{
tree tcmp;
+ fold_defer_overflow_warnings ();
+
tcmp = fold_binary_to_constant (LT_EXPR, boolean_type_node, val, val2);
+
+ fold_undefer_and_ignore_overflow_warnings ();
+
if (!tcmp)
return -2;
return;
}
- /* If we have a RSHIFT_EXPR with a possibly negative shift
- count or an anti-range shift count drop to VR_VARYING.
- We currently cannot handle the overflow cases correctly. */
- if (code == RSHIFT_EXPR
- && (vr1.type == VR_ANTI_RANGE
- || !vrp_expr_computes_nonnegative (op1, &sop)))
+ /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
+ then drop to VR_VARYING. Outside of this range we get undefined
+ behaviour 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. */
+ if (code == RSHIFT_EXPR)
{
- set_value_range_to_varying (vr);
- return;
+ if (vr1.type == VR_ANTI_RANGE
+ || !vrp_expr_computes_nonnegative (op1, &sop)
+ || (operand_less_p
+ (build_int_cst (TREE_TYPE (vr1.max),
+ TYPE_PRECISION (TREE_TYPE (expr)) - 1),
+ vr1.max) != 0))
+ {
+ set_value_range_to_varying (vr);
+ return;
+ }
}
/* Multiplications and divisions are a bit tricky to handle,
the new range. */
/* Divisions by zero result in a VARYING value. */
- if ((code != MULT_EXPR
- && code != RSHIFT_EXPR)
- && (vr0.type == VR_ANTI_RANGE || range_includes_zero_p (&vr1)))
+ else if (code != MULT_EXPR
+ && (vr0.type == VR_ANTI_RANGE || range_includes_zero_p (&vr1)))
{
set_value_range_to_varying (vr);
return;
return;
}
+ /* We punt if:
+ 1) [-INF, +INF]
+ 2) [-INF, +-INF(OVF)]
+ 3) [+-INF(OVF), +INF]
+ 4) [+-INF(OVF), +-INF(OVF)]
+ We learn nothing when we have INF and INF(OVF) on both sides.
+ Note that we do accept [-INF, -INF] and [+INF, +INF] without
+ overflow. */
if ((min == TYPE_MIN_VALUE (TREE_TYPE (min))
- || is_negative_overflow_infinity (min))
+ || is_overflow_infinity (min))
&& (max == TYPE_MAX_VALUE (TREE_TYPE (max))
- || is_positive_overflow_infinity (max)))
+ || is_overflow_infinity (max)))
{
set_value_range_to_varying (vr);
return;
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;
+ unsigned num_uses, num_loads, num_stores;
- count_uses_and_derefs (op, stmt, &num_uses, &num_derefs, &is_store);
- if (num_derefs > 0)
+ count_uses_and_derefs (op, stmt, &num_uses, &num_loads, &num_stores);
+ if (num_loads + num_stores > 0)
{
*val_p = build_int_cst (TREE_TYPE (op), 0);
*comp_code_p = NE_EXPR;
/* Determine whether the outgoing edges of BB should receive an
ASSERT_EXPR for each of the operands of BB's LAST statement.
- The last statement of BB must be a COND_EXPR or a SWITCH_EXPR.
+ The last statement of BB must be a COND_EXPR.
If any of the sub-graphs rooted at BB have an interesting use of
the predicate operands, an assert location node is added to the
return need_assert;
}
+/* Compare two case labels sorting first by the destination label uid
+ and then by the case value. */
+
+static int
+compare_case_labels (const void *p1, const void *p2)
+{
+ tree case1 = *(tree *)p1;
+ tree case2 = *(tree *)p2;
+ unsigned int uid1 = DECL_UID (CASE_LABEL (case1));
+ unsigned int uid2 = DECL_UID (CASE_LABEL (case2));
+
+ if (uid1 < uid2)
+ return -1;
+ else if (uid1 == uid2)
+ {
+ /* Make sure the default label is first in a group. */
+ if (!CASE_LOW (case1))
+ return -1;
+ else if (!CASE_LOW (case2))
+ return 1;
+ else
+ return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
+ }
+ else
+ return 1;
+}
+
+/* Determine whether the outgoing edges of BB should receive an
+ ASSERT_EXPR for each of the operands of BB's LAST statement.
+ The last statement of BB must be a SWITCH_EXPR.
+
+ If any of the sub-graphs rooted at BB have an interesting use of
+ the predicate operands, an assert location node is added to the
+ list of assertions for the corresponding operands. */
+
+static bool
+find_switch_asserts (basic_block bb, tree last)
+{
+ bool need_assert;
+ block_stmt_iterator bsi;
+ tree op, cond;
+ edge e;
+ tree vec = SWITCH_LABELS (last), vec2;
+ size_t n = TREE_VEC_LENGTH (vec);
+ unsigned int idx;
+
+ need_assert = false;
+ bsi = bsi_for_stmt (last);
+ op = TREE_OPERAND (last, 0);
+ if (TREE_CODE (op) != SSA_NAME)
+ return false;
+
+ /* Build a vector of case labels sorted by destination label. */
+ vec2 = make_tree_vec (n);
+ for (idx = 0; idx < n; ++idx)
+ TREE_VEC_ELT (vec2, idx) = TREE_VEC_ELT (vec, idx);
+ qsort (&TREE_VEC_ELT (vec2, 0), n, sizeof (tree), compare_case_labels);
+
+ for (idx = 0; idx < n; ++idx)
+ {
+ tree min, max;
+ tree cl = TREE_VEC_ELT (vec2, idx);
+
+ min = CASE_LOW (cl);
+ max = CASE_HIGH (cl);
+
+ /* If there are multiple case labels with the same destination
+ we need to combine them to a single value range for the edge. */
+ if (idx + 1 < n
+ && CASE_LABEL (cl) == CASE_LABEL (TREE_VEC_ELT (vec2, idx + 1)))
+ {
+ /* Skip labels until the last of the group. */
+ do {
+ ++idx;
+ } while (idx < n
+ && CASE_LABEL (cl) == CASE_LABEL (TREE_VEC_ELT (vec2, idx)));
+ --idx;
+
+ /* Pick up the maximum of the case label range. */
+ if (CASE_HIGH (TREE_VEC_ELT (vec2, idx)))
+ max = CASE_HIGH (TREE_VEC_ELT (vec2, idx));
+ else
+ max = CASE_LOW (TREE_VEC_ELT (vec2, idx));
+ }
+
+ /* Nothing to do if the range includes the default label until we
+ can register anti-ranges. */
+ if (min == NULL_TREE)
+ continue;
+
+ /* Find the edge to register the assert expr on. */
+ e = find_edge (bb, label_to_block (CASE_LABEL (cl)));
+
+ /* Remove the SWITCH_EXPR operand from the FOUND_IN_SUBGRAPH bitmap.
+ Otherwise, when we finish traversing each of the sub-graphs, we
+ won't know whether the variables were found in the sub-graphs or
+ if they had been found in a block upstream from BB. */
+ RESET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
+
+ /* Traverse the strictly dominated sub-graph rooted at E->DEST
+ to determine if any of the operands in the conditional
+ predicate are used. */
+ if (e->dest != bb)
+ need_assert |= find_assert_locations (e->dest);
+
+ /* Register the necessary assertions for the operand in the
+ SWITCH_EXPR. */
+ cond = build2 (max ? GE_EXPR : EQ_EXPR, boolean_type_node,
+ op, fold_convert (TREE_TYPE (op), min));
+ need_assert |= register_edge_assert_for (op, e, bsi, cond);
+ if (max)
+ {
+ cond = build2 (LE_EXPR, boolean_type_node,
+ op, fold_convert (TREE_TYPE (op), max));
+ need_assert |= register_edge_assert_for (op, e, bsi, cond);
+ }
+ }
+
+ /* Finally, indicate that we have found the operand in the
+ SWITCH_EXPR. */
+ SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));
+
+ return need_assert;
+}
+
/* Traverse all the statements in block BB looking for statements that
may generate useful assertions for the SSA names in their operand.
If this function returns true, then it means that there are names
for which we need to generate ASSERT_EXPRs. Those assertions are
- inserted by process_assert_insertions.
-
- TODO. Handle SWITCH_EXPR. */
+ inserted by process_assert_insertions. */
static bool
find_assert_locations (basic_block bb)
&& !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
need_assert |= find_conditional_asserts (bb, last);
+ if (last
+ && TREE_CODE (last) == SWITCH_EXPR
+ && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
+ need_assert |= find_switch_asserts (bb, last);
+
/* Recurse into the dominator children of BB. */
for (son = first_dom_son (CDI_DOMINATORS, bb);
son;
*taken_edge_p = NULL;
- /* FIXME. Handle SWITCH_EXPRs. But first, the assert pass needs to
- add ASSERT_EXPRs for them. */
+ /* FIXME. Handle SWITCH_EXPRs. */
if (TREE_CODE (stmt) == SWITCH_EXPR)
return SSA_PROP_VARYING;
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