#include "params.h"
#include "diagnostic-core.h"
#include "builtins.h"
+#include "gimplify.h"
+#include "optabs.h"
/* This is a simple global reassociation pass. It is, in part, based
on the LLVM pass of the same name (They do some things more/less
/* Operand->rank hashtable. */
static hash_map<tree, long> *operand_rank;
+/* Vector of SSA_NAMEs on which after reassociate_bb is done with
+ all basic blocks the CFG should be adjusted - basic blocks
+ split right after that SSA_NAME's definition statement and before
+ the only use, which must be a bit ior. */
+static vec<tree> reassoc_branch_fixups;
+
/* Forward decls. */
static long get_rank (tree);
static bool reassoc_stmt_dominates_stmt_p (gimple, gimple);
/* Helper routine of optimize_range_test.
[EXP, IN_P, LOW, HIGH, STRICT_OVERFLOW_P] is a merged range for
RANGE and OTHERRANGE through OTHERRANGE + COUNT - 1 ranges,
- OPCODE and OPS are arguments of optimize_range_tests. Return
+ OPCODE and OPS are arguments of optimize_range_tests. If OTHERRANGE
+ is NULL, OTHERRANGEP should not be and then OTHERRANGEP points to
+ an array of COUNT pointers to other ranges. Return
true if the range merge has been successful.
If OPCODE is ERROR_MARK, this is called from within
maybe_optimize_range_tests and is performing inter-bb range optimization.
static bool
update_range_test (struct range_entry *range, struct range_entry *otherrange,
+ struct range_entry **otherrangep,
unsigned int count, enum tree_code opcode,
- vec<operand_entry_t> *ops, tree exp, bool in_p,
- tree low, tree high, bool strict_overflow_p)
+ vec<operand_entry_t> *ops, tree exp, gimple_seq seq,
+ bool in_p, tree low, tree high, bool strict_overflow_p)
{
operand_entry_t oe = (*ops)[range->idx];
tree op = oe->op;
last_stmt (BASIC_BLOCK_FOR_FN (cfun, oe->id));
location_t loc = gimple_location (stmt);
tree optype = op ? TREE_TYPE (op) : boolean_type_node;
- tree tem = build_range_check (loc, optype, exp, in_p, low, high);
+ tree tem = build_range_check (loc, optype, unshare_expr (exp),
+ in_p, low, high);
enum warn_strict_overflow_code wc = WARN_STRICT_OVERFLOW_COMPARISON;
gimple_stmt_iterator gsi;
+ unsigned int i;
if (tem == NULL_TREE)
return false;
fprintf (dump_file, ", ");
print_generic_expr (dump_file, range->high, 0);
fprintf (dump_file, "]");
- for (r = otherrange; r < otherrange + count; r++)
+ for (i = 0; i < count; i++)
{
+ if (otherrange)
+ r = otherrange + i;
+ else
+ r = otherrangep[i];
fprintf (dump_file, " and %c[", r->in_p ? '+' : '-');
print_generic_expr (dump_file, r->low, 0);
fprintf (dump_file, ", ");
In that case we have to insert after the stmt rather then before
it. */
if (op == range->exp)
- tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, false,
- GSI_CONTINUE_LINKING);
+ {
+ gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING);
+ tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, false,
+ GSI_CONTINUE_LINKING);
+ }
else
{
+ gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, true,
GSI_SAME_STMT);
gsi_prev (&gsi);
range->in_p = in_p;
range->strict_overflow_p = false;
- for (range = otherrange; range < otherrange + count; range++)
+ for (i = 0; i < count; i++)
{
+ if (otherrange)
+ range = otherrange + i;
+ else
+ range = otherrangep[i];
oe = (*ops)[range->idx];
/* Now change all the other range test immediate uses, so that
those tests will be optimized away. */
struct range_entry *rangej)
{
tree lowxor, highxor, tem, exp;
- /* Check highi ^ lowi == highj ^ lowj and
- popcount (highi ^ lowi) == 1. */
+ /* Check lowi ^ lowj == highi ^ highj and
+ popcount (lowi ^ lowj) == 1. */
lowxor = fold_binary (BIT_XOR_EXPR, type, lowi, lowj);
if (lowxor == NULL_TREE || TREE_CODE (lowxor) != INTEGER_CST)
return false;
exp = fold_build2 (BIT_AND_EXPR, type, rangei->exp, tem);
lowj = fold_build2 (BIT_AND_EXPR, type, lowi, tem);
highj = fold_build2 (BIT_AND_EXPR, type, highi, tem);
- if (update_range_test (rangei, rangej, 1, opcode, ops, exp,
- rangei->in_p, lowj, highj,
+ if (update_range_test (rangei, rangej, NULL, 1, opcode, ops, exp,
+ NULL, rangei->in_p, lowj, highj,
rangei->strict_overflow_p
|| rangej->strict_overflow_p))
return true;
fold_convert (type, rangei->exp), lowi);
tem1 = fold_build2 (BIT_AND_EXPR, type, tem1, mask);
lowj = build_int_cst (type, 0);
- if (update_range_test (rangei, rangej, 1, opcode, ops, tem1,
- rangei->in_p, lowj, tem2,
+ if (update_range_test (rangei, rangej, NULL, 1, opcode, ops, tem1,
+ NULL, rangei->in_p, lowj, tem2,
rangei->strict_overflow_p
|| rangej->strict_overflow_p))
return true;
return any_changes;
}
+/* Helper function of optimize_range_tests_to_bit_test. Handle a single
+ range, EXP, LOW, HIGH, compute bit mask of bits to test and return
+ EXP on success, NULL otherwise. */
+
+static tree
+extract_bit_test_mask (tree exp, int prec, tree totallow, tree low, tree high,
+ wide_int *mask, tree *totallowp)
+{
+ tree tem = int_const_binop (MINUS_EXPR, high, low);
+ if (tem == NULL_TREE
+ || TREE_CODE (tem) != INTEGER_CST
+ || TREE_OVERFLOW (tem)
+ || tree_int_cst_sgn (tem) == -1
+ || compare_tree_int (tem, prec) != -1)
+ return NULL_TREE;
+
+ unsigned HOST_WIDE_INT max = tree_to_uhwi (tem) + 1;
+ *mask = wi::shifted_mask (0, max, false, prec);
+ if (TREE_CODE (exp) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST)
+ {
+ widest_int msk = wi::to_widest (TREE_OPERAND (exp, 1));
+ msk = wi::zext (~msk, TYPE_PRECISION (TREE_TYPE (exp)));
+ if (wi::popcount (msk) == 1
+ && wi::ltu_p (msk, prec - max))
+ {
+ *mask |= wi::shifted_mask (msk.to_uhwi (), max, false, prec);
+ max += msk.to_uhwi ();
+ exp = TREE_OPERAND (exp, 0);
+ if (integer_zerop (low)
+ && TREE_CODE (exp) == PLUS_EXPR
+ && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST)
+ {
+ widest_int bias
+ = wi::neg (wi::sext (wi::to_widest (TREE_OPERAND (exp, 1)),
+ TYPE_PRECISION (TREE_TYPE (low))));
+ tree tbias = wide_int_to_tree (TREE_TYPE (low), bias);
+ if (totallowp)
+ {
+ *totallowp = tbias;
+ exp = TREE_OPERAND (exp, 0);
+ STRIP_NOPS (exp);
+ return exp;
+ }
+ else if (!tree_int_cst_lt (totallow, tbias))
+ return NULL_TREE;
+ bias -= wi::to_widest (totallow);
+ if (wi::ges_p (bias, 0) && wi::lts_p (bias, prec - max))
+ {
+ *mask = wi::lshift (*mask, bias);
+ exp = TREE_OPERAND (exp, 0);
+ STRIP_NOPS (exp);
+ return exp;
+ }
+ }
+ }
+ }
+ if (totallowp)
+ return exp;
+ if (!tree_int_cst_lt (totallow, low))
+ return exp;
+ tem = int_const_binop (MINUS_EXPR, low, totallow);
+ if (tem == NULL_TREE
+ || TREE_CODE (tem) != INTEGER_CST
+ || TREE_OVERFLOW (tem)
+ || compare_tree_int (tem, prec - max) == 1)
+ return NULL_TREE;
+
+ *mask = wi::lshift (*mask, wi::to_widest (tem));
+ return exp;
+}
+
+/* Attempt to optimize small range tests using bit test.
+ E.g.
+ X != 43 && X != 76 && X != 44 && X != 78 && X != 49
+ && X != 77 && X != 46 && X != 75 && X != 45 && X != 82
+ has been by earlier optimizations optimized into:
+ ((X - 43U) & ~32U) > 3U && X != 49 && X != 82
+ As all the 43 through 82 range is less than 64 numbers,
+ for 64-bit word targets optimize that into:
+ (X - 43U) > 40U && ((1 << (X - 43U)) & 0x8F0000004FULL) == 0 */
+
+static bool
+optimize_range_tests_to_bit_test (enum tree_code opcode, int first, int length,
+ vec<operand_entry_t> *ops,
+ struct range_entry *ranges)
+{
+ int i, j;
+ bool any_changes = false;
+ int prec = GET_MODE_BITSIZE (word_mode);
+ auto_vec<struct range_entry *, 64> candidates;
+
+ for (i = first; i < length - 2; i++)
+ {
+ tree lowi, highi, lowj, highj, type;
+
+ if (ranges[i].exp == NULL_TREE || ranges[i].in_p)
+ continue;
+ type = TREE_TYPE (ranges[i].exp);
+ if (!INTEGRAL_TYPE_P (type))
+ continue;
+ lowi = ranges[i].low;
+ if (lowi == NULL_TREE)
+ lowi = TYPE_MIN_VALUE (type);
+ highi = ranges[i].high;
+ if (highi == NULL_TREE)
+ continue;
+ wide_int mask;
+ tree exp = extract_bit_test_mask (ranges[i].exp, prec, lowi, lowi,
+ highi, &mask, &lowi);
+ if (exp == NULL_TREE)
+ continue;
+ bool strict_overflow_p = ranges[i].strict_overflow_p;
+ candidates.truncate (0);
+ int end = MIN (i + 64, length);
+ for (j = i + 1; j < end; j++)
+ {
+ tree exp2;
+ if (ranges[j].exp == NULL_TREE || ranges[j].in_p)
+ continue;
+ if (ranges[j].exp == exp)
+ ;
+ else if (TREE_CODE (ranges[j].exp) == BIT_AND_EXPR)
+ {
+ exp2 = TREE_OPERAND (ranges[j].exp, 0);
+ if (exp2 == exp)
+ ;
+ else if (TREE_CODE (exp2) == PLUS_EXPR)
+ {
+ exp2 = TREE_OPERAND (exp2, 0);
+ STRIP_NOPS (exp2);
+ if (exp2 != exp)
+ continue;
+ }
+ else
+ continue;
+ }
+ else
+ continue;
+ lowj = ranges[j].low;
+ if (lowj == NULL_TREE)
+ continue;
+ highj = ranges[j].high;
+ if (highj == NULL_TREE)
+ highj = TYPE_MAX_VALUE (type);
+ wide_int mask2;
+ exp2 = extract_bit_test_mask (ranges[j].exp, prec, lowi, lowj,
+ highj, &mask2, NULL);
+ if (exp2 != exp)
+ continue;
+ mask |= mask2;
+ strict_overflow_p |= ranges[j].strict_overflow_p;
+ candidates.safe_push (&ranges[j]);
+ }
+
+ /* If we need otherwise 3 or more comparisons, use a bit test. */
+ if (candidates.length () >= 2)
+ {
+ tree high = wide_int_to_tree (TREE_TYPE (lowi),
+ wi::to_widest (lowi)
+ + prec - wi::clz (mask));
+ operand_entry_t oe = (*ops)[ranges[i].idx];
+ tree op = oe->op;
+ gimple stmt = op ? SSA_NAME_DEF_STMT (op)
+ : last_stmt (BASIC_BLOCK_FOR_FN (cfun, oe->id));
+ location_t loc = gimple_location (stmt);
+ tree optype = op ? TREE_TYPE (op) : boolean_type_node;
+
+ /* See if it isn't cheaper to pretend the minimum value of the
+ range is 0, if maximum value is small enough.
+ We can avoid then subtraction of the minimum value, but the
+ mask constant could be perhaps more expensive. */
+ if (compare_tree_int (lowi, 0) > 0
+ && compare_tree_int (high, prec) < 0)
+ {
+ int cost_diff;
+ HOST_WIDE_INT m = tree_to_uhwi (lowi);
+ rtx reg = gen_raw_REG (word_mode, 10000);
+ bool speed_p = optimize_bb_for_speed_p (gimple_bb (stmt));
+ cost_diff = set_rtx_cost (gen_rtx_PLUS (word_mode, reg,
+ GEN_INT (-m)), speed_p);
+ rtx r = immed_wide_int_const (mask, word_mode);
+ cost_diff += set_src_cost (gen_rtx_AND (word_mode, reg, r),
+ speed_p);
+ r = immed_wide_int_const (wi::lshift (mask, m), word_mode);
+ cost_diff -= set_src_cost (gen_rtx_AND (word_mode, reg, r),
+ speed_p);
+ if (cost_diff > 0)
+ {
+ mask = wi::lshift (mask, m);
+ lowi = build_zero_cst (TREE_TYPE (lowi));
+ }
+ }
+
+ tree tem = build_range_check (loc, optype, unshare_expr (exp),
+ false, lowi, high);
+ if (tem == NULL_TREE || is_gimple_val (tem))
+ continue;
+ tree etype = unsigned_type_for (TREE_TYPE (exp));
+ exp = fold_build2_loc (loc, MINUS_EXPR, etype,
+ fold_convert_loc (loc, etype, exp),
+ fold_convert_loc (loc, etype, lowi));
+ exp = fold_convert_loc (loc, integer_type_node, exp);
+ tree word_type = lang_hooks.types.type_for_mode (word_mode, 1);
+ exp = fold_build2_loc (loc, LSHIFT_EXPR, word_type,
+ build_int_cst (word_type, 1), exp);
+ exp = fold_build2_loc (loc, BIT_AND_EXPR, word_type, exp,
+ wide_int_to_tree (word_type, mask));
+ exp = fold_build2_loc (loc, EQ_EXPR, optype, exp,
+ build_zero_cst (word_type));
+ if (is_gimple_val (exp))
+ continue;
+
+ /* The shift might have undefined behavior if TEM is true,
+ but reassociate_bb isn't prepared to have basic blocks
+ split when it is running. So, temporarily emit a code
+ with BIT_IOR_EXPR instead of &&, and fix it up in
+ branch_fixup. */
+ gimple_seq seq;
+ tem = force_gimple_operand (tem, &seq, true, NULL_TREE);
+ gcc_assert (TREE_CODE (tem) == SSA_NAME);
+ gimple_set_visited (SSA_NAME_DEF_STMT (tem), true);
+ gimple_seq seq2;
+ exp = force_gimple_operand (exp, &seq2, true, NULL_TREE);
+ gimple_seq_add_seq_without_update (&seq, seq2);
+ gcc_assert (TREE_CODE (exp) == SSA_NAME);
+ gimple_set_visited (SSA_NAME_DEF_STMT (exp), true);
+ gimple g
+ = gimple_build_assign_with_ops (BIT_IOR_EXPR,
+ make_ssa_name (optype, NULL),
+ tem, exp);
+ gimple_set_location (g, loc);
+ gimple_seq_add_stmt_without_update (&seq, g);
+ exp = gimple_assign_lhs (g);
+ tree val = build_zero_cst (optype);
+ if (update_range_test (&ranges[i], NULL, candidates.address (),
+ candidates.length (), opcode, ops, exp,
+ seq, false, val, val, strict_overflow_p))
+ {
+ any_changes = true;
+ reassoc_branch_fixups.safe_push (tem);
+ }
+ else
+ gimple_seq_discard (seq);
+ }
+ }
+ return any_changes;
+}
+
/* Optimize range tests, similarly how fold_range_test optimizes
it on trees. The tree code for the binary
operation between all the operands is OPCODE.
if (j == i + 1)
continue;
- if (update_range_test (ranges + i, ranges + i + 1, j - i - 1, opcode,
- ops, ranges[i].exp, in_p, low, high,
- strict_overflow_p))
+ if (update_range_test (ranges + i, ranges + i + 1, NULL, j - i - 1,
+ opcode, ops, ranges[i].exp, NULL, in_p,
+ low, high, strict_overflow_p))
{
i = j - 1;
any_changes = true;
if (BRANCH_COST (optimize_function_for_speed_p (cfun), false) >= 2)
any_changes |= optimize_range_tests_1 (opcode, first, length, false,
ops, ranges);
+ if (lshift_cheap_p (optimize_function_for_speed_p (cfun)))
+ any_changes |= optimize_range_tests_to_bit_test (opcode, first, length,
+ ops, ranges);
if (any_changes && opcode != ERROR_MARK)
{
reassociate_bb (son);
}
+/* Add jumps around shifts for range tests turned into bit tests.
+ For each SSA_NAME VAR we have code like:
+ VAR = ...; // final stmt of range comparison
+ // bit test here...;
+ OTHERVAR = ...; // final stmt of the bit test sequence
+ RES = VAR | OTHERVAR;
+ Turn the above into:
+ VAR = ...;
+ if (VAR != 0)
+ goto <l3>;
+ else
+ goto <l2>;
+ <l2>:
+ // bit test here...;
+ OTHERVAR = ...;
+ <l3>:
+ # RES = PHI<1(l1), OTHERVAR(l2)>; */
+
+static void
+branch_fixup (void)
+{
+ tree var;
+ unsigned int i;
+
+ FOR_EACH_VEC_ELT (reassoc_branch_fixups, i, var)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (var);
+ gimple use_stmt;
+ use_operand_p use;
+ bool ok = single_imm_use (var, &use, &use_stmt);
+ gcc_assert (ok
+ && is_gimple_assign (use_stmt)
+ && gimple_assign_rhs_code (use_stmt) == BIT_IOR_EXPR
+ && gimple_bb (def_stmt) == gimple_bb (use_stmt));
+
+ basic_block cond_bb = gimple_bb (def_stmt);
+ basic_block then_bb = split_block (cond_bb, def_stmt)->dest;
+ basic_block merge_bb = split_block (then_bb, use_stmt)->dest;
+
+ gimple_stmt_iterator gsi = gsi_for_stmt (def_stmt);
+ gimple g = gimple_build_cond (NE_EXPR, var,
+ build_zero_cst (TREE_TYPE (var)),
+ NULL_TREE, NULL_TREE);
+ location_t loc = gimple_location (use_stmt);
+ gimple_set_location (g, loc);
+ gsi_insert_after (&gsi, g, GSI_NEW_STMT);
+
+ edge etrue = make_edge (cond_bb, merge_bb, EDGE_TRUE_VALUE);
+ etrue->probability = REG_BR_PROB_BASE / 2;
+ etrue->count = cond_bb->count / 2;
+ edge efalse = find_edge (cond_bb, then_bb);
+ efalse->flags = EDGE_FALSE_VALUE;
+ efalse->probability -= etrue->probability;
+ efalse->count -= etrue->count;
+ then_bb->count -= etrue->count;
+
+ tree othervar = NULL_TREE;
+ if (gimple_assign_rhs1 (use_stmt) == var)
+ othervar = gimple_assign_rhs2 (use_stmt);
+ else if (gimple_assign_rhs2 (use_stmt) == var)
+ othervar = gimple_assign_rhs1 (use_stmt);
+ else
+ gcc_unreachable ();
+ tree lhs = gimple_assign_lhs (use_stmt);
+ gimple phi = create_phi_node (lhs, merge_bb);
+ add_phi_arg (phi, build_one_cst (TREE_TYPE (lhs)), etrue, loc);
+ add_phi_arg (phi, othervar, single_succ_edge (then_bb), loc);
+ gsi = gsi_for_stmt (use_stmt);
+ gsi_remove (&gsi, true);
+
+ set_immediate_dominator (CDI_DOMINATORS, merge_bb, cond_bb);
+ set_immediate_dominator (CDI_POST_DOMINATORS, cond_bb, merge_bb);
+ }
+ reassoc_branch_fixups.release ();
+}
+
void dump_ops_vector (FILE *file, vec<operand_entry_t> ops);
void debug_ops_vector (vec<operand_entry_t> ops);
do_reassoc ();
repropagate_negates ();
+ branch_fixup ();
fini_reassoc ();
return 0;
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