/* Optimization of PHI nodes by converting them into straightline code.
- Copyright (C) 2004-2015 Free Software Foundation, Inc.
+ Copyright (C) 2004-2016 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "hash-table.h"
-#include "tm.h"
-#include "hash-set.h"
-#include "machmode.h"
-#include "vec.h"
-#include "double-int.h"
-#include "input.h"
-#include "alias.h"
-#include "symtab.h"
-#include "wide-int.h"
-#include "inchash.h"
+#include "backend.h"
+#include "insn-codes.h"
+#include "rtl.h"
#include "tree.h"
+#include "gimple.h"
+#include "cfghooks.h"
+#include "tree-pass.h"
+#include "ssa.h"
+#include "optabs-tree.h"
+#include "insn-config.h"
+#include "gimple-pretty-print.h"
#include "fold-const.h"
#include "stor-layout.h"
-#include "flags.h"
-#include "tm_p.h"
-#include "predict.h"
-#include "hard-reg-set.h"
-#include "function.h"
-#include "dominance.h"
-#include "cfg.h"
#include "cfganal.h"
-#include "basic-block.h"
-#include "tree-ssa-alias.h"
-#include "internal-fn.h"
-#include "gimple-expr.h"
-#include "is-a.h"
-#include "gimple.h"
#include "gimplify.h"
#include "gimple-iterator.h"
#include "gimplify-me.h"
-#include "gimple-ssa.h"
#include "tree-cfg.h"
-#include "tree-phinodes.h"
-#include "ssa-iterators.h"
-#include "stringpool.h"
-#include "tree-ssanames.h"
-#include "hashtab.h"
-#include "rtl.h"
-#include "statistics.h"
-#include "real.h"
-#include "fixed-value.h"
-#include "insn-config.h"
-#include "expmed.h"
-#include "dojump.h"
-#include "explow.h"
-#include "calls.h"
-#include "emit-rtl.h"
-#include "varasm.h"
-#include "stmt.h"
-#include "expr.h"
#include "tree-dfa.h"
-#include "tree-pass.h"
-#include "langhooks.h"
#include "domwalk.h"
#include "cfgloop.h"
#include "tree-data-ref.h"
-#include "gimple-pretty-print.h"
-#include "insn-codes.h"
-#include "optabs.h"
#include "tree-scalar-evolution.h"
#include "tree-inline.h"
-
-#ifndef HAVE_conditional_move
-#define HAVE_conditional_move (0)
-#endif
+#include "params.h"
static unsigned int tree_ssa_phiopt_worker (bool, bool);
static bool conditional_replacement (basic_block, basic_block,
edge, edge, gphi *, tree, tree);
+static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree, tree);
static int value_replacement (basic_block, basic_block,
- edge, edge, gimple, tree, tree);
+ edge, edge, gimple *, tree, tree);
static bool minmax_replacement (basic_block, basic_block,
- edge, edge, gimple, tree, tree);
+ edge, edge, gimple *, tree, tree);
static bool abs_replacement (basic_block, basic_block,
- edge, edge, gimple, tree, tree);
+ edge, edge, gimple *, tree, tree);
static bool cond_store_replacement (basic_block, basic_block, edge, edge,
hash_set<tree> *);
static bool cond_if_else_store_replacement (basic_block, basic_block, basic_block);
static hash_set<tree> * get_non_trapping ();
-static void replace_phi_edge_with_variable (basic_block, edge, gimple, tree);
+static void replace_phi_edge_with_variable (basic_block, edge, gimple *, tree);
static void hoist_adjacent_loads (basic_block, basic_block,
basic_block, basic_block);
static bool gate_hoist_loads (void);
for (i = 0; i < n; i++)
{
- gimple cond_stmt;
+ gimple *cond_stmt;
gphi *phi;
basic_block bb1, bb2;
edge e1, e2;
;
else if (EDGE_SUCC (bb2, 0)->dest == bb1)
{
- basic_block bb_tmp = bb1;
- edge e_tmp = e1;
- bb1 = bb2;
- bb2 = bb_tmp;
- e1 = e2;
- e2 = e_tmp;
+ std::swap (bb1, bb2);
+ std::swap (e1, e2);
}
else if (do_store_elim
&& EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest)
/* Something is wrong if we cannot find the arguments in the PHI
node. */
- gcc_assert (arg0 != NULL && arg1 != NULL);
+ gcc_assert (arg0 != NULL_TREE && arg1 != NULL_TREE);
+
+ gphi *newphi = factor_out_conditional_conversion (e1, e2, phi,
+ arg0, arg1);
+ if (newphi != NULL)
+ {
+ phi = newphi;
+ /* factor_out_conditional_conversion may create a new PHI in
+ BB2 and eliminate an existing PHI in BB2. Recompute values
+ that may be affected by that change. */
+ arg0 = gimple_phi_arg_def (phi, e1->dest_idx);
+ arg1 = gimple_phi_arg_def (phi, e2->dest_idx);
+ gcc_assert (arg0 != NULL_TREE && arg1 != NULL_TREE);
+ }
/* Do the replacement of conditional if it can be done. */
if (conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
static void
replace_phi_edge_with_variable (basic_block cond_block,
- edge e, gimple phi, tree new_tree)
+ edge e, gimple *phi, tree new_tree)
{
basic_block bb = gimple_bb (phi);
basic_block block_to_remove;
bb->index);
}
+/* PR66726: Factor conversion out of COND_EXPR. If the arguments of the PHI
+ stmt are CONVERT_STMT, factor out the conversion and perform the conversion
+ to the result of PHI stmt. Return the newly-created PHI, if any. */
+
+static gphi *
+factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
+ tree arg0, tree arg1)
+{
+ gimple *arg0_def_stmt = NULL, *arg1_def_stmt = NULL, *new_stmt;
+ tree new_arg0 = NULL_TREE, new_arg1 = NULL_TREE;
+ tree temp, result;
+ gphi *newphi;
+ gimple_stmt_iterator gsi, gsi_for_def;
+ source_location locus = gimple_location (phi);
+ enum tree_code convert_code;
+
+ /* Handle only PHI statements with two arguments. TODO: If all
+ other arguments to PHI are INTEGER_CST or if their defining
+ statement have the same unary operation, we can handle more
+ than two arguments too. */
+ if (gimple_phi_num_args (phi) != 2)
+ return NULL;
+
+ /* First canonicalize to simplify tests. */
+ if (TREE_CODE (arg0) != SSA_NAME)
+ {
+ std::swap (arg0, arg1);
+ std::swap (e0, e1);
+ }
+
+ if (TREE_CODE (arg0) != SSA_NAME
+ || (TREE_CODE (arg1) != SSA_NAME
+ && TREE_CODE (arg1) != INTEGER_CST))
+ return NULL;
+
+ /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is
+ a conversion. */
+ arg0_def_stmt = SSA_NAME_DEF_STMT (arg0);
+ if (!is_gimple_assign (arg0_def_stmt)
+ || !gimple_assign_cast_p (arg0_def_stmt))
+ return NULL;
+
+ /* Use the RHS as new_arg0. */
+ convert_code = gimple_assign_rhs_code (arg0_def_stmt);
+ new_arg0 = gimple_assign_rhs1 (arg0_def_stmt);
+ if (convert_code == VIEW_CONVERT_EXPR)
+ new_arg0 = TREE_OPERAND (new_arg0, 0);
+
+ if (TREE_CODE (arg1) == SSA_NAME)
+ {
+ /* Check if arg1 is an SSA_NAME and the stmt which defines arg1
+ is a conversion. */
+ arg1_def_stmt = SSA_NAME_DEF_STMT (arg1);
+ if (!is_gimple_assign (arg1_def_stmt)
+ || gimple_assign_rhs_code (arg1_def_stmt) != convert_code)
+ return NULL;
+
+ /* Use the RHS as new_arg1. */
+ new_arg1 = gimple_assign_rhs1 (arg1_def_stmt);
+ if (convert_code == VIEW_CONVERT_EXPR)
+ new_arg1 = TREE_OPERAND (new_arg1, 0);
+ }
+ else
+ {
+ /* If arg1 is an INTEGER_CST, fold it to new type. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0))
+ && int_fits_type_p (arg1, TREE_TYPE (new_arg0)))
+ {
+ if (gimple_assign_cast_p (arg0_def_stmt))
+ new_arg1 = fold_convert (TREE_TYPE (new_arg0), arg1);
+ else
+ return NULL;
+ }
+ else
+ return NULL;
+ }
+
+ /* If arg0/arg1 have > 1 use, then this transformation actually increases
+ the number of expressions evaluated at runtime. */
+ if (!has_single_use (arg0)
+ || (arg1_def_stmt && !has_single_use (arg1)))
+ return NULL;
+
+ /* If types of new_arg0 and new_arg1 are different bailout. */
+ if (!types_compatible_p (TREE_TYPE (new_arg0), TREE_TYPE (new_arg1)))
+ return NULL;
+
+ /* Create a new PHI stmt. */
+ result = PHI_RESULT (phi);
+ temp = make_ssa_name (TREE_TYPE (new_arg0), NULL);
+ newphi = create_phi_node (temp, gimple_bb (phi));
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "PHI ");
+ print_generic_expr (dump_file, gimple_phi_result (phi), 0);
+ fprintf (dump_file,
+ " changed to factor conversion out from COND_EXPR.\n");
+ fprintf (dump_file, "New stmt with CAST that defines ");
+ print_generic_expr (dump_file, result, 0);
+ fprintf (dump_file, ".\n");
+ }
+
+ /* Remove the old cast(s) that has single use. */
+ gsi_for_def = gsi_for_stmt (arg0_def_stmt);
+ gsi_remove (&gsi_for_def, true);
+ release_defs (arg0_def_stmt);
+
+ if (arg1_def_stmt)
+ {
+ gsi_for_def = gsi_for_stmt (arg1_def_stmt);
+ gsi_remove (&gsi_for_def, true);
+ release_defs (arg1_def_stmt);
+ }
+
+ add_phi_arg (newphi, new_arg0, e0, locus);
+ add_phi_arg (newphi, new_arg1, e1, locus);
+
+ /* Create the conversion stmt and insert it. */
+ if (convert_code == VIEW_CONVERT_EXPR)
+ temp = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (result), temp);
+ new_stmt = gimple_build_assign (result, convert_code, temp);
+ gsi = gsi_after_labels (gimple_bb (phi));
+ gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
+
+ /* Remove the original PHI stmt. */
+ gsi = gsi_for_stmt (phi);
+ gsi_remove (&gsi, true);
+ return newphi;
+}
+
/* The function conditional_replacement does the main work of doing the
conditional replacement. Return true if the replacement is done.
Otherwise return false.
tree arg0, tree arg1)
{
tree result;
- gimple stmt;
+ gimple *stmt;
gassign *new_stmt;
tree cond;
gimple_stmt_iterator gsi;
}
replace_phi_edge_with_variable (cond_bb, e1, phi, new_var);
+ reset_flow_sensitive_info_in_bb (cond_bb);
/* Note that we optimized this PHI. */
return true;
statement is made dead by that rewriting. */
static bool
-jump_function_from_stmt (tree *arg, gimple stmt)
+jump_function_from_stmt (tree *arg, gimple *stmt)
{
enum tree_code code = gimple_assign_rhs_code (stmt);
if (code == ADDR_EXPR)
statement. */
if (TREE_CODE (rhs) == SSA_NAME)
{
- gimple def1 = SSA_NAME_DEF_STMT (rhs);
+ gimple *def1 = SSA_NAME_DEF_STMT (rhs);
/* Verify the defining statement has an EQ_EXPR on the RHS. */
if (is_gimple_assign (def1) && gimple_assign_rhs_code (def1) == EQ_EXPR)
static bool
operand_equal_for_value_replacement (const_tree arg0, const_tree arg1,
- enum tree_code *code, gimple cond)
+ enum tree_code *code, gimple *cond)
{
- gimple def;
+ gimple *def;
tree lhs = gimple_cond_lhs (cond);
tree rhs = gimple_cond_rhs (cond);
static int
value_replacement (basic_block cond_bb, basic_block middle_bb,
- edge e0, edge e1, gimple phi,
+ edge e0, edge e1, gimple *phi,
tree arg0, tree arg1)
{
gimple_stmt_iterator gsi;
- gimple cond;
+ gimple *cond;
edge true_edge, false_edge;
enum tree_code code;
bool emtpy_or_with_defined_p = true;
gsi = gsi_start_nondebug_after_labels_bb (middle_bb);
while (!gsi_end_p (gsi))
{
- gimple stmt = gsi_stmt (gsi);
+ gimple *stmt = gsi_stmt (gsi);
tree lhs;
gsi_next_nondebug (&gsi);
if (!is_gimple_assign (stmt))
/* Now optimize (x != 0) ? x + y : y to just y.
The following condition is too restrictive, there can easily be another
stmt in middle_bb, for instance a CONVERT_EXPR for the second argument. */
- gimple assign = last_and_only_stmt (middle_bb);
+ gimple *assign = last_and_only_stmt (middle_bb);
if (!assign || gimple_code (assign) != GIMPLE_ASSIGN
|| gimple_assign_rhs_class (assign) != GIMPLE_BINARY_RHS
|| (!INTEGRAL_TYPE_P (TREE_TYPE (arg0))
<bb 4>:
# u_3 = PHI <u_6(3), 4294967295(2)> */
SSA_NAME_RANGE_INFO (lhs) = NULL;
- SSA_NAME_ANTI_RANGE_P (lhs) = 0;
/* If available, we can use VR of phi result at least. */
tree phires = gimple_phi_result (phi);
struct range_info_def *phires_range_info
static bool
minmax_replacement (basic_block cond_bb, basic_block middle_bb,
- edge e0, edge e1, gimple phi,
+ edge e0, edge e1, gimple *phi,
tree arg0, tree arg1)
{
tree result, type;
b = MAX (a, d);
x = MIN (b, u); */
- gimple assign = last_and_only_stmt (middle_bb);
+ gimple *assign = last_and_only_stmt (middle_bb);
tree lhs, op0, op1, bound;
if (!assign
gsi_move_before (&gsi_from, &gsi);
}
+ /* Create an SSA var to hold the min/max result. If we're the only
+ things setting the target PHI, then we can clone the PHI
+ variable. Otherwise we must create a new one. */
+ result = PHI_RESULT (phi);
+ if (EDGE_COUNT (gimple_bb (phi)->preds) == 2)
+ result = duplicate_ssa_name (result, NULL);
+ else
+ result = make_ssa_name (TREE_TYPE (result));
+
/* Emit the statement to compute min/max. */
- result = duplicate_ssa_name (PHI_RESULT (phi), NULL);
new_stmt = gimple_build_assign (result, minmax, arg0, arg1);
gsi = gsi_last_bb (cond_bb);
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
replace_phi_edge_with_variable (cond_bb, e1, phi, result);
+ reset_flow_sensitive_info_in_bb (cond_bb);
+
return true;
}
static bool
abs_replacement (basic_block cond_bb, basic_block middle_bb,
edge e0 ATTRIBUTE_UNUSED, edge e1,
- gimple phi, tree arg0, tree arg1)
+ gimple *phi, tree arg0, tree arg1)
{
tree result;
gassign *new_stmt;
- gimple cond;
+ gimple *cond;
gimple_stmt_iterator gsi;
edge true_edge, false_edge;
- gimple assign;
+ gimple *assign;
edge e;
tree rhs, lhs;
bool negate;
}
replace_phi_edge_with_variable (cond_bb, e1, phi, result);
+ reset_flow_sensitive_info_in_bb (cond_bb);
/* Note that we optimized this PHI. */
return true;
/* Hashtable helpers. */
-struct ssa_names_hasher : typed_free_remove <name_to_bb>
+struct ssa_names_hasher : free_ptr_hash <name_to_bb>
{
- typedef name_to_bb *value_type;
- typedef name_to_bb *compare_type;
static inline hashval_t hash (const name_to_bb *);
static inline bool equal (const name_to_bb *, const name_to_bb *);
};
nontrapping_dom_walker (cdi_direction direction, hash_set<tree> *ps)
: dom_walker (direction), m_nontrapping (ps), m_seen_ssa_names (128) {}
- virtual void before_dom_children (basic_block);
+ virtual edge before_dom_children (basic_block);
virtual void after_dom_children (basic_block);
private:
};
/* Called by walk_dominator_tree, when entering the block BB. */
-void
+edge
nontrapping_dom_walker::before_dom_children (basic_block bb)
{
edge e;
/* And walk the statements in order. */
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple stmt = gsi_stmt (gsi);
+ gimple *stmt = gsi_stmt (gsi);
- if (is_gimple_call (stmt) && !nonfreeing_call_p (stmt))
+ if ((gimple_code (stmt) == GIMPLE_ASM && gimple_vdef (stmt))
+ || (is_gimple_call (stmt)
+ && (!nonfreeing_call_p (stmt) || !nonbarrier_call_p (stmt))))
nt_call_phase++;
else if (gimple_assign_single_p (stmt) && !gimple_has_volatile_ops (stmt))
{
add_or_mark_expr (bb, gimple_assign_rhs1 (stmt), false);
}
}
+ return NULL;
}
/* Called by walk_dominator_tree, when basic block BB is exited. */
cond_store_replacement (basic_block middle_bb, basic_block join_bb,
edge e0, edge e1, hash_set<tree> *nontrap)
{
- gimple assign = last_and_only_stmt (middle_bb);
+ gimple *assign = last_and_only_stmt (middle_bb);
tree lhs, rhs, name, name2;
gphi *newphi;
gassign *new_stmt;
static bool
cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb,
- basic_block join_bb, gimple then_assign,
- gimple else_assign)
+ basic_block join_bb, gimple *then_assign,
+ gimple *else_assign)
{
tree lhs_base, lhs, then_rhs, else_rhs, name;
source_location then_locus, else_locus;
cond_if_else_store_replacement (basic_block then_bb, basic_block else_bb,
basic_block join_bb)
{
- gimple then_assign = last_and_only_stmt (then_bb);
- gimple else_assign = last_and_only_stmt (else_bb);
+ gimple *then_assign = last_and_only_stmt (then_bb);
+ gimple *else_assign = last_and_only_stmt (else_bb);
vec<data_reference_p> then_datarefs, else_datarefs;
vec<ddr_p> then_ddrs, else_ddrs;
- gimple then_store, else_store;
+ gimple *then_store, *else_store;
bool found, ok = false, res;
struct data_dependence_relation *ddr;
data_reference_p then_dr, else_dr;
}
/* Find pairs of stores with equal LHS. */
- auto_vec<gimple, 1> then_stores, else_stores;
+ auto_vec<gimple *, 1> then_stores, else_stores;
FOR_EACH_VEC_ELT (then_datarefs, i, then_dr)
{
if (DR_IS_READ (then_dr))
/* Return TRUE if STMT has a VUSE whose corresponding VDEF is in BB. */
static bool
-local_mem_dependence (gimple stmt, basic_block bb)
+local_mem_dependence (gimple *stmt, basic_block bb)
{
tree vuse = gimple_vuse (stmt);
- gimple def;
+ gimple *def;
if (!vuse)
return false;
for (gsi = gsi_start_phis (bb3); !gsi_end_p (gsi); gsi_next (&gsi))
{
gphi *phi_stmt = gsi.phi ();
- gimple def1, def2, defswap;
- tree arg1, arg2, ref1, ref2, field1, field2, fieldswap;
+ gimple *def1, *def2;
+ tree arg1, arg2, ref1, ref2, field1, field2;
tree tree_offset1, tree_offset2, tree_size2, next;
int offset1, offset2, size2;
unsigned align1;
if (next != field1)
continue;
- fieldswap = field1;
- field1 = field2;
- field2 = fieldswap;
- defswap = def1;
- def1 = def2;
- def2 = defswap;
+ std::swap (field1, field2);
+ std::swap (def1, def2);
}
bb_for_def1 = gimple_bb (def1);
This pass also performs a fifth transformation of a slightly different
flavor.
+ Factor conversion in COND_EXPR
+ ------------------------------
+
+ This transformation factors the conversion out of COND_EXPR with
+ factor_out_conditional_conversion.
+
+ For example:
+ if (a <= CST) goto <bb 3>; else goto <bb 4>;
+ <bb 3>:
+ tmp = (int) a;
+ <bb 4>:
+ tmp = PHI <tmp, CST>
+
+ Into:
+ if (a <= CST) goto <bb 3>; else goto <bb 4>;
+ <bb 3>:
+ <bb 4>:
+ a = PHI <a, CST>
+ tmp = (int) a;
+
Adjacent Load Hoisting
----------------------
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