indeterminate. */
static bool
-vrp_int_const_binop (enum tree_code code, tree val1, tree val2, wide_int *res)
+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 = wi::OVF_NONE;
- signop sign = TYPE_SIGN (TREE_TYPE (val1));
- wide_int w1 = wi::to_wide (val1);
- wide_int w2 = wi::to_wide (val2);
-
- switch (code)
- {
- case RSHIFT_EXPR:
- case LSHIFT_EXPR:
- w2 = wi::to_wide (val2, TYPE_PRECISION (TREE_TYPE (val1)));
- /* FALLTHRU */
- case MULT_EXPR:
- case TRUNC_DIV_EXPR:
- case EXACT_DIV_EXPR:
- case FLOOR_DIV_EXPR:
- case CEIL_DIV_EXPR:
- case ROUND_DIV_EXPR:
- if (!wide_int_binop (*res, code, w1, w2, sign, &overflow))
- return false;
- break;
-
- default:
- gcc_unreachable ();
- }
+ 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
- && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1)))
- {
- int sign1 = tree_int_cst_sgn (val1);
- int sign2 = tree_int_cst_sgn (val2);
-
- /* Notice that we only need to handle the restricted set of
- operations handled by extract_range_from_binary_expr.
- Among them, only multiplication, addition and subtraction
- can yield overflow without overflown operands because we
- are working with integral types only... except in the
- case VAL1 = -INF and VAL2 = -1 which overflows to +INF
- for division too. */
-
- /* For multiplication, the sign of the overflow is given
- by the comparison of the signs of the operands. */
- if ((code == MULT_EXPR && sign1 == sign2)
+ 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. */
- || code == TRUNC_DIV_EXPR
- || code == FLOOR_DIV_EXPR
- || code == CEIL_DIV_EXPR
- || code == EXACT_DIV_EXPR
- || code == ROUND_DIV_EXPR)
- *res = wi::max_value (TYPE_PRECISION (TREE_TYPE (val1)), sign);
- else
- *res = wi::min_value (TYPE_PRECISION (TREE_TYPE (val1)), sign);
- return true;
- }
+ res = wi::max_value (w0.get_precision (), sign);
+ return true;
+ default:
+ gcc_unreachable ();
+ }
+ }
return !overflow;
}
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]. */
+
+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;
+}
+
/* Helper to extract a value-range *VR for a multiplicative operation
*VR0 CODE *VR1. */
enum tree_code code,
value_range *vr0, value_range *vr1)
{
- enum value_range_type rtype;
- wide_int val, min, max;
- tree type;
-
/* 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
gcc_assert (vr0->type == VR_RANGE
&& vr0->type == vr1->type);
- rtype = vr0->type;
- type = TREE_TYPE (vr0->min);
- signop sgn = TYPE_SIGN (type);
+ tree type = TREE_TYPE (vr0->min);
+ wide_int res_lb, res_ub;
+ wide_int vr0_lb = wi::to_wide (vr0->min);
+ wide_int vr0_ub = wi::to_wide (vr0->max);
+ wide_int vr1_lb = wi::to_wide (vr1->min);
+ wide_int vr1_ub = wi::to_wide (vr1->max);
+ bool overflow_undefined = TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr0->min));
- /* Compute the 4 cross operations and their minimum and maximum value. */
- if (!vrp_int_const_binop (code, vr0->min, vr1->min, &val))
+ if (!wide_int_range_cross_product (res_lb, res_ub,
+ code, TYPE_SIGN (type),
+ vr0_lb, vr0_ub, vr1_lb, vr1_ub,
+ overflow_undefined))
{
set_value_range_to_varying (vr);
return;
}
- min = max = val;
-
- if (vr1->max != vr1->min)
- {
- if (!vrp_int_const_binop (code, vr0->min, vr1->max, &val))
- {
- set_value_range_to_varying (vr);
- return;
- }
- if (wi::lt_p (val, min, sgn))
- min = val;
- else if (wi::gt_p (val, max, sgn))
- max = val;
- }
-
- if (vr0->max != vr0->min)
- {
- if (!vrp_int_const_binop (code, vr0->max, vr1->min, &val))
- {
- set_value_range_to_varying (vr);
- return;
- }
- if (wi::lt_p (val, min, sgn))
- min = val;
- else if (wi::gt_p (val, max, sgn))
- max = val;
- }
-
- if (vr0->min != vr0->max && vr1->min != vr1->max)
- {
- if (!vrp_int_const_binop (code, vr0->max, vr1->max, &val))
- {
- set_value_range_to_varying (vr);
- return;
- }
- if (wi::lt_p (val, min, sgn))
- min = val;
- else if (wi::gt_p (val, max, sgn))
- max = val;
- }
-
- /* If the new range has its limits swapped around (MIN > MAX),
- then the operation caused one of them to wrap around, mark
- the new range VARYING. */
- if (wi::gt_p (min, max, sgn))
- {
- set_value_range_to_varying (vr);
- return;
- }
-
- /* We punt for [-INF, +INF].
- We learn nothing when we have INF on both sides.
- Note that we do accept [-INF, -INF] and [+INF, +INF]. */
- if (wi::eq_p (min, wi::min_value (TYPE_PRECISION (type), sgn))
- && wi::eq_p (max, wi::max_value (TYPE_PRECISION (type), sgn)))
- {
- set_value_range_to_varying (vr);
- return;
- }
-
- set_value_range (vr, rtype,
- wide_int_to_tree (type, min),
- wide_int_to_tree (type, max), NULL);
+ set_value_range (vr, VR_RANGE,
+ wide_int_to_tree (type, res_lb),
+ wide_int_to_tree (type, res_ub), NULL);
}
/* For op & or | attempt to optimize:
}
else if (code == MULT_EXPR)
{
- /* Fancy code so that with unsigned, [-3,-1]*[-3,-1] does not
- drop to varying. This test requires 2*prec bits if both
- operands are signed and 2*prec + 2 bits if either is not. */
-
- signop sign = TYPE_SIGN (expr_type);
- unsigned int prec = TYPE_PRECISION (expr_type);
-
if (!range_int_cst_p (&vr0)
|| !range_int_cst_p (&vr1))
{
set_value_range_to_varying (vr);
return;
}
-
if (TYPE_OVERFLOW_WRAPS (expr_type))
{
- typedef FIXED_WIDE_INT (WIDE_INT_MAX_PRECISION * 2) vrp_int;
- typedef generic_wide_int
- <wi::extended_tree <WIDE_INT_MAX_PRECISION * 2> > vrp_int_cst;
- vrp_int sizem1 = wi::mask <vrp_int> (prec, false);
- vrp_int size = sizem1 + 1;
-
- /* 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. */
- vrp_int min0 = vrp_int_cst (vr0.min);
- vrp_int max0 = vrp_int_cst (vr0.max);
- vrp_int min1 = vrp_int_cst (vr1.min);
- vrp_int max1 = vrp_int_cst (vr1.max);
- /* 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;
- }
- }
-
- vrp_int prod0 = min0 * min1;
- vrp_int prod1 = min0 * max1;
- vrp_int prod2 = max0 * min1;
- vrp_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))
+ signop sign = TYPE_SIGN (expr_type);
+ unsigned int prec = TYPE_PRECISION (expr_type);
+ wide_int res_lb, res_ub;
+ if (!wide_int_range_mult_wrapping (res_lb, res_ub,
+ sign, prec,
+ wi::to_wide (vr0.min),
+ wi::to_wide (vr0.max),
+ wi::to_wide (vr1.min),
+ wi::to_wide (vr1.max)))
{
- /* the range covers all values. */
set_value_range_to_varying (vr);
return;
}
-
- /* The following should handle the wrapping and selecting
- VR_ANTI_RANGE for us. */
- min = wide_int_to_tree (expr_type, prod0);
- max = wide_int_to_tree (expr_type, prod3);
+ min = wide_int_to_tree (expr_type, res_lb);
+ max = wide_int_to_tree (expr_type, res_ub);
set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
return;
}
-
- /* If we have an unsigned MULT_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 == 65536 and op1 == 65536 with their ranges both being
- ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
- we cannot claim that the product is in ~[0,0]. Note that we
- are guaranteed to have vr0.type == vr1.type at this
- point. */
- if (vr0.type == VR_ANTI_RANGE
- && !TYPE_OVERFLOW_UNDEFINED (expr_type))
- {
- set_value_range_to_varying (vr);
- return;
- }
-
extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
return;
}
projects / thirdparty / gcc.git / commitdiff
