static bool
prefer_and_bit_test (machine_mode mode, int bitnum)
{
bool speed_p;
wide_int mask = wi::set_bit_in_zero (bitnum, GET_MODE_PRECISION (mode));
if (and_test == 0)
{
/* Set up rtxes for the two variations. Use NULL as a placeholder
for the BITNUM-based constants. */
and_reg = gen_rtx_REG (mode, LAST_VIRTUAL_REGISTER + 1);
and_test = gen_rtx_AND (mode, and_reg, NULL);
shift_test = gen_rtx_AND (mode, gen_rtx_ASHIFTRT (mode, and_reg, NULL),
const1_rtx);
}
else
{
/* Change the mode of the previously-created rtxes. */
PUT_MODE (and_reg, mode);
PUT_MODE (and_test, mode);
PUT_MODE (shift_test, mode);
PUT_MODE (XEXP (shift_test, 0), mode);
}
/* Fill in the integers. */
XEXP (and_test, 1) = immed_wide_int_const (mask, mode);
XEXP (XEXP (shift_test, 0), 1) = GEN_INT (bitnum);
speed_p = optimize_insn_for_speed_p ();
return (rtx_cost (and_test, mode, IF_THEN_ELSE, 0, speed_p)
<= rtx_cost (shift_test, mode, IF_THEN_ELSE, 0, speed_p));
}
static bool
prefer_and_bit_test (enum machine_mode mode, int bitnum)
{
if (and_test == 0)
{
/* Set up rtxes for the two variations. Use NULL as a placeholder
for the BITNUM-based constants. */
and_reg = gen_rtx_REG (mode, FIRST_PSEUDO_REGISTER);
and_test = gen_rtx_AND (mode, and_reg, NULL);
shift_test = gen_rtx_AND (mode, gen_rtx_ASHIFTRT (mode, and_reg, NULL),
const1_rtx);
}
else
{
/* Change the mode of the previously-created rtxes. */
PUT_MODE (and_reg, mode);
PUT_MODE (and_test, mode);
PUT_MODE (shift_test, mode);
PUT_MODE (XEXP (shift_test, 0), mode);
}
/* Fill in the integers. */
XEXP (and_test, 1)
= immed_double_int_const (double_int_setbit (double_int_zero, bitnum),
mode);
XEXP (XEXP (shift_test, 0), 1) = GEN_INT (bitnum);
return (rtx_cost (and_test, IF_THEN_ELSE, optimize_insn_for_speed_p ())
<= rtx_cost (shift_test, IF_THEN_ELSE, optimize_insn_for_speed_p ()));
}
static unsigned int arm_pertask_ssp_rtl_execute(void)
{
rtx_insn *insn;
for (insn = get_insns(); insn; insn = NEXT_INSN(insn)) {
const char *sym;
rtx body;
rtx mask, masked_sp;
/*
* Find a SET insn involving a SYMBOL_REF to __stack_chk_guard
*/
if (!INSN_P(insn))
continue;
body = PATTERN(insn);
if (GET_CODE(body) != SET ||
GET_CODE(SET_SRC(body)) != SYMBOL_REF)
continue;
sym = XSTR(SET_SRC(body), 0);
if (strcmp(sym, "__stack_chk_guard"))
continue;
/*
* Replace the source of the SET insn with an expression that
* produces the address of the copy of the stack canary value
* stored in struct thread_info
*/
mask = GEN_INT(sext_hwi(sp_mask, GET_MODE_PRECISION(Pmode)));
masked_sp = gen_reg_rtx(Pmode);
emit_insn_before(gen_rtx_set(masked_sp,
gen_rtx_AND(Pmode,
stack_pointer_rtx,
mask)),
insn);
SET_SRC(body) = gen_rtx_PLUS(Pmode, masked_sp,
GEN_INT(canary_offset));
}
return 0;
}
static void
emit_case_bit_tests (gswitch *swtch, tree index_expr,
tree minval, tree range, tree maxval)
{
struct case_bit_test test[MAX_CASE_BIT_TESTS];
unsigned int i, j, k;
unsigned int count;
basic_block switch_bb = gimple_bb (swtch);
basic_block default_bb, new_default_bb, new_bb;
edge default_edge;
bool update_dom = dom_info_available_p (CDI_DOMINATORS);
vec<basic_block> bbs_to_fix_dom = vNULL;
tree index_type = TREE_TYPE (index_expr);
tree unsigned_index_type = unsigned_type_for (index_type);
unsigned int branch_num = gimple_switch_num_labels (swtch);
gimple_stmt_iterator gsi;
gassign *shift_stmt;
tree idx, tmp, csui;
tree word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
tree word_mode_zero = fold_convert (word_type_node, integer_zero_node);
tree word_mode_one = fold_convert (word_type_node, integer_one_node);
int prec = TYPE_PRECISION (word_type_node);
wide_int wone = wi::one (prec);
memset (&test, 0, sizeof (test));
/* Get the edge for the default case. */
tmp = gimple_switch_default_label (swtch);
default_bb = label_to_block (CASE_LABEL (tmp));
default_edge = find_edge (switch_bb, default_bb);
/* Go through all case labels, and collect the case labels, profile
counts, and other information we need to build the branch tests. */
count = 0;
for (i = 1; i < branch_num; i++)
{
unsigned int lo, hi;
tree cs = gimple_switch_label (swtch, i);
tree label = CASE_LABEL (cs);
edge e = find_edge (switch_bb, label_to_block (label));
for (k = 0; k < count; k++)
if (e == test[k].target_edge)
break;
if (k == count)
{
gcc_checking_assert (count < MAX_CASE_BIT_TESTS);
test[k].mask = wi::zero (prec);
test[k].target_edge = e;
test[k].label = label;
test[k].bits = 1;
count++;
}
else
test[k].bits++;
lo = tree_to_uhwi (int_const_binop (MINUS_EXPR,
CASE_LOW (cs), minval));
if (CASE_HIGH (cs) == NULL_TREE)
hi = lo;
else
hi = tree_to_uhwi (int_const_binop (MINUS_EXPR,
CASE_HIGH (cs), minval));
for (j = lo; j <= hi; j++)
test[k].mask |= wi::lshift (wone, j);
}
qsort (test, count, sizeof (*test), case_bit_test_cmp);
/* If all values are in the 0 .. BITS_PER_WORD-1 range, we can get rid of
the minval subtractions, but it might make the mask constants more
expensive. So, compare the costs. */
if (compare_tree_int (minval, 0) > 0
&& compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0)
{
int cost_diff;
HOST_WIDE_INT m = tree_to_uhwi (minval);
rtx reg = gen_raw_REG (word_mode, 10000);
bool speed_p = optimize_bb_for_speed_p (gimple_bb (swtch));
cost_diff = set_rtx_cost (gen_rtx_PLUS (word_mode, reg,
GEN_INT (-m)), speed_p);
for (i = 0; i < count; i++)
{
rtx r = immed_wide_int_const (test[i].mask, word_mode);
cost_diff += set_src_cost (gen_rtx_AND (word_mode, reg, r),
word_mode, speed_p);
r = immed_wide_int_const (wi::lshift (test[i].mask, m), word_mode);
cost_diff -= set_src_cost (gen_rtx_AND (word_mode, reg, r),
word_mode, speed_p);
}
if (cost_diff > 0)
{
for (i = 0; i < count; i++)
test[i].mask = wi::lshift (test[i].mask, m);
minval = build_zero_cst (TREE_TYPE (minval));
range = maxval;
}
}
/* We generate two jumps to the default case label.
Split the default edge, so that we don't have to do any PHI node
updating. */
new_default_bb = split_edge (default_edge);
if (update_dom)
{
bbs_to_fix_dom.create (10);
bbs_to_fix_dom.quick_push (switch_bb);
bbs_to_fix_dom.quick_push (default_bb);
bbs_to_fix_dom.quick_push (new_default_bb);
}
/* Now build the test-and-branch code. */
gsi = gsi_last_bb (switch_bb);
/* idx = (unsigned)x - minval. */
idx = fold_convert (unsigned_index_type, index_expr);
idx = fold_build2 (MINUS_EXPR, unsigned_index_type, idx,
fold_convert (unsigned_index_type, minval));
idx = force_gimple_operand_gsi (&gsi, idx,
/*simple=*/true, NULL_TREE,
/*before=*/true, GSI_SAME_STMT);
/* if (idx > range) goto default */
range = force_gimple_operand_gsi (&gsi,
fold_convert (unsigned_index_type, range),
/*simple=*/true, NULL_TREE,
/*before=*/true, GSI_SAME_STMT);
tmp = fold_build2 (GT_EXPR, boolean_type_node, idx, range);
new_bb = hoist_edge_and_branch_if_true (&gsi, tmp, default_edge, update_dom);
if (update_dom)
bbs_to_fix_dom.quick_push (new_bb);
gcc_assert (gimple_bb (swtch) == new_bb);
gsi = gsi_last_bb (new_bb);
/* Any blocks dominated by the GIMPLE_SWITCH, but that are not successors
of NEW_BB, are still immediately dominated by SWITCH_BB. Make it so. */
if (update_dom)
{
vec<basic_block> dom_bbs;
basic_block dom_son;
dom_bbs = get_dominated_by (CDI_DOMINATORS, new_bb);
FOR_EACH_VEC_ELT (dom_bbs, i, dom_son)
{
edge e = find_edge (new_bb, dom_son);
if (e && single_pred_p (e->dest))
continue;
set_immediate_dominator (CDI_DOMINATORS, dom_son, switch_bb);
bbs_to_fix_dom.safe_push (dom_son);
}
dom_bbs.release ();
}
