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Commit 933a2c39 by Marc Glisse Committed by Marc Glisse
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re PR tree-optimization/30318 (VRP does not create ANTI_RANGEs on overflow) 

2012-07-25 Marc Glisse <marc.glisse@inria.fr>

	PR tree-optimization/30318
	* tree-vrp.c (extract_range_from_binary_expr_1) [PLUS_EXPR]:
	Handle __int128.
	[MINUS_EXPR]: Merge with PLUS_EXPR.

From-SVN: r189861
parent d45eae79
Showing with 78 additions and 54 deletions
gcc/ChangeLog
2012-07-25 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/30318
* tree-vrp.c (extract_range_from_binary_expr_1) [PLUS_EXPR]:
Handle __int128.
[MINUS_EXPR]: Merge with PLUS_EXPR.
2012-07-25 Sandra Loosemore <sandra@codesourcery.com>
Paul Brook <paul@codesourcery.com>
......
gcc/tree-vrp.c
......@@ -2352,15 +2352,14 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
/* For integer ranges, apply the operation to each end of the
range and see what we end up with. */
if (code == PLUS_EXPR)
if (code == PLUS_EXPR || code == MINUS_EXPR)
{
/* If we have a PLUS_EXPR with two VR_RANGE integer constant
ranges compute the precise range for such case if possible. */
if (range_int_cst_p (&vr0)
&& range_int_cst_p (&vr1)
/* We attempt to do infinite precision signed integer arithmetic,
thus we need two more bits than the possibly unsigned inputs. */
&& TYPE_PRECISION (expr_type) < HOST_BITS_PER_DOUBLE_INT - 1)
/* We need as many bits as the possibly unsigned inputs. */
&& TYPE_PRECISION (expr_type) <= HOST_BITS_PER_DOUBLE_INT)
{
double_int min0 = tree_to_double_int (vr0.min);
double_int max0 = tree_to_double_int (vr0.max);
......@@ -2372,9 +2371,60 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
double_int type_max
= double_int_max_value (TYPE_PRECISION (expr_type), uns);
double_int dmin, dmax;
int min_ovf = 0;
int max_ovf = 0;
dmin = double_int_add (min0, min1);
dmax = double_int_add (max0, max1);
if (code == PLUS_EXPR)
{
dmin = double_int_add (min0, min1);
dmax = double_int_add (max0, max1);
/* Check for overflow in double_int. */
if (double_int_cmp (min1, double_int_zero, uns)
!= double_int_cmp (dmin, min0, uns))
min_ovf = double_int_cmp (min0, dmin, uns);
if (double_int_cmp (max1, double_int_zero, uns)
!= double_int_cmp (dmax, max0, uns))
max_ovf = double_int_cmp (max0, dmax, uns);
}
else /* if (code == MINUS_EXPR) */
{
dmin = double_int_sub (min0, max1);
dmax = double_int_sub (max0, min1);
if (double_int_cmp (double_int_zero, max1, uns)
!= double_int_cmp (dmin, min0, uns))
min_ovf = double_int_cmp (min0, max1, uns);
if (double_int_cmp (double_int_zero, min1, uns)
!= double_int_cmp (dmax, max0, uns))
max_ovf = double_int_cmp (max0, min1, uns);
}
/* For non-wrapping arithmetic look at possibly smaller
value-ranges of the type. */
if (!TYPE_OVERFLOW_WRAPS (expr_type))
{
if (vrp_val_min (expr_type))
type_min = tree_to_double_int (vrp_val_min (expr_type));
if (vrp_val_max (expr_type))
type_max = tree_to_double_int (vrp_val_max (expr_type));
}
/* Check for type overflow. */
if (min_ovf == 0)
{
if (double_int_cmp (dmin, type_min, uns) == -1)
min_ovf = -1;
else if (double_int_cmp (dmin, type_max, uns) == 1)
min_ovf = 1;
}
if (max_ovf == 0)
{
if (double_int_cmp (dmax, type_min, uns) == -1)
max_ovf = -1;
else if (double_int_cmp (dmax, type_max, uns) == 1)
max_ovf = 1;
}
if (TYPE_OVERFLOW_WRAPS (expr_type))
{
......@@ -2384,21 +2434,15 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
= double_int_ext (dmin, TYPE_PRECISION (expr_type), uns);
double_int tmax
= double_int_ext (dmax, TYPE_PRECISION (expr_type), uns);
gcc_assert (double_int_scmp (dmin, dmax) <= 0);
if ((double_int_scmp (dmin, type_min) == -1
&& double_int_scmp (dmax, type_min) == -1)
|| (double_int_scmp (dmin, type_max) == 1
&& double_int_scmp (dmax, type_max) == 1)
|| (double_int_scmp (type_min, dmin) <= 0
&& double_int_scmp (dmax, type_max) <= 0))
if (min_ovf == max_ovf)
{
/* No overflow or both overflow or underflow. The
range kind stays VR_RANGE. */
min = double_int_to_tree (expr_type, tmin);
max = double_int_to_tree (expr_type, tmax);
}
else if (double_int_scmp (dmin, type_min) == -1
&& double_int_scmp (dmax, type_max) == 1)
else if (min_ovf == -1
&& max_ovf == 1)
{
/* Underflow and overflow, drop to VR_VARYING. */
set_value_range_to_varying (vr);
......@@ -2409,12 +2453,8 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
/* Min underflow or max overflow. The range kind
changes to VR_ANTI_RANGE. */
double_int tem = tmin;
gcc_assert ((double_int_scmp (dmin, type_min) == -1
&& double_int_scmp (dmax, type_min) >= 0
&& double_int_scmp (dmax, type_max) <= 0)
|| (double_int_scmp (dmax, type_max) == 1
&& double_int_scmp (dmin, type_min) >= 0
&& double_int_scmp (dmin, type_max) <= 0));
gcc_assert ((min_ovf == -1 && max_ovf == 0)
|| (max_ovf == 1 && min_ovf == 0));
type = VR_ANTI_RANGE;
tmin = double_int_add (tmax, double_int_one);
tmax = double_int_add (tem, double_int_minus_one);
......@@ -2434,16 +2474,9 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
}
else
{
/* For non-wrapping arithmetic look at possibly smaller
value-ranges of the type. */
if (vrp_val_min (expr_type))
type_min = tree_to_double_int (vrp_val_min (expr_type));
if (vrp_val_max (expr_type))
type_max = tree_to_double_int (vrp_val_max (expr_type));
/* If overflow does not wrap, saturate to the types min/max
value. */
if (double_int_scmp (dmin, type_min) == -1)
if (min_ovf == -1)
{
if (needs_overflow_infinity (expr_type)
&& supports_overflow_infinity (expr_type))
......@@ -2451,7 +2484,7 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
else
min = double_int_to_tree (expr_type, type_min);
}
else if (double_int_scmp (dmin, type_max) == 1)
else if (min_ovf == 1)
{
if (needs_overflow_infinity (expr_type)
&& supports_overflow_infinity (expr_type))
......@@ -2462,7 +2495,7 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
else
min = double_int_to_tree (expr_type, dmin);
if (double_int_scmp (dmax, type_min) == -1)
if (max_ovf == -1)
{
if (needs_overflow_infinity (expr_type)
&& supports_overflow_infinity (expr_type))
......@@ -2470,7 +2503,7 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
else
max = double_int_to_tree (expr_type, type_min);
}
else if (double_int_scmp (dmax, type_max) == 1)
else if (max_ovf == 1)
{
if (needs_overflow_infinity (expr_type)
&& supports_overflow_infinity (expr_type))
......@@ -2485,10 +2518,14 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
&& supports_overflow_infinity (expr_type))
{
if (is_negative_overflow_infinity (vr0.min)
|| is_negative_overflow_infinity (vr1.min))
|| (code == PLUS_EXPR
? is_negative_overflow_infinity (vr1.min)
: is_positive_overflow_infinity (vr1.max)))
min = negative_overflow_infinity (expr_type);
if (is_positive_overflow_infinity (vr0.max)
|| is_positive_overflow_infinity (vr1.max))
|| (code == PLUS_EXPR
? is_positive_overflow_infinity (vr1.max)
: is_negative_overflow_infinity (vr1.min)))
max = positive_overflow_infinity (expr_type);
}
}
......@@ -2717,26 +2754,6 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
else
min = fold_unary_to_constant (NEGATE_EXPR, expr_type, max);
}
else if (code == MINUS_EXPR)
{
/* If we have a MINUS_EXPR with two VR_ANTI_RANGEs, drop to
VR_VARYING. It would take more effort to compute a precise
range for such a case. For example, if we have op0 == 1 and
op1 == 1 with their ranges both being ~[0,0], we would have
op0 - op1 == 0, so we cannot claim that the difference is in
~[0,0]. Note that we are guaranteed to have
vr0.type == vr1.type at this point. */
if (vr0.type == VR_ANTI_RANGE)
{
set_value_range_to_varying (vr);
return;
}
/* For MINUS_EXPR, apply the operation to the opposite ends of
each range. */
min = vrp_int_const_binop (code, vr0.min, vr1.max);
max = vrp_int_const_binop (code, vr0.max, vr1.min);
}
else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR)
{
bool int_cst_range0, int_cst_range1;
......
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