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Makefile.in (wide-int-range.o): New. 

* Makefile.in (wide-int-range.o): New.
	* tree-vrp.c: Move all the wide_int_* functions to...
	* wide-int-range.cc: ...here.
	* tree-vrp.h: Move all the wide_int_* prototypes to...
	* wide-int-range.h: ...here.

From-SVN: r263288
This commit is contained in:
Aldy Hernandez 2018-08-03 11:31:22 +00:00 committed by Aldy Hernandez
parent d989dba8ef
commit c9f8fca6d6
6 changed files with 737 additions and 682 deletions
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8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2018-08-03 Aldy Hernandez <aldyh@redhat.com>
* Makefile.in (wide-int-range.o): New.
* tree-vrp.c: Move all the wide_int_* functions to...
* wide-int-range.cc: ...here.
* tree-vrp.h: Move all the wide_int_* prototypes to...
* wide-int-range.h: ...here.
2018-08-03 Tom de Vries <tdevries@suse.de> 2018-08-03 Tom de Vries <tdevries@suse.de>
* common/config/nvptx/nvptx-common.c (nvptx_except_unwind_info): Return * common/config/nvptx/nvptx-common.c (nvptx_except_unwind_info): Return

1
gcc/Makefile.in
View File

@ -1601,6 +1601,7 @@ OBJS = \
web.o \ web.o \
wide-int.o \ wide-int.o \
wide-int-print.o \ wide-int-print.o \
wide-int-range.o \
xcoffout.o \ xcoffout.o \
$(out_object_file) \ $(out_object_file) \
$(EXTRA_OBJS) \ $(EXTRA_OBJS) \

611
gcc/tree-vrp.c
View File

@ -67,6 +67,7 @@ along with GCC; see the file COPYING3. If not see
#include "attribs.h" #include "attribs.h"
#include "vr-values.h" #include "vr-values.h"
#include "builtins.h" #include "builtins.h"
#include "wide-int-range.h"
/* Set of SSA names found live during the RPO traversal of the function /* Set of SSA names found live during the RPO traversal of the function
for still active basic-blocks. */ for still active basic-blocks. */
@ -956,98 +957,7 @@ value_range_constant_singleton (value_range *vr)
return NULL_TREE; return NULL_TREE;
} }
/* Wrapper around wide_int_binop that adjusts for overflow. /* Value range wrapper for wide_int_range_set_zero_nonzero_bits.
Return true if we can compute the result; i.e. if the operation
doesn't overflow or if the overflow is undefined. In the latter
case (if the operation overflows and overflow is undefined), then
adjust the result to be -INF or +INF depending on CODE, VAL1 and
VAL2. Return the value in *RES.
Return false for division by zero, for which the result is
indeterminate. */
static bool
wide_int_binop_overflow (wide_int &res,
enum tree_code code,
const wide_int &w0, const wide_int &w1,
signop sign, bool overflow_undefined)
{
wi::overflow_type overflow;
if (!wide_int_binop (res, code, w0, w1, sign, &overflow))
return false;
/* If the operation overflowed return -INF or +INF depending on the
operation and the combination of signs of the operands. */
if (overflow && overflow_undefined)
{
switch (code)
{
case MULT_EXPR:
/* For multiplication, the sign of the overflow is given
by the comparison of the signs of the operands. */
if (sign == UNSIGNED || w0.sign_mask () == w1.sign_mask ())
res = wi::max_value (w0.get_precision (), sign);
else
res = wi::min_value (w0.get_precision (), sign);
return true;
case TRUNC_DIV_EXPR:
case FLOOR_DIV_EXPR:
case CEIL_DIV_EXPR:
case EXACT_DIV_EXPR:
case ROUND_DIV_EXPR:
/* For division, the only case is -INF / -1 = +INF. */
res = wi::max_value (w0.get_precision (), sign);
return true;
default:
gcc_unreachable ();
}
}
return !overflow;
}
/* For range [LB, UB] compute two wide_int bit masks.
In the MAY_BE_NONZERO bit mask, if some bit is unset, it means that
for all numbers in the range the bit is 0, otherwise it might be 0
or 1.
In the MUST_BE_NONZERO bit mask, if some bit is set, it means that
for all numbers in the range the bit is 1, otherwise it might be 0
or 1. */
void
wide_int_set_zero_nonzero_bits (signop sign,
const wide_int &lb, const wide_int &ub,
wide_int &may_be_nonzero,
wide_int &must_be_nonzero)
{
may_be_nonzero = wi::minus_one (lb.get_precision ());
must_be_nonzero = wi::zero (lb.get_precision ());
if (wi::eq_p (lb, ub))
{
may_be_nonzero = lb;
must_be_nonzero = may_be_nonzero;
}
else if (wi::ge_p (lb, 0, sign) || wi::lt_p (ub, 0, sign))
{
wide_int xor_mask = lb ^ ub;
may_be_nonzero = lb | ub;
must_be_nonzero = lb & ub;
if (xor_mask != 0)
{
wide_int mask = wi::mask (wi::floor_log2 (xor_mask), false,
may_be_nonzero.get_precision ());
may_be_nonzero = may_be_nonzero | mask;
must_be_nonzero = wi::bit_and_not (must_be_nonzero, mask);
}
}
}
/* Value range wrapper for wide_int_set_zero_nonzero_bits.
Compute MAY_BE_NONZERO and MUST_BE_NONZERO bit masks for range in VR. Compute MAY_BE_NONZERO and MUST_BE_NONZERO bit masks for range in VR.
@ -1066,9 +976,10 @@ vrp_set_zero_nonzero_bits (const tree expr_type,
*must_be_nonzero = wi::zero (TYPE_PRECISION (expr_type)); *must_be_nonzero = wi::zero (TYPE_PRECISION (expr_type));
return false; return false;
} }
wide_int_set_zero_nonzero_bits (TYPE_SIGN (expr_type), wide_int_range_set_zero_nonzero_bits (TYPE_SIGN (expr_type),
wi::to_wide (vr->min), wi::to_wide (vr->max), wi::to_wide (vr->min),
*may_be_nonzero, *must_be_nonzero); wi::to_wide (vr->max),
*may_be_nonzero, *must_be_nonzero);
return true; return true;
} }
@ -1114,516 +1025,6 @@ ranges_from_anti_range (value_range *ar,
return vr0->type != VR_UNDEFINED; return vr0->type != VR_UNDEFINED;
} }
/* Order 2 sets of wide int ranges (w0/w1, w2/w3) and set MIN/MAX
accordingly. */
static void
wide_int_range_min_max (wide_int &min, wide_int &max,
wide_int &w0, wide_int &w1, wide_int &w2, wide_int &w3,
signop sign)
{
/* Order pairs w0,w1 and w2,w3. */
if (wi::gt_p (w0, w1, sign))
std::swap (w0, w1);
if (wi::gt_p (w2, w3, sign))
std::swap (w2, w3);
/* Choose min and max from the ordered pairs. */
min = wi::min (w0, w2, sign);
max = wi::max (w1, w3, sign);
}
/* Calculate the cross product of two sets of ranges (VR0 and VR1) and
store the result in [RES_LB, RES_UB].
CODE is the operation to perform with sign SIGN.
OVERFLOW_UNDEFINED is set if overflow is undefined for the operation type.
Return TRUE if we were able to calculate the cross product. */
bool
wide_int_range_cross_product (wide_int &res_lb, wide_int &res_ub,
enum tree_code code, signop sign,
const wide_int &vr0_lb, const wide_int &vr0_ub,
const wide_int &vr1_lb, const wide_int &vr1_ub,
bool overflow_undefined)
{
wide_int cp1, cp2, cp3, cp4;
/* Compute the 4 cross operations, bailing if we get an overflow we
can't handle. */
if (!wide_int_binop_overflow (cp1, code, vr0_lb, vr1_lb, sign,
overflow_undefined))
return false;
if (wi::eq_p (vr0_lb, vr0_ub))
cp3 = cp1;
else if (!wide_int_binop_overflow (cp3, code, vr0_ub, vr1_lb, sign,
overflow_undefined))
return false;
if (wi::eq_p (vr1_lb, vr1_ub))
cp2 = cp1;
else if (!wide_int_binop_overflow (cp2, code, vr0_lb, vr1_ub, sign,
overflow_undefined))
return false;
if (wi::eq_p (vr0_lb, vr0_ub))
cp4 = cp2;
else if (!wide_int_binop_overflow (cp4, code, vr0_ub, vr1_ub, sign,
overflow_undefined))
return false;
wide_int_range_min_max (res_lb, res_ub, cp1, cp2, cp3, cp4, sign);
return true;
}
/* Multiply two ranges when TYPE_OVERFLOW_WRAPS:
[RES_LB, RES_UB] = [MIN0, MAX0] * [MIN1, MAX1]
This is basically fancy code so we don't drop to varying with an
unsigned [-3,-1]*[-3,-1].
Return TRUE if we were able to perform the operation. */
bool
wide_int_range_mult_wrapping (wide_int &res_lb,
wide_int &res_ub,
signop sign,
unsigned prec,
const wide_int &min0_,
const wide_int &max0_,
const wide_int &min1_,
const wide_int &max1_)
{
/* This test requires 2*prec bits if both operands are signed and
2*prec + 2 bits if either is not. Therefore, extend the values
using the sign of the result to PREC2. From here on out,
everthing is just signed math no matter what the input types
were. */
widest2_int min0 = widest2_int::from (min0_, sign);
widest2_int max0 = widest2_int::from (max0_, sign);
widest2_int min1 = widest2_int::from (min1_, sign);
widest2_int max1 = widest2_int::from (max1_, sign);
widest2_int sizem1 = wi::mask <widest2_int> (prec, false);
widest2_int size = sizem1 + 1;
/* Canonicalize the intervals. */
if (sign == UNSIGNED)
{
if (wi::ltu_p (size, min0 + max0))
{
min0 -= size;
max0 -= size;
}
if (wi::ltu_p (size, min1 + max1))
{
min1 -= size;
max1 -= size;
}
}
widest2_int prod0 = min0 * min1;
widest2_int prod1 = min0 * max1;
widest2_int prod2 = max0 * min1;
widest2_int prod3 = max0 * max1;
/* Sort the 4 products so that min is in prod0 and max is in
prod3. */
/* min0min1 > max0max1 */
if (prod0 > prod3)
std::swap (prod0, prod3);
/* min0max1 > max0min1 */
if (prod1 > prod2)
std::swap (prod1, prod2);
if (prod0 > prod1)
std::swap (prod0, prod1);
if (prod2 > prod3)
std::swap (prod2, prod3);
/* diff = max - min. */
prod2 = prod3 - prod0;
if (wi::geu_p (prod2, sizem1))
/* The range covers all values. */
return false;
res_lb = wide_int::from (prod0, prec, sign);
res_ub = wide_int::from (prod3, prec, sign);
return true;
}
/* Perform multiplicative operation CODE on two ranges:
[RES_LB, RES_UB] = [VR0_LB, VR0_UB] .CODE. [VR1_LB, VR1_LB]
Return TRUE if we were able to perform the operation.
NOTE: If code is MULT_EXPR and TYPE_OVERFLOW_WRAPS, the resulting
range must be canonicalized by the caller because its components
may be swapped. */
bool
wide_int_range_multiplicative_op (wide_int &res_lb, wide_int &res_ub,
enum tree_code code,
signop sign,
unsigned prec,
const wide_int &vr0_lb,
const wide_int &vr0_ub,
const wide_int &vr1_lb,
const wide_int &vr1_ub,
bool overflow_undefined,
bool overflow_wraps)
{
/* Multiplications, divisions and shifts are a bit tricky to handle,
depending on the mix of signs we have in the two ranges, we
need to operate on different values to get the minimum and
maximum values for the new range. One approach is to figure
out all the variations of range combinations and do the
operations.
However, this involves several calls to compare_values and it
is pretty convoluted. It's simpler to do the 4 operations
(MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
MAX1) and then figure the smallest and largest values to form
the new range. */
if (code == MULT_EXPR && overflow_wraps)
return wide_int_range_mult_wrapping (res_lb, res_ub,
sign, prec,
vr0_lb, vr0_ub, vr1_lb, vr1_ub);
return wide_int_range_cross_product (res_lb, res_ub,
code, sign,
vr0_lb, vr0_ub, vr1_lb, vr1_ub,
overflow_undefined);
}
/* Perform a left shift operation on two ranges:
[RES_LB, RES_UB] = [VR0_LB, VR0_UB] << [VR1_LB, VR1_LB]
Return TRUE if we were able to perform the operation.
NOTE: The resulting range must be canonicalized by the caller
because its contents components may be swapped. */
bool
wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
signop sign, unsigned prec,
const wide_int &vr0_lb, const wide_int &vr0_ub,
const wide_int &vr1_lb, const wide_int &vr1_ub,
bool overflow_undefined, bool overflow_wraps)
{
/* Transform left shifts by constants into multiplies. */
if (wi::eq_p (vr1_lb, vr1_ub))
{
int shift = wi::extract_uhwi (vr1_ub, 0, vr1_ub.get_precision ());
wide_int tmp = wi::set_bit_in_zero (shift, prec);
return wide_int_range_multiplicative_op (res_lb, res_ub,
MULT_EXPR, sign, prec,
vr0_lb, vr0_ub, tmp, tmp,
overflow_undefined,
/*overflow_wraps=*/true);
}
int overflow_pos = prec;
if (sign == SIGNED)
overflow_pos -= 1;
int bound_shift = overflow_pos - vr1_ub.to_shwi ();
/* If bound_shift == HOST_BITS_PER_WIDE_INT, the llshift can
overflow. However, for that to happen, vr1.max needs to be
zero, which means vr1 is a singleton range of zero, which
means it should be handled by the previous LSHIFT_EXPR
if-clause. */
wide_int bound = wi::set_bit_in_zero (bound_shift, prec);
wide_int complement = ~(bound - 1);
wide_int low_bound, high_bound;
bool in_bounds = false;
if (sign == UNSIGNED)
{
low_bound = bound;
high_bound = complement;
if (wi::ltu_p (vr0_ub, low_bound))
{
/* [5, 6] << [1, 2] == [10, 24]. */
/* We're shifting out only zeroes, the value increases
monotonically. */
in_bounds = true;
}
else if (wi::ltu_p (high_bound, vr0_lb))
{
/* [0xffffff00, 0xffffffff] << [1, 2]
== [0xfffffc00, 0xfffffffe]. */
/* We're shifting out only ones, the value decreases
monotonically. */
in_bounds = true;
}
}
else
{
/* [-1, 1] << [1, 2] == [-4, 4]. */
low_bound = complement;
high_bound = bound;
if (wi::lts_p (vr0_ub, high_bound)
&& wi::lts_p (low_bound, vr0_lb))
{
/* For non-negative numbers, we're shifting out only
zeroes, the value increases monotonically.
For negative numbers, we're shifting out only ones, the
value decreases monotomically. */
in_bounds = true;
}
}
if (in_bounds)
return wide_int_range_multiplicative_op (res_lb, res_ub,
LSHIFT_EXPR, sign, prec,
vr0_lb, vr0_ub,
vr1_lb, vr1_ub,
overflow_undefined,
overflow_wraps);
return false;
}
/* Return TRUE if a bit operation on two ranges can be easily
optimized in terms of a mask.
Basically, for BIT_AND_EXPR or BIT_IOR_EXPR see if we can optimize:
[LB, UB] op Z
into:
[LB op Z, UB op Z]
It is up to the caller to perform the actual folding above. */
bool
wide_int_range_can_optimize_bit_op (tree_code code,
const wide_int &lb, const wide_int &ub,
const wide_int &mask)
{
if (code != BIT_AND_EXPR && code != BIT_IOR_EXPR)
return false;
/* If Z is a constant which (for op | its bitwise not) has n
consecutive least significant bits cleared followed by m 1
consecutive bits set immediately above it and either
m + n == precision, or (x >> (m + n)) == (y >> (m + n)).
The least significant n bits of all the values in the range are
cleared or set, the m bits above it are preserved and any bits
above these are required to be the same for all values in the
range. */
wide_int w = mask;
int m = 0, n = 0;
if (code == BIT_IOR_EXPR)
w = ~w;
if (wi::eq_p (w, 0))
n = w.get_precision ();
else
{
n = wi::ctz (w);
w = ~(w | wi::mask (n, false, w.get_precision ()));
if (wi::eq_p (w, 0))
m = w.get_precision () - n;
else
m = wi::ctz (w) - n;
}
wide_int new_mask = wi::mask (m + n, true, w.get_precision ());
if ((new_mask & lb) == (new_mask & ub))
return true;
return false;
}
/* Return TRUE if shifting by range [MIN, MAX] is undefined behavior.
FIXME: Make this inline when it moves outside of tree-vrp. */
bool
wide_int_range_shift_undefined_p (signop sign, unsigned prec,
const wide_int &min, const wide_int &max)
{
/* ?? Note: The original comment said this only applied to
RSHIFT_EXPR, but it was being applied to both left and right
shifts. Is this OK? */
/* Shifting by any values outside [0..prec-1], gets undefined
behavior from the shift operation. We cannot even trust
SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
shifts, and the operation at the tree level may be widened. */
return wi::lt_p (min, 0, sign) || wi::ge_p (max, prec, sign);
}
/* Calculate the XOR of two ranges and store the result in [WMIN,WMAX].
The two input ranges are described by their MUST_BE_NONZERO and
MAY_BE_NONZERO bit masks.
Return TRUE if we were able to successfully calculate the new range. */
bool
wide_int_range_bit_xor (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1)
{
wide_int result_zero_bits = ((must_be_nonzero0 & must_be_nonzero1)
| ~(may_be_nonzero0 | may_be_nonzero1));
wide_int result_one_bits
= (wi::bit_and_not (must_be_nonzero0, may_be_nonzero1)
| wi::bit_and_not (must_be_nonzero1, may_be_nonzero0));
wmax = ~result_zero_bits;
wmin = result_one_bits;
/* If the range has all positive or all negative values, the result
is better than VARYING. */
if (wi::lt_p (wmin, 0, sign) || wi::ge_p (wmax, 0, sign))
return true;
wmin = wi::min_value (prec, sign);
wmax = wi::max_value (prec, sign);
return false;
}
/* Calculate the IOR of two ranges and store the result in [WMIN,WMAX].
Return TRUE if we were able to successfully calculate the new range. */
bool
wide_int_range_bit_ior (wide_int &wmin, wide_int &wmax,
signop sign,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1)
{
wmin = must_be_nonzero0 | must_be_nonzero1;
wmax = may_be_nonzero0 | may_be_nonzero1;
/* If the input ranges contain only positive values we can
truncate the minimum of the result range to the maximum
of the input range minima. */
if (wi::ge_p (vr0_min, 0, sign)
&& wi::ge_p (vr1_min, 0, sign))
{
wmin = wi::max (wmin, vr0_min, sign);
wmin = wi::max (wmin, vr1_min, sign);
}
/* If either input range contains only negative values
we can truncate the minimum of the result range to the
respective minimum range. */
if (wi::lt_p (vr0_max, 0, sign))
wmin = wi::max (wmin, vr0_min, sign);
if (wi::lt_p (vr1_max, 0, sign))
wmin = wi::max (wmin, vr1_min, sign);
/* If the limits got swapped around, indicate error so we can adjust
the range to VARYING. */
if (wi::gt_p (wmin, wmax,sign))
return false;
return true;
}
/* Calculate the bitwise AND of two ranges and store the result in [WMIN,WMAX].
Return TRUE if we were able to successfully calculate the new range. */
bool
wide_int_range_bit_and (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1)
{
wmin = must_be_nonzero0 & must_be_nonzero1;
wmax = may_be_nonzero0 & may_be_nonzero1;
/* If both input ranges contain only negative values we can
truncate the result range maximum to the minimum of the
input range maxima. */
if (wi::lt_p (vr0_max, 0, sign) && wi::lt_p (vr1_max, 0, sign))
{
wmax = wi::min (wmax, vr0_max, sign);
wmax = wi::min (wmax, vr1_max, sign);
}
/* If either input range contains only non-negative values
we can truncate the result range maximum to the respective
maximum of the input range. */
if (wi::ge_p (vr0_min, 0, sign))
wmax = wi::min (wmax, vr0_max, sign);
if (wi::ge_p (vr1_min, 0, sign))
wmax = wi::min (wmax, vr1_max, sign);
/* PR68217: In case of signed & sign-bit-CST should
result in [-INF, 0] instead of [-INF, INF]. */
if (wi::gt_p (wmin, wmax, sign))
{
wide_int sign_bit = wi::set_bit_in_zero (prec - 1, prec);
if (sign == SIGNED
&& ((wi::eq_p (vr0_min, vr0_max)
&& !wi::cmps (vr0_min, sign_bit))
|| (wi::eq_p (vr1_min, vr1_max)
&& !wi::cmps (vr1_min, sign_bit))))
{
wmin = wi::min_value (prec, sign);
wmax = wi::zero (prec);
}
}
/* If the limits got swapped around, indicate error so we can adjust
the range to VARYING. */
if (wi::gt_p (wmin, wmax,sign))
return false;
return true;
}
/* Calculate TRUNC_MOD_EXPR on two ranges and store the result in
[WMIN,WMAX]. */
void
wide_int_range_trunc_mod (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max)
{
wide_int tmp;
/* ABS (A % B) < ABS (B) and either
0 <= A % B <= A or A <= A % B <= 0. */
wmax = vr1_max - 1;
if (sign == SIGNED)
{
tmp = -1 - vr1_min;
wmax = wi::smax (wmax, tmp);
}
if (sign == UNSIGNED)
wmin = wi::zero (prec);
else
{
wmin = -wmax;
tmp = vr0_min;
if (wi::gts_p (tmp, 0))
tmp = wi::zero (prec);
wmin = wi::smax (wmin, tmp);
}
tmp = vr0_max;
if (sign == SIGNED && wi::neg_p (tmp))
tmp = wi::zero (prec);
wmax = wi::min (wmax, tmp, sign);
}
/* Extract the components of a value range into a pair of wide ints in /* Extract the components of a value range into a pair of wide ints in
[WMIN, WMAX]. [WMIN, WMAX].

77
gcc/tree-vrp.h
View File

@ -105,83 +105,6 @@ extern bool vrp_val_is_min (const_tree);
extern bool vrp_val_is_max (const_tree); extern bool vrp_val_is_max (const_tree);
extern void copy_value_range (value_range *, value_range *); extern void copy_value_range (value_range *, value_range *);
extern void set_value_range_to_value (value_range *, tree, bitmap); extern void set_value_range_to_value (value_range *, tree, bitmap);
extern bool wide_int_range_cross_product (wide_int &res_lb, wide_int &res_ub,
enum tree_code code, signop sign,
const wide_int &, const wide_int &,
const wide_int &, const wide_int &,
bool overflow_undefined);
extern bool wide_int_range_mult_wrapping (wide_int &res_lb,
wide_int &res_ub,
signop sign,
unsigned prec,
const wide_int &min0_,
const wide_int &max0_,
const wide_int &min1_,
const wide_int &max1_);
extern bool wide_int_range_multiplicative_op (wide_int &res_lb,
wide_int &res_ub,
enum tree_code code,
signop sign,
unsigned prec,
const wide_int &vr0_lb,
const wide_int &vr0_ub,
const wide_int &vr1_lb,
const wide_int &vr1_ub,
bool overflow_undefined,
bool overflow_wraps);
extern bool wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
signop sign, unsigned prec,
const wide_int &, const wide_int &,
const wide_int &, const wide_int &,
bool overflow_undefined,
bool overflow_wraps);
extern bool wide_int_range_shift_undefined_p (signop sign, unsigned prec,
const wide_int &min,
const wide_int &max);
extern void wide_int_set_zero_nonzero_bits (signop,
const wide_int &lb,
const wide_int &ub,
wide_int &may_be_nonzero,
wide_int &must_be_nonzero);
extern bool wide_int_range_can_optimize_bit_op (tree_code,
const wide_int &lb,
const wide_int &ub,
const wide_int &mask);
extern bool wide_int_range_bit_xor (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1);
extern bool wide_int_range_bit_ior (wide_int &wmin, wide_int &wmax,
signop sign,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1);
extern bool wide_int_range_bit_and (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1);
extern void wide_int_range_trunc_mod (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max);
extern void extract_range_from_binary_expr_1 (value_range *, enum tree_code, extern void extract_range_from_binary_expr_1 (value_range *, enum tree_code,
tree, value_range *, tree, value_range *,
value_range *); value_range *);

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/* Support routines for range operations on wide ints.
Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "fold-const.h"
#include "wide-int-range.h"
/* Wrapper around wide_int_binop that adjusts for overflow.
Return true if we can compute the result; i.e. if the operation
doesn't overflow or if the overflow is undefined. In the latter
case (if the operation overflows and overflow is undefined), then
adjust the result to be -INF or +INF depending on CODE, VAL1 and
VAL2. Return the value in *RES.
Return false for division by zero, for which the result is
indeterminate. */
static bool
wide_int_binop_overflow (wide_int &res,
enum tree_code code,
const wide_int &w0, const wide_int &w1,
signop sign, bool overflow_undefined)
{
wi::overflow_type overflow;
if (!wide_int_binop (res, code, w0, w1, sign, &overflow))
return false;
/* If the operation overflowed return -INF or +INF depending on the
operation and the combination of signs of the operands. */
if (overflow && overflow_undefined)
{
switch (code)
{
case MULT_EXPR:
/* For multiplication, the sign of the overflow is given
by the comparison of the signs of the operands. */
if (sign == UNSIGNED || w0.sign_mask () == w1.sign_mask ())
res = wi::max_value (w0.get_precision (), sign);
else
res = wi::min_value (w0.get_precision (), sign);
return true;
case TRUNC_DIV_EXPR:
case FLOOR_DIV_EXPR:
case CEIL_DIV_EXPR:
case EXACT_DIV_EXPR:
case ROUND_DIV_EXPR:
/* For division, the only case is -INF / -1 = +INF. */
res = wi::max_value (w0.get_precision (), sign);
return true;
default:
gcc_unreachable ();
}
}
return !overflow;
}
/* For range [LB, UB] compute two wide_int bit masks.
In the MAY_BE_NONZERO bit mask, if some bit is unset, it means that
for all numbers in the range the bit is 0, otherwise it might be 0
or 1.
In the MUST_BE_NONZERO bit mask, if some bit is set, it means that
for all numbers in the range the bit is 1, otherwise it might be 0
or 1. */
void
wide_int_range_set_zero_nonzero_bits (signop sign,
const wide_int &lb, const wide_int &ub,
wide_int &may_be_nonzero,
wide_int &must_be_nonzero)
{
may_be_nonzero = wi::minus_one (lb.get_precision ());
must_be_nonzero = wi::zero (lb.get_precision ());
if (wi::eq_p (lb, ub))
{
may_be_nonzero = lb;
must_be_nonzero = may_be_nonzero;
}
else if (wi::ge_p (lb, 0, sign) || wi::lt_p (ub, 0, sign))
{
wide_int xor_mask = lb ^ ub;
may_be_nonzero = lb | ub;
must_be_nonzero = lb & ub;
if (xor_mask != 0)
{
wide_int mask = wi::mask (wi::floor_log2 (xor_mask), false,
may_be_nonzero.get_precision ());
may_be_nonzero = may_be_nonzero | mask;
must_be_nonzero = wi::bit_and_not (must_be_nonzero, mask);
}
}
}
/* Order 2 sets of wide int ranges (w0/w1, w2/w3) and set MIN/MAX
accordingly. */
static void
wide_int_range_min_max (wide_int &min, wide_int &max,
wide_int &w0, wide_int &w1, wide_int &w2, wide_int &w3,
signop sign)
{
/* Order pairs w0,w1 and w2,w3. */
if (wi::gt_p (w0, w1, sign))
std::swap (w0, w1);
if (wi::gt_p (w2, w3, sign))
std::swap (w2, w3);
/* Choose min and max from the ordered pairs. */
min = wi::min (w0, w2, sign);
max = wi::max (w1, w3, sign);
}
/* Calculate the cross product of two sets of ranges (VR0 and VR1) and
store the result in [RES_LB, RES_UB].
CODE is the operation to perform with sign SIGN.
OVERFLOW_UNDEFINED is set if overflow is undefined for the operation type.
Return TRUE if we were able to calculate the cross product. */
bool
wide_int_range_cross_product (wide_int &res_lb, wide_int &res_ub,
enum tree_code code, signop sign,
const wide_int &vr0_lb, const wide_int &vr0_ub,
const wide_int &vr1_lb, const wide_int &vr1_ub,
bool overflow_undefined)
{
wide_int cp1, cp2, cp3, cp4;
/* Compute the 4 cross operations, bailing if we get an overflow we
can't handle. */
if (!wide_int_binop_overflow (cp1, code, vr0_lb, vr1_lb, sign,
overflow_undefined))
return false;
if (wi::eq_p (vr0_lb, vr0_ub))
cp3 = cp1;
else if (!wide_int_binop_overflow (cp3, code, vr0_ub, vr1_lb, sign,
overflow_undefined))
return false;
if (wi::eq_p (vr1_lb, vr1_ub))
cp2 = cp1;
else if (!wide_int_binop_overflow (cp2, code, vr0_lb, vr1_ub, sign,
overflow_undefined))
return false;
if (wi::eq_p (vr0_lb, vr0_ub))
cp4 = cp2;
else if (!wide_int_binop_overflow (cp4, code, vr0_ub, vr1_ub, sign,
overflow_undefined))
return false;
wide_int_range_min_max (res_lb, res_ub, cp1, cp2, cp3, cp4, sign);
return true;
}
/* Multiply two ranges when TYPE_OVERFLOW_WRAPS:
[RES_LB, RES_UB] = [MIN0, MAX0] * [MIN1, MAX1]
This is basically fancy code so we don't drop to varying with an
unsigned [-3,-1]*[-3,-1].
Return TRUE if we were able to perform the operation. */
bool
wide_int_range_mult_wrapping (wide_int &res_lb,
wide_int &res_ub,
signop sign,
unsigned prec,
const wide_int &min0_,
const wide_int &max0_,
const wide_int &min1_,
const wide_int &max1_)
{
/* This test requires 2*prec bits if both operands are signed and
2*prec + 2 bits if either is not. Therefore, extend the values
using the sign of the result to PREC2. From here on out,
everthing is just signed math no matter what the input types
were. */
widest2_int min0 = widest2_int::from (min0_, sign);
widest2_int max0 = widest2_int::from (max0_, sign);
widest2_int min1 = widest2_int::from (min1_, sign);
widest2_int max1 = widest2_int::from (max1_, sign);
widest2_int sizem1 = wi::mask <widest2_int> (prec, false);
widest2_int size = sizem1 + 1;
/* Canonicalize the intervals. */
if (sign == UNSIGNED)
{
if (wi::ltu_p (size, min0 + max0))
{
min0 -= size;
max0 -= size;
}
if (wi::ltu_p (size, min1 + max1))
{
min1 -= size;
max1 -= size;
}
}
widest2_int prod0 = min0 * min1;
widest2_int prod1 = min0 * max1;
widest2_int prod2 = max0 * min1;
widest2_int prod3 = max0 * max1;
/* Sort the 4 products so that min is in prod0 and max is in
prod3. */
/* min0min1 > max0max1 */
if (prod0 > prod3)
std::swap (prod0, prod3);
/* min0max1 > max0min1 */
if (prod1 > prod2)
std::swap (prod1, prod2);
if (prod0 > prod1)
std::swap (prod0, prod1);
if (prod2 > prod3)
std::swap (prod2, prod3);
/* diff = max - min. */
prod2 = prod3 - prod0;
if (wi::geu_p (prod2, sizem1))
/* The range covers all values. */
return false;
res_lb = wide_int::from (prod0, prec, sign);
res_ub = wide_int::from (prod3, prec, sign);
return true;
}
/* Perform multiplicative operation CODE on two ranges:
[RES_LB, RES_UB] = [VR0_LB, VR0_UB] .CODE. [VR1_LB, VR1_LB]
Return TRUE if we were able to perform the operation.
NOTE: If code is MULT_EXPR and TYPE_OVERFLOW_WRAPS, the resulting
range must be canonicalized by the caller because its components
may be swapped. */
bool
wide_int_range_multiplicative_op (wide_int &res_lb, wide_int &res_ub,
enum tree_code code,
signop sign,
unsigned prec,
const wide_int &vr0_lb,
const wide_int &vr0_ub,
const wide_int &vr1_lb,
const wide_int &vr1_ub,
bool overflow_undefined,
bool overflow_wraps)
{
/* Multiplications, divisions and shifts are a bit tricky to handle,
depending on the mix of signs we have in the two ranges, we
need to operate on different values to get the minimum and
maximum values for the new range. One approach is to figure
out all the variations of range combinations and do the
operations.
However, this involves several calls to compare_values and it
is pretty convoluted. It's simpler to do the 4 operations
(MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
MAX1) and then figure the smallest and largest values to form
the new range. */
if (code == MULT_EXPR && overflow_wraps)
return wide_int_range_mult_wrapping (res_lb, res_ub,
sign, prec,
vr0_lb, vr0_ub, vr1_lb, vr1_ub);
return wide_int_range_cross_product (res_lb, res_ub,
code, sign,
vr0_lb, vr0_ub, vr1_lb, vr1_ub,
overflow_undefined);
}
/* Perform a left shift operation on two ranges:
[RES_LB, RES_UB] = [VR0_LB, VR0_UB] << [VR1_LB, VR1_LB]
Return TRUE if we were able to perform the operation.
NOTE: The resulting range must be canonicalized by the caller
because its contents components may be swapped. */
bool
wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
signop sign, unsigned prec,
const wide_int &vr0_lb, const wide_int &vr0_ub,
const wide_int &vr1_lb, const wide_int &vr1_ub,
bool overflow_undefined, bool overflow_wraps)
{
/* Transform left shifts by constants into multiplies. */
if (wi::eq_p (vr1_lb, vr1_ub))
{
int shift = wi::extract_uhwi (vr1_ub, 0, vr1_ub.get_precision ());
wide_int tmp = wi::set_bit_in_zero (shift, prec);
return wide_int_range_multiplicative_op (res_lb, res_ub,
MULT_EXPR, sign, prec,
vr0_lb, vr0_ub, tmp, tmp,
overflow_undefined,
/*overflow_wraps=*/true);
}
int overflow_pos = prec;
if (sign == SIGNED)
overflow_pos -= 1;
int bound_shift = overflow_pos - vr1_ub.to_shwi ();
/* If bound_shift == HOST_BITS_PER_WIDE_INT, the llshift can
overflow. However, for that to happen, vr1.max needs to be
zero, which means vr1 is a singleton range of zero, which
means it should be handled by the previous LSHIFT_EXPR
if-clause. */
wide_int bound = wi::set_bit_in_zero (bound_shift, prec);
wide_int complement = ~(bound - 1);
wide_int low_bound, high_bound;
bool in_bounds = false;
if (sign == UNSIGNED)
{
low_bound = bound;
high_bound = complement;
if (wi::ltu_p (vr0_ub, low_bound))
{
/* [5, 6] << [1, 2] == [10, 24]. */
/* We're shifting out only zeroes, the value increases
monotonically. */
in_bounds = true;
}
else if (wi::ltu_p (high_bound, vr0_lb))
{
/* [0xffffff00, 0xffffffff] << [1, 2]
== [0xfffffc00, 0xfffffffe]. */
/* We're shifting out only ones, the value decreases
monotonically. */
in_bounds = true;
}
}
else
{
/* [-1, 1] << [1, 2] == [-4, 4]. */
low_bound = complement;
high_bound = bound;
if (wi::lts_p (vr0_ub, high_bound)
&& wi::lts_p (low_bound, vr0_lb))
{
/* For non-negative numbers, we're shifting out only
zeroes, the value increases monotonically.
For negative numbers, we're shifting out only ones, the
value decreases monotomically. */
in_bounds = true;
}
}
if (in_bounds)
return wide_int_range_multiplicative_op (res_lb, res_ub,
LSHIFT_EXPR, sign, prec,
vr0_lb, vr0_ub,
vr1_lb, vr1_ub,
overflow_undefined,
overflow_wraps);
return false;
}
/* Return TRUE if a bit operation on two ranges can be easily
optimized in terms of a mask.
Basically, for BIT_AND_EXPR or BIT_IOR_EXPR see if we can optimize:
[LB, UB] op Z
into:
[LB op Z, UB op Z]
It is up to the caller to perform the actual folding above. */
bool
wide_int_range_can_optimize_bit_op (tree_code code,
const wide_int &lb, const wide_int &ub,
const wide_int &mask)
{
if (code != BIT_AND_EXPR && code != BIT_IOR_EXPR)
return false;
/* If Z is a constant which (for op | its bitwise not) has n
consecutive least significant bits cleared followed by m 1
consecutive bits set immediately above it and either
m + n == precision, or (x >> (m + n)) == (y >> (m + n)).
The least significant n bits of all the values in the range are
cleared or set, the m bits above it are preserved and any bits
above these are required to be the same for all values in the
range. */
wide_int w = mask;
int m = 0, n = 0;
if (code == BIT_IOR_EXPR)
w = ~w;
if (wi::eq_p (w, 0))
n = w.get_precision ();
else
{
n = wi::ctz (w);
w = ~(w | wi::mask (n, false, w.get_precision ()));
if (wi::eq_p (w, 0))
m = w.get_precision () - n;
else
m = wi::ctz (w) - n;
}
wide_int new_mask = wi::mask (m + n, true, w.get_precision ());
if ((new_mask & lb) == (new_mask & ub))
return true;
return false;
}
/* Calculate the XOR of two ranges and store the result in [WMIN,WMAX].
The two input ranges are described by their MUST_BE_NONZERO and
MAY_BE_NONZERO bit masks.
Return TRUE if we were able to successfully calculate the new range. */
bool
wide_int_range_bit_xor (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1)
{
wide_int result_zero_bits = ((must_be_nonzero0 & must_be_nonzero1)
| ~(may_be_nonzero0 | may_be_nonzero1));
wide_int result_one_bits
= (wi::bit_and_not (must_be_nonzero0, may_be_nonzero1)
| wi::bit_and_not (must_be_nonzero1, may_be_nonzero0));
wmax = ~result_zero_bits;
wmin = result_one_bits;
/* If the range has all positive or all negative values, the result
is better than VARYING. */
if (wi::lt_p (wmin, 0, sign) || wi::ge_p (wmax, 0, sign))
return true;
wmin = wi::min_value (prec, sign);
wmax = wi::max_value (prec, sign);
return false;
}
/* Calculate the IOR of two ranges and store the result in [WMIN,WMAX].
Return TRUE if we were able to successfully calculate the new range. */
bool
wide_int_range_bit_ior (wide_int &wmin, wide_int &wmax,
signop sign,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1)
{
wmin = must_be_nonzero0 | must_be_nonzero1;
wmax = may_be_nonzero0 | may_be_nonzero1;
/* If the input ranges contain only positive values we can
truncate the minimum of the result range to the maximum
of the input range minima. */
if (wi::ge_p (vr0_min, 0, sign)
&& wi::ge_p (vr1_min, 0, sign))
{
wmin = wi::max (wmin, vr0_min, sign);
wmin = wi::max (wmin, vr1_min, sign);
}
/* If either input range contains only negative values
we can truncate the minimum of the result range to the
respective minimum range. */
if (wi::lt_p (vr0_max, 0, sign))
wmin = wi::max (wmin, vr0_min, sign);
if (wi::lt_p (vr1_max, 0, sign))
wmin = wi::max (wmin, vr1_min, sign);
/* If the limits got swapped around, indicate error so we can adjust
the range to VARYING. */
if (wi::gt_p (wmin, wmax,sign))
return false;
return true;
}
/* Calculate the bitwise AND of two ranges and store the result in [WMIN,WMAX].
Return TRUE if we were able to successfully calculate the new range. */
bool
wide_int_range_bit_and (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1)
{
wmin = must_be_nonzero0 & must_be_nonzero1;
wmax = may_be_nonzero0 & may_be_nonzero1;
/* If both input ranges contain only negative values we can
truncate the result range maximum to the minimum of the
input range maxima. */
if (wi::lt_p (vr0_max, 0, sign) && wi::lt_p (vr1_max, 0, sign))
{
wmax = wi::min (wmax, vr0_max, sign);
wmax = wi::min (wmax, vr1_max, sign);
}
/* If either input range contains only non-negative values
we can truncate the result range maximum to the respective
maximum of the input range. */
if (wi::ge_p (vr0_min, 0, sign))
wmax = wi::min (wmax, vr0_max, sign);
if (wi::ge_p (vr1_min, 0, sign))
wmax = wi::min (wmax, vr1_max, sign);
/* PR68217: In case of signed & sign-bit-CST should
result in [-INF, 0] instead of [-INF, INF]. */
if (wi::gt_p (wmin, wmax, sign))
{
wide_int sign_bit = wi::set_bit_in_zero (prec - 1, prec);
if (sign == SIGNED
&& ((wi::eq_p (vr0_min, vr0_max)
&& !wi::cmps (vr0_min, sign_bit))
|| (wi::eq_p (vr1_min, vr1_max)
&& !wi::cmps (vr1_min, sign_bit))))
{
wmin = wi::min_value (prec, sign);
wmax = wi::zero (prec);
}
}
/* If the limits got swapped around, indicate error so we can adjust
the range to VARYING. */
if (wi::gt_p (wmin, wmax,sign))
return false;
return true;
}
/* Calculate TRUNC_MOD_EXPR on two ranges and store the result in
[WMIN,WMAX]. */
void
wide_int_range_trunc_mod (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max)
{
wide_int tmp;
/* ABS (A % B) < ABS (B) and either
0 <= A % B <= A or A <= A % B <= 0. */
wmax = vr1_max - 1;
if (sign == SIGNED)
{
tmp = -1 - vr1_min;
wmax = wi::smax (wmax, tmp);
}
if (sign == UNSIGNED)
wmin = wi::zero (prec);
else
{
wmin = -wmax;
tmp = vr0_min;
if (wi::gts_p (tmp, 0))
tmp = wi::zero (prec);
wmin = wi::smax (wmin, tmp);
}
tmp = vr0_max;
if (sign == SIGNED && wi::neg_p (tmp))
tmp = wi::zero (prec);
wmax = wi::min (wmax, tmp, sign);
}

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/* Support routines for range operations on wide ints.
Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#ifndef GCC_WIDE_INT_RANGE_H
#define GCC_WIDE_INT_RANGE_H
extern bool wide_int_range_cross_product (wide_int &res_lb, wide_int &res_ub,
enum tree_code code, signop sign,
const wide_int &, const wide_int &,
const wide_int &, const wide_int &,
bool overflow_undefined);
extern bool wide_int_range_mult_wrapping (wide_int &res_lb,
wide_int &res_ub,
signop sign,
unsigned prec,
const wide_int &min0_,
const wide_int &max0_,
const wide_int &min1_,
const wide_int &max1_);
extern bool wide_int_range_multiplicative_op (wide_int &res_lb,
wide_int &res_ub,
enum tree_code code,
signop sign,
unsigned prec,
const wide_int &vr0_lb,
const wide_int &vr0_ub,
const wide_int &vr1_lb,
const wide_int &vr1_ub,
bool overflow_undefined,
bool overflow_wraps);
extern bool wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
signop sign, unsigned prec,
const wide_int &, const wide_int &,
const wide_int &, const wide_int &,
bool overflow_undefined,
bool overflow_wraps);
extern void wide_int_range_set_zero_nonzero_bits (signop,
const wide_int &lb,
const wide_int &ub,
wide_int &may_be_nonzero,
wide_int &must_be_nonzero);
extern bool wide_int_range_can_optimize_bit_op (tree_code,
const wide_int &lb,
const wide_int &ub,
const wide_int &mask);
extern bool wide_int_range_bit_xor (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1);
extern bool wide_int_range_bit_ior (wide_int &wmin, wide_int &wmax,
signop sign,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1);
extern bool wide_int_range_bit_and (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max,
const wide_int &must_be_nonzero0,
const wide_int &may_be_nonzero0,
const wide_int &must_be_nonzero1,
const wide_int &may_be_nonzero1);
extern void wide_int_range_trunc_mod (wide_int &wmin, wide_int &wmax,
signop sign,
unsigned prec,
const wide_int &vr0_min,
const wide_int &vr0_max,
const wide_int &vr1_min,
const wide_int &vr1_max);
/* Return TRUE if shifting by range [MIN, MAX] is undefined behavior. */
inline bool
wide_int_range_shift_undefined_p (signop sign, unsigned prec,
const wide_int &min, const wide_int &max)
{
/* ?? Note: The original comment said this only applied to
RSHIFT_EXPR, but it was being applied to both left and right
shifts. */
/* Shifting by any values outside [0..prec-1], gets undefined
behavior from the shift operation. We cannot even trust
SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
shifts, and the operation at the tree level may be widened. */
return wi::lt_p (min, 0, sign) || wi::ge_p (max, prec, sign);
}
#endif /* GCC_WIDE_INT_RANGE_H */