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 rtx
may_unswitch_on (basic_block bb, struct loop *loop, rtx *cinsn)
{
rtx test, at, op[2], stest;
struct rtx_iv iv;
unsigned i;
enum machine_mode mode;
/* BB must end in a simple conditional jump. */
if (EDGE_COUNT (bb->succs) != 2)
return NULL_RTX;
if (!any_condjump_p (BB_END (bb)))
return NULL_RTX;
/* With branches inside loop. */
if (!flow_bb_inside_loop_p (loop, EDGE_SUCC (bb, 0)->dest)
|| !flow_bb_inside_loop_p (loop, EDGE_SUCC (bb, 1)->dest))
return NULL_RTX;
/* It must be executed just once each iteration (because otherwise we
are unable to update dominator/irreducible loop information correctly). */
if (!just_once_each_iteration_p (loop, bb))
return NULL_RTX;
/* Condition must be invariant. */
test = get_condition (BB_END (bb), &at, true, false);
if (!test)
return NULL_RTX;
for (i = 0; i < 2; i++)
{
op[i] = XEXP (test, i);
if (CONSTANT_P (op[i]))
continue;
if (!iv_analyze (at, op[i], &iv))
return NULL_RTX;
if (iv.step != const0_rtx
|| iv.first_special)
return NULL_RTX;
op[i] = get_iv_value (&iv, const0_rtx);
}
mode = GET_MODE (op[0]);
if (mode == VOIDmode)
mode = GET_MODE (op[1]);
if (GET_MODE_CLASS (mode) == MODE_CC)
{
if (at != BB_END (bb))
return NULL_RTX;
if (!rtx_equal_p (op[0], XEXP (test, 0))
|| !rtx_equal_p (op[1], XEXP (test, 1)))
return NULL_RTX;
*cinsn = BB_END (bb);
return test;
}
stest = simplify_gen_relational (GET_CODE (test), SImode,
mode, op[0], op[1]);
if (stest == const0_rtx
|| stest == const_true_rtx)
return stest;
return canon_condition (gen_rtx_fmt_ee (GET_CODE (test), SImode,
op[0], op[1]));
}
