diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/tree-vrp.c | 106 |
2 files changed, 107 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index db61759..93ac1f5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2012-08-01 Tom de Vries <tom@codesourcery.com> + + * tree-vrp.c (find_case_label_ranges): New function. + (vrp_visit_switch_stmt, simplify_switch_using_ranges): Use + find_case_label_ranges instead of find_case_label_range. Handle second + range. + 2012-08-01 Michael Matz <matz@suse.de> * tree-complex.c (init_parameter_lattice_values): Don't call var_ann. diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 1a4c7c9f..9a18b22 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -6754,6 +6754,84 @@ find_case_label_range (gimple stmt, tree min, tree max, size_t *min_idx, } } +/* Searches the case label vector VEC for the ranges of CASE_LABELs that are + used in range VR. The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and + MAX_IDX2. If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1. + Returns true if the default label is not needed. */ + +static bool +find_case_label_ranges (gimple stmt, value_range_t *vr, size_t *min_idx1, + size_t *max_idx1, size_t *min_idx2, + size_t *max_idx2) +{ + size_t i, j, k, l; + unsigned int n = gimple_switch_num_labels (stmt); + bool take_default; + tree case_low, case_high; + tree min = vr->min, max = vr->max; + + gcc_checking_assert (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE); + + take_default = !find_case_label_range (stmt, min, max, &i, &j); + + /* Set second range to emtpy. */ + *min_idx2 = 1; + *max_idx2 = 0; + + if (vr->type == VR_RANGE) + { + *min_idx1 = i; + *max_idx1 = j; + return !take_default; + } + + /* Set first range to all case labels. */ + *min_idx1 = 1; + *max_idx1 = n - 1; + + if (i > j) + return false; + + /* Make sure all the values of case labels [i , j] are contained in + range [MIN, MAX]. */ + case_low = CASE_LOW (gimple_switch_label (stmt, i)); + case_high = CASE_HIGH (gimple_switch_label (stmt, j)); + if (tree_int_cst_compare (case_low, min) < 0) + i += 1; + if (case_high != NULL_TREE + && tree_int_cst_compare (max, case_high) < 0) + j -= 1; + + if (i > j) + return false; + + /* If the range spans case labels [i, j], the corresponding anti-range spans + the labels [1, i - 1] and [j + 1, n - 1]. */ + k = j + 1; + l = n - 1; + if (k > l) + { + k = 1; + l = 0; + } + + j = i - 1; + i = 1; + if (i > j) + { + i = k; + j = l; + k = 1; + l = 0; + } + + *min_idx1 = i; + *max_idx1 = j; + *min_idx2 = k; + *max_idx2 = l; + return false; +} + /* Visit switch statement STMT. If we can determine which edge will be taken out of STMT's basic block, record it in *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return @@ -6764,7 +6842,7 @@ vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p) { tree op, val; value_range_t *vr; - size_t i = 0, j = 0; + size_t i = 0, j = 0, k, l; bool take_default; *taken_edge_p = NULL; @@ -6782,12 +6860,13 @@ vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p) fprintf (dump_file, "\n"); } - if (vr->type != VR_RANGE + if ((vr->type != VR_RANGE + && vr->type != VR_ANTI_RANGE) || symbolic_range_p (vr)) return SSA_PROP_VARYING; /* Find the single edge that is taken from the switch expression. */ - take_default = !find_case_label_range (stmt, vr->min, vr->max, &i, &j); + take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l); /* Check if the range spans no CASE_LABEL. If so, we only reach the default label */ @@ -6821,6 +6900,16 @@ vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p) return SSA_PROP_VARYING; } } + for (; k <= l; ++k) + { + if (CASE_LABEL (gimple_switch_label (stmt, k)) != CASE_LABEL (val)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " not a single destination for this " + "range\n"); + return SSA_PROP_VARYING; + } + } } *taken_edge_p = find_edge (gimple_bb (stmt), @@ -8215,18 +8304,20 @@ simplify_switch_using_ranges (gimple stmt) size_t i = 0, j = 0, n, n2; tree vec2; switch_update su; + size_t k = 1, l = 0; if (TREE_CODE (op) == SSA_NAME) { vr = get_value_range (op); /* We can only handle integer ranges. */ - if (vr->type != VR_RANGE + if ((vr->type != VR_RANGE + && vr->type != VR_ANTI_RANGE) || symbolic_range_p (vr)) return false; /* Find case label for min/max of the value range. */ - take_default = !find_case_label_range (stmt, vr->min, vr->max, &i, &j); + take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l); } else if (TREE_CODE (op) == INTEGER_CST) { @@ -8253,7 +8344,7 @@ simplify_switch_using_ranges (gimple stmt) return false; /* Build a new vector of taken case labels. */ - vec2 = make_tree_vec (j - i + 1 + (int)take_default); + vec2 = make_tree_vec (j - i + 1 + l - k + 1 + (int)take_default); n2 = 0; /* Add the default edge, if necessary. */ @@ -8263,6 +8354,9 @@ simplify_switch_using_ranges (gimple stmt) for (; i <= j; ++i, ++n2) TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, i); + for (; k <= l; ++k, ++n2) + TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, k); + /* Mark needed edges. */ for (i = 0; i < n2; ++i) { |