set_value_range (to, from->type, from->min, from->max, from->equiv);
}
+/* Set value range VR to a non-negative range of type TYPE. */
+
+static inline void
+set_value_range_to_nonnegative (value_range_t *vr, tree type)
+{
+ tree zero = build_int_cst (type, 0);
+ set_value_range (vr, VR_RANGE, zero, TYPE_MAX_VALUE (type), vr->equiv);
+}
/* Set value range VR to a non-NULL range of type TYPE. */
}
-/* Return value range information for VAR. Create an empty range
- if none existed. */
+/* Return value range information for VAR.
+
+ If we have no values ranges recorded (ie, VRP is not running), then
+ return NULL. Otherwise create an empty range if none existed for VAR. */
static value_range_t *
get_value_range (tree var)
tree sym;
unsigned ver = SSA_NAME_VERSION (var);
+ /* If we have no recorded ranges, then return NULL. */
+ if (! vr_value)
+ return NULL;
+
vr = vr_value[ver];
if (vr)
return vr;
|| !is_gimple_min_invariant (vr->max));
}
+/* Like tree_expr_nonnegative_p, but this function uses value ranges
+ obtained so far. */
+
+static bool
+vrp_expr_computes_nonnegative (tree expr)
+{
+ return tree_expr_nonnegative_p (expr);
+}
/* Like tree_expr_nonzero_p, but this function uses value ranges
obtained so far. */
gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1))
== POINTER_TYPE_P (TREE_TYPE (val2)));
- /* Do some limited symbolic comparisons. */
- if (!POINTER_TYPE_P (TREE_TYPE (val1)))
- {
- /* We can determine some comparisons against +INF and -INF even
- if the other value is an expression. */
- if (val1 == TYPE_MAX_VALUE (TREE_TYPE (val1))
- && TREE_CODE (val2) == MINUS_EXPR)
- {
- /* +INF > NAME - CST. */
- return 1;
- }
- else if (val1 == TYPE_MIN_VALUE (TREE_TYPE (val1))
- && TREE_CODE (val2) == PLUS_EXPR)
- {
- /* -INF < NAME + CST. */
- return -1;
- }
- else if (TREE_CODE (val1) == MINUS_EXPR
- && val2 == TYPE_MAX_VALUE (TREE_TYPE (val2)))
- {
- /* NAME - CST < +INF. */
- return -1;
- }
- else if (TREE_CODE (val1) == PLUS_EXPR
- && val2 == TYPE_MIN_VALUE (TREE_TYPE (val2)))
- {
- /* NAME + CST > -INF. */
- return 1;
- }
- }
-
if ((TREE_CODE (val1) == SSA_NAME
|| TREE_CODE (val1) == PLUS_EXPR
|| TREE_CODE (val1) == MINUS_EXPR)
|| TREE_CODE (val2) == MINUS_EXPR))
{
tree n1, c1, n2, c2;
+ enum tree_code code1, code2;
/* If VAL1 and VAL2 are of the form 'NAME [+-] CST' or 'NAME',
return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
same name, return -2. */
if (TREE_CODE (val1) == SSA_NAME)
{
+ code1 = SSA_NAME;
n1 = val1;
c1 = NULL_TREE;
}
else
{
+ code1 = TREE_CODE (val1);
n1 = TREE_OPERAND (val1, 0);
c1 = TREE_OPERAND (val1, 1);
+ if (tree_int_cst_sgn (c1) == -1)
+ {
+ c1 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c1), c1);
+ if (!c1)
+ return -2;
+ code1 = code1 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR;
+ }
}
if (TREE_CODE (val2) == SSA_NAME)
{
+ code2 = SSA_NAME;
n2 = val2;
c2 = NULL_TREE;
}
else
{
+ code2 = TREE_CODE (val2);
n2 = TREE_OPERAND (val2, 0);
c2 = TREE_OPERAND (val2, 1);
+ if (tree_int_cst_sgn (c2) == -1)
+ {
+ c2 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c2), c2);
+ if (!c2)
+ return -2;
+ code2 = code2 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR;
+ }
}
/* Both values must use the same name. */
if (n1 != n2)
return -2;
- if (TREE_CODE (val1) == SSA_NAME)
+ if (code1 == SSA_NAME
+ && code2 == SSA_NAME)
+ /* NAME == NAME */
+ return 0;
+
+ /* If overflow is defined we cannot simplify more. */
+ if (TYPE_UNSIGNED (TREE_TYPE (val1))
+ || flag_wrapv)
+ return -2;
+
+ if (code1 == SSA_NAME)
{
- if (TREE_CODE (val2) == SSA_NAME)
- /* NAME == NAME */
- return 0;
- else if (TREE_CODE (val2) == PLUS_EXPR)
+ if (code2 == PLUS_EXPR)
/* NAME < NAME + CST */
return -1;
- else if (TREE_CODE (val2) == MINUS_EXPR)
+ else if (code2 == MINUS_EXPR)
/* NAME > NAME - CST */
return 1;
}
- else if (TREE_CODE (val1) == PLUS_EXPR)
+ else if (code1 == PLUS_EXPR)
{
- if (TREE_CODE (val2) == SSA_NAME)
+ if (code2 == SSA_NAME)
/* NAME + CST > NAME */
return 1;
- else if (TREE_CODE (val2) == PLUS_EXPR)
+ else if (code2 == PLUS_EXPR)
/* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
return compare_values (c1, c2);
- else if (TREE_CODE (val2) == MINUS_EXPR)
+ else if (code2 == MINUS_EXPR)
/* NAME + CST1 > NAME - CST2 */
return 1;
}
- else if (TREE_CODE (val1) == MINUS_EXPR)
+ else if (code1 == MINUS_EXPR)
{
- if (TREE_CODE (val2) == SSA_NAME)
+ if (code2 == SSA_NAME)
/* NAME - CST < NAME */
return -1;
- else if (TREE_CODE (val2) == PLUS_EXPR)
+ else if (code2 == PLUS_EXPR)
/* NAME - CST1 < NAME + CST2 */
return -1;
- else if (TREE_CODE (val2) == MINUS_EXPR)
+ else if (code2 == MINUS_EXPR)
/* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
C1 and C2 are swapped in the call to compare_values. */
return compare_values (c2, c1);
static inline int
value_inside_range (tree val, value_range_t *vr)
{
- int cmp1, cmp2;
+ tree cmp1, cmp2;
- cmp1 = compare_values (val, vr->min);
- if (cmp1 == -2 || cmp1 == 2)
+ cmp1 = fold_binary_to_constant (GE_EXPR, boolean_type_node, val, vr->min);
+ if (!cmp1)
return -2;
- cmp2 = compare_values (val, vr->max);
- if (cmp2 == -2 || cmp2 == 2)
+ cmp2 = fold_binary_to_constant (LE_EXPR, boolean_type_node, val, vr->max);
+ if (!cmp2)
return -2;
- return (cmp1 == 0 || cmp1 == 1) && (cmp2 == -1 || cmp2 == 0);
+ return cmp1 == boolean_true_node && cmp2 == boolean_true_node;
}
return (value_inside_range (zero, vr) == 1);
}
+/* Return true if T, an SSA_NAME, is known to be nonnegative. Return
+ false otherwise or if no value range information is available. */
+
+bool
+ssa_name_nonnegative_p (tree t)
+{
+ value_range_t *vr = get_value_range (t);
+
+ if (!vr)
+ return false;
+
+ /* Testing for VR_ANTI_RANGE is not useful here as any anti-range
+ which would return a useful value should be encoded as a VR_RANGE. */
+ if (vr->type == VR_RANGE)
+ {
+ int result = compare_values (vr->min, integer_zero_node);
+
+ return (result == 0 || result == 1);
+ }
+ return false;
+}
+
+/* Return true if T, an SSA_NAME, is known to be nonzero. Return
+ false otherwise or if no value range information is available. */
+
+bool
+ssa_name_nonzero_p (tree t)
+{
+ value_range_t *vr = get_value_range (t);
+
+ if (!vr)
+ return false;
+
+ /* A VR_RANGE which does not include zero is a nonzero value. */
+ if (vr->type == VR_RANGE && !symbolic_range_p (vr))
+ return ! range_includes_zero_p (vr);
+
+ /* A VR_ANTI_RANGE which does include zero is a nonzero value. */
+ if (vr->type == VR_ANTI_RANGE && !symbolic_range_p (vr))
+ return range_includes_zero_p (vr);
+
+ return false;
+}
+
/* When extracting ranges from X_i = ASSERT_EXPR <Y_j, pred>, we will
initially consider X_i and Y_j equivalent, so the equivalence set
|| symbolic_range_p (limit_vr)))
limit_vr = NULL;
- /* Special handling for integral types with super-types. Some FEs
- construct integral types derived from other types and restrict
- the range of values these new types may take.
-
- It may happen that LIMIT is actually smaller than TYPE's minimum
- value. For instance, the Ada FE is generating code like this
- during bootstrap:
-
- D.1480_32 = nam_30 - 300000361;
- if (D.1480_32 <= 1) goto <L112>; else goto <L52>;
- <L112>:;
- D.1480_94 = ASSERT_EXPR <D.1480_32, D.1480_32 <= 1>;
-
- All the names are of type types__name_id___XDLU_300000000__399999999
- which has min == 300000000 and max == 399999999. This means that
- the ASSERT_EXPR would try to create the range [3000000, 1] which
- is invalid.
-
- The fact that the type specifies MIN and MAX values does not
- automatically mean that every variable of that type will always
- be within that range, so the predicate may well be true at run
- time. If we had symbolic -INF and +INF values, we could
- represent this range, but we currently represent -INF and +INF
- using the type's min and max values.
-
- So, the only sensible thing we can do for now is set the
- resulting range to VR_VARYING. TODO, would having symbolic -INF
- and +INF values be worth the trouble? */
- if (TREE_CODE (limit) != SSA_NAME
- && INTEGRAL_TYPE_P (type)
- && TREE_TYPE (type))
- {
- if (cond_code == LE_EXPR || cond_code == LT_EXPR)
- {
- tree type_min = TYPE_MIN_VALUE (type);
- int cmp = compare_values (limit, type_min);
-
- /* For < or <= comparisons, if LIMIT is smaller than
- TYPE_MIN, set the range to VR_VARYING. */
- if (cmp == -1 || cmp == 0)
- {
- set_value_range_to_varying (vr_p);
- return;
- }
- }
- else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
- {
- tree type_max = TYPE_MIN_VALUE (type);
- int cmp = compare_values (limit, type_max);
-
- /* For > or >= comparisons, if LIMIT is bigger than
- TYPE_MAX, set the range to VR_VARYING. */
- if (cmp == 1 || cmp == 0)
- {
- set_value_range_to_varying (vr_p);
- return;
- }
- }
- }
-
/* Initially, the new range has the same set of equivalences of
VAR's range. This will be revised before returning the final
value. Since assertions may be chained via mutually exclusive
there are three cases to consider.
- 1. The VR_ANTI_RANGE range is competely within the
+ 1. The VR_ANTI_RANGE range is completely within the
VR_RANGE and the endpoints of the ranges are
different. In that case the resulting range
should be whichever range is more precise.
}
/* Case 3a, the anti-range extends into the low
part of the real range. Thus creating a new
- low for the real reange. */
+ low for the real range. */
else if ((compare_values (anti_max, real_min) == 1
|| compare_values (anti_max, real_min) == 0)
&& compare_values (anti_max, real_max) == -1)
}
/* Case 3b, the anti-range extends into the high
part of the real range. Thus creating a new
- higher for the real reange. */
+ higher for the real range. */
else if (compare_values (anti_min, real_min) == 1
&& (compare_values (anti_min, real_max) == -1
|| compare_values (anti_min, real_max) == 0))
if (TYPE_UNSIGNED (TREE_TYPE (val1)))
{
int checkz = compare_values (res, val1);
+ bool overflow = false;
/* Ensure that res = val1 [+*] val2 >= val1
or that res = val1 - val2 <= val1. */
- if (((code == PLUS_EXPR || code == MULT_EXPR)
+ if ((code == PLUS_EXPR
&& !(checkz == 1 || checkz == 0))
|| (code == MINUS_EXPR
&& !(checkz == 0 || checkz == -1)))
{
+ overflow = true;
+ }
+ /* Checking for multiplication overflow is done by dividing the
+ output of the multiplication by the first input of the
+ multiplication. If the result of that division operation is
+ not equal to the second input of the multiplication, then the
+ multiplication overflowed. */
+ else if (code == MULT_EXPR && !integer_zerop (val1))
+ {
+ tree tmp = int_const_binop (TRUNC_DIV_EXPR,
+ TYPE_MAX_VALUE (TREE_TYPE (val1)),
+ val1, 0);
+ int check = compare_values (tmp, val2);
+
+ if (check != 0)
+ overflow = true;
+ }
+
+ if (overflow)
+ {
res = copy_node (res);
TREE_OVERFLOW (res) = 1;
}
+
}
else if (TREE_OVERFLOW (res)
&& !TREE_OVERFLOW (val1)
return;
}
- /* Refuse to operate on varying and symbolic ranges. Also, if the
- operand is neither a pointer nor an integral type, set the
- resulting range to VARYING. TODO, in some cases we may be able
- to derive anti-ranges (like nonzero values). */
- if (vr0.type == VR_VARYING
- || (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
- && !POINTER_TYPE_P (TREE_TYPE (op0)))
- || symbolic_range_p (&vr0))
+ /* Refuse to operate on symbolic ranges, or if neither operand is
+ a pointer or integral type. */
+ if ((!INTEGRAL_TYPE_P (TREE_TYPE (op0))
+ && !POINTER_TYPE_P (TREE_TYPE (op0)))
+ || (vr0.type != VR_VARYING
+ && symbolic_range_p (&vr0)))
{
set_value_range_to_varying (vr);
return;
or equal to the new max, then we can safely use the newly
computed range for EXPR. This allows us to compute
accurate ranges through many casts. */
- if (vr0.type == VR_RANGE)
+ if (vr0.type == VR_RANGE
+ || (vr0.type == VR_VARYING
+ && TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type)))
{
- tree new_min, new_max;
+ tree new_min, new_max, orig_min, orig_max;
- /* Convert VR0's min/max to OUTER_TYPE. */
- new_min = fold_convert (outer_type, vr0.min);
- new_max = fold_convert (outer_type, vr0.max);
+ /* Convert the input operand min/max to OUTER_TYPE. If
+ the input has no range information, then use the min/max
+ for the input's type. */
+ if (vr0.type == VR_RANGE)
+ {
+ orig_min = vr0.min;
+ orig_max = vr0.max;
+ }
+ else
+ {
+ orig_min = TYPE_MIN_VALUE (inner_type);
+ orig_max = TYPE_MAX_VALUE (inner_type);
+ }
+
+ new_min = fold_convert (outer_type, orig_min);
+ new_max = fold_convert (outer_type, orig_max);
/* Verify the new min/max values are gimple values and
- that they compare equal to VR0's min/max values. */
+ that they compare equal to the original input's
+ min/max values. */
if (is_gimple_val (new_min)
&& is_gimple_val (new_max)
- && tree_int_cst_equal (new_min, vr0.min)
- && tree_int_cst_equal (new_max, vr0.max)
+ && tree_int_cst_equal (new_min, orig_min)
+ && tree_int_cst_equal (new_max, orig_max)
&& compare_values (new_min, new_max) <= 0
&& compare_values (new_min, new_max) >= -1)
{
}
}
+ /* Conversion of a VR_VARYING value to a wider type can result
+ in a usable range. So wait until after we've handled conversions
+ before dropping the result to VR_VARYING if we had a source
+ operand that is VR_VARYING. */
+ if (vr0.type == VR_VARYING)
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
+
/* Apply the operation to each end of the range and see what we end
up with. */
if (code == NEGATE_EXPR
max = (vr0.min == TYPE_MIN_VALUE (TREE_TYPE (expr)) && !flag_wrapv)
? TYPE_MAX_VALUE (TREE_TYPE (expr))
: fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);
+
+ }
+ else if (code == NEGATE_EXPR
+ && TYPE_UNSIGNED (TREE_TYPE (expr)))
+ {
+ if (!range_includes_zero_p (&vr0))
+ {
+ max = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);
+ min = fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);
+ }
+ else
+ {
+ if (range_is_null (&vr0))
+ set_value_range_to_null (vr, TREE_TYPE (expr));
+ else
+ set_value_range_to_varying (vr);
+ return;
+ }
}
else if (code == ABS_EXPR
&& !TYPE_UNSIGNED (TREE_TYPE (expr)))
extract_range_from_comparison (vr, expr);
else if (is_gimple_min_invariant (expr))
set_value_range (vr, VR_RANGE, expr, expr, NULL);
- else if (vrp_expr_computes_nonzero (expr))
- set_value_range_to_nonnull (vr, TREE_TYPE (expr));
else
set_value_range_to_varying (vr);
+
+ /* If we got a varying range from the tests above, try a final
+ time to derive a nonnegative or nonzero range. This time
+ relying primarily on generic routines in fold in conjunction
+ with range data. */
+ if (vr->type == VR_VARYING)
+ {
+ if (INTEGRAL_TYPE_P (TREE_TYPE (expr))
+ && vrp_expr_computes_nonnegative (expr))
+ set_value_range_to_nonnegative (vr, TREE_TYPE (expr));
+ else if (vrp_expr_computes_nonzero (expr))
+ set_value_range_to_nonnull (vr, TREE_TYPE (expr));
+ }
}
/* Given a range VR, a LOOP and a variable VAR, determine whether it
if (stmt_ends_bb_p (stmt) && EDGE_COUNT (bb_for_stmt (stmt)->succs) == 0)
return false;
- if (POINTER_TYPE_P (TREE_TYPE (op)))
+ /* We can only assume that a pointer dereference will yield
+ non-NULL if -fdelete-null-pointer-checks is enabled. */
+ if (flag_delete_null_pointer_checks && POINTER_TYPE_P (TREE_TYPE (op)))
{
bool is_store;
unsigned num_uses, num_derefs;
count_uses_and_derefs (op, stmt, &num_uses, &num_derefs, &is_store);
- if (num_derefs > 0 && flag_delete_null_pointer_checks)
+ if (num_derefs > 0)
{
- /* We can only assume that a pointer dereference will yield
- non-NULL if -fdelete-null-pointer-checks is enabled. */
*val_p = build_int_cst (TREE_TYPE (op), 0);
*comp_code_p = NE_EXPR;
return true;
operands it was looking for was present in the sub-graph. */
SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
- /* If OP is used only once, namely in this STMT, don't
- bother creating an ASSERT_EXPR for it. Such an
- ASSERT_EXPR would do nothing but increase compile time.
- Experiments show that with this simple check, we can save
- more than 20% of ASSERT_EXPRs. */
- if (has_single_use (op))
- continue;
-
/* If OP is used in such a way that we can infer a value
range for it, and we don't find a previous assertion for
it, create a new assertion location node for OP. */
if (infer_value_range (stmt, op, &comp_code, &value))
{
- register_new_assert_for (op, comp_code, value, bb, NULL, si);
- need_assert = true;
+ /* If we are able to infer a nonzero value range for OP,
+ then walk backwards through the use-def chain to see if OP
+ was set via a typecast.
+
+ If so, then we can also infer a nonzero value range
+ for the operand of the NOP_EXPR. */
+ if (comp_code == NE_EXPR && integer_zerop (value))
+ {
+ tree t = op;
+ tree def_stmt = SSA_NAME_DEF_STMT (t);
+
+ while (TREE_CODE (def_stmt) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (def_stmt, 1)) == NOP_EXPR
+ && TREE_CODE (TREE_OPERAND (TREE_OPERAND (def_stmt, 1), 0)) == SSA_NAME
+ && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (def_stmt, 1), 0))))
+ {
+ t = TREE_OPERAND (TREE_OPERAND (def_stmt, 1), 0);
+ def_stmt = SSA_NAME_DEF_STMT (t);
+
+ /* Note we want to register the assert for the
+ operand of the NOP_EXPR after SI, not after the
+ conversion. */
+ if (! has_single_use (t))
+ {
+ register_new_assert_for (t, comp_code, value,
+ bb, NULL, si);
+ need_assert = true;
+ }
+ }
+ }
+
+ /* If OP is used only once, namely in this STMT, don't
+ bother creating an ASSERT_EXPR for it. Such an
+ ASSERT_EXPR would do nothing but increase compile time. */
+ if (!has_single_use (op))
+ {
+ register_new_assert_for (op, comp_code, value, bb, NULL, si);
+ need_assert = true;
+ }
}
}
for (si = bsi_start (bb); !bsi_end_p (si);)
{
tree stmt = bsi_stmt (si);
+ tree use_stmt;
if (TREE_CODE (stmt) == MODIFY_EXPR
&& TREE_CODE (TREE_OPERAND (stmt, 1)) == ASSERT_EXPR)
{
- tree rhs = TREE_OPERAND (stmt, 1);
+ tree rhs = TREE_OPERAND (stmt, 1), var;
tree cond = fold (ASSERT_EXPR_COND (rhs));
use_operand_p use_p;
imm_use_iterator iter;
gcc_assert (cond != boolean_false_node);
- TREE_OPERAND (stmt, 1) = ASSERT_EXPR_VAR (rhs);
- update_stmt (stmt);
- /* The statement is now a copy. Propagate the RHS into
- every use of the LHS. */
- FOR_EACH_IMM_USE_SAFE (use_p, iter, TREE_OPERAND (stmt, 0))
- {
- SET_USE (use_p, ASSERT_EXPR_VAR (rhs));
- update_stmt (USE_STMT (use_p));
- }
+ /* Propagate the RHS into every use of the LHS. */
+ var = ASSERT_EXPR_VAR (rhs);
+ FOR_EACH_IMM_USE_STMT (use_stmt, iter, TREE_OPERAND (stmt, 0))
+ FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+ {
+ SET_USE (use_p, var);
+ gcc_assert (TREE_CODE (var) == SSA_NAME);
+ }
/* And finally, remove the copy, it is not needed. */
bsi_remove (&si, true);
else if (TREE_CODE (stmt) == MODIFY_EXPR)
{
tree lhs = TREE_OPERAND (stmt, 0);
+ tree rhs = TREE_OPERAND (stmt, 1);
+ /* In general, assignments with virtual operands are not useful
+ for deriving ranges, with the obvious exception of calls to
+ builtin functions. */
if (TREE_CODE (lhs) == SSA_NAME
&& (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
|| POINTER_TYPE_P (TREE_TYPE (lhs)))
- && ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
+ && ((TREE_CODE (rhs) == CALL_EXPR
+ && TREE_CODE (TREE_OPERAND (rhs, 0)) == ADDR_EXPR
+ && DECL_P (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0))
+ && DECL_IS_BUILTIN (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0)))
+ || ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)))
return true;
}
else if (TREE_CODE (stmt) == COND_EXPR || TREE_CODE (stmt) == SWITCH_EXPR)
/* We only keep track of ranges in integral and pointer types. */
if (TREE_CODE (lhs) == SSA_NAME
- && (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ /* It is valid to have NULL MIN/MAX values on a type. See
+ build_range_type. */
+ && TYPE_MIN_VALUE (TREE_TYPE (lhs))
+ && TYPE_MAX_VALUE (TREE_TYPE (lhs)))
|| POINTER_TYPE_P (TREE_TYPE (lhs))))
{
struct loop *l;
}
ann = stmt_ann (stmt);
- if (TREE_CODE (stmt) == MODIFY_EXPR
- && ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
- return vrp_visit_assignment (stmt, output_p);
+ if (TREE_CODE (stmt) == MODIFY_EXPR)
+ {
+ tree rhs = TREE_OPERAND (stmt, 1);
+
+ /* In general, assignments with virtual operands are not useful
+ for deriving ranges, with the obvious exception of calls to
+ builtin functions. */
+ if ((TREE_CODE (rhs) == CALL_EXPR
+ && TREE_CODE (TREE_OPERAND (rhs, 0)) == ADDR_EXPR
+ && DECL_P (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0))
+ && DECL_IS_BUILTIN (TREE_OPERAND (TREE_OPERAND (rhs, 0), 0)))
+ || ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
+ return vrp_visit_assignment (stmt, output_p);
+ }
else if (TREE_CODE (stmt) == COND_EXPR || TREE_CODE (stmt) == SWITCH_EXPR)
return vrp_visit_cond_stmt (stmt, taken_edge_p);
free (single_val_range);
free (vr_value);
+
+ /* So that we can distinguish between VRP data being available
+ and not available. */
+ vr_value = NULL;
}
DON'T KNOW. In the future, it may be worthwhile to propagate
probabilities to aid branch prediction. */
-static void
+static unsigned int
execute_vrp (void)
{
insert_range_assertions ();
update_ssa (TODO_update_ssa);
finalize_jump_threads ();
-
+ return 0;
}
static bool
TV_TREE_VRP, /* tv_id */
PROP_ssa | PROP_alias, /* properties_required */
0, /* properties_provided */
- 0, /* properties_destroyed */
+ PROP_smt_usage, /* properties_destroyed */
0, /* todo_flags_start */
TODO_cleanup_cfg
| TODO_ggc_collect
| TODO_verify_ssa
| TODO_dump_func
- | TODO_update_ssa, /* todo_flags_finish */
+ | TODO_update_ssa
+ | TODO_update_smt_usage, /* todo_flags_finish */
0 /* letter */
};
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