/* Global, SSA-based optimizations using mathematical identities.
- Copyright (C) 2005 Free Software Foundation, Inc.
-
+ Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+
This file is part of GCC.
-
+
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
-Free Software Foundation; either version 2, or (at your option) any
+Free Software Foundation; either version 3, or (at your option) any
later version.
-
+
GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
-
+
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/* Currently, the only mini-pass in this file tries to CSE reciprocal
operations. These are common in sequences such as this one:
#include "alloc-pool.h"
#include "basic-block.h"
#include "target.h"
-
+#include "diagnostic.h"
+#include "rtl.h"
+#include "expr.h"
+#include "optabs.h"
/* This structure represents one basic block that either computes a
division, or is a common dominator for basic block that compute a
inserted in BB. */
tree recip_def;
- /* If non-NULL, the MODIFY_EXPR for a reciprocal computation that
+ /* If non-NULL, the GIMPLE_ASSIGN for a reciprocal computation that
was inserted in BB. */
- tree recip_def_stmt;
+ gimple recip_def_stmt;
/* Pointer to a list of "struct occurrence"s for blocks dominated
by BB. */
{
struct occurrence *occ;
- occ = bb->aux = pool_alloc (occ_pool);
+ bb->aux = occ = (struct occurrence *) pool_alloc (occ_pool);
memset (occ, 0, sizeof (struct occurrence));
occ->bb = bb;
/* Return whether USE_STMT is a floating-point division by DEF. */
static inline bool
-is_division_by (tree use_stmt, tree def)
+is_division_by (gimple use_stmt, tree def)
{
- return TREE_CODE (use_stmt) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (use_stmt, 1)) == RDIV_EXPR
- && TREE_OPERAND (TREE_OPERAND (use_stmt, 1), 1) == def;
-}
-
-/* Return the LHS of a RDIV_EXPR that computes a reciprocal in type TYPE. */
-static tree
-get_constant_one (tree type)
-{
- tree scalar, cst;
- int i;
-
- gcc_assert (FLOAT_TYPE_P (type));
- switch (TREE_CODE (type))
- {
- case REAL_TYPE:
- return build_real (type, dconst1);
-
- case VECTOR_TYPE:
- scalar = build_real (TREE_TYPE (type), dconst1);
-
- /* Create 'vect_cst_ = {cst,cst,...,cst}' */
- cst = NULL_TREE;
- for (i = TYPE_VECTOR_SUBPARTS (type); --i >= 0; )
- cst = tree_cons (NULL_TREE, scalar, cst);
-
- return build_vector (type, cst);
-
- default:
- /* Complex operations have been split already. */
- gcc_unreachable ();
- }
+ return is_gimple_assign (use_stmt)
+ && gimple_assign_rhs_code (use_stmt) == RDIV_EXPR
+ && gimple_assign_rhs2 (use_stmt) == def
+ /* Do not recognize x / x as valid division, as we are getting
+ confused later by replacing all immediate uses x in such
+ a stmt. */
+ && gimple_assign_rhs1 (use_stmt) != def;
}
/* Walk the subset of the dominator tree rooted at OCC, setting the
be used. */
static void
-insert_reciprocals (block_stmt_iterator *def_bsi, struct occurrence *occ,
+insert_reciprocals (gimple_stmt_iterator *def_gsi, struct occurrence *occ,
tree def, tree recip_def, int threshold)
{
- tree type, new_stmt;
- block_stmt_iterator bsi;
+ tree type;
+ gimple new_stmt;
+ gimple_stmt_iterator gsi;
struct occurrence *occ_child;
if (!recip_def
/* Make a variable with the replacement and substitute it. */
type = TREE_TYPE (def);
recip_def = make_rename_temp (type, "reciptmp");
- new_stmt = build2 (MODIFY_EXPR, void_type_node, recip_def,
- fold_build2 (RDIV_EXPR, type, get_constant_one (type),
- def));
-
-
+ new_stmt = gimple_build_assign_with_ops (RDIV_EXPR, recip_def,
+ build_one_cst (type), def);
+
if (occ->bb_has_division)
{
/* Case 1: insert before an existing division. */
- bsi = bsi_after_labels (occ->bb);
- while (!bsi_end_p (bsi) && !is_division_by (bsi_stmt (bsi), def))
- bsi_next (&bsi);
+ gsi = gsi_after_labels (occ->bb);
+ while (!gsi_end_p (gsi) && !is_division_by (gsi_stmt (gsi), def))
+ gsi_next (&gsi);
- bsi_insert_before (&bsi, new_stmt, BSI_SAME_STMT);
+ gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
}
- else if (def_bsi && occ->bb == def_bsi->bb)
+ else if (def_gsi && occ->bb == def_gsi->bb)
{
/* Case 2: insert right after the definition. Note that this will
never happen if the definition statement can throw, because in
that case the sole successor of the statement's basic block will
dominate all the uses as well. */
- bsi_insert_after (def_bsi, new_stmt, BSI_NEW_STMT);
+ gsi_insert_after (def_gsi, new_stmt, GSI_NEW_STMT);
}
else
{
/* Case 3: insert in a basic block not containing defs/uses. */
- bsi = bsi_after_labels (occ->bb);
- bsi_insert_before (&bsi, new_stmt, BSI_SAME_STMT);
+ gsi = gsi_after_labels (occ->bb);
+ gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
}
occ->recip_def_stmt = new_stmt;
occ->recip_def = recip_def;
for (occ_child = occ->children; occ_child; occ_child = occ_child->next)
- insert_reciprocals (def_bsi, occ_child, def, recip_def, threshold);
+ insert_reciprocals (def_gsi, occ_child, def, recip_def, threshold);
}
static inline void
replace_reciprocal (use_operand_p use_p)
{
- tree use_stmt = USE_STMT (use_p);
- basic_block bb = bb_for_stmt (use_stmt);
+ gimple use_stmt = USE_STMT (use_p);
+ basic_block bb = gimple_bb (use_stmt);
struct occurrence *occ = (struct occurrence *) bb->aux;
- if (occ->recip_def && use_stmt != occ->recip_def_stmt)
+ if (optimize_bb_for_speed_p (bb)
+ && occ->recip_def && use_stmt != occ->recip_def_stmt)
{
- TREE_SET_CODE (TREE_OPERAND (use_stmt, 1), MULT_EXPR);
+ gimple_assign_set_rhs_code (use_stmt, MULT_EXPR);
SET_USE (use_p, occ->recip_def);
fold_stmt_inplace (use_stmt);
update_stmt (use_stmt);
DEF must be a GIMPLE register of a floating-point type. */
static void
-execute_cse_reciprocals_1 (block_stmt_iterator *def_bsi, tree def)
+execute_cse_reciprocals_1 (gimple_stmt_iterator *def_gsi, tree def)
{
use_operand_p use_p;
imm_use_iterator use_iter;
FOR_EACH_IMM_USE_FAST (use_p, use_iter, def)
{
- tree use_stmt = USE_STMT (use_p);
+ gimple use_stmt = USE_STMT (use_p);
if (is_division_by (use_stmt, def))
{
- register_division_in (bb_for_stmt (use_stmt));
+ register_division_in (gimple_bb (use_stmt));
count++;
}
}
-
+
/* Do the expensive part only if we can hope to optimize something. */
threshold = targetm.min_divisions_for_recip_mul (TYPE_MODE (TREE_TYPE (def)));
if (count >= threshold)
{
- tree use_stmt;
+ gimple use_stmt;
for (occ = occ_head; occ; occ = occ->next)
{
compute_merit (occ);
- insert_reciprocals (def_bsi, occ, def, NULL, threshold);
+ insert_reciprocals (def_gsi, occ, def, NULL, threshold);
}
FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, def)
occ_head = NULL;
}
-
static bool
gate_cse_reciprocals (void)
{
- return optimize && !optimize_size && flag_unsafe_math_optimizations;
+ return optimize && flag_reciprocal_math;
}
-
/* Go through all the floating-point SSA_NAMEs, and call
execute_cse_reciprocals_1 on each of them. */
static unsigned int
#endif
for (arg = DECL_ARGUMENTS (cfun->decl); arg; arg = TREE_CHAIN (arg))
- if (default_def (arg)
+ if (gimple_default_def (cfun, arg)
&& FLOAT_TYPE_P (TREE_TYPE (arg))
&& is_gimple_reg (arg))
- execute_cse_reciprocals_1 (NULL, default_def (arg));
+ execute_cse_reciprocals_1 (NULL, gimple_default_def (cfun, arg));
FOR_EACH_BB (bb)
{
- block_stmt_iterator bsi;
- tree phi, def;
+ gimple_stmt_iterator gsi;
+ gimple phi;
+ tree def;
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
+ phi = gsi_stmt (gsi);
def = PHI_RESULT (phi);
if (FLOAT_TYPE_P (TREE_TYPE (def))
&& is_gimple_reg (def))
execute_cse_reciprocals_1 (NULL, def);
}
- for (bsi = bsi_after_labels (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- tree stmt = bsi_stmt (bsi);
- if (TREE_CODE (stmt) == MODIFY_EXPR
+ gimple stmt = gsi_stmt (gsi);
+
+ if (gimple_has_lhs (stmt)
&& (def = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_DEF)) != NULL
&& FLOAT_TYPE_P (TREE_TYPE (def))
&& TREE_CODE (def) == SSA_NAME)
- execute_cse_reciprocals_1 (&bsi, def);
+ execute_cse_reciprocals_1 (&gsi, def);
+ }
+
+ if (optimize_bb_for_size_p (bb))
+ continue;
+
+ /* Scan for a/func(b) and convert it to reciprocal a*rfunc(b). */
+ for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ tree fndecl;
+
+ if (is_gimple_assign (stmt)
+ && gimple_assign_rhs_code (stmt) == RDIV_EXPR)
+ {
+ tree arg1 = gimple_assign_rhs2 (stmt);
+ gimple stmt1;
+
+ if (TREE_CODE (arg1) != SSA_NAME)
+ continue;
+
+ stmt1 = SSA_NAME_DEF_STMT (arg1);
+
+ if (is_gimple_call (stmt1)
+ && gimple_call_lhs (stmt1)
+ && (fndecl = gimple_call_fndecl (stmt1))
+ && (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
+ || DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD))
+ {
+ enum built_in_function code;
+ bool md_code, fail;
+ imm_use_iterator ui;
+ use_operand_p use_p;
+
+ code = DECL_FUNCTION_CODE (fndecl);
+ md_code = DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD;
+
+ fndecl = targetm.builtin_reciprocal (code, md_code, false);
+ if (!fndecl)
+ continue;
+
+ /* Check that all uses of the SSA name are divisions,
+ otherwise replacing the defining statement will do
+ the wrong thing. */
+ fail = false;
+ FOR_EACH_IMM_USE_FAST (use_p, ui, arg1)
+ {
+ gimple stmt2 = USE_STMT (use_p);
+ if (is_gimple_debug (stmt2))
+ continue;
+ if (!is_gimple_assign (stmt2)
+ || gimple_assign_rhs_code (stmt2) != RDIV_EXPR
+ || gimple_assign_rhs1 (stmt2) == arg1
+ || gimple_assign_rhs2 (stmt2) != arg1)
+ {
+ fail = true;
+ break;
+ }
+ }
+ if (fail)
+ continue;
+
+ gimple_replace_lhs (stmt1, arg1);
+ gimple_call_set_fndecl (stmt1, fndecl);
+ update_stmt (stmt1);
+
+ FOR_EACH_IMM_USE_STMT (stmt, ui, arg1)
+ {
+ gimple_assign_set_rhs_code (stmt, MULT_EXPR);
+ fold_stmt_inplace (stmt);
+ update_stmt (stmt);
+ }
+ }
+ }
}
}
return 0;
}
-struct tree_opt_pass pass_cse_reciprocals =
+struct gimple_opt_pass pass_cse_reciprocals =
{
+ {
+ GIMPLE_PASS,
"recip", /* name */
gate_cse_reciprocals, /* gate */
execute_cse_reciprocals, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- 0, /* tv_id */
+ TV_NONE, /* tv_id */
PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_dump_func | TODO_update_ssa | TODO_verify_ssa
- | TODO_verify_stmts, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_stmts /* todo_flags_finish */
+ }
+};
+
+/* Records an occurrence at statement USE_STMT in the vector of trees
+ STMTS if it is dominated by *TOP_BB or dominates it or this basic block
+ is not yet initialized. Returns true if the occurrence was pushed on
+ the vector. Adjusts *TOP_BB to be the basic block dominating all
+ statements in the vector. */
+
+static bool
+maybe_record_sincos (VEC(gimple, heap) **stmts,
+ basic_block *top_bb, gimple use_stmt)
+{
+ basic_block use_bb = gimple_bb (use_stmt);
+ if (*top_bb
+ && (*top_bb == use_bb
+ || dominated_by_p (CDI_DOMINATORS, use_bb, *top_bb)))
+ VEC_safe_push (gimple, heap, *stmts, use_stmt);
+ else if (!*top_bb
+ || dominated_by_p (CDI_DOMINATORS, *top_bb, use_bb))
+ {
+ VEC_safe_push (gimple, heap, *stmts, use_stmt);
+ *top_bb = use_bb;
+ }
+ else
+ return false;
+
+ return true;
+}
+
+/* Look for sin, cos and cexpi calls with the same argument NAME and
+ create a single call to cexpi CSEing the result in this case.
+ We first walk over all immediate uses of the argument collecting
+ statements that we can CSE in a vector and in a second pass replace
+ the statement rhs with a REALPART or IMAGPART expression on the
+ result of the cexpi call we insert before the use statement that
+ dominates all other candidates. */
+
+static void
+execute_cse_sincos_1 (tree name)
+{
+ gimple_stmt_iterator gsi;
+ imm_use_iterator use_iter;
+ tree fndecl, res, type;
+ gimple def_stmt, use_stmt, stmt;
+ int seen_cos = 0, seen_sin = 0, seen_cexpi = 0;
+ VEC(gimple, heap) *stmts = NULL;
+ basic_block top_bb = NULL;
+ int i;
+
+ type = TREE_TYPE (name);
+ FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, name)
+ {
+ if (gimple_code (use_stmt) != GIMPLE_CALL
+ || !gimple_call_lhs (use_stmt)
+ || !(fndecl = gimple_call_fndecl (use_stmt))
+ || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
+ continue;
+
+ switch (DECL_FUNCTION_CODE (fndecl))
+ {
+ CASE_FLT_FN (BUILT_IN_COS):
+ seen_cos |= maybe_record_sincos (&stmts, &top_bb, use_stmt) ? 1 : 0;
+ break;
+
+ CASE_FLT_FN (BUILT_IN_SIN):
+ seen_sin |= maybe_record_sincos (&stmts, &top_bb, use_stmt) ? 1 : 0;
+ break;
+
+ CASE_FLT_FN (BUILT_IN_CEXPI):
+ seen_cexpi |= maybe_record_sincos (&stmts, &top_bb, use_stmt) ? 1 : 0;
+ break;
+
+ default:;
+ }
+ }
+
+ if (seen_cos + seen_sin + seen_cexpi <= 1)
+ {
+ VEC_free(gimple, heap, stmts);
+ return;
+ }
+
+ /* Simply insert cexpi at the beginning of top_bb but not earlier than
+ the name def statement. */
+ fndecl = mathfn_built_in (type, BUILT_IN_CEXPI);
+ if (!fndecl)
+ return;
+ res = make_rename_temp (TREE_TYPE (TREE_TYPE (fndecl)), "sincostmp");
+ stmt = gimple_build_call (fndecl, 1, name);
+ gimple_call_set_lhs (stmt, res);
+
+ def_stmt = SSA_NAME_DEF_STMT (name);
+ if (!SSA_NAME_IS_DEFAULT_DEF (name)
+ && gimple_code (def_stmt) != GIMPLE_PHI
+ && gimple_bb (def_stmt) == top_bb)
+ {
+ gsi = gsi_for_stmt (def_stmt);
+ gsi_insert_after (&gsi, stmt, GSI_SAME_STMT);
+ }
+ else
+ {
+ gsi = gsi_after_labels (top_bb);
+ gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
+ }
+ update_stmt (stmt);
+
+ /* And adjust the recorded old call sites. */
+ for (i = 0; VEC_iterate(gimple, stmts, i, use_stmt); ++i)
+ {
+ tree rhs = NULL;
+ fndecl = gimple_call_fndecl (use_stmt);
+
+ switch (DECL_FUNCTION_CODE (fndecl))
+ {
+ CASE_FLT_FN (BUILT_IN_COS):
+ rhs = fold_build1 (REALPART_EXPR, type, res);
+ break;
+
+ CASE_FLT_FN (BUILT_IN_SIN):
+ rhs = fold_build1 (IMAGPART_EXPR, type, res);
+ break;
+
+ CASE_FLT_FN (BUILT_IN_CEXPI):
+ rhs = res;
+ break;
+
+ default:;
+ gcc_unreachable ();
+ }
+
+ /* Replace call with a copy. */
+ stmt = gimple_build_assign (gimple_call_lhs (use_stmt), rhs);
+
+ gsi = gsi_for_stmt (use_stmt);
+ gsi_insert_after (&gsi, stmt, GSI_SAME_STMT);
+ gsi_remove (&gsi, true);
+ }
+
+ VEC_free(gimple, heap, stmts);
+}
+
+/* Go through all calls to sin, cos and cexpi and call execute_cse_sincos_1
+ on the SSA_NAME argument of each of them. */
+
+static unsigned int
+execute_cse_sincos (void)
+{
+ basic_block bb;
+
+ calculate_dominance_info (CDI_DOMINATORS);
+
+ FOR_EACH_BB (bb)
+ {
+ gimple_stmt_iterator gsi;
+
+ for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ tree fndecl;
+
+ if (is_gimple_call (stmt)
+ && gimple_call_lhs (stmt)
+ && (fndecl = gimple_call_fndecl (stmt))
+ && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+ {
+ tree arg;
+
+ switch (DECL_FUNCTION_CODE (fndecl))
+ {
+ CASE_FLT_FN (BUILT_IN_COS):
+ CASE_FLT_FN (BUILT_IN_SIN):
+ CASE_FLT_FN (BUILT_IN_CEXPI):
+ arg = gimple_call_arg (stmt, 0);
+ if (TREE_CODE (arg) == SSA_NAME)
+ execute_cse_sincos_1 (arg);
+ break;
+
+ default:;
+ }
+ }
+ }
+ }
+
+ free_dominance_info (CDI_DOMINATORS);
+ return 0;
+}
+
+static bool
+gate_cse_sincos (void)
+{
+ /* Make sure we have either sincos or cexp. */
+ return (TARGET_HAS_SINCOS
+ || TARGET_C99_FUNCTIONS)
+ && optimize;
+}
+
+struct gimple_opt_pass pass_cse_sincos =
+{
+ {
+ GIMPLE_PASS,
+ "sincos", /* name */
+ gate_cse_sincos, /* gate */
+ execute_cse_sincos, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_NONE, /* tv_id */
+ PROP_ssa, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_dump_func | TODO_update_ssa | TODO_verify_ssa
+ | TODO_verify_stmts /* todo_flags_finish */
+ }
+};
+
+/* A symbolic number is used to detect byte permutation and selection
+ patterns. Therefore the field N contains an artificial number
+ consisting of byte size markers:
+
+ 0 - byte has the value 0
+ 1..size - byte contains the content of the byte
+ number indexed with that value minus one */
+
+struct symbolic_number {
+ unsigned HOST_WIDEST_INT n;
+ int size;
+};
+
+/* Perform a SHIFT or ROTATE operation by COUNT bits on symbolic
+ number N. Return false if the requested operation is not permitted
+ on a symbolic number. */
+
+static inline bool
+do_shift_rotate (enum tree_code code,
+ struct symbolic_number *n,
+ int count)
+{
+ if (count % 8 != 0)
+ return false;
+
+ /* Zero out the extra bits of N in order to avoid them being shifted
+ into the significant bits. */
+ if (n->size < (int)sizeof (HOST_WIDEST_INT))
+ n->n &= ((unsigned HOST_WIDEST_INT)1 << (n->size * BITS_PER_UNIT)) - 1;
+
+ switch (code)
+ {
+ case LSHIFT_EXPR:
+ n->n <<= count;
+ break;
+ case RSHIFT_EXPR:
+ n->n >>= count;
+ break;
+ case LROTATE_EXPR:
+ n->n = (n->n << count) | (n->n >> ((n->size * BITS_PER_UNIT) - count));
+ break;
+ case RROTATE_EXPR:
+ n->n = (n->n >> count) | (n->n << ((n->size * BITS_PER_UNIT) - count));
+ break;
+ default:
+ return false;
+ }
+ return true;
+}
+
+/* Perform sanity checking for the symbolic number N and the gimple
+ statement STMT. */
+
+static inline bool
+verify_symbolic_number_p (struct symbolic_number *n, gimple stmt)
+{
+ tree lhs_type;
+
+ lhs_type = gimple_expr_type (stmt);
+
+ if (TREE_CODE (lhs_type) != INTEGER_TYPE)
+ return false;
+
+ if (TYPE_PRECISION (lhs_type) != n->size * BITS_PER_UNIT)
+ return false;
+
+ return true;
+}
+
+/* find_bswap_1 invokes itself recursively with N and tries to perform
+ the operation given by the rhs of STMT on the result. If the
+ operation could successfully be executed the function returns the
+ tree expression of the source operand and NULL otherwise. */
+
+static tree
+find_bswap_1 (gimple stmt, struct symbolic_number *n, int limit)
+{
+ enum tree_code code;
+ tree rhs1, rhs2 = NULL;
+ gimple rhs1_stmt, rhs2_stmt;
+ tree source_expr1;
+ enum gimple_rhs_class rhs_class;
+
+ if (!limit || !is_gimple_assign (stmt))
+ return NULL_TREE;
+
+ rhs1 = gimple_assign_rhs1 (stmt);
+
+ if (TREE_CODE (rhs1) != SSA_NAME)
+ return NULL_TREE;
+
+ code = gimple_assign_rhs_code (stmt);
+ rhs_class = gimple_assign_rhs_class (stmt);
+ rhs1_stmt = SSA_NAME_DEF_STMT (rhs1);
+
+ if (rhs_class == GIMPLE_BINARY_RHS)
+ rhs2 = gimple_assign_rhs2 (stmt);
+
+ /* Handle unary rhs and binary rhs with integer constants as second
+ operand. */
+
+ if (rhs_class == GIMPLE_UNARY_RHS
+ || (rhs_class == GIMPLE_BINARY_RHS
+ && TREE_CODE (rhs2) == INTEGER_CST))
+ {
+ if (code != BIT_AND_EXPR
+ && code != LSHIFT_EXPR
+ && code != RSHIFT_EXPR
+ && code != LROTATE_EXPR
+ && code != RROTATE_EXPR
+ && code != NOP_EXPR
+ && code != CONVERT_EXPR)
+ return NULL_TREE;
+
+ source_expr1 = find_bswap_1 (rhs1_stmt, n, limit - 1);
+
+ /* If find_bswap_1 returned NULL STMT is a leaf node and we have
+ to initialize the symbolic number. */
+ if (!source_expr1)
+ {
+ /* Set up the symbolic number N by setting each byte to a
+ value between 1 and the byte size of rhs1. The highest
+ order byte is set to 1 and the lowest order byte to
+ n.size. */
+ n->size = TYPE_PRECISION (TREE_TYPE (rhs1));
+ if (n->size % BITS_PER_UNIT != 0)
+ return NULL_TREE;
+ n->size /= BITS_PER_UNIT;
+ n->n = (sizeof (HOST_WIDEST_INT) < 8 ? 0 :
+ (unsigned HOST_WIDEST_INT)0x01020304 << 32 | 0x05060708);
+ n->n >>= (sizeof (HOST_WIDEST_INT) - n->size) * BITS_PER_UNIT;
+
+ source_expr1 = rhs1;
+ }
+
+ switch (code)
+ {
+ case BIT_AND_EXPR:
+ {
+ int i;
+ unsigned HOST_WIDEST_INT val = widest_int_cst_value (rhs2);
+ unsigned HOST_WIDEST_INT tmp = val;
+
+ /* Only constants masking full bytes are allowed. */
+ for (i = 0; i < n->size; i++, tmp >>= BITS_PER_UNIT)
+ if ((tmp & 0xff) != 0 && (tmp & 0xff) != 0xff)
+ return NULL_TREE;
+
+ n->n &= val;
+ }
+ break;
+ case LSHIFT_EXPR:
+ case RSHIFT_EXPR:
+ case LROTATE_EXPR:
+ case RROTATE_EXPR:
+ if (!do_shift_rotate (code, n, (int)TREE_INT_CST_LOW (rhs2)))
+ return NULL_TREE;
+ break;
+ CASE_CONVERT:
+ {
+ int type_size;
+
+ type_size = TYPE_PRECISION (gimple_expr_type (stmt));
+ if (type_size % BITS_PER_UNIT != 0)
+ return NULL_TREE;
+
+ if (type_size / BITS_PER_UNIT < (int)(sizeof (HOST_WIDEST_INT)))
+ {
+ /* If STMT casts to a smaller type mask out the bits not
+ belonging to the target type. */
+ n->size = type_size / BITS_PER_UNIT;
+ n->n &= ((unsigned HOST_WIDEST_INT)1 << type_size) - 1;
+ }
+ }
+ break;
+ default:
+ return NULL_TREE;
+ };
+ return verify_symbolic_number_p (n, stmt) ? source_expr1 : NULL;
+ }
+
+ /* Handle binary rhs. */
+
+ if (rhs_class == GIMPLE_BINARY_RHS)
+ {
+ struct symbolic_number n1, n2;
+ tree source_expr2;
+
+ if (code != BIT_IOR_EXPR)
+ return NULL_TREE;
+
+ if (TREE_CODE (rhs2) != SSA_NAME)
+ return NULL_TREE;
+
+ rhs2_stmt = SSA_NAME_DEF_STMT (rhs2);
+
+ switch (code)
+ {
+ case BIT_IOR_EXPR:
+ source_expr1 = find_bswap_1 (rhs1_stmt, &n1, limit - 1);
+
+ if (!source_expr1)
+ return NULL_TREE;
+
+ source_expr2 = find_bswap_1 (rhs2_stmt, &n2, limit - 1);
+
+ if (source_expr1 != source_expr2
+ || n1.size != n2.size)
+ return NULL_TREE;
+
+ n->size = n1.size;
+ n->n = n1.n | n2.n;
+
+ if (!verify_symbolic_number_p (n, stmt))
+ return NULL_TREE;
+
+ break;
+ default:
+ return NULL_TREE;
+ }
+ return source_expr1;
+ }
+ return NULL_TREE;
+}
+
+/* Check if STMT completes a bswap implementation consisting of ORs,
+ SHIFTs and ANDs. Return the source tree expression on which the
+ byte swap is performed and NULL if no bswap was found. */
+
+static tree
+find_bswap (gimple stmt)
+{
+/* The number which the find_bswap result should match in order to
+ have a full byte swap. The insignificant bytes are masked out
+ before using it. */
+ unsigned HOST_WIDEST_INT cmp =
+ sizeof (HOST_WIDEST_INT) < 8 ? 0 :
+ (unsigned HOST_WIDEST_INT)0x08070605 << 32 | 0x04030201;
+
+ struct symbolic_number n;
+ tree source_expr;
+
+ /* The last parameter determines the depth search limit. It usually
+ correlates directly to the number of bytes to be touched. We
+ increase that number by one here in order to also cover signed ->
+ unsigned conversions of the src operand as can be seen in
+ libgcc. */
+ source_expr = find_bswap_1 (stmt, &n,
+ TREE_INT_CST_LOW (
+ TYPE_SIZE_UNIT (gimple_expr_type (stmt))) + 1);
+
+ if (!source_expr)
+ return NULL_TREE;
+
+ /* Zero out the extra bits of N and CMP. */
+ if (n.size < (int)sizeof (HOST_WIDEST_INT))
+ {
+ unsigned HOST_WIDEST_INT mask =
+ ((unsigned HOST_WIDEST_INT)1 << (n.size * BITS_PER_UNIT)) - 1;
+
+ n.n &= mask;
+ cmp &= mask;
+ }
+
+ /* A complete byte swap should make the symbolic number to start
+ with the largest digit in the highest order byte. */
+ if (cmp != n.n)
+ return NULL_TREE;
+
+ return source_expr;
+}
+
+/* Find manual byte swap implementations and turn them into a bswap
+ builtin invokation. */
+
+static unsigned int
+execute_optimize_bswap (void)
+{
+ basic_block bb;
+ bool bswap32_p, bswap64_p;
+ bool changed = false;
+ tree bswap32_type = NULL_TREE, bswap64_type = NULL_TREE;
+
+ if (BITS_PER_UNIT != 8)
+ return 0;
+
+ if (sizeof (HOST_WIDEST_INT) < 8)
+ return 0;
+
+ bswap32_p = (built_in_decls[BUILT_IN_BSWAP32]
+ && optab_handler (bswap_optab, SImode)->insn_code !=
+ CODE_FOR_nothing);
+ bswap64_p = (built_in_decls[BUILT_IN_BSWAP64]
+ && (optab_handler (bswap_optab, DImode)->insn_code !=
+ CODE_FOR_nothing
+ || (bswap32_p && word_mode == SImode)));
+
+ if (!bswap32_p && !bswap64_p)
+ return 0;
+
+ /* Determine the argument type of the builtins. The code later on
+ assumes that the return and argument type are the same. */
+ if (bswap32_p)
+ {
+ tree fndecl = built_in_decls[BUILT_IN_BSWAP32];
+ bswap32_type = TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fndecl)));
+ }
+
+ if (bswap64_p)
+ {
+ tree fndecl = built_in_decls[BUILT_IN_BSWAP64];
+ bswap64_type = TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fndecl)));
+ }
+
+ FOR_EACH_BB (bb)
+ {
+ gimple_stmt_iterator gsi;
+
+ for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ tree bswap_src, bswap_type;
+ tree bswap_tmp;
+ tree fndecl = NULL_TREE;
+ int type_size;
+ gimple call;
+
+ if (!is_gimple_assign (stmt)
+ || gimple_assign_rhs_code (stmt) != BIT_IOR_EXPR)
+ continue;
+
+ type_size = TYPE_PRECISION (gimple_expr_type (stmt));
+
+ switch (type_size)
+ {
+ case 32:
+ if (bswap32_p)
+ {
+ fndecl = built_in_decls[BUILT_IN_BSWAP32];
+ bswap_type = bswap32_type;
+ }
+ break;
+ case 64:
+ if (bswap64_p)
+ {
+ fndecl = built_in_decls[BUILT_IN_BSWAP64];
+ bswap_type = bswap64_type;
+ }
+ break;
+ default:
+ continue;
+ }
+
+ if (!fndecl)
+ continue;
+
+ bswap_src = find_bswap (stmt);
+
+ if (!bswap_src)
+ continue;
+
+ changed = true;
+
+ bswap_tmp = bswap_src;
+
+ /* Convert the src expression if necessary. */
+ if (!useless_type_conversion_p (TREE_TYPE (bswap_tmp), bswap_type))
+ {
+ gimple convert_stmt;
+
+ bswap_tmp = create_tmp_var (bswap_type, "bswapsrc");
+ add_referenced_var (bswap_tmp);
+ bswap_tmp = make_ssa_name (bswap_tmp, NULL);
+
+ convert_stmt = gimple_build_assign_with_ops (
+ CONVERT_EXPR, bswap_tmp, bswap_src, NULL);
+ gsi_insert_before (&gsi, convert_stmt, GSI_SAME_STMT);
+ }
+
+ call = gimple_build_call (fndecl, 1, bswap_tmp);
+
+ bswap_tmp = gimple_assign_lhs (stmt);
+
+ /* Convert the result if necessary. */
+ if (!useless_type_conversion_p (TREE_TYPE (bswap_tmp), bswap_type))
+ {
+ gimple convert_stmt;
+
+ bswap_tmp = create_tmp_var (bswap_type, "bswapdst");
+ add_referenced_var (bswap_tmp);
+ bswap_tmp = make_ssa_name (bswap_tmp, NULL);
+ convert_stmt = gimple_build_assign_with_ops (
+ CONVERT_EXPR, gimple_assign_lhs (stmt), bswap_tmp, NULL);
+ gsi_insert_after (&gsi, convert_stmt, GSI_SAME_STMT);
+ }
+
+ gimple_call_set_lhs (call, bswap_tmp);
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "%d bit bswap implementation found at: ",
+ (int)type_size);
+ print_gimple_stmt (dump_file, stmt, 0, 0);
+ }
+
+ gsi_insert_after (&gsi, call, GSI_SAME_STMT);
+ gsi_remove (&gsi, true);
+ }
+ }
+
+ return (changed ? TODO_dump_func | TODO_update_ssa | TODO_verify_ssa
+ | TODO_verify_stmts : 0);
+}
+
+static bool
+gate_optimize_bswap (void)
+{
+ return flag_expensive_optimizations && optimize;
+}
+
+struct gimple_opt_pass pass_optimize_bswap =
+{
+ {
+ GIMPLE_PASS,
+ "bswap", /* name */
+ gate_optimize_bswap, /* gate */
+ execute_optimize_bswap, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_NONE, /* tv_id */
+ PROP_ssa, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0 /* todo_flags_finish */
+ }
};
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