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/* Tree lowering to gimple for middle end use only.
This converts the GENERIC functions-as-trees tree representation into
the GIMPLE form.
Copyright (C) 2013-2018 Free Software Foundation, Inc.
Major work done by Sebastian Pop <s.pop@laposte.net>,
Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
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 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 COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "tree.h"
#include "gimple.h"
#include "ssa.h"
#include "stmt.h"
#include "stor-layout.h"
#include "tree-eh.h"
#include "gimple-iterator.h"
#include "gimplify.h"
#include "gimplify-me.h"
/* Expand EXPR to list of gimple statements STMTS. GIMPLE_TEST_F specifies
the predicate that will hold for the result. If VAR is not NULL, make the
base variable of the final destination be VAR if suitable. */
tree
force_gimple_operand_1 (tree expr, gimple_seq *stmts,
gimple_predicate gimple_test_f, tree var)
{
enum gimplify_status ret;
location_t saved_location;
*stmts = NULL;
/* gimple_test_f might be more strict than is_gimple_val, make
sure we pass both. Just checking gimple_test_f doesn't work
because most gimple predicates do not work recursively. */
if (is_gimple_val (expr)
&& (*gimple_test_f) (expr))
return expr;
push_gimplify_context (gimple_in_ssa_p (cfun), true);
saved_location = input_location;
input_location = UNKNOWN_LOCATION;
if (var)
{
if (gimple_in_ssa_p (cfun) && is_gimple_reg (var))
var = make_ssa_name (var);
expr = build2 (MODIFY_EXPR, TREE_TYPE (var), var, expr);
}
if (TREE_CODE (expr) != MODIFY_EXPR
&& TREE_TYPE (expr) == void_type_node)
{
gimplify_and_add (expr, stmts);
expr = NULL_TREE;
}
else
{
ret = gimplify_expr (&expr, stmts, NULL, gimple_test_f, fb_rvalue);
gcc_assert (ret != GS_ERROR);
}
input_location = saved_location;
pop_gimplify_context (NULL);
return expr;
}
/* Expand EXPR to list of gimple statements STMTS. If SIMPLE is true,
force the result to be either ssa_name or an invariant, otherwise
just force it to be a rhs expression. If VAR is not NULL, make the
base variable of the final destination be VAR if suitable. */
tree
force_gimple_operand (tree expr, gimple_seq *stmts, bool simple, tree var)
{
return force_gimple_operand_1 (expr, stmts,
simple ? is_gimple_val : is_gimple_reg_rhs,
var);
}
/* Invoke force_gimple_operand_1 for EXPR with parameters GIMPLE_TEST_F
and VAR. If some statements are produced, emits them at GSI.
If BEFORE is true. the statements are appended before GSI, otherwise
they are appended after it. M specifies the way GSI moves after
insertion (GSI_SAME_STMT or GSI_CONTINUE_LINKING are the usual values). */
tree
force_gimple_operand_gsi_1 (gimple_stmt_iterator *gsi, tree expr,
gimple_predicate gimple_test_f,
tree var, bool before,
enum gsi_iterator_update m)
{
gimple_seq stmts;
expr = force_gimple_operand_1 (expr, &stmts, gimple_test_f, var);
if (!gimple_seq_empty_p (stmts))
{
if (before)
gsi_insert_seq_before (gsi, stmts, m);
else
gsi_insert_seq_after (gsi, stmts, m);
}
return expr;
}
/* Invoke force_gimple_operand_1 for EXPR with parameter VAR.
If SIMPLE is true, force the result to be either ssa_name or an invariant,
otherwise just force it to be a rhs expression. If some statements are
produced, emits them at GSI. If BEFORE is true, the statements are
appended before GSI, otherwise they are appended after it. M specifies
the way GSI moves after insertion (GSI_SAME_STMT or GSI_CONTINUE_LINKING
are the usual values). */
tree
force_gimple_operand_gsi (gimple_stmt_iterator *gsi, tree expr,
bool simple_p, tree var, bool before,
enum gsi_iterator_update m)
{
return force_gimple_operand_gsi_1 (gsi, expr,
simple_p
? is_gimple_val : is_gimple_reg_rhs,
var, before, m);
}
/* Some transformations like inlining may invalidate the GIMPLE form
for operands. This function traverses all the operands in STMT and
gimplifies anything that is not a valid gimple operand. Any new
GIMPLE statements are inserted before *GSI_P. */
void
gimple_regimplify_operands (gimple *stmt, gimple_stmt_iterator *gsi_p)
{
size_t i, num_ops;
tree lhs;
gimple_seq pre = NULL;
gimple *post_stmt = NULL;
push_gimplify_context (gimple_in_ssa_p (cfun));
switch (gimple_code (stmt))
{
case GIMPLE_COND:
{
gcond *cond_stmt = as_a <gcond *> (stmt);
gimplify_expr (gimple_cond_lhs_ptr (cond_stmt), &pre, NULL,
is_gimple_val, fb_rvalue);
gimplify_expr (gimple_cond_rhs_ptr (cond_stmt), &pre, NULL,
is_gimple_val, fb_rvalue);
}
break;
case GIMPLE_SWITCH:
gimplify_expr (gimple_switch_index_ptr (as_a <gswitch *> (stmt)),
&pre, NULL, is_gimple_val, fb_rvalue);
break;
case GIMPLE_OMP_ATOMIC_LOAD:
gimplify_expr (gimple_omp_atomic_load_rhs_ptr (
as_a <gomp_atomic_load *> (stmt)),
&pre, NULL, is_gimple_val, fb_rvalue);
break;
case GIMPLE_ASM:
{
gasm *asm_stmt = as_a <gasm *> (stmt);
size_t i, noutputs = gimple_asm_noutputs (asm_stmt);
const char *constraint, **oconstraints;
bool allows_mem, allows_reg, is_inout;
oconstraints
= (const char **) alloca ((noutputs) * sizeof (const char *));
for (i = 0; i < noutputs; i++)
{
tree op = gimple_asm_output_op (asm_stmt, i);
constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
oconstraints[i] = constraint;
parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
&allows_reg, &is_inout);
gimplify_expr (&TREE_VALUE (op), &pre, NULL,
is_inout ? is_gimple_min_lval : is_gimple_lvalue,
fb_lvalue | fb_mayfail);
}
for (i = 0; i < gimple_asm_ninputs (asm_stmt); i++)
{
tree op = gimple_asm_input_op (asm_stmt, i);
constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
parse_input_constraint (&constraint, 0, 0, noutputs, 0,
oconstraints, &allows_mem, &allows_reg);
if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (op))) && allows_mem)
allows_reg = 0;
if (!allows_reg && allows_mem)
gimplify_expr (&TREE_VALUE (op), &pre, NULL,
is_gimple_lvalue, fb_lvalue | fb_mayfail);
else
gimplify_expr (&TREE_VALUE (op), &pre, NULL,
is_gimple_asm_val, fb_rvalue);
}
}
break;
default:
/* NOTE: We start gimplifying operands from last to first to
make sure that side-effects on the RHS of calls, assignments
and ASMs are executed before the LHS. The ordering is not
important for other statements. */
num_ops = gimple_num_ops (stmt);
for (i = num_ops; i > 0; i--)
{
tree op = gimple_op (stmt, i - 1);
if (op == NULL_TREE)
continue;
if (i == 1 && (is_gimple_call (stmt) || is_gimple_assign (stmt)))
gimplify_expr (&op, &pre, NULL, is_gimple_lvalue, fb_lvalue);
else if (i == 2
&& is_gimple_assign (stmt)
&& num_ops == 2
&& get_gimple_rhs_class (gimple_expr_code (stmt))
== GIMPLE_SINGLE_RHS)
gimplify_expr (&op, &pre, NULL,
rhs_predicate_for (gimple_assign_lhs (stmt)),
fb_rvalue);
else if (i == 2 && is_gimple_call (stmt))
{
if (TREE_CODE (op) == FUNCTION_DECL)
continue;
gimplify_expr (&op, &pre, NULL, is_gimple_call_addr, fb_rvalue);
}
else
gimplify_expr (&op, &pre, NULL, is_gimple_val, fb_rvalue);
gimple_set_op (stmt, i - 1, op);
}
lhs = gimple_get_lhs (stmt);
/* If the LHS changed it in a way that requires a simple RHS,
create temporary. */
if (lhs && !is_gimple_reg (lhs))
{
bool need_temp = false;
if (is_gimple_assign (stmt)
&& num_ops == 2
&& get_gimple_rhs_class (gimple_expr_code (stmt))
== GIMPLE_SINGLE_RHS)
gimplify_expr (gimple_assign_rhs1_ptr (stmt), &pre, NULL,
rhs_predicate_for (gimple_assign_lhs (stmt)),
fb_rvalue);
else if (is_gimple_reg (lhs))
{
if (is_gimple_reg_type (TREE_TYPE (lhs)))
{
if (is_gimple_call (stmt))
{
i = gimple_call_flags (stmt);
if ((i & ECF_LOOPING_CONST_OR_PURE)
|| !(i & (ECF_CONST | ECF_PURE)))
need_temp = true;
}
if (stmt_can_throw_internal (stmt))
need_temp = true;
}
}
else
{
if (is_gimple_reg_type (TREE_TYPE (lhs)))
need_temp = true;
else if (TYPE_MODE (TREE_TYPE (lhs)) != BLKmode)
{
if (is_gimple_call (stmt))
{
tree fndecl = gimple_call_fndecl (stmt);
if (!aggregate_value_p (TREE_TYPE (lhs), fndecl)
&& !(fndecl && DECL_RESULT (fndecl)
&& DECL_BY_REFERENCE (DECL_RESULT (fndecl))))
need_temp = true;
}
else
need_temp = true;
}
}
if (need_temp)
{
tree temp = create_tmp_reg (TREE_TYPE (lhs));
if (gimple_in_ssa_p (cfun)
&& is_gimple_reg_type (TREE_TYPE (lhs)))
temp = make_ssa_name (temp);
gimple_set_lhs (stmt, temp);
post_stmt = gimple_build_assign (lhs, temp);
}
}
break;
}
if (!gimple_seq_empty_p (pre))
gsi_insert_seq_before (gsi_p, pre, GSI_SAME_STMT);
if (post_stmt)
gsi_insert_after (gsi_p, post_stmt, GSI_NEW_STMT);
pop_gimplify_context (NULL);
update_stmt (stmt);
}