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Commit 94ee1558 by Aldy Hernandez Committed by Aldy Hernandez
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Abstract a lot of the {PLUS,MINUS}_EXPR code in 

extract_range_from_binary_expr_1 into separate functions.

From-SVN: r262306
parent d9957cf9
Showing with 220 additions and 221 deletions
gcc/ChangeLog
2018-07-02 Aldy Hernandez <aldyh@redhat.com> 2018-07-02 Aldy Hernandez <aldyh@redhat.com>
* tree-vrp.c (extract_range_from_binary_expr_1): Abstract a lot of the
{PLUS,MINUS}_EXPR code to...
(adjust_symbolic_bound): ...here,
(combine_bound): ...here,
(set_value_range_with_overflow): ...and here.
2018-07-02 Aldy Hernandez <aldyh@redhat.com>
* tree-vrp.c (extract_range_from_unary_expr): Abstract ABS_EXPR * tree-vrp.c (extract_range_from_unary_expr): Abstract ABS_EXPR
code... code...
(extract_range_from_abs_expr): ...here. (extract_range_from_abs_expr): ...here.
......
gcc/tree-vrp.c
...@@ -1275,6 +1275,196 @@ extract_range_from_multiplicative_op_1 (value_range *vr, ...@@ -1275,6 +1275,196 @@ extract_range_from_multiplicative_op_1 (value_range *vr,
wide_int_to_tree (type, max), NULL); wide_int_to_tree (type, max), NULL);
} }
/* If BOUND will include a symbolic bound, adjust it accordingly,
otherwise leave it as is.
CODE is the original operation that combined the bounds (PLUS_EXPR
or MINUS_EXPR).
TYPE is the type of the original operation.
SYM_OPn is the symbolic for OPn if it has a symbolic.
NEG_OPn is TRUE if the OPn was negated. */
static void
adjust_symbolic_bound (tree &bound, enum tree_code code, tree type,
tree sym_op0, tree sym_op1,
bool neg_op0, bool neg_op1)
{
bool minus_p = (code == MINUS_EXPR);
/* If the result bound is constant, we're done; otherwise, build the
symbolic lower bound. */
if (sym_op0 == sym_op1)
;
else if (sym_op0)
bound = build_symbolic_expr (type, sym_op0,
neg_op0, bound);
else if (sym_op1)
{
/* We may not negate if that might introduce
undefined overflow. */
if (!minus_p
|| neg_op1
|| TYPE_OVERFLOW_WRAPS (type))
bound = build_symbolic_expr (type, sym_op1,
neg_op1 ^ minus_p, bound);
else
bound = NULL_TREE;
}
}
/* Combine OP1 and OP1, which are two parts of a bound, into one wide
int bound according to CODE. CODE is the operation combining the
bound (either a PLUS_EXPR or a MINUS_EXPR).
TYPE is the type of the combine operation.
WI is the wide int to store the result.
OVF is -1 if an underflow occurred, +1 if an overflow occurred or 0
if over/underflow occurred. */
static void
combine_bound (enum tree_code code, wide_int &wi, int &ovf,
tree type, tree op0, tree op1)
{
bool minus_p = (code == MINUS_EXPR);
const signop sgn = TYPE_SIGN (type);
const unsigned int prec = TYPE_PRECISION (type);
/* Combine the bounds, if any. */
if (op0 && op1)
{
if (minus_p)
{
wi = wi::to_wide (op0) - wi::to_wide (op1);
/* Check for overflow. */
if (wi::cmp (0, wi::to_wide (op1), sgn)
!= wi::cmp (wi, wi::to_wide (op0), sgn))
ovf = wi::cmp (wi::to_wide (op0),
wi::to_wide (op1), sgn);
}
else
{
wi = wi::to_wide (op0) + wi::to_wide (op1);
/* Check for overflow. */
if (wi::cmp (wi::to_wide (op1), 0, sgn)
!= wi::cmp (wi, wi::to_wide (op0), sgn))
ovf = wi::cmp (wi::to_wide (op0), wi, sgn);
}
}
else if (op0)
wi = wi::to_wide (op0);
else if (op1)
{
if (minus_p)
{
wi = -wi::to_wide (op1);
/* Check for overflow. */
if (sgn == SIGNED
&& wi::neg_p (wi::to_wide (op1))
&& wi::neg_p (wi))
ovf = 1;
else if (sgn == UNSIGNED && wi::to_wide (op1) != 0)
ovf = -1;
}
else
wi = wi::to_wide (op1);
}
else
wi = wi::shwi (0, prec);
}
/* Given a range in [WMIN, WMAX], adjust it for possible overflow and
put the result in VR.
TYPE is the type of the range.
MIN_OVF and MAX_OVF indicate what type of overflow, if any,
occurred while originally calculating WMIN or WMAX. -1 indicates
underflow. +1 indicates overflow. 0 indicates neither. */
static void
set_value_range_with_overflow (value_range &vr,
tree type,
const wide_int &wmin, const wide_int &wmax,
int min_ovf, int max_ovf)
{
const signop sgn = TYPE_SIGN (type);
const unsigned int prec = TYPE_PRECISION (type);
vr.type = VR_RANGE;
vr.equiv = NULL;
if (TYPE_OVERFLOW_WRAPS (type))
{
/* If overflow wraps, truncate the values and adjust the
range kind and bounds appropriately. */
wide_int tmin = wide_int::from (wmin, prec, sgn);
wide_int tmax = wide_int::from (wmax, prec, sgn);
if (min_ovf == max_ovf)
{
/* No overflow or both overflow or underflow. The
range kind stays VR_RANGE. */
vr.min = wide_int_to_tree (type, tmin);
vr.max = wide_int_to_tree (type, tmax);
}
else if ((min_ovf == -1 && max_ovf == 0)
|| (max_ovf == 1 && min_ovf == 0))
{
/* Min underflow or max overflow. The range kind
changes to VR_ANTI_RANGE. */
bool covers = false;
wide_int tem = tmin;
vr.type = VR_ANTI_RANGE;
tmin = tmax + 1;
if (wi::cmp (tmin, tmax, sgn) < 0)
covers = true;
tmax = tem - 1;
if (wi::cmp (tmax, tem, sgn) > 0)
covers = true;
/* If the anti-range would cover nothing, drop to varying.
Likewise if the anti-range bounds are outside of the
types values. */
if (covers || wi::cmp (tmin, tmax, sgn) > 0)
{
set_value_range_to_varying (&vr);
return;
}
vr.min = wide_int_to_tree (type, tmin);
vr.max = wide_int_to_tree (type, tmax);
}
else
{
/* Other underflow and/or overflow, drop to VR_VARYING. */
set_value_range_to_varying (&vr);
return;
}
}
else
{
/* If overflow does not wrap, saturate to the types min/max
value. */
wide_int type_min = wi::min_value (prec, sgn);
wide_int type_max = wi::max_value (prec, sgn);
if (min_ovf == -1)
vr.min = wide_int_to_tree (type, type_min);
else if (min_ovf == 1)
vr.min = wide_int_to_tree (type, type_max);
else
vr.min = wide_int_to_tree (type, wmin);
if (max_ovf == -1)
vr.max = wide_int_to_tree (type, type_min);
else if (max_ovf == 1)
vr.max = wide_int_to_tree (type, type_max);
else
vr.max = wide_int_to_tree (type, wmax);
}
}
/* Extract range information from a binary operation CODE based on /* Extract range information from a binary operation CODE based on
the ranges of each of its operands *VR0 and *VR1 with resulting the ranges of each of its operands *VR0 and *VR1 with resulting
type EXPR_TYPE. The resulting range is stored in *VR. */ type EXPR_TYPE. The resulting range is stored in *VR. */
...@@ -1495,128 +1685,13 @@ extract_range_from_binary_expr_1 (value_range *vr, ...@@ -1495,128 +1685,13 @@ extract_range_from_binary_expr_1 (value_range *vr,
|| (sym_max_op0 == sym_max_op1 || (sym_max_op0 == sym_max_op1
&& neg_max_op0 == (minus_p ? neg_max_op1 : !neg_max_op1)))) && neg_max_op0 == (minus_p ? neg_max_op1 : !neg_max_op1))))
{ {
const signop sgn = TYPE_SIGN (expr_type); wide_int wmin, wmax;
const unsigned int prec = TYPE_PRECISION (expr_type);
wide_int type_min, type_max, wmin, wmax;
int min_ovf = 0; int min_ovf = 0;
int max_ovf = 0; int max_ovf = 0;
/* Get the lower and upper bounds of the type. */ /* Build the bounds. */
if (TYPE_OVERFLOW_WRAPS (expr_type)) combine_bound (code, wmin, min_ovf, expr_type, min_op0, min_op1);
{ combine_bound (code, wmax, max_ovf, expr_type, max_op0, max_op1);
type_min = wi::min_value (prec, sgn);
type_max = wi::max_value (prec, sgn);
}
else
{
type_min = wi::to_wide (vrp_val_min (expr_type));
type_max = wi::to_wide (vrp_val_max (expr_type));
}
/* Combine the lower bounds, if any. */
if (min_op0 && min_op1)
{
if (minus_p)
{
wmin = wi::to_wide (min_op0) - wi::to_wide (min_op1);
/* Check for overflow. */
if (wi::cmp (0, wi::to_wide (min_op1), sgn)
!= wi::cmp (wmin, wi::to_wide (min_op0), sgn))
min_ovf = wi::cmp (wi::to_wide (min_op0),
wi::to_wide (min_op1), sgn);
}
else
{
wmin = wi::to_wide (min_op0) + wi::to_wide (min_op1);
/* Check for overflow. */
if (wi::cmp (wi::to_wide (min_op1), 0, sgn)
!= wi::cmp (wmin, wi::to_wide (min_op0), sgn))
min_ovf = wi::cmp (wi::to_wide (min_op0), wmin, sgn);
}
}
else if (min_op0)
wmin = wi::to_wide (min_op0);
else if (min_op1)
{
if (minus_p)
{
wmin = -wi::to_wide (min_op1);
/* Check for overflow. */
if (sgn == SIGNED
&& wi::neg_p (wi::to_wide (min_op1))
&& wi::neg_p (wmin))
min_ovf = 1;
else if (sgn == UNSIGNED && wi::to_wide (min_op1) != 0)
min_ovf = -1;
}
else
wmin = wi::to_wide (min_op1);
}
else
wmin = wi::shwi (0, prec);
/* Combine the upper bounds, if any. */
if (max_op0 && max_op1)
{
if (minus_p)
{
wmax = wi::to_wide (max_op0) - wi::to_wide (max_op1);
/* Check for overflow. */
if (wi::cmp (0, wi::to_wide (max_op1), sgn)
!= wi::cmp (wmax, wi::to_wide (max_op0), sgn))
max_ovf = wi::cmp (wi::to_wide (max_op0),
wi::to_wide (max_op1), sgn);
}
else
{
wmax = wi::to_wide (max_op0) + wi::to_wide (max_op1);
if (wi::cmp (wi::to_wide (max_op1), 0, sgn)
!= wi::cmp (wmax, wi::to_wide (max_op0), sgn))
max_ovf = wi::cmp (wi::to_wide (max_op0), wmax, sgn);
}
}
else if (max_op0)
wmax = wi::to_wide (max_op0);
else if (max_op1)
{
if (minus_p)
{
wmax = -wi::to_wide (max_op1);
/* Check for overflow. */
if (sgn == SIGNED
&& wi::neg_p (wi::to_wide (max_op1))
&& wi::neg_p (wmax))
max_ovf = 1;
else if (sgn == UNSIGNED && wi::to_wide (max_op1) != 0)
max_ovf = -1;
}
else
wmax = wi::to_wide (max_op1);
}
else
wmax = wi::shwi (0, prec);
/* Check for type overflow. */
if (min_ovf == 0)
{
if (wi::cmp (wmin, type_min, sgn) == -1)
min_ovf = -1;
else if (wi::cmp (wmin, type_max, sgn) == 1)
min_ovf = 1;
}
if (max_ovf == 0)
{
if (wi::cmp (wmax, type_min, sgn) == -1)
max_ovf = -1;
else if (wi::cmp (wmax, type_max, sgn) == 1)
max_ovf = 1;
}
/* If we have overflow for the constant part and the resulting /* If we have overflow for the constant part and the resulting
range will be symbolic, drop to VR_VARYING. */ range will be symbolic, drop to VR_VARYING. */
...@@ -1627,108 +1702,24 @@ extract_range_from_binary_expr_1 (value_range *vr, ...@@ -1627,108 +1702,24 @@ extract_range_from_binary_expr_1 (value_range *vr,
return; return;
} }
if (TYPE_OVERFLOW_WRAPS (expr_type)) /* Adjust the range for possible overflow. */
{ set_value_range_with_overflow (*vr, expr_type,
/* If overflow wraps, truncate the values and adjust the wmin, wmax, min_ovf, max_ovf);
range kind and bounds appropriately. */ if (vr->type == VR_VARYING)
wide_int tmin = wide_int::from (wmin, prec, sgn); return;
wide_int tmax = wide_int::from (wmax, prec, sgn);
if (min_ovf == max_ovf) /* Build the symbolic bounds if needed. */
{ adjust_symbolic_bound (vr->min, code, expr_type,
/* No overflow or both overflow or underflow. The sym_min_op0, sym_min_op1,
range kind stays VR_RANGE. */ neg_min_op0, neg_min_op1);
min = wide_int_to_tree (expr_type, tmin); adjust_symbolic_bound (vr->max, code, expr_type,
max = wide_int_to_tree (expr_type, tmax); sym_max_op0, sym_max_op1,
} neg_max_op0, neg_max_op1);
else if ((min_ovf == -1 && max_ovf == 0) /* ?? It would probably be cleaner to eliminate min/max/type
|| (max_ovf == 1 && min_ovf == 0)) entirely and hold these values in VR directly. */
{ min = vr->min;
/* Min underflow or max overflow. The range kind max = vr->max;
changes to VR_ANTI_RANGE. */ type = vr->type;
bool covers = false;
wide_int tem = tmin;
type = VR_ANTI_RANGE;
tmin = tmax + 1;
if (wi::cmp (tmin, tmax, sgn) < 0)
covers = true;
tmax = tem - 1;
if (wi::cmp (tmax, tem, sgn) > 0)
covers = true;
/* If the anti-range would cover nothing, drop to varying.
Likewise if the anti-range bounds are outside of the
types values. */
if (covers || wi::cmp (tmin, tmax, sgn) > 0)
{
set_value_range_to_varying (vr);
return;
}
min = wide_int_to_tree (expr_type, tmin);
max = wide_int_to_tree (expr_type, tmax);
}
else
{
/* Other underflow and/or overflow, drop to VR_VARYING. */
set_value_range_to_varying (vr);
return;
}
}
else
{
/* If overflow does not wrap, saturate to the types min/max
value. */
if (min_ovf == -1)
min = wide_int_to_tree (expr_type, type_min);
else if (min_ovf == 1)
min = wide_int_to_tree (expr_type, type_max);
else
min = wide_int_to_tree (expr_type, wmin);
if (max_ovf == -1)
max = wide_int_to_tree (expr_type, type_min);
else if (max_ovf == 1)
max = wide_int_to_tree (expr_type, type_max);
else
max = wide_int_to_tree (expr_type, wmax);
}
/* If the result lower bound is constant, we're done;
otherwise, build the symbolic lower bound. */
if (sym_min_op0 == sym_min_op1)
;
else if (sym_min_op0)
min = build_symbolic_expr (expr_type, sym_min_op0,
neg_min_op0, min);
else if (sym_min_op1)
{
/* We may not negate if that might introduce
undefined overflow. */
if (! minus_p
|| neg_min_op1
|| TYPE_OVERFLOW_WRAPS (expr_type))
min = build_symbolic_expr (expr_type, sym_min_op1,
neg_min_op1 ^ minus_p, min);
else
min = NULL_TREE;
}
/* Likewise for the upper bound. */
if (sym_max_op0 == sym_max_op1)
;
else if (sym_max_op0)
max = build_symbolic_expr (expr_type, sym_max_op0,
neg_max_op0, max);
else if (sym_max_op1)
{
/* We may not negate if that might introduce
undefined overflow. */
if (! minus_p
|| neg_max_op1
|| TYPE_OVERFLOW_WRAPS (expr_type))
max = build_symbolic_expr (expr_type, sym_max_op1,
neg_max_op1 ^ minus_p, max);
else
max = NULL_TREE;
}
} }
else else
{ {
......
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