[patch] Cleanup tree-switch-conversion a bit
Steven Bosscher
stevenb.gcc@gmail.com
Tue Apr 17 22:05:00 GMT 2012
Hello,
This is another step towards moving GIMPLE_SWITCH expansion to an
earlier point in the pipeline.
With the attached patch, some of the logic from stmt.c:add_case_node()
is moved to gimplify.c:gimplify_switch_expr(). This includes:
* Code to drop case labels that are out of range for the switch index
expression. (Actually, I suspect this code hasn't worked properly
since gimplification was introduced, because the switch index
expression can be promoted by language specific gimplification, so
expand_case never actually sees the proper type with the current
implementation in stmt.c.)
* Code to fold_convert case label values to the right type. I've opted
to go for folding to the original type of the SWITCH_EXPR, rather than
to the post-gimplification switch index type.
* Code to canonicalize CASE_LABEL's subnodes, CASE_LOW and CASE_HIGH.
I've chosen to impose strict requirements that CASE_HIGH > CASE_LOW if
CASE_HIGH is non-zero. This is different from what add_case_node does,
but I think it makes sense to go for the minimal representation here:
The case labels in stmt.c never lived very long (only during expand)
but GIMPLE_SWITCH statements stay around for much of the compilation
process and can also be streamed out, etc.
Bootstrapped and tested on powerpc-unknown-linux-gnu. OK for trunk?
Ciao!
Steven
-------------- next part --------------
* targhooks.c (default_case_values_threshold): Fix code style nit.
* stmt.c (add_case_node, expand_case): Move logic to remove/reduce
case range and type folding from here...
* gimplify.c (gimplify_switch_expr): ... to here.
Index: targhooks.c
===================================================================
--- targhooks.c (revision 186526)
+++ targhooks.c (working copy)
@@ -1200,7 +1200,8 @@ default_target_can_inline_p (tree caller, tree cal
this means extra overhead for dispatch tables, which raises the
threshold for using them. */
-unsigned int default_case_values_threshold (void)
+unsigned int
+default_case_values_threshold (void)
{
return (HAVE_casesi ? 4 : 5);
}
Index: tree-switch-conversion.c
===================================================================
--- tree-switch-conversion.c (revision 186526)
+++ tree-switch-conversion.c (working copy)
@@ -24,8 +24,8 @@ Software Foundation, 51 Franklin Street, Fifth Flo
Switch initialization conversion
The following pass changes simple initializations of scalars in a switch
-statement into initializations from a static array. Obviously, the values must
-be constant and known at compile time and a default branch must be
+statement into initializations from a static array. Obviously, the values
+must be constant and known at compile time and a default branch must be
provided. For example, the following code:
int a,b;
@@ -162,16 +162,12 @@ struct switch_conv_info
basic_block bit_test_bb[2];
};
-/* Global pass info. */
-static struct switch_conv_info info;
-
-
/* Checks whether the range given by individual case statements of the SWTCH
switch statement isn't too big and whether the number of branches actually
satisfies the size of the new array. */
static bool
-check_range (gimple swtch)
+check_range (gimple swtch, struct switch_conv_info *info)
{
tree min_case, max_case;
unsigned int branch_num = gimple_switch_num_labels (swtch);
@@ -181,7 +177,7 @@ static bool
is a default label which is the first in the vector. */
min_case = gimple_switch_label (swtch, 1);
- info.range_min = CASE_LOW (min_case);
+ info->range_min = CASE_LOW (min_case);
gcc_assert (branch_num > 1);
gcc_assert (CASE_LOW (gimple_switch_label (swtch, 0)) == NULL_TREE);
@@ -191,22 +187,22 @@ static bool
else
range_max = CASE_LOW (max_case);
- gcc_assert (info.range_min);
+ gcc_assert (info->range_min);
gcc_assert (range_max);
- info.range_size = int_const_binop (MINUS_EXPR, range_max, info.range_min);
+ info->range_size = int_const_binop (MINUS_EXPR, range_max, info->range_min);
- gcc_assert (info.range_size);
- if (!host_integerp (info.range_size, 1))
+ gcc_assert (info->range_size);
+ if (!host_integerp (info->range_size, 1))
{
- info.reason = "index range way too large or otherwise unusable.\n";
+ info->reason = "index range way too large or otherwise unusable";
return false;
}
- if ((unsigned HOST_WIDE_INT) tree_low_cst (info.range_size, 1)
+ if ((unsigned HOST_WIDE_INT) tree_low_cst (info->range_size, 1)
> ((unsigned) branch_num * SWITCH_CONVERSION_BRANCH_RATIO))
{
- info.reason = "the maximum range-branch ratio exceeded.\n";
+ info->reason = "the maximum range-branch ratio exceeded";
return false;
}
@@ -219,7 +215,7 @@ static bool
and returns true. Otherwise returns false. */
static bool
-check_process_case (tree cs)
+check_process_case (tree cs, struct switch_conv_info *info)
{
tree ldecl;
basic_block label_bb, following_bb;
@@ -228,48 +224,48 @@ static bool
ldecl = CASE_LABEL (cs);
label_bb = label_to_block (ldecl);
- e = find_edge (info.switch_bb, label_bb);
+ e = find_edge (info->switch_bb, label_bb);
gcc_assert (e);
if (CASE_LOW (cs) == NULL_TREE)
{
/* Default branch. */
- info.default_prob = e->probability;
- info.default_count = e->count;
+ info->default_prob = e->probability;
+ info->default_count = e->count;
}
else
{
int i;
- info.other_count += e->count;
+ info->other_count += e->count;
for (i = 0; i < 2; i++)
- if (info.bit_test_bb[i] == label_bb)
+ if (info->bit_test_bb[i] == label_bb)
break;
- else if (info.bit_test_bb[i] == NULL)
+ else if (info->bit_test_bb[i] == NULL)
{
- info.bit_test_bb[i] = label_bb;
- info.bit_test_uniq++;
+ info->bit_test_bb[i] = label_bb;
+ info->bit_test_uniq++;
break;
}
if (i == 2)
- info.bit_test_uniq = 3;
+ info->bit_test_uniq = 3;
if (CASE_HIGH (cs) != NULL_TREE
&& ! tree_int_cst_equal (CASE_LOW (cs), CASE_HIGH (cs)))
- info.bit_test_count += 2;
+ info->bit_test_count += 2;
else
- info.bit_test_count++;
+ info->bit_test_count++;
}
if (!label_bb)
{
- info.reason = " Bad case - cs BB label is NULL\n";
+ info->reason = "bad case - cs BB label is NULL";
return false;
}
if (!single_pred_p (label_bb))
{
- if (info.final_bb && info.final_bb != label_bb)
+ if (info->final_bb && info->final_bb != label_bb)
{
- info.reason = " Bad case - a non-final BB has two predecessors\n";
+ info->reason = "bad case - a non-final BB has two predecessors";
return false; /* sth complex going on in this branch */
}
@@ -279,7 +275,7 @@ static bool
{
if (!empty_block_p (label_bb))
{
- info.reason = " Bad case - a non-final BB not empty\n";
+ info->reason = "bad case - a non-final BB not empty";
return false;
}
@@ -287,11 +283,11 @@ static bool
following_bb = single_succ (label_bb);
}
- if (!info.final_bb)
- info.final_bb = following_bb;
- else if (info.final_bb != following_bb)
+ if (!info->final_bb)
+ info->final_bb = following_bb;
+ else if (info->final_bb != following_bb)
{
- info.reason = " Bad case - different final BB\n";
+ info->reason = "bad case - different final BB";
return false; /* the only successor is not common for all the branches */
}
@@ -304,31 +300,31 @@ static bool
phi nodes are OK, otherwise false. */
static bool
-check_final_bb (void)
+check_final_bb (struct switch_conv_info *info)
{
gimple_stmt_iterator gsi;
- info.phi_count = 0;
- for (gsi = gsi_start_phis (info.final_bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ info->phi_count = 0;
+ for (gsi = gsi_start_phis (info->final_bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gimple phi = gsi_stmt (gsi);
unsigned int i;
- info.phi_count++;
+ info->phi_count++;
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
basic_block bb = gimple_phi_arg_edge (phi, i)->src;
- if (bb == info.switch_bb
- || (single_pred_p (bb) && single_pred (bb) == info.switch_bb))
+ if (bb == info->switch_bb
+ || (single_pred_p (bb) && single_pred (bb) == info->switch_bb))
{
tree reloc, val;
val = gimple_phi_arg_def (phi, i);
if (!is_gimple_ip_invariant (val))
{
- info.reason = " Non-invariant value from a case\n";
+ info->reason = "non-invariant value from a case";
return false; /* Non-invariant argument. */
}
reloc = initializer_constant_valid_p (val, TREE_TYPE (val));
@@ -336,11 +332,11 @@ static bool
|| (!flag_pic && reloc == NULL_TREE))
{
if (reloc)
- info.reason
- = " Value from a case would need runtime relocations\n";
+ info->reason
+ = "value from a case would need runtime relocations";
else
- info.reason
- = " Value from a case is not a valid initializer\n";
+ info->reason
+ = "value from a case is not a valid initializer";
return false;
}
}
@@ -355,17 +351,17 @@ static bool
vectors that will become constructors of new arrays. */
static void
-create_temp_arrays (void)
+create_temp_arrays (struct switch_conv_info *info)
{
int i;
- info.default_values = XCNEWVEC (tree, info.phi_count * 3);
- info.constructors = XCNEWVEC (VEC (constructor_elt, gc) *, info.phi_count);
- info.target_inbound_names = info.default_values + info.phi_count;
- info.target_outbound_names = info.target_inbound_names + info.phi_count;
- for (i = 0; i < info.phi_count; i++)
- info.constructors[i]
- = VEC_alloc (constructor_elt, gc, tree_low_cst (info.range_size, 1) + 1);
+ info->default_values = XCNEWVEC (tree, info->phi_count * 3);
+ info->constructors = XCNEWVEC (VEC (constructor_elt, gc) *, info->phi_count);
+ info->target_inbound_names = info->default_values + info->phi_count;
+ info->target_outbound_names = info->target_inbound_names + info->phi_count;
+ for (i = 0; i < info->phi_count; i++)
+ info->constructors[i]
+ = VEC_alloc (constructor_elt, gc, tree_low_cst (info->range_size, 1) + 1);
}
/* Free the arrays created by create_temp_arrays(). The vectors that are
@@ -373,17 +369,17 @@ static void
already become constructors and must be preserved. */
static void
-free_temp_arrays (void)
+free_temp_arrays (struct switch_conv_info *info)
{
- XDELETEVEC (info.constructors);
- XDELETEVEC (info.default_values);
+ XDELETEVEC (info->constructors);
+ XDELETEVEC (info->default_values);
}
/* Populate the array of default values in the order of phi nodes.
DEFAULT_CASE is the CASE_LABEL_EXPR for the default switch branch. */
static void
-gather_default_values (tree default_case)
+gather_default_values (tree default_case, struct switch_conv_info *info)
{
gimple_stmt_iterator gsi;
basic_block bb = label_to_block (CASE_LABEL (default_case));
@@ -392,17 +388,17 @@ static void
gcc_assert (CASE_LOW (default_case) == NULL_TREE);
- if (bb == info.final_bb)
- e = find_edge (info.switch_bb, bb);
+ if (bb == info->final_bb)
+ e = find_edge (info->switch_bb, bb);
else
e = single_succ_edge (bb);
- for (gsi = gsi_start_phis (info.final_bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ for (gsi = gsi_start_phis (info->final_bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gimple phi = gsi_stmt (gsi);
tree val = PHI_ARG_DEF_FROM_EDGE (phi, e);
gcc_assert (val);
- info.default_values[i++] = val;
+ info->default_values[i++] = val;
}
}
@@ -411,10 +407,10 @@ static void
order of phi nodes. SWTCH is the switch statement being converted. */
static void
-build_constructors (gimple swtch)
+build_constructors (gimple swtch, struct switch_conv_info *info)
{
unsigned i, branch_num = gimple_switch_num_labels (swtch);
- tree pos = info.range_min;
+ tree pos = info->range_min;
for (i = 1; i < branch_num; i++)
{
@@ -425,8 +421,8 @@ static void
gimple_stmt_iterator gsi;
int j;
- if (bb == info.final_bb)
- e = find_edge (info.switch_bb, bb);
+ if (bb == info->final_bb)
+ e = find_edge (info->switch_bb, bb);
else
e = single_succ_edge (bb);
gcc_assert (e);
@@ -434,15 +430,15 @@ static void
while (tree_int_cst_lt (pos, CASE_LOW (cs)))
{
int k;
- for (k = 0; k < info.phi_count; k++)
+ for (k = 0; k < info->phi_count; k++)
{
constructor_elt *elt;
elt = VEC_quick_push (constructor_elt,
- info.constructors[k], NULL);
+ info->constructors[k], NULL);
elt->index = int_const_binop (MINUS_EXPR, pos,
- info.range_min);
- elt->value = info.default_values[k];
+ info->range_min);
+ elt->value = info->default_values[k];
}
pos = int_const_binop (PLUS_EXPR, pos, integer_one_node);
@@ -454,7 +450,7 @@ static void
high = CASE_HIGH (cs);
else
high = CASE_LOW (cs);
- for (gsi = gsi_start_phis (info.final_bb);
+ for (gsi = gsi_start_phis (info->final_bb);
!gsi_end_p (gsi); gsi_next (&gsi))
{
gimple phi = gsi_stmt (gsi);
@@ -467,8 +463,8 @@ static void
constructor_elt *elt;
elt = VEC_quick_push (constructor_elt,
- info.constructors[j], NULL);
- elt->index = int_const_binop (MINUS_EXPR, pos, info.range_min);
+ info->constructors[j], NULL);
+ elt->index = int_const_binop (MINUS_EXPR, pos, info->range_min);
elt->value = val;
pos = int_const_binop (PLUS_EXPR, pos, integer_one_node);
@@ -505,9 +501,10 @@ constructor_contains_same_values_p (VEC (construct
all the constants. */
static tree
-array_value_type (gimple swtch, tree type, int num)
+array_value_type (gimple swtch, tree type, int num,
+ struct switch_conv_info *info)
{
- unsigned int i, len = VEC_length (constructor_elt, info.constructors[num]);
+ unsigned int i, len = VEC_length (constructor_elt, info->constructors[num]);
constructor_elt *elt;
enum machine_mode mode;
int sign = 0;
@@ -523,7 +520,7 @@ static tree
if (len < (optimize_bb_for_size_p (gimple_bb (swtch)) ? 2 : 32))
return type;
- FOR_EACH_VEC_ELT (constructor_elt, info.constructors[num], i, elt)
+ FOR_EACH_VEC_ELT (constructor_elt, info->constructors[num], i, elt)
{
double_int cst;
@@ -585,37 +582,37 @@ static tree
static void
build_one_array (gimple swtch, int num, tree arr_index_type, gimple phi,
- tree tidx)
+ tree tidx, struct switch_conv_info *info)
{
tree name, cst;
gimple load;
gimple_stmt_iterator gsi = gsi_for_stmt (swtch);
location_t loc = gimple_location (swtch);
- gcc_assert (info.default_values[num]);
+ gcc_assert (info->default_values[num]);
name = make_ssa_name (SSA_NAME_VAR (PHI_RESULT (phi)), NULL);
- info.target_inbound_names[num] = name;
+ info->target_inbound_names[num] = name;
- cst = constructor_contains_same_values_p (info.constructors[num]);
+ cst = constructor_contains_same_values_p (info->constructors[num]);
if (cst)
load = gimple_build_assign (name, cst);
else
{
tree array_type, ctor, decl, value_type, fetch, default_type;
- default_type = TREE_TYPE (info.default_values[num]);
- value_type = array_value_type (swtch, default_type, num);
+ default_type = TREE_TYPE (info->default_values[num]);
+ value_type = array_value_type (swtch, default_type, num, info);
array_type = build_array_type (value_type, arr_index_type);
if (default_type != value_type)
{
unsigned int i;
constructor_elt *elt;
- FOR_EACH_VEC_ELT (constructor_elt, info.constructors[num], i, elt)
+ FOR_EACH_VEC_ELT (constructor_elt, info->constructors[num], i, elt)
elt->value = fold_convert (value_type, elt->value);
}
- ctor = build_constructor (array_type, info.constructors[num]);
+ ctor = build_constructor (array_type, info->constructors[num]);
TREE_CONSTANT (ctor) = true;
TREE_STATIC (ctor) = true;
@@ -645,7 +642,7 @@ build_one_array (gimple swtch, int num, tree arr_i
SSA_NAME_DEF_STMT (name) = load;
gsi_insert_before (&gsi, load, GSI_SAME_STMT);
update_stmt (load);
- info.arr_ref_last = load;
+ info->arr_ref_last = load;
}
/* Builds and initializes static arrays initialized with values gathered from
@@ -653,7 +650,7 @@ build_one_array (gimple swtch, int num, tree arr_i
them. */
static void
-build_arrays (gimple swtch)
+build_arrays (gimple swtch, struct switch_conv_info *info)
{
tree arr_index_type;
tree tidx, sub, tmp, utype;
@@ -665,19 +662,19 @@ static void
gsi = gsi_for_stmt (swtch);
/* Make sure we do not generate arithmetics in a subrange. */
- utype = TREE_TYPE (info.index_expr);
+ utype = TREE_TYPE (info->index_expr);
if (TREE_TYPE (utype))
utype = lang_hooks.types.type_for_mode (TYPE_MODE (TREE_TYPE (utype)), 1);
else
utype = lang_hooks.types.type_for_mode (TYPE_MODE (utype), 1);
- arr_index_type = build_index_type (info.range_size);
+ arr_index_type = build_index_type (info->range_size);
tmp = create_tmp_var (utype, "csui");
add_referenced_var (tmp);
tidx = make_ssa_name (tmp, NULL);
sub = fold_build2_loc (loc, MINUS_EXPR, utype,
- fold_convert_loc (loc, utype, info.index_expr),
- fold_convert_loc (loc, utype, info.range_min));
+ fold_convert_loc (loc, utype, info->index_expr),
+ fold_convert_loc (loc, utype, info->range_min));
sub = force_gimple_operand_gsi (&gsi, sub,
false, NULL, true, GSI_SAME_STMT);
stmt = gimple_build_assign (tidx, sub);
@@ -685,29 +682,29 @@ static void
gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
update_stmt (stmt);
- info.arr_ref_first = stmt;
+ info->arr_ref_first = stmt;
- for (gsi = gsi_start_phis (info.final_bb), i = 0;
+ for (gsi = gsi_start_phis (info->final_bb), i = 0;
!gsi_end_p (gsi); gsi_next (&gsi), i++)
- build_one_array (swtch, i, arr_index_type, gsi_stmt (gsi), tidx);
+ build_one_array (swtch, i, arr_index_type, gsi_stmt (gsi), tidx, info);
}
/* Generates and appropriately inserts loads of default values at the position
given by BSI. Returns the last inserted statement. */
static gimple
-gen_def_assigns (gimple_stmt_iterator *gsi)
+gen_def_assigns (gimple_stmt_iterator *gsi, struct switch_conv_info *info)
{
int i;
gimple assign = NULL;
- for (i = 0; i < info.phi_count; i++)
+ for (i = 0; i < info->phi_count; i++)
{
tree name
- = make_ssa_name (SSA_NAME_VAR (info.target_inbound_names[i]), NULL);
+ = make_ssa_name (SSA_NAME_VAR (info->target_inbound_names[i]), NULL);
- info.target_outbound_names[i] = name;
- assign = gimple_build_assign (name, info.default_values[i]);
+ info->target_outbound_names[i] = name;
+ assign = gimple_build_assign (name, info->default_values[i]);
SSA_NAME_DEF_STMT (name) = assign;
gsi_insert_before (gsi, assign, GSI_SAME_STMT);
update_stmt (assign);
@@ -743,7 +740,8 @@ prune_bbs (basic_block bbd, basic_block final)
bbf description in the comment below). */
static void
-fix_phi_nodes (edge e1f, edge e2f, basic_block bbf)
+fix_phi_nodes (edge e1f, edge e2f, basic_block bbf,
+ struct switch_conv_info *info)
{
gimple_stmt_iterator gsi;
int i;
@@ -752,10 +750,9 @@ static void
!gsi_end_p (gsi); gsi_next (&gsi), i++)
{
gimple phi = gsi_stmt (gsi);
- add_phi_arg (phi, info.target_inbound_names[i], e1f, UNKNOWN_LOCATION);
- add_phi_arg (phi, info.target_outbound_names[i], e2f, UNKNOWN_LOCATION);
+ add_phi_arg (phi, info->target_inbound_names[i], e1f, UNKNOWN_LOCATION);
+ add_phi_arg (phi, info->target_outbound_names[i], e2f, UNKNOWN_LOCATION);
}
-
}
/* Creates a check whether the switch expression value actually falls into the
@@ -780,7 +777,7 @@ static void
*/
static void
-gen_inbound_check (gimple swtch)
+gen_inbound_check (gimple swtch, struct switch_conv_info *info)
{
tree label_decl1 = create_artificial_label (UNKNOWN_LOCATION);
tree label_decl2 = create_artificial_label (UNKNOWN_LOCATION);
@@ -797,17 +794,17 @@ static void
edge e01, e02, e21, e1d, e1f, e2f;
location_t loc = gimple_location (swtch);
- gcc_assert (info.default_values);
+ gcc_assert (info->default_values);
bb0 = gimple_bb (swtch);
- tidx = gimple_assign_lhs (info.arr_ref_first);
+ tidx = gimple_assign_lhs (info->arr_ref_first);
utype = TREE_TYPE (tidx);
/* (end of) block 0 */
- gsi = gsi_for_stmt (info.arr_ref_first);
+ gsi = gsi_for_stmt (info->arr_ref_first);
gsi_next (&gsi);
- bound = fold_convert_loc (loc, utype, info.range_size);
+ bound = fold_convert_loc (loc, utype, info->range_size);
cond_stmt = gimple_build_cond (LE_EXPR, tidx, bound, NULL_TREE, NULL_TREE);
gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);
update_stmt (cond_stmt);
@@ -815,14 +812,14 @@ static void
/* block 2 */
label2 = gimple_build_label (label_decl2);
gsi_insert_before (&gsi, label2, GSI_SAME_STMT);
- last_assign = gen_def_assigns (&gsi);
+ last_assign = gen_def_assigns (&gsi, info);
/* block 1 */
label1 = gimple_build_label (label_decl1);
gsi_insert_before (&gsi, label1, GSI_SAME_STMT);
/* block F */
- gsi = gsi_start_bb (info.final_bb);
+ gsi = gsi_start_bb (info->final_bb);
label3 = gimple_build_label (label_decl3);
gsi_insert_before (&gsi, label3, GSI_SAME_STMT);
@@ -834,40 +831,40 @@ static void
bb1 = e21->dest;
remove_edge (e21);
- e1d = split_block (bb1, info.arr_ref_last);
+ e1d = split_block (bb1, info->arr_ref_last);
bbd = e1d->dest;
remove_edge (e1d);
/* flags and profiles of the edge for in-range values */
e01 = make_edge (bb0, bb1, EDGE_TRUE_VALUE);
- e01->probability = REG_BR_PROB_BASE - info.default_prob;
- e01->count = info.other_count;
+ e01->probability = REG_BR_PROB_BASE - info->default_prob;
+ e01->count = info->other_count;
/* flags and profiles of the edge taking care of out-of-range values */
e02->flags &= ~EDGE_FALLTHRU;
e02->flags |= EDGE_FALSE_VALUE;
- e02->probability = info.default_prob;
- e02->count = info.default_count;
+ e02->probability = info->default_prob;
+ e02->count = info->default_count;
- bbf = info.final_bb;
+ bbf = info->final_bb;
e1f = make_edge (bb1, bbf, EDGE_FALLTHRU);
e1f->probability = REG_BR_PROB_BASE;
- e1f->count = info.other_count;
+ e1f->count = info->other_count;
e2f = make_edge (bb2, bbf, EDGE_FALLTHRU);
e2f->probability = REG_BR_PROB_BASE;
- e2f->count = info.default_count;
+ e2f->count = info->default_count;
/* frequencies of the new BBs */
bb1->frequency = EDGE_FREQUENCY (e01);
bb2->frequency = EDGE_FREQUENCY (e02);
bbf->frequency = EDGE_FREQUENCY (e1f) + EDGE_FREQUENCY (e2f);
- prune_bbs (bbd, info.final_bb); /* To keep calc_dfs_tree() in dominance.c
+ prune_bbs (bbd, info->final_bb); /* To keep calc_dfs_tree() in dominance.c
happy. */
- fix_phi_nodes (e1f, e2f, bbf);
+ fix_phi_nodes (e1f, e2f, bbf, info);
free_dominance_info (CDI_DOMINATORS);
free_dominance_info (CDI_POST_DOMINATORS);
@@ -875,25 +872,25 @@ static void
/* The following function is invoked on every switch statement (the current one
is given in SWTCH) and runs the individual phases of switch conversion on it
- one after another until one fails or the conversion is completed. */
+ one after another until one fails or the conversion is completed.
+ Returns NULL on success, or a pointer to a string with the reason why the
+ conversion failed. */
-static bool
+static const char *
process_switch (gimple swtch)
{
unsigned int i, branch_num = gimple_switch_num_labels (swtch);
tree index_type;
+ struct switch_conv_info info;
/* Operand 2 is either NULL_TREE or a vector of cases (stmt.c). */
if (branch_num < 2)
- {
- info.reason = "switch has no labels\n";
- return false;
- }
+ return "switch has no labels";
+ info.reason = NULL;
info.final_bb = NULL;
info.switch_bb = gimple_bb (swtch);
info.index_expr = gimple_switch_index (swtch);
- index_type = TREE_TYPE (info.index_expr);
info.arr_ref_first = NULL;
info.arr_ref_last = NULL;
info.default_prob = 0;
@@ -906,24 +903,26 @@ process_switch (gimple swtch)
/* An ERROR_MARK occurs for various reasons including invalid data type.
(comment from stmt.c) */
+ index_type = TREE_TYPE (info.index_expr);
if (index_type == error_mark_node)
+ return "index error\n";
+
+ /* Check the case label values are within reasonable range: */
+ if (!check_range (swtch, &info))
{
- info.reason = "index error.\n";
- return false;
+ gcc_assert (info.reason);
+ return info.reason;
}
- /* Check the case label values are within reasonable range: */
- if (!check_range (swtch))
- return false;
-
/* For all the cases, see whether they are empty, the assignments they
represent constant and so on... */
for (i = 0; i < branch_num; i++)
- if (!check_process_case (gimple_switch_label (swtch, i)))
+ if (!check_process_case (gimple_switch_label (swtch, i), &info))
{
+ gcc_assert (info.reason);
if (dump_file)
- fprintf (dump_file, "Processing of case %i failed\n", i);
- return false;
+ fprintf (dump_file, "processing of case %i failed\n\t", i);
+ return info.reason;
}
if (info.bit_test_uniq <= 2)
@@ -933,27 +932,29 @@ process_switch (gimple swtch)
info.range_size, info.bit_test_uniq,
info.bit_test_count))
{
- info.reason = " Expanding as bit test is preferable\n";
- return false;
+ return "expanding as bit test is preferable";
}
}
- if (!check_final_bb ())
- return false;
+ if (!check_final_bb (&info))
+ {
+ gcc_assert (info.reason);
+ return info.reason;
+ }
/* At this point all checks have passed and we can proceed with the
transformation. */
- create_temp_arrays ();
- gather_default_values (gimple_switch_label (swtch, 0));
- build_constructors (swtch);
+ create_temp_arrays (&info);
+ gather_default_values (gimple_switch_label (swtch, 0), &info);
+ build_constructors (swtch, &info);
- build_arrays (swtch); /* Build the static arrays and assignments. */
- gen_inbound_check (swtch); /* Build the bounds check. */
+ build_arrays (swtch, &info); /* Build the static arrays and assignments. */
+ gen_inbound_check (swtch, &info); /* Build the bounds check. */
/* Cleanup: */
- free_temp_arrays ();
- return true;
+ free_temp_arrays (&info);
+ return NULL;
}
/* The main function of the pass scans statements for switches and invokes
@@ -966,6 +967,7 @@ do_switchconv (void)
FOR_EACH_BB (bb)
{
+ const char *failure_reason;
gimple stmt = last_stmt (bb);
if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
{
@@ -980,8 +982,8 @@ do_switchconv (void)
putc ('\n', dump_file);
}
- info.reason = NULL;
- if (process_switch (stmt))
+ failure_reason = process_switch (stmt);
+ if (! failure_reason)
{
if (dump_file)
{
@@ -993,10 +995,9 @@ do_switchconv (void)
{
if (dump_file)
{
- gcc_assert (info.reason);
fputs ("Bailing out - ", dump_file);
- fputs (info.reason, dump_file);
- fputs ("--------------------------------\n", dump_file);
+ fputs (failure_reason, dump_file);
+ fputs ("\n--------------------------------\n", dump_file);
}
}
}
Index: stmt.c
===================================================================
--- stmt.c (revision 186526)
+++ stmt.c (working copy)
@@ -1822,66 +1822,25 @@ expand_stack_restore (tree var)
fed to us in descending order from the sorted vector of case labels used
in the tree part of the middle end. So the list we construct is
sorted in ascending order. The bounds on the case range, LOW and HIGH,
- are converted to case's index type TYPE. */
+ are converted to case's index type TYPE. Note that the original type
+ of the case index in the source code is usually "lost" during
+ gimplification due to type promotion, but the case labels retain the
+ original type. */
static struct case_node *
add_case_node (struct case_node *head, tree type, tree low, tree high,
tree label, alloc_pool case_node_pool)
{
- tree min_value, max_value;
struct case_node *r;
- gcc_assert (TREE_CODE (low) == INTEGER_CST);
- gcc_assert (!high || TREE_CODE (high) == INTEGER_CST);
+ gcc_checking_assert (low);
+ gcc_checking_assert (! high || (TREE_TYPE (low) == TREE_TYPE (high)));
- min_value = TYPE_MIN_VALUE (type);
- max_value = TYPE_MAX_VALUE (type);
-
- /* If there's no HIGH value, then this is not a case range; it's
- just a simple case label. But that's just a degenerate case
- range.
- If the bounds are equal, turn this into the one-value case. */
- if (!high || tree_int_cst_equal (low, high))
- {
- /* If the simple case value is unreachable, ignore it. */
- if ((TREE_CODE (min_value) == INTEGER_CST
- && tree_int_cst_compare (low, min_value) < 0)
- || (TREE_CODE (max_value) == INTEGER_CST
- && tree_int_cst_compare (low, max_value) > 0))
- return head;
- low = fold_convert (type, low);
- high = low;
- }
- else
- {
- /* If the entire case range is unreachable, ignore it. */
- if ((TREE_CODE (min_value) == INTEGER_CST
- && tree_int_cst_compare (high, min_value) < 0)
- || (TREE_CODE (max_value) == INTEGER_CST
- && tree_int_cst_compare (low, max_value) > 0))
- return head;
-
- /* If the lower bound is less than the index type's minimum
- value, truncate the range bounds. */
- if (TREE_CODE (min_value) == INTEGER_CST
- && tree_int_cst_compare (low, min_value) < 0)
- low = min_value;
- low = fold_convert (type, low);
-
- /* If the upper bound is greater than the index type's maximum
- value, truncate the range bounds. */
- if (TREE_CODE (max_value) == INTEGER_CST
- && tree_int_cst_compare (high, max_value) > 0)
- high = max_value;
- high = fold_convert (type, high);
- }
-
-
/* Add this label to the chain. Make sure to drop overflow flags. */
r = (struct case_node *) pool_alloc (case_node_pool);
- r->low = build_int_cst_wide (TREE_TYPE (low), TREE_INT_CST_LOW (low),
+ r->low = build_int_cst_wide (type, TREE_INT_CST_LOW (low),
TREE_INT_CST_HIGH (low));
- r->high = build_int_cst_wide (TREE_TYPE (high), TREE_INT_CST_LOW (high),
+ r->high = build_int_cst_wide (type, TREE_INT_CST_LOW (high),
TREE_INT_CST_HIGH (high));
r->code_label = label;
r->parent = r->left = NULL;
@@ -2151,9 +2110,12 @@ expand_case (gimple stmt)
gcc_assert (low);
high = CASE_HIGH (elt);
- /* Discard empty ranges. */
- if (high && tree_int_cst_lt (high, low))
- continue;
+ /* The canonical from of a case label in GIMPLE is that a simple case
+ has an empty CASE_HIGH. For the casesi and tablejump expanders,
+ the back ends want simple cases to have high == low. */
+ gcc_assert (! high || tree_int_cst_lt (low, high));
+ if (! high)
+ high = low;
case_list = add_case_node (case_list, index_type, low, high,
CASE_LABEL (elt), case_node_pool);
@@ -2199,16 +2161,10 @@ expand_case (gimple stmt)
BITMAP_FREE (label_bitmap);
/* cleanup_tree_cfg removes all SWITCH_EXPR with a single
- destination, such as one with a default case only. However,
- it doesn't remove cases that are out of range for the switch
- type, so we may still get a zero here. */
- if (count == 0)
- {
- if (default_label)
- emit_jump (default_label);
- free_alloc_pool (case_node_pool);
- return;
- }
+ destination, such as one with a default case only.
+ It also removes cases that are out of range for the switch
+ type, so we should never get a zero here. */
+ gcc_assert (count > 0);
/* Compute span of values. */
range = fold_build2 (MINUS_EXPR, index_type, maxval, minval);
Index: gimplify.c
===================================================================
--- gimplify.c (revision 186526)
+++ gimplify.c (working copy)
@@ -1575,6 +1575,9 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pr
tree switch_expr = *expr_p;
gimple_seq switch_body_seq = NULL;
enum gimplify_status ret;
+ tree index_type = TREE_TYPE (switch_expr);
+ if (index_type == void_type_node)
+ index_type = TREE_TYPE (SWITCH_COND (switch_expr));
ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL, is_gimple_val,
fb_rvalue);
@@ -1585,6 +1588,7 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pr
{
VEC (tree,heap) *labels;
VEC (tree,heap) *saved_labels;
+ tree min_value, max_value;
tree default_case = NULL_TREE;
size_t i, len;
gimple gimple_switch;
@@ -1593,7 +1597,7 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pr
be bothered to null out the body too. */
gcc_assert (!SWITCH_LABELS (switch_expr));
- /* save old labels, get new ones from body, then restore the old
+ /* Save old labels, get new ones from body, then restore the old
labels. Save all the things from the switch body to append after. */
saved_labels = gimplify_ctxp->case_labels;
gimplify_ctxp->case_labels = VEC_alloc (tree, heap, 8);
@@ -1603,18 +1607,82 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pr
gimplify_ctxp->case_labels = saved_labels;
i = 0;
+ min_value = TYPE_MIN_VALUE (index_type);
+ max_value = TYPE_MAX_VALUE (index_type);
while (i < VEC_length (tree, labels))
{
tree elt = VEC_index (tree, labels, i);
tree low = CASE_LOW (elt);
+ tree high = CASE_HIGH (elt);
bool remove_element = FALSE;
+
if (low)
{
- /* Discard empty ranges. */
- tree high = CASE_HIGH (elt);
- if (high && tree_int_cst_lt (high, low))
- remove_element = TRUE;
+ gcc_checking_assert (TREE_CODE (low) == INTEGER_CST);
+ gcc_checking_assert (!high || TREE_CODE (high) == INTEGER_CST);
+
+ /* This is a non-default case label, i.e. it has a value.
+
+ See if the case label is reachable within the range of
+ the index type. Remove out-of-range case values. Turn
+ case ranges into a canonical form (high > low strictly)
+ and convert the case label values to the index type.
+
+ NB: The type of gimple_switch_index() may be the promoted
+ type, but the case labels retain the original type. */
+
+ if (high)
+ {
+ /* This is a case range. Discard empty ranges.
+ If the bounds or the range are equal, turn this
+ into a simple (one-value) case. */
+ int cmp = tree_int_cst_compare (high, low);
+ if (cmp < 0)
+ remove_element = TRUE;
+ else if (cmp == 0)
+ high = NULL_TREE;
+ }
+
+ if (! high)
+ {
+ /* If the simple case value is unreachable, ignore it. */
+ if ((TREE_CODE (min_value) == INTEGER_CST
+ && tree_int_cst_compare (low, min_value) < 0)
+ || (TREE_CODE (max_value) == INTEGER_CST
+ && tree_int_cst_compare (low, max_value) > 0))
+ remove_element = TRUE;
+ else
+ low = fold_convert (index_type, low);
+ }
+ else
+ {
+ /* If the entire case range is unreachable, ignore it. */
+ if ((TREE_CODE (min_value) == INTEGER_CST
+ && tree_int_cst_compare (high, min_value) < 0)
+ || (TREE_CODE (max_value) == INTEGER_CST
+ && tree_int_cst_compare (low, max_value) > 0))
+ remove_element = TRUE;
+ else
+ {
+ /* If the lower bound is less than the index type's
+ minimum value, truncate the range bounds. */
+ if (TREE_CODE (min_value) == INTEGER_CST
+ && tree_int_cst_compare (low, min_value) < 0)
+ low = min_value;
+ low = fold_convert (index_type, low);
+
+ /* If the upper bound is greater than the index type's
+ maximum value, truncate the range bounds. */
+ if (TREE_CODE (max_value) == INTEGER_CST
+ && tree_int_cst_compare (high, max_value) > 0)
+ high = max_value;
+ high = fold_convert (index_type, high);
+ }
+ }
+
+ CASE_LOW (elt) = low;
+ CASE_HIGH (elt) = high;
}
else
{
@@ -1636,25 +1704,21 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pr
if (!default_case)
{
- tree type = TREE_TYPE (switch_expr);
-
/* If the switch has no default label, add one, so that we jump
around the switch body. If the labels already cover the whole
- range of type, add the default label pointing to one of the
- existing labels. */
- if (type == void_type_node)
- type = TREE_TYPE (SWITCH_COND (switch_expr));
+ range of the switch index_type, add the default label pointing
+ to one of the existing labels. */
if (len
- && INTEGRAL_TYPE_P (type)
- && TYPE_MIN_VALUE (type)
- && TYPE_MAX_VALUE (type)
+ && INTEGRAL_TYPE_P (index_type)
+ && TYPE_MIN_VALUE (index_type)
+ && TYPE_MAX_VALUE (index_type)
&& tree_int_cst_equal (CASE_LOW (VEC_index (tree, labels, 0)),
- TYPE_MIN_VALUE (type)))
+ TYPE_MIN_VALUE (index_type)))
{
tree low, high = CASE_HIGH (VEC_index (tree, labels, len - 1));
if (!high)
high = CASE_LOW (VEC_index (tree, labels, len - 1));
- if (tree_int_cst_equal (high, TYPE_MAX_VALUE (type)))
+ if (tree_int_cst_equal (high, TYPE_MAX_VALUE (index_type)))
{
for (i = 1; i < len; i++)
{
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