static bool
prefer_and_bit_test (enum machine_mode mode, int bitnum)
{
if (and_test == 0)
{
/* Set up rtxes for the two variations. Use NULL as a placeholder
for the BITNUM-based constants. */
and_reg = gen_rtx_REG (mode, FIRST_PSEUDO_REGISTER);
and_test = gen_rtx_AND (mode, and_reg, NULL);
shift_test = gen_rtx_AND (mode, gen_rtx_ASHIFTRT (mode, and_reg, NULL),
const1_rtx);
}
else
{
/* Change the mode of the previously-created rtxes. */
PUT_MODE (and_reg, mode);
PUT_MODE (and_test, mode);
PUT_MODE (shift_test, mode);
PUT_MODE (XEXP (shift_test, 0), mode);
}
/* Fill in the integers. */
XEXP (and_test, 1)
= immed_double_int_const (double_int_setbit (double_int_zero, bitnum),
mode);
XEXP (XEXP (shift_test, 0), 1) = GEN_INT (bitnum);
return (rtx_cost (and_test, IF_THEN_ELSE, optimize_insn_for_speed_p ())
<= rtx_cost (shift_test, IF_THEN_ELSE, optimize_insn_for_speed_p ()));
}
/* FIXME: This is the function that we need rtl.h and optabs.h for.
This function (and similar RTL-related cost code in e.g. IVOPTS) should
be moved to some kind of interface file for GIMPLE/RTL interactions. */
static bool
lshift_cheap_p (void)
{
/* FIXME: This should be made target dependent via this "this_target"
mechanism, similar to e.g. can_copy_init_p in gcse.c. */
static bool init[2] = {false, false};
static bool cheap[2] = {true, true};
bool speed_p;
/* If the targer has no lshift in word_mode, the operation will most
probably not be cheap. ??? Does GCC even work for such targets? */
if (optab_handler (ashl_optab, word_mode) == CODE_FOR_nothing)
return false;
speed_p = optimize_insn_for_speed_p ();
if (!init[speed_p])
{
rtx reg = gen_raw_REG (word_mode, 10000);
int cost = set_src_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg),
speed_p);
cheap[speed_p] = cost < COSTS_N_INSNS (MAX_CASE_BIT_TESTS);
init[speed_p] = true;
}
return cheap[speed_p];
}
static bool
prefer_and_bit_test (machine_mode mode, int bitnum)
{
bool speed_p;
wide_int mask = wi::set_bit_in_zero (bitnum, GET_MODE_PRECISION (mode));
if (and_test == 0)
{
/* Set up rtxes for the two variations. Use NULL as a placeholder
for the BITNUM-based constants. */
and_reg = gen_rtx_REG (mode, LAST_VIRTUAL_REGISTER + 1);
and_test = gen_rtx_AND (mode, and_reg, NULL);
shift_test = gen_rtx_AND (mode, gen_rtx_ASHIFTRT (mode, and_reg, NULL),
const1_rtx);
}
else
{
/* Change the mode of the previously-created rtxes. */
PUT_MODE (and_reg, mode);
PUT_MODE (and_test, mode);
PUT_MODE (shift_test, mode);
PUT_MODE (XEXP (shift_test, 0), mode);
}
/* Fill in the integers. */
XEXP (and_test, 1) = immed_wide_int_const (mask, mode);
XEXP (XEXP (shift_test, 0), 1) = GEN_INT (bitnum);
speed_p = optimize_insn_for_speed_p ();
return (rtx_cost (and_test, mode, IF_THEN_ELSE, 0, speed_p)
<= rtx_cost (shift_test, mode, IF_THEN_ELSE, 0, speed_p));
}
void
do_jump (tree exp, rtx if_false_label, rtx if_true_label, int prob)
{
enum tree_code code = TREE_CODE (exp);
rtx temp;
int i;
tree type;
enum machine_mode mode;
rtx drop_through_label = 0;
switch (code)
{
case ERROR_MARK:
break;
case INTEGER_CST:
temp = integer_zerop (exp) ? if_false_label : if_true_label;
if (temp)
emit_jump (temp);
break;
#if 0
/* This is not true with #pragma weak */
case ADDR_EXPR:
/* The address of something can never be zero. */
if (if_true_label)
emit_jump (if_true_label);
break;
#endif
case NOP_EXPR:
if (TREE_CODE (TREE_OPERAND (exp, 0)) == COMPONENT_REF
|| TREE_CODE (TREE_OPERAND (exp, 0)) == BIT_FIELD_REF
|| TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_REF
|| TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_RANGE_REF)
goto normal;
case CONVERT_EXPR:
/* If we are narrowing the operand, we have to do the compare in the
narrower mode. */
if ((TYPE_PRECISION (TREE_TYPE (exp))
< TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0)))))
goto normal;
case NON_LVALUE_EXPR:
case ABS_EXPR:
case NEGATE_EXPR:
case LROTATE_EXPR:
case RROTATE_EXPR:
/* These cannot change zero->nonzero or vice versa. */
do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label, prob);
break;
case TRUTH_NOT_EXPR:
do_jump (TREE_OPERAND (exp, 0), if_true_label, if_false_label,
inv (prob));
break;
case COND_EXPR:
{
rtx label1 = gen_label_rtx ();
if (!if_true_label || !if_false_label)
{
drop_through_label = gen_label_rtx ();
if (!if_true_label)
if_true_label = drop_through_label;
if (!if_false_label)
if_false_label = drop_through_label;
}
do_pending_stack_adjust ();
do_jump (TREE_OPERAND (exp, 0), label1, NULL_RTX, -1);
do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label, prob);
emit_label (label1);
do_jump (TREE_OPERAND (exp, 2), if_false_label, if_true_label, prob);
break;
}
case COMPOUND_EXPR:
/* Lowered by gimplify.c. */
gcc_unreachable ();
case COMPONENT_REF:
case BIT_FIELD_REF:
case ARRAY_REF:
case ARRAY_RANGE_REF:
{
HOST_WIDE_INT bitsize, bitpos;
int unsignedp;
enum machine_mode mode;
tree type;
tree offset;
int volatilep = 0;
/* Get description of this reference. We don't actually care
about the underlying object here. */
get_inner_reference (exp, &bitsize, &bitpos, &offset, &mode,
&unsignedp, &volatilep, false);
type = lang_hooks.types.type_for_size (bitsize, unsignedp);
if (! SLOW_BYTE_ACCESS
&& type != 0 && bitsize >= 0
&& TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp))
&& have_insn_for (COMPARE, TYPE_MODE (type)))
{
do_jump (fold_convert (type, exp), if_false_label, if_true_label,
prob);
break;
}
goto normal;
}
case MINUS_EXPR:
/* Nonzero iff operands of minus differ. */
code = NE_EXPR;
/* FALLTHRU */
case EQ_EXPR:
case NE_EXPR:
case LT_EXPR:
case LE_EXPR:
case GT_EXPR:
case GE_EXPR:
case ORDERED_EXPR:
case UNORDERED_EXPR:
case UNLT_EXPR:
case UNLE_EXPR:
case UNGT_EXPR:
case UNGE_EXPR:
case UNEQ_EXPR:
case LTGT_EXPR:
case TRUTH_ANDIF_EXPR:
case TRUTH_ORIF_EXPR:
other_code:
do_jump_1 (code, TREE_OPERAND (exp, 0), TREE_OPERAND (exp, 1),
if_false_label, if_true_label, prob);
break;
case BIT_AND_EXPR:
/* fold_single_bit_test() converts (X & (1 << C)) into (X >> C) & 1.
See if the former is preferred for jump tests and restore it
if so. */
if (integer_onep (TREE_OPERAND (exp, 1)))
{
tree exp0 = TREE_OPERAND (exp, 0);
rtx set_label, clr_label;
int setclr_prob = prob;
/* Strip narrowing integral type conversions. */
while (CONVERT_EXPR_P (exp0)
&& TREE_OPERAND (exp0, 0) != error_mark_node
&& TYPE_PRECISION (TREE_TYPE (exp0))
<= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp0, 0))))
exp0 = TREE_OPERAND (exp0, 0);
/* "exp0 ^ 1" inverts the sense of the single bit test. */
if (TREE_CODE (exp0) == BIT_XOR_EXPR
&& integer_onep (TREE_OPERAND (exp0, 1)))
{
exp0 = TREE_OPERAND (exp0, 0);
clr_label = if_true_label;
set_label = if_false_label;
setclr_prob = inv (prob);
}
else
{
clr_label = if_false_label;
set_label = if_true_label;
}
if (TREE_CODE (exp0) == RSHIFT_EXPR)
{
tree arg = TREE_OPERAND (exp0, 0);
tree shift = TREE_OPERAND (exp0, 1);
tree argtype = TREE_TYPE (arg);
if (TREE_CODE (shift) == INTEGER_CST
&& compare_tree_int (shift, 0) >= 0
&& compare_tree_int (shift, HOST_BITS_PER_WIDE_INT) < 0
&& prefer_and_bit_test (TYPE_MODE (argtype),
TREE_INT_CST_LOW (shift)))
{
unsigned HOST_WIDE_INT mask
= (unsigned HOST_WIDE_INT) 1 << TREE_INT_CST_LOW (shift);
do_jump (build2 (BIT_AND_EXPR, argtype, arg,
build_int_cstu (argtype, mask)),
clr_label, set_label, setclr_prob);
break;
}
}
}
/* If we are AND'ing with a small constant, do this comparison in the
smallest type that fits. If the machine doesn't have comparisons
that small, it will be converted back to the wider comparison.
This helps if we are testing the sign bit of a narrower object.
combine can't do this for us because it can't know whether a
ZERO_EXTRACT or a compare in a smaller mode exists, but we do. */
if (! SLOW_BYTE_ACCESS
&& TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST
&& TYPE_PRECISION (TREE_TYPE (exp)) <= HOST_BITS_PER_WIDE_INT
&& (i = tree_floor_log2 (TREE_OPERAND (exp, 1))) >= 0
&& (mode = mode_for_size (i + 1, MODE_INT, 0)) != BLKmode
&& (type = lang_hooks.types.type_for_mode (mode, 1)) != 0
&& TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp))
&& have_insn_for (COMPARE, TYPE_MODE (type)))
{
do_jump (fold_convert (type, exp), if_false_label, if_true_label,
prob);
break;
}
if (TYPE_PRECISION (TREE_TYPE (exp)) > 1
|| TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST)
goto normal;
/* Boolean comparisons can be compiled as TRUTH_AND_EXPR. */
case TRUTH_AND_EXPR:
/* High branch cost, expand as the bitwise AND of the conditions.
Do the same if the RHS has side effects, because we're effectively
turning a TRUTH_AND_EXPR into a TRUTH_ANDIF_EXPR. */
if (BRANCH_COST (optimize_insn_for_speed_p (),
false) >= 4
|| TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
goto normal;
code = TRUTH_ANDIF_EXPR;
goto other_code;
case BIT_IOR_EXPR:
case TRUTH_OR_EXPR:
/* High branch cost, expand as the bitwise OR of the conditions.
Do the same if the RHS has side effects, because we're effectively
turning a TRUTH_OR_EXPR into a TRUTH_ORIF_EXPR. */
if (BRANCH_COST (optimize_insn_for_speed_p (), false) >= 4
|| TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
goto normal;
code = TRUTH_ORIF_EXPR;
goto other_code;
/* Fall through and generate the normal code. */
default:
normal:
temp = expand_normal (exp);
do_pending_stack_adjust ();
/* The RTL optimizers prefer comparisons against pseudos. */
if (GET_CODE (temp) == SUBREG)
{
/* Compare promoted variables in their promoted mode. */
if (SUBREG_PROMOTED_VAR_P (temp)
&& REG_P (XEXP (temp, 0)))
temp = XEXP (temp, 0);
else
temp = copy_to_reg (temp);
}
do_compare_rtx_and_jump (temp, CONST0_RTX (GET_MODE (temp)),
NE, TYPE_UNSIGNED (TREE_TYPE (exp)),
GET_MODE (temp), NULL_RTX,
if_false_label, if_true_label, prob);
}
if (drop_through_label)
{
do_pending_stack_adjust ();
emit_label (drop_through_label);
}
}
/* Expand conditional compare gimple G. A typical CCMP sequence is like:
CC0 = CMP (a, b);
CC1 = CCMP (NE (CC0, 0), CMP (e, f));
...
CCn = CCMP (NE (CCn-1, 0), CMP (...));
hook gen_ccmp_first is used to expand the first compare.
hook gen_ccmp_next is used to expand the following CCMP.
PREP_SEQ returns all insns to prepare opearand.
GEN_SEQ returns all compare insns. */
static rtx
expand_ccmp_expr_1 (gimple *g, rtx_insn **prep_seq, rtx_insn **gen_seq)
{
tree exp = gimple_assign_rhs_to_tree (g);
tree_code code = TREE_CODE (exp);
gimple *gs0 = get_gimple_for_ssa_name (TREE_OPERAND (exp, 0));
gimple *gs1 = get_gimple_for_ssa_name (TREE_OPERAND (exp, 1));
rtx tmp;
tree_code code0 = gimple_assign_rhs_code (gs0);
tree_code code1 = gimple_assign_rhs_code (gs1);
gcc_assert (code == BIT_AND_EXPR || code == BIT_IOR_EXPR);
gcc_assert (gs0 && gs1 && is_gimple_assign (gs0) && is_gimple_assign (gs1));
if (TREE_CODE_CLASS (code0) == tcc_comparison)
{
if (TREE_CODE_CLASS (code1) == tcc_comparison)
{
int unsignedp0, unsignedp1;
rtx_code rcode0, rcode1;
int speed_p = optimize_insn_for_speed_p ();
rtx tmp2 = NULL_RTX, ret = NULL_RTX, ret2 = NULL_RTX;
unsigned cost1 = MAX_COST;
unsigned cost2 = MAX_COST;
unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (gs0)));
unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (gs1)));
rcode0 = get_rtx_code (code0, unsignedp0);
rcode1 = get_rtx_code (code1, unsignedp1);
rtx_insn *prep_seq_1, *gen_seq_1;
tmp = targetm.gen_ccmp_first (&prep_seq_1, &gen_seq_1, rcode0,
gimple_assign_rhs1 (gs0),
gimple_assign_rhs2 (gs0));
if (tmp != NULL)
{
ret = expand_ccmp_next (gs1, code, tmp, &prep_seq_1, &gen_seq_1);
cost1 = seq_cost (prep_seq_1, speed_p);
cost1 += seq_cost (gen_seq_1, speed_p);
}
/* FIXME: Temporary workaround for PR69619.
Avoid exponential compile time due to expanding gs0 and gs1 twice.
If gs0 and gs1 are complex, the cost will be high, so avoid
reevaluation if above an arbitrary threshold. */
rtx_insn *prep_seq_2, *gen_seq_2;
if (tmp == NULL || cost1 < COSTS_N_INSNS (25))
tmp2 = targetm.gen_ccmp_first (&prep_seq_2, &gen_seq_2, rcode1,
gimple_assign_rhs1 (gs1),
gimple_assign_rhs2 (gs1));
if (!tmp && !tmp2)
return NULL_RTX;
if (tmp2 != NULL)
{
ret2 = expand_ccmp_next (gs0, code, tmp2, &prep_seq_2,
&gen_seq_2);
cost2 = seq_cost (prep_seq_2, speed_p);
cost2 += seq_cost (gen_seq_2, speed_p);
}
if (cost2 < cost1)
{
*prep_seq = prep_seq_2;
*gen_seq = gen_seq_2;
return ret2;
}
*prep_seq = prep_seq_1;
*gen_seq = gen_seq_1;
return ret;
}
else
{
tmp = expand_ccmp_expr_1 (gs1, prep_seq, gen_seq);
if (!tmp)
return NULL_RTX;
return expand_ccmp_next (gs0, code, tmp, prep_seq, gen_seq);
}
}
else
{
gcc_assert (gimple_assign_rhs_code (gs0) == BIT_AND_EXPR
|| gimple_assign_rhs_code (gs0) == BIT_IOR_EXPR);
if (TREE_CODE_CLASS (gimple_assign_rhs_code (gs1)) == tcc_comparison)
{
tmp = expand_ccmp_expr_1 (gs0, prep_seq, gen_seq);
if (!tmp)
return NULL_RTX;
return expand_ccmp_next (gs1, code, tmp, prep_seq, gen_seq);
}
else
{
gcc_assert (gimple_assign_rhs_code (gs1) == BIT_AND_EXPR
|| gimple_assign_rhs_code (gs1) == BIT_IOR_EXPR);
}
}
return NULL_RTX;
}
