static bool
propagate_rtx_1 (rtx *px, rtx old_rtx, rtx new_rtx, int flags)
{
rtx x = *px, tem = NULL_RTX, op0, op1, op2;
enum rtx_code code = GET_CODE (x);
machine_mode mode = GET_MODE (x);
machine_mode op_mode;
bool can_appear = (flags & PR_CAN_APPEAR) != 0;
bool valid_ops = true;
if (!(flags & PR_HANDLE_MEM) && MEM_P (x) && !MEM_READONLY_P (x))
{
/* If unsafe, change MEMs to CLOBBERs or SCRATCHes (to preserve whether
they have side effects or not). */
*px = (side_effects_p (x)
? gen_rtx_CLOBBER (GET_MODE (x), const0_rtx)
: gen_rtx_SCRATCH (GET_MODE (x)));
return false;
}
/* If X is OLD_RTX, return NEW_RTX. But not if replacing only within an
address, and we are *not* inside one. */
if (x == old_rtx)
{
*px = new_rtx;
return can_appear;
}
/* If this is an expression, try recursive substitution. */
switch (GET_RTX_CLASS (code))
{
case RTX_UNARY:
op0 = XEXP (x, 0);
op_mode = GET_MODE (op0);
valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
if (op0 == XEXP (x, 0))
return true;
tem = simplify_gen_unary (code, mode, op0, op_mode);
break;
case RTX_BIN_ARITH:
case RTX_COMM_ARITH:
op0 = XEXP (x, 0);
op1 = XEXP (x, 1);
valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
return true;
tem = simplify_gen_binary (code, mode, op0, op1);
break;
case RTX_COMPARE:
case RTX_COMM_COMPARE:
op0 = XEXP (x, 0);
op1 = XEXP (x, 1);
op_mode = GET_MODE (op0) != VOIDmode ? GET_MODE (op0) : GET_MODE (op1);
valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
return true;
tem = simplify_gen_relational (code, mode, op_mode, op0, op1);
break;
case RTX_TERNARY:
case RTX_BITFIELD_OPS:
op0 = XEXP (x, 0);
op1 = XEXP (x, 1);
op2 = XEXP (x, 2);
op_mode = GET_MODE (op0);
valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
valid_ops &= propagate_rtx_1 (&op2, old_rtx, new_rtx, flags);
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1) && op2 == XEXP (x, 2))
return true;
if (op_mode == VOIDmode)
op_mode = GET_MODE (op0);
tem = simplify_gen_ternary (code, mode, op_mode, op0, op1, op2);
break;
case RTX_EXTRA:
/* The only case we try to handle is a SUBREG. */
if (code == SUBREG)
{
op0 = XEXP (x, 0);
valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
if (op0 == XEXP (x, 0))
return true;
tem = simplify_gen_subreg (mode, op0, GET_MODE (SUBREG_REG (x)),
SUBREG_BYTE (x));
}
break;
case RTX_OBJ:
if (code == MEM && x != new_rtx)
{
rtx new_op0;
op0 = XEXP (x, 0);
/* There are some addresses that we cannot work on. */
if (!can_simplify_addr (op0))
return true;
op0 = new_op0 = targetm.delegitimize_address (op0);
valid_ops &= propagate_rtx_1 (&new_op0, old_rtx, new_rtx,
flags | PR_CAN_APPEAR);
/* Dismiss transformation that we do not want to carry on. */
if (!valid_ops
|| new_op0 == op0
|| !(GET_MODE (new_op0) == GET_MODE (op0)
|| GET_MODE (new_op0) == VOIDmode))
return true;
canonicalize_address (new_op0);
/* Copy propagations are always ok. Otherwise check the costs. */
if (!(REG_P (old_rtx) && REG_P (new_rtx))
&& !should_replace_address (op0, new_op0, GET_MODE (x),
MEM_ADDR_SPACE (x),
flags & PR_OPTIMIZE_FOR_SPEED))
return true;
tem = replace_equiv_address_nv (x, new_op0);
}
else if (code == LO_SUM)
{
op0 = XEXP (x, 0);
op1 = XEXP (x, 1);
/* The only simplification we do attempts to remove references to op0
or make it constant -- in both cases, op0's invalidity will not
make the result invalid. */
propagate_rtx_1 (&op0, old_rtx, new_rtx, flags | PR_CAN_APPEAR);
valid_ops &= propagate_rtx_1 (&op1, old_rtx, new_rtx, flags);
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
return true;
/* (lo_sum (high x) x) -> x */
if (GET_CODE (op0) == HIGH && rtx_equal_p (XEXP (op0, 0), op1))
tem = op1;
else
tem = gen_rtx_LO_SUM (mode, op0, op1);
/* OP1 is likely not a legitimate address, otherwise there would have
been no LO_SUM. We want it to disappear if it is invalid, return
false in that case. */
return memory_address_p (mode, tem);
}
else if (code == REG)
{
if (rtx_equal_p (x, old_rtx))
{
*px = new_rtx;
return can_appear;
}
}
break;
default:
break;
}
/* No change, no trouble. */
if (tem == NULL_RTX)
return true;
*px = tem;
/* Allow replacements that simplify operations on a vector or complex
value to a component. The most prominent case is
(subreg ([vec_]concat ...)). */
if (REG_P (tem) && !HARD_REGISTER_P (tem)
&& (VECTOR_MODE_P (GET_MODE (new_rtx))
|| COMPLEX_MODE_P (GET_MODE (new_rtx)))
&& GET_MODE (tem) == GET_MODE_INNER (GET_MODE (new_rtx)))
return true;
/* The replacement we made so far is valid, if all of the recursive
replacements were valid, or we could simplify everything to
a constant. */
return valid_ops || can_appear || CONSTANT_P (tem);
}
static void
force_move_args_size_note (basic_block bb, rtx prev, rtx insn)
{
rtx note, test, next_candidate, prev_candidate;
/* If PREV exists, tail-call to the logic in the other function. */
if (prev)
{
maybe_move_args_size_note (prev, insn, false);
return;
}
/* First, make sure there's anything that needs doing. */
note = find_reg_note (insn, REG_ARGS_SIZE, NULL_RTX);
if (note == NULL)
return;
/* We need to find a spot between the previous and next exception points
where we can place the note and "properly" deallocate the arguments. */
next_candidate = prev_candidate = NULL;
/* It is often the case that we have insns in the order:
call
add sp (previous deallocation)
sub sp (align for next arglist)
push arg
and the add/sub cancel. Therefore we begin by searching forward. */
test = insn;
while ((test = next_active_insn_bb (bb, test)) != NULL)
{
/* Found an existing note: nothing to do. */
if (find_reg_note (test, REG_ARGS_SIZE, NULL_RTX))
return;
/* Found something that affects unwinding. Stop searching. */
if (CALL_P (test) || !insn_nothrow_p (test))
break;
if (next_candidate == NULL)
next_candidate = test;
}
test = insn;
while ((test = prev_active_insn_bb (bb, test)) != NULL)
{
rtx tnote;
/* Found a place that seems logical to adjust the stack. */
tnote = find_reg_note (test, REG_ARGS_SIZE, NULL_RTX);
if (tnote)
{
XEXP (tnote, 0) = XEXP (note, 0);
return;
}
if (prev_candidate == NULL)
prev_candidate = test;
/* Found something that affects unwinding. Stop searching. */
if (CALL_P (test) || !insn_nothrow_p (test))
break;
}
if (prev_candidate)
test = prev_candidate;
else if (next_candidate)
test = next_candidate;
else
{
/* ??? We *must* have a place, lest we ICE on the lost adjustment.
Options are: dummy clobber insn, nop, or prevent the removal of
the sp += 0 insn. */
/* TODO: Find another way to indicate to the dwarf2 code that we
have not in fact lost an adjustment. */
test = emit_insn_before (gen_rtx_CLOBBER (VOIDmode, const0_rtx), insn);
}
add_reg_note (test, REG_ARGS_SIZE, XEXP (note, 0));
}
