rtx
compare_from_rtx (rtx op0, rtx op1, enum rtx_code code, int unsignedp,
enum machine_mode mode, rtx size)
{
enum rtx_code ucode;
rtx tem;
/* If one operand is constant, make it the second one. Only do this
if the other operand is not constant as well. */
if (swap_commutative_operands_p (op0, op1))
{
tem = op0;
op0 = op1;
op1 = tem;
code = swap_condition (code);
}
if (flag_force_mem)
{
op0 = force_not_mem (op0);
op1 = force_not_mem (op1);
}
do_pending_stack_adjust ();
ucode = unsignedp ? unsigned_condition (code) : code;
if ((tem = simplify_relational_operation (ucode, mode, op0, op1)) != 0)
return tem;
#if 0
/* There's no need to do this now that combine.c can eliminate lots of
sign extensions. This can be less efficient in certain cases on other
machines. */
/* If this is a signed equality comparison, we can do it as an
unsigned comparison since zero-extension is cheaper than sign
extension and comparisons with zero are done as unsigned. This is
the case even on machines that can do fast sign extension, since
zero-extension is easier to combine with other operations than
sign-extension is. If we are comparing against a constant, we must
convert it to what it would look like unsigned. */
if ((code == EQ || code == NE) && ! unsignedp
&& GET_MODE_BITSIZE (GET_MODE (op0)) <= HOST_BITS_PER_WIDE_INT)
{
if (GET_CODE (op1) == CONST_INT
&& (INTVAL (op1) & GET_MODE_MASK (GET_MODE (op0))) != INTVAL (op1))
op1 = GEN_INT (INTVAL (op1) & GET_MODE_MASK (GET_MODE (op0)));
unsignedp = 1;
}
#endif
emit_cmp_insn (op0, op1, code, size, mode, unsignedp);
#if HAVE_cc0
return gen_rtx_fmt_ee (code, VOIDmode, cc0_rtx, const0_rtx);
#else
return gen_rtx_fmt_ee (code, VOIDmode, op0, op1);
#endif
}
rtx
compare_from_rtx (rtx op0, rtx op1, enum rtx_code code, int unsignedp,
enum machine_mode mode, rtx size)
{
rtx tem;
/* If one operand is constant, make it the second one. Only do this
if the other operand is not constant as well. */
if (swap_commutative_operands_p (op0, op1))
{
tem = op0;
op0 = op1;
op1 = tem;
code = swap_condition (code);
}
do_pending_stack_adjust ();
code = unsignedp ? unsigned_condition (code) : code;
tem = simplify_relational_operation (code, VOIDmode, mode, op0, op1);
if (tem)
{
if (CONSTANT_P (tem))
return tem;
if (COMPARISON_P (tem))
{
code = GET_CODE (tem);
op0 = XEXP (tem, 0);
op1 = XEXP (tem, 1);
mode = GET_MODE (op0);
unsignedp = (code == GTU || code == LTU
|| code == GEU || code == LEU);
}
}
emit_cmp_insn (op0, op1, code, size, mode, unsignedp);
#if HAVE_cc0
return gen_rtx_fmt_ee (code, VOIDmode, cc0_rtx, const0_rtx);
#else
return gen_rtx_fmt_ee (code, VOIDmode, op0, op1);
#endif
}
/* Reverses CONDition; returns NULL if we cannot. */
rtx
reversed_condition (rtx cond)
{
enum rtx_code reversed;
reversed = reversed_comparison_code (cond, NULL);
if (reversed == UNKNOWN)
return NULL_RTX;
else
return gen_rtx_fmt_ee (reversed,
GET_MODE (cond), XEXP (cond, 0),
XEXP (cond, 1));
}
static void
gen_int_relational (enum rtx_code code,
rtx result,
rtx cmp0,
rtx cmp1,
rtx destination)
{
machine_mode mode;
int branch_p;
mode = GET_MODE (cmp0);
if (mode == VOIDmode)
mode = GET_MODE (cmp1);
/* Is this a branch or compare. */
branch_p = (destination != 0);
/* Instruction set doesn't support LE or LT, so swap operands and use
GE, GT. */
switch (code)
{
case LE:
case LT:
case LEU:
case LTU:
{
rtx temp;
code = swap_condition (code);
temp = cmp0;
cmp0 = cmp1;
cmp1 = temp;
break;
}
default:
break;
}
if (branch_p)
{
rtx insn, cond, label;
/* Operands must be in registers. */
if (!register_operand (cmp0, mode))
cmp0 = force_reg (mode, cmp0);
if (!register_operand (cmp1, mode))
cmp1 = force_reg (mode, cmp1);
/* Generate conditional branch instruction. */
cond = gen_rtx_fmt_ee (code, mode, cmp0, cmp1);
label = gen_rtx_LABEL_REF (VOIDmode, destination);
insn = gen_rtx_SET (pc_rtx, gen_rtx_IF_THEN_ELSE (VOIDmode,
cond, label, pc_rtx));
emit_jump_insn (insn);
}
else
{
/* We can't have const_ints in cmp0, other than 0. */
if ((GET_CODE (cmp0) == CONST_INT) && (INTVAL (cmp0) != 0))
cmp0 = force_reg (mode, cmp0);
/* If the comparison is against an int not in legal range
move it into a register. */
if (GET_CODE (cmp1) == CONST_INT)
{
switch (code)
{
case EQ:
case NE:
case LE:
case LT:
case GE:
case GT:
if (!satisfies_constraint_K (cmp1))
cmp1 = force_reg (mode, cmp1);
break;
case LEU:
case LTU:
case GEU:
case GTU:
if (!satisfies_constraint_L (cmp1))
cmp1 = force_reg (mode, cmp1);
break;
default:
gcc_unreachable ();
}
}
/* Generate compare instruction. */
emit_move_insn (result, gen_rtx_fmt_ee (code, mode, cmp0, cmp1));
}
}
void
gen_int_relational (enum rtx_code code, /* relational test (EQ, etc) */
rtx result, /* result to store comp. or 0 if branch */
rtx cmp0, /* first operand to compare */
rtx cmp1, /* second operand to compare */
rtx destination) /* destination of the branch, or 0 if compare */
{
enum machine_mode mode;
int branch_p;
mode = GET_MODE (cmp0);
if (mode == VOIDmode)
mode = GET_MODE (cmp1);
/* Is this a branch or compare */
branch_p = (destination != 0);
/* Instruction set doesn't support LE or LT, so swap operands and use GE, GT */
switch (code)
{
case LE:
case LT:
case LEU:
case LTU:
code = swap_condition (code);
rtx temp = cmp0;
cmp0 = cmp1;
cmp1 = temp;
break;
default:
break;
}
if (branch_p)
{
rtx insn;
/* Operands must be in registers */
if (!register_operand (cmp0, mode))
cmp0 = force_reg (mode, cmp0);
if (!register_operand (cmp1, mode))
cmp1 = force_reg (mode, cmp1);
/* Generate conditional branch instruction */
rtx cond = gen_rtx_fmt_ee (code, mode, cmp0, cmp1);
rtx label = gen_rtx_LABEL_REF (VOIDmode, destination);
insn = gen_rtx_SET (VOIDmode, pc_rtx,
gen_rtx_IF_THEN_ELSE (VOIDmode,
cond, label, pc_rtx));
emit_jump_insn (insn);
}
else
{
/* We can't have const_ints in cmp0, other than 0 */
if ((GET_CODE (cmp0) == CONST_INT) && (INTVAL (cmp0) != 0))
cmp0 = force_reg (mode, cmp0);
/* If the comparison is against an int not in legal range
move it into a register */
if (GET_CODE (cmp1) == CONST_INT)
{
HOST_WIDE_INT value = INTVAL (cmp1);
switch (code)
{
case EQ:
case NE:
case LE:
case LT:
case GE:
case GT:
if (!MEDIUM_INT(value))
cmp1 = force_reg (mode, cmp1);
break;
case LEU:
case LTU:
case GEU:
case GTU:
if (!MEDIUM_UINT(value))
cmp1 = force_reg (mode, cmp1);
break;
default:
abort ();
}
}
/* Generate compare instruction */
emit_move_insn (result, gen_rtx_fmt_ee (code, mode, cmp0, cmp1));
}
}
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]));
}
/* Scan X and replace any eliminable registers (such as fp) with a
replacement (such as sp) if SUBST_P, plus an offset. The offset is
a change in the offset between the eliminable register and its
substitution if UPDATE_P, or the full offset if FULL_P, or
otherwise zero. If FULL_P, we also use the SP offsets for
elimination to SP. If UPDATE_P, use UPDATE_SP_OFFSET for updating
offsets of register elimnable to SP. If UPDATE_SP_OFFSET is
non-zero, don't use difference of the offset and the previous
offset.
MEM_MODE is the mode of an enclosing MEM. We need this to know how
much to adjust a register for, e.g., PRE_DEC. Also, if we are
inside a MEM, we are allowed to replace a sum of a hard register
and the constant zero with the hard register, which we cannot do
outside a MEM. In addition, we need to record the fact that a
hard register is referenced outside a MEM.
If we make full substitution to SP for non-null INSN, add the insn
sp offset. */
rtx
lra_eliminate_regs_1 (rtx_insn *insn, rtx x, machine_mode mem_mode,
bool subst_p, bool update_p,
HOST_WIDE_INT update_sp_offset, bool full_p)
{
enum rtx_code code = GET_CODE (x);
struct lra_elim_table *ep;
rtx new_rtx;
int i, j;
const char *fmt;
int copied = 0;
lra_assert (!update_p || !full_p);
lra_assert (update_sp_offset == 0 || (!subst_p && update_p && !full_p));
if (! current_function_decl)
return x;
switch (code)
{
CASE_CONST_ANY:
case CONST:
case SYMBOL_REF:
case CODE_LABEL:
case PC:
case CC0:
case ASM_INPUT:
case ADDR_VEC:
case ADDR_DIFF_VEC:
case RETURN:
return x;
case REG:
/* First handle the case where we encounter a bare hard register
that is eliminable. Replace it with a PLUS. */
if ((ep = get_elimination (x)) != NULL)
{
rtx to = subst_p ? ep->to_rtx : ep->from_rtx;
if (update_sp_offset != 0)
{
if (ep->to_rtx == stack_pointer_rtx)
return plus_constant (Pmode, to, update_sp_offset);
return to;
}
else if (update_p)
return plus_constant (Pmode, to, ep->offset - ep->previous_offset);
else if (full_p)
return plus_constant (Pmode, to,
ep->offset
- (insn != NULL_RTX
&& ep->to_rtx == stack_pointer_rtx
? lra_get_insn_recog_data (insn)->sp_offset
: 0));
else
return to;
}
return x;
case PLUS:
/* If this is the sum of an eliminable register and a constant, rework
the sum. */
if (REG_P (XEXP (x, 0)) && CONSTANT_P (XEXP (x, 1)))
{
if ((ep = get_elimination (XEXP (x, 0))) != NULL)
{
HOST_WIDE_INT offset;
rtx to = subst_p ? ep->to_rtx : ep->from_rtx;
if (! update_p && ! full_p)
return gen_rtx_PLUS (Pmode, to, XEXP (x, 1));
if (update_sp_offset != 0)
offset = ep->to_rtx == stack_pointer_rtx ? update_sp_offset : 0;
else
offset = (update_p
? ep->offset - ep->previous_offset : ep->offset);
if (full_p && insn != NULL_RTX && ep->to_rtx == stack_pointer_rtx)
offset -= lra_get_insn_recog_data (insn)->sp_offset;
if (CONST_INT_P (XEXP (x, 1)) && INTVAL (XEXP (x, 1)) == -offset)
return to;
else
return gen_rtx_PLUS (Pmode, to,
plus_constant (Pmode,
XEXP (x, 1), offset));
}
/* If the hard register is not eliminable, we are done since
the other operand is a constant. */
return x;
}
/* If this is part of an address, we want to bring any constant
to the outermost PLUS. We will do this by doing hard
register replacement in our operands and seeing if a constant
shows up in one of them.
Note that there is no risk of modifying the structure of the
insn, since we only get called for its operands, thus we are
either modifying the address inside a MEM, or something like
an address operand of a load-address insn. */
{
rtx new0 = lra_eliminate_regs_1 (insn, XEXP (x, 0), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
rtx new1 = lra_eliminate_regs_1 (insn, XEXP (x, 1), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
new0 = move_plus_up (new0);
new1 = move_plus_up (new1);
if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
return form_sum (new0, new1);
}
return x;
case MULT:
/* If this is the product of an eliminable hard register and a
constant, apply the distribute law and move the constant out
so that we have (plus (mult ..) ..). This is needed in order
to keep load-address insns valid. This case is pathological.
We ignore the possibility of overflow here. */
if (REG_P (XEXP (x, 0)) && CONST_INT_P (XEXP (x, 1))
&& (ep = get_elimination (XEXP (x, 0))) != NULL)
{
rtx to = subst_p ? ep->to_rtx : ep->from_rtx;
if (update_sp_offset != 0)
{
if (ep->to_rtx == stack_pointer_rtx)
return plus_constant (Pmode,
gen_rtx_MULT (Pmode, to, XEXP (x, 1)),
update_sp_offset * INTVAL (XEXP (x, 1)));
return gen_rtx_MULT (Pmode, to, XEXP (x, 1));
}
else if (update_p)
return plus_constant (Pmode,
gen_rtx_MULT (Pmode, to, XEXP (x, 1)),
(ep->offset - ep->previous_offset)
* INTVAL (XEXP (x, 1)));
else if (full_p)
{
HOST_WIDE_INT offset = ep->offset;
if (insn != NULL_RTX && ep->to_rtx == stack_pointer_rtx)
offset -= lra_get_insn_recog_data (insn)->sp_offset;
return
plus_constant (Pmode,
gen_rtx_MULT (Pmode, to, XEXP (x, 1)),
offset * INTVAL (XEXP (x, 1)));
}
else
return gen_rtx_MULT (Pmode, to, XEXP (x, 1));
}
/* fall through */
case CALL:
case COMPARE:
/* See comments before PLUS about handling MINUS. */
case MINUS:
case DIV: case UDIV:
case MOD: case UMOD:
case AND: case IOR: case XOR:
case ROTATERT: case ROTATE:
case ASHIFTRT: case LSHIFTRT: case ASHIFT:
case NE: case EQ:
case GE: case GT: case GEU: case GTU:
case LE: case LT: case LEU: case LTU:
{
rtx new0 = lra_eliminate_regs_1 (insn, XEXP (x, 0), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
rtx new1 = XEXP (x, 1)
? lra_eliminate_regs_1 (insn, XEXP (x, 1), mem_mode,
subst_p, update_p,
update_sp_offset, full_p) : 0;
if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
return gen_rtx_fmt_ee (code, GET_MODE (x), new0, new1);
}
return x;
case EXPR_LIST:
/* If we have something in XEXP (x, 0), the usual case,
eliminate it. */
if (XEXP (x, 0))
{
new_rtx = lra_eliminate_regs_1 (insn, XEXP (x, 0), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
if (new_rtx != XEXP (x, 0))
{
/* If this is a REG_DEAD note, it is not valid anymore.
Using the eliminated version could result in creating a
REG_DEAD note for the stack or frame pointer. */
if (REG_NOTE_KIND (x) == REG_DEAD)
return (XEXP (x, 1)
? lra_eliminate_regs_1 (insn, XEXP (x, 1), mem_mode,
subst_p, update_p,
update_sp_offset, full_p)
: NULL_RTX);
x = alloc_reg_note (REG_NOTE_KIND (x), new_rtx, XEXP (x, 1));
}
}
/* fall through */
case INSN_LIST:
case INT_LIST:
/* Now do eliminations in the rest of the chain. If this was
an EXPR_LIST, this might result in allocating more memory than is
strictly needed, but it simplifies the code. */
if (XEXP (x, 1))
{
new_rtx = lra_eliminate_regs_1 (insn, XEXP (x, 1), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
if (new_rtx != XEXP (x, 1))
return
gen_rtx_fmt_ee (GET_CODE (x), GET_MODE (x),
XEXP (x, 0), new_rtx);
}
return x;
case PRE_INC:
case POST_INC:
case PRE_DEC:
case POST_DEC:
/* We do not support elimination of a register that is modified.
elimination_effects has already make sure that this does not
happen. */
return x;
case PRE_MODIFY:
case POST_MODIFY:
/* We do not support elimination of a hard register that is
modified. LRA has already make sure that this does not
happen. The only remaining case we need to consider here is
that the increment value may be an eliminable register. */
if (GET_CODE (XEXP (x, 1)) == PLUS
&& XEXP (XEXP (x, 1), 0) == XEXP (x, 0))
{
rtx new_rtx = lra_eliminate_regs_1 (insn, XEXP (XEXP (x, 1), 1),
mem_mode, subst_p, update_p,
update_sp_offset, full_p);
if (new_rtx != XEXP (XEXP (x, 1), 1))
return gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (x, 0),
gen_rtx_PLUS (GET_MODE (x),
XEXP (x, 0), new_rtx));
}
return x;
case STRICT_LOW_PART:
case NEG: case NOT:
case SIGN_EXTEND: case ZERO_EXTEND:
case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
case FLOAT: case FIX:
case UNSIGNED_FIX: case UNSIGNED_FLOAT:
case ABS:
case SQRT:
case FFS:
case CLZ:
case CTZ:
case POPCOUNT:
case PARITY:
case BSWAP:
new_rtx = lra_eliminate_regs_1 (insn, XEXP (x, 0), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
if (new_rtx != XEXP (x, 0))
return gen_rtx_fmt_e (code, GET_MODE (x), new_rtx);
return x;
case SUBREG:
new_rtx = lra_eliminate_regs_1 (insn, SUBREG_REG (x), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
if (new_rtx != SUBREG_REG (x))
{
int x_size = GET_MODE_SIZE (GET_MODE (x));
int new_size = GET_MODE_SIZE (GET_MODE (new_rtx));
if (MEM_P (new_rtx) && x_size <= new_size)
{
SUBREG_REG (x) = new_rtx;
alter_subreg (&x, false);
return x;
}
else if (! subst_p)
{
/* LRA can transform subregs itself. So don't call
simplify_gen_subreg until LRA transformations are
finished. Function simplify_gen_subreg can do
non-trivial transformations (like truncation) which
might make LRA work to fail. */
SUBREG_REG (x) = new_rtx;
return x;
}
else
return simplify_gen_subreg (GET_MODE (x), new_rtx,
GET_MODE (new_rtx), SUBREG_BYTE (x));
}
return x;
case MEM:
/* Our only special processing is to pass the mode of the MEM to our
recursive call and copy the flags. While we are here, handle this
case more efficiently. */
return
replace_equiv_address_nv
(x,
lra_eliminate_regs_1 (insn, XEXP (x, 0), GET_MODE (x),
subst_p, update_p, update_sp_offset, full_p));
case USE:
/* Handle insn_list USE that a call to a pure function may generate. */
new_rtx = lra_eliminate_regs_1 (insn, XEXP (x, 0), VOIDmode,
subst_p, update_p, update_sp_offset, full_p);
if (new_rtx != XEXP (x, 0))
return gen_rtx_USE (GET_MODE (x), new_rtx);
return x;
case CLOBBER:
case SET:
gcc_unreachable ();
default:
break;
}
/* Process each of our operands recursively. If any have changed, make a
copy of the rtx. */
fmt = GET_RTX_FORMAT (code);
for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
{
if (*fmt == 'e')
{
new_rtx = lra_eliminate_regs_1 (insn, XEXP (x, i), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
if (new_rtx != XEXP (x, i) && ! copied)
{
x = shallow_copy_rtx (x);
copied = 1;
}
XEXP (x, i) = new_rtx;
}
else if (*fmt == 'E')
{
int copied_vec = 0;
for (j = 0; j < XVECLEN (x, i); j++)
{
new_rtx = lra_eliminate_regs_1 (insn, XVECEXP (x, i, j), mem_mode,
subst_p, update_p,
update_sp_offset, full_p);
if (new_rtx != XVECEXP (x, i, j) && ! copied_vec)
{
rtvec new_v = gen_rtvec_v (XVECLEN (x, i),
XVEC (x, i)->elem);
if (! copied)
{
x = shallow_copy_rtx (x);
copied = 1;
}
XVEC (x, i) = new_v;
copied_vec = 1;
}
XVECEXP (x, i, j) = new_rtx;
}
}
}
return x;
}
