYPE_P (TREE_TYPE (lhs))
- && ((vr->type == VR_RANGE
- && range_includes_zero_p (vr->min,
- vr->max) == 0)
- || (vr->type == VR_ANTI_RANGE
- && range_includes_zero_p (vr->min,
- vr->max) == 1)))
+ && range_includes_zero_p (vr) == 0)
set_ptr_nonnull (lhs);
}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 735b3646e81..84da2635624 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -502,17 +502,6 @@ vrp_bitmap_equal_p (const_bitmap b1, const_bitmap b2)
&& bitmap_equal_p (b1, b2)));
}
-/* Return true if VR is ~[0, 0]. */
-
-bool
-range_is_nonnull (value_range *vr)
-{
- return vr->type == VR_ANTI_RANGE
- && integer_zerop (vr->min)
- && integer_zerop (vr->max);
-}
-
-
/* Return true if VR is [0, 0]. */
static inline bool
@@ -880,14 +869,25 @@ value_ranges_intersect_p (value_range *vr0, value_range *vr1)
}
-/* Return 1 if [MIN, MAX] includes the value zero, 0 if it does not
- include the value zero, -2 if we cannot tell. */
+/* Return TRUE if *VR includes the value zero. */
-int
-range_includes_zero_p (tree min, tree max)
+bool
+range_includes_zero_p (const value_range *vr)
{
- tree zero = build_int_cst (TREE_TYPE (min), 0);
- return value_inside_range (zero, min, max);
+ if (vr->type == VR_VARYING)
+ return true;
+
+ /* Ughh, we don't know. We choose not to optimize. */
+ if (vr->type == VR_UNDEFINED)
+ return true;
+
+ tree zero = build_int_cst (TREE_TYPE (vr->min), 0);
+ if (vr->type == VR_ANTI_RANGE)
+ {
+ int res = value_inside_range (zero, vr->min, vr->max);
+ return res == 0 || res == -2;
+ }
+ return value_inside_range (zero, vr->min, vr->max) != 0;
}
/* Return true if *VR is know to only contain nonnegative values. */
@@ -1407,7 +1407,10 @@ extract_range_from_binary_expr_1 (value_range *vr,
&& code != POINTER_PLUS_EXPR
&& (vr0.type == VR_VARYING
|| vr1.type == VR_VARYING
- || vr0.type != vr1.type
+ || (vr0.type != vr1.type
+ /* We can handle POINTER_PLUS_EXPR(~[0,0], [x,y]) below,
+ even though we have differing range kinds. */
+ && code != POINTER_PLUS_EXPR)
|| symbolic_range_p (&vr0)
|| symbolic_range_p (&vr1)))
{
@@ -1424,7 +1427,7 @@ extract_range_from_binary_expr_1 (value_range *vr,
nullness, if both are non null, then the result is nonnull.
If both are null, then the result is null. Otherwise they
are varying. */
- if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1))
+ if (!range_includes_zero_p (&vr0) && !range_includes_zero_p (&vr1))
set_value_range_to_nonnull (vr, expr_type);
else if (range_is_null (&vr0) && range_is_null (&vr1))
set_value_range_to_null (vr, expr_type);
@@ -1435,11 +1438,8 @@ extract_range_from_binary_expr_1 (value_range *vr,
{
/* For pointer types, we are really only interested in asserting
whether the expression evaluates to non-NULL. */
- if (range_is_nonnull (&vr0)
- || range_is_nonnull (&vr1)
- || (vr1.type == VR_RANGE
- && !symbolic_range_p (&vr1)
- && !range_includes_zero_p (vr1.min, vr1.max)))
+ if (!range_includes_zero_p (&vr0)
+ || !range_includes_zero_p (&vr1))
set_value_range_to_nonnull (vr, expr_type);
else if (range_is_null (&vr0) && range_is_null (&vr1))
set_value_range_to_null (vr, expr_type);
@@ -1450,7 +1450,7 @@ extract_range_from_binary_expr_1 (value_range *vr,
{
/* For pointer types, we are really only interested in asserting
whether the expression evaluates to non-NULL. */
- if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1))
+ if (!range_includes_zero_p (&vr0) && !range_includes_zero_p (&vr1))
set_value_range_to_nonnull (vr, expr_type);
else if (range_is_null (&vr0) || range_is_null (&vr1))
set_value_range_to_null (vr, expr_type);
@@ -1888,7 +1888,7 @@ extract_range_from_unary_expr (value_range *vr,
determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
if (POINTER_TYPE_P (type))
{
- if (range_is_nonnull (&vr0))
+ if (!range_includes_zero_p (&vr0))
set_value_range_to_nonnull (vr, type);
else if (range_is_null (&vr0))
set_value_range_to_null (vr, type);
@@ -6020,17 +6020,9 @@ vrp_meet_1 (value_range *vr0, const value_range *vr1)
{
/* Failed to find an efficient meet. Before giving up and setting
the result to VARYING, see if we can at least derive a useful
- anti-range. FIXME, all this nonsense about distinguishing
- anti-ranges from ranges is necessary because of the odd
- semantics of range_includes_zero_p and friends. */
- if (((saved.type == VR_RANGE
- && range_includes_zero_p (saved.min, saved.max) == 0)
- || (saved.type == VR_ANTI_RANGE
- && range_includes_zero_p (saved.min, saved.max) == 1))
- && ((vr1->type == VR_RANGE
- && range_includes_zero_p (vr1->min, vr1->max) == 0)
- || (vr1->type == VR_ANTI_RANGE
- && range_includes_zero_p (vr1->min, vr1->max) == 1)))
+ anti-range. */
+ if (range_includes_zero_p (&saved) == 0
+ && range_includes_zero_p (vr1) == 0)
{
set_value_range_to_nonnull (vr0, TREE_TYPE (saved.min));
@@ -6540,10 +6532,7 @@ vrp_prop::vrp_finalize (bool warn_array_bounds_p)
continue;
if (POINTER_TYPE_P (TREE_TYPE (name))
- && ((vr->type == VR_RANGE
- && range_includes_zero_p (vr->min, vr->max) == 0)
- || (vr->type == VR_ANTI_RANGE
- && range_includes_zero_p (vr->min, vr->max) == 1)))
+ && range_includes_zero_p (vr) == 0)
set_ptr_nonnull (name);
else if (!POINTER_TYPE_P (TREE_TYPE (name)))
set_range_info (name, vr->type,
diff --git a/gcc/tree-vrp.h b/gcc/tree-vrp.h
index 0c1fb3637cf..f8c1c0c8f72 100644
--- a/gcc/tree-vrp.h
+++ b/gcc/tree-vrp.h
@@ -86,7 +86,7 @@ extern void register_edge_assert_for (tree, edge, enum tree_code,
tree, tree, vec<assert_info> &);
extern bool stmt_interesting_for_vrp (gimple *);
extern void set_value_range_to_varying (value_range *);
-extern int range_includes_zero_p (tree, tree);
+extern bool range_includes_zero_p (const value_range *);
extern bool infer_value_range (gimple *, tree, tree_code *, tree *);
extern void set_value_range_to_nonnull (value_range *, tree);
@@ -96,7 +96,6 @@ extern void set_and_canonicalize_value_range (value_range *,
enum value_range_type,
tree, tree, bitmap);
extern bool vrp_bitmap_equal_p (const_bitmap, const_bitmap);
-extern bool range_is_nonnull (value_range *);
extern tree value_range_constant_singleton (value_range *);
extern bool symbolic_range_p (value_range *);
extern int compare_values (tree, tree);
diff --git a/gcc/vr-values.c b/gcc/vr-values.c
index 33335f3da31..072d9a7b454 100644
--- a/gcc/vr-values.c
+++ b/gcc/vr-values.c
@@ -343,7 +343,7 @@ vr_values::vrp_stmt_computes_nonzero (gimple *stmt)
&& TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
{
value_range *vr = get_value_range (TREE_OPERAND (base, 0));
- if (range_is_nonnull (vr))
+ if (!range_includes_zero_p (vr))
return true;
}
}
@@ -1107,12 +1107,8 @@ vr_values::extract_range_basic (value_range *vr, gimple *stmt)
if (TREE_CODE (arg) == SSA_NAME)
{
value_range *vr0 = get_value_range (arg);
- /* If arg is non-zero, then ffs or popcount
- are non-zero. */
- if ((vr0->type == VR_RANGE
- && range_includes_zero_p (vr0->min, vr0->max) == 0)
- || (vr0->type == VR_ANTI_RANGE
- && range_includes_zero_p (vr0->min, vr0->max) == 1))
+ /* If arg is non-zero, then ffs or popcount are non-zero. */
+ if (range_includes_zero_p (vr0) == 0)
mini = 1;
/* If some high bits are known to be zero,
we can decrease the maximum. */
