4.4BSD/usr/src/contrib/gcc-2.3.3/cp-expr.c
/* Convert language-specific tree expression to rtl instructions,
for GNU compiler.
Copyright (C) 1988, 1992 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC 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 later version.
GNU CC 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 GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "config.h"
#include "rtl.h"
#include "tree.h"
#include "flags.h"
#include "expr.h"
#include "cp-tree.h"
#define NULL 0
/* Hook used by expand_expr to expand language-specific tree codes. */
rtx
cplus_expand_expr (exp, target, tmode, modifier)
tree exp;
rtx target;
enum machine_mode tmode;
enum expand_modifier modifier;
{
tree type = TREE_TYPE (exp);
register enum machine_mode mode = TYPE_MODE (type);
register enum tree_code code = TREE_CODE (exp);
rtx original_target = target;
int ignore = target == const0_rtx;
if (ignore) target = 0, original_target = 0;
/* No sense saving up arithmetic to be done
if it's all in the wrong mode to form part of an address.
And force_operand won't know whether to sign-extend or zero-extend. */
if (mode != Pmode && modifier == EXPAND_SUM)
modifier = EXPAND_NORMAL;
switch (code)
{
case NEW_EXPR:
{
/* Something needs to be initialized, but we didn't know
where that thing was when building the tree. For example,
it could be the return value of a function, or a parameter
to a function which lays down in the stack, or a temporary
variable which must be passed by reference.
Cleanups are handled in a language-specific way: they
might be run by the called function (true in GNU C++
for parameters with cleanups), or they might be
run by the caller, after the call (true in GNU C++
for other cleanup needs). */
tree func = TREE_OPERAND (exp, 0);
tree args = TREE_OPERAND (exp, 1);
tree type = TREE_TYPE (exp), slot;
tree fn_type = TREE_TYPE (TREE_TYPE (func));
tree return_type = TREE_TYPE (fn_type);
rtx call_target, return_target;
/* The expression `init' wants to initialize what
`target' represents. SLOT holds the slot for TARGET. */
slot = TREE_OPERAND (exp, 2);
if (target == 0)
{
/* Should always be called with a target in BLKmode case. */
my_friendly_assert (mode != BLKmode, 205);
my_friendly_assert (DECL_RTL (slot) != 0, 206);
target = gen_reg_rtx (mode);
}
/* The target the initializer will initialize (CALL_TARGET)
must now be directed to initialize the target we are
supposed to initialize (TARGET). The semantics for
choosing what CALL_TARGET is is language-specific,
as is building the call which will perform the
initialization. It is left here to show the choices that
exist for C++. */
if (TREE_CODE (func) == ADDR_EXPR
&& TREE_CODE (TREE_OPERAND (func, 0)) == FUNCTION_DECL
&& DECL_CONSTRUCTOR_P (TREE_OPERAND (func, 0)))
{
type = TYPE_POINTER_TO (type);
/* Don't clobber a value that might be part of a default
parameter value. */
if (TREE_PERMANENT (args))
args = tree_cons (0, build1 (ADDR_EXPR, type, slot),
TREE_CHAIN (args));
else
TREE_VALUE (args) = build1 (ADDR_EXPR, type, slot);
call_target = 0;
}
else if (TREE_CODE (return_type) == REFERENCE_TYPE)
{
type = return_type;
call_target = 0;
}
else
{
call_target = target;
}
if (call_target)
preserve_temp_slots (call_target);
preserve_temp_slots (DECL_RTL (slot));
return_target = expand_expr (build (CALL_EXPR, type, func, args, 0), call_target, mode, 0);
free_temp_slots ();
if (call_target == 0)
call_target = return_target;
else if (call_target != return_target)
{
if (GET_MODE (return_target) == BLKmode)
emit_block_move (call_target, return_target, expr_size (exp),
TYPE_ALIGN (type) / BITS_PER_UNIT);
else
emit_move_insn (call_target, return_target);
}
if (TREE_CODE (return_type) == REFERENCE_TYPE)
{
tree init;
if (GET_CODE (call_target) == REG
&& REGNO (call_target) < FIRST_PSEUDO_REGISTER)
my_friendly_abort (39);
type = TREE_TYPE (exp);
init = build (RTL_EXPR, return_type, 0, call_target);
/* We got back a reference to the type we want. Now initialize
target with that. */
expand_aggr_init (slot, init, 0);
}
if (DECL_RTL (slot) != target)
emit_move_insn (DECL_RTL (slot), target);
return DECL_RTL (slot);
}
case OFFSET_REF:
{
tree base = build_unary_op (ADDR_EXPR, TREE_OPERAND (exp, 0), 0);
tree offset = build_unary_op (ADDR_EXPR, TREE_OPERAND (exp, 1), 0);
return expand_expr (build (PLUS_EXPR, TREE_TYPE (exp), base, offset),
target, tmode, EXPAND_NORMAL);
}
default:
break;
}
my_friendly_abort (40);
/* NOTREACHED */
return NULL;
}
void
init_cplus_expand ()
{
lang_expand_expr = cplus_expand_expr;
}
/* If DECL had its rtl moved from where callers expect it
to be, fix it up. RESULT is the nominal rtl for the RESULT_DECL,
which may be a pseudo instead of a hard register. */
void
fixup_result_decl (decl, result)
tree decl;
rtx result;
{
if (REG_P (result))
{
if (REGNO (result) >= FIRST_PSEUDO_REGISTER)
{
rtx real_decl_result;
#ifdef FUNCTION_OUTGOING_VALUE
real_decl_result
= FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl), current_function_decl);
#else
real_decl_result
= FUNCTION_VALUE (TREE_TYPE (decl), current_function_decl);
#endif
REG_FUNCTION_VALUE_P (real_decl_result) = 1;
result = real_decl_result;
}
emit_move_insn (result, DECL_RTL (decl));
emit_insn (gen_rtx (USE, VOIDmode, result));
}
}
/* Return nonzero iff DECL is memory-based. The DECL_RTL of
certain const variables might be a CONST_INT, or a REG
in some cases. We cannot use `memory_operand' as a test
here because on most RISC machines, a variable's address
is not, by itself, a legitimate address. */
int
decl_in_memory_p (decl)
tree decl;
{
return DECL_RTL (decl) != 0 && GET_CODE (DECL_RTL (decl)) == MEM;
}