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/* Target-dependent costs for expmed.cc.
Copyright (C) 1987-2024 Free Software Foundation, Inc.
This file is part of GCC.
GCC 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 3, or (at your option) any later
version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#ifndef EXPMED_H
#define EXPMED_H 1
#include "insn-codes.h"
enum alg_code {
alg_unknown,
alg_zero,
alg_m, alg_shift,
alg_add_t_m2,
alg_sub_t_m2,
alg_add_factor,
alg_sub_factor,
alg_add_t2_m,
alg_sub_t2_m,
alg_impossible
};
/* Indicates the type of fixup needed after a constant multiplication.
BASIC_VARIANT means no fixup is needed, NEGATE_VARIANT means that
the result should be negated, and ADD_VARIANT means that the
multiplicand should be added to the result. */
enum mult_variant {basic_variant, negate_variant, add_variant};
bool choose_mult_variant (machine_mode, HOST_WIDE_INT,
struct algorithm *, enum mult_variant *, int);
/* This structure holds the "cost" of a multiply sequence. The
"cost" field holds the total rtx_cost of every operator in the
synthetic multiplication sequence, hence cost(a op b) is defined
as rtx_cost(op) + cost(a) + cost(b), where cost(leaf) is zero.
The "latency" field holds the minimum possible latency of the
synthetic multiply, on a hypothetical infinitely parallel CPU.
This is the critical path, or the maximum height, of the expression
tree which is the sum of rtx_costs on the most expensive path from
any leaf to the root. Hence latency(a op b) is defined as zero for
leaves and rtx_cost(op) + max(latency(a), latency(b)) otherwise. */
struct mult_cost {
short cost; /* Total rtx_cost of the multiplication sequence. */
short latency; /* The latency of the multiplication sequence. */
};
/* This macro is used to compare a pointer to a mult_cost against an
single integer "rtx_cost" value. This is equivalent to the macro
CHEAPER_MULT_COST(X,Z) where Z = {Y,Y}. */
#define MULT_COST_LESS(X,Y) ((X)->cost < (Y) \
|| ((X)->cost == (Y) && (X)->latency < (Y)))
/* This macro is used to compare two pointers to mult_costs against
each other. The macro returns true if X is cheaper than Y.
Currently, the cheaper of two mult_costs is the one with the
lower "cost". If "cost"s are tied, the lower latency is cheaper. */
#define CHEAPER_MULT_COST(X,Y) ((X)->cost < (Y)->cost \
|| ((X)->cost == (Y)->cost \
&& (X)->latency < (Y)->latency))
/* This structure records a sequence of operations.
`ops' is the number of operations recorded.
`cost' is their total cost.
The operations are stored in `op' and the corresponding
logarithms of the integer coefficients in `log'.
These are the operations:
alg_zero total := 0;
alg_m total := multiplicand;
alg_shift total := total * coeff
alg_add_t_m2 total := total + multiplicand * coeff;
alg_sub_t_m2 total := total - multiplicand * coeff;
alg_add_factor total := total * coeff + total;
alg_sub_factor total := total * coeff - total;
alg_add_t2_m total := total * coeff + multiplicand;
alg_sub_t2_m total := total * coeff - multiplicand;
The first operand must be either alg_zero or alg_m. */
struct algorithm
{
struct mult_cost cost;
short ops;
/* The size of the OP and LOG fields are not directly related to the
word size, but the worst-case algorithms will be if we have few
consecutive ones or zeros, i.e., a multiplicand like 10101010101...
In that case we will generate shift-by-2, add, shift-by-2, add,...,
in total wordsize operations. */
enum alg_code op[MAX_BITS_PER_WORD];
char log[MAX_BITS_PER_WORD];
};
/* The entry for our multiplication cache/hash table. */
struct alg_hash_entry {
/* The number we are multiplying by. */
unsigned HOST_WIDE_INT t;
/* The mode in which we are multiplying something by T. */
machine_mode mode;
/* The best multiplication algorithm for t. */
enum alg_code alg;
/* The cost of multiplication if ALG_CODE is not alg_impossible.
Otherwise, the cost within which multiplication by T is
impossible. */
struct mult_cost cost;
/* Optimized for speed? */
bool speed;
};
/* The number of cache/hash entries. */
#if HOST_BITS_PER_WIDE_INT == 64
#define NUM_ALG_HASH_ENTRIES 1031
#else
#define NUM_ALG_HASH_ENTRIES 307
#endif
#define NUM_MODE_IP_INT (NUM_MODE_INT + NUM_MODE_PARTIAL_INT)
#define NUM_MODE_IPV_INT (NUM_MODE_IP_INT + NUM_MODE_VECTOR_INT)
struct expmed_op_cheap {
bool cheap[2][NUM_MODE_IPV_INT];
};
struct expmed_op_costs {
int cost[2][NUM_MODE_IPV_INT];
};
/* Target-dependent globals. */
struct target_expmed {
/* Each entry of ALG_HASH caches alg_code for some integer. This is
actually a hash table. If we have a collision, that the older
entry is kicked out. */
struct alg_hash_entry x_alg_hash[NUM_ALG_HASH_ENTRIES];
/* True if x_alg_hash might already have been used. */
bool x_alg_hash_used_p;
/* Nonzero means divides or modulus operations are relatively cheap for
powers of two, so don't use branches; emit the operation instead.
Usually, this will mean that the MD file will emit non-branch
sequences. */
struct expmed_op_cheap x_sdiv_pow2_cheap;
struct expmed_op_cheap x_smod_pow2_cheap;
/* Cost of various pieces of RTL. */
int x_zero_cost[2];
struct expmed_op_costs x_add_cost;
struct expmed_op_costs x_neg_cost;
int x_shift_cost[2][NUM_MODE_IPV_INT][MAX_BITS_PER_WORD];
int x_shiftadd_cost[2][NUM_MODE_IPV_INT][MAX_BITS_PER_WORD];
int x_shiftsub0_cost[2][NUM_MODE_IPV_INT][MAX_BITS_PER_WORD];
int x_shiftsub1_cost[2][NUM_MODE_IPV_INT][MAX_BITS_PER_WORD];
struct expmed_op_costs x_mul_cost;
struct expmed_op_costs x_sdiv_cost;
struct expmed_op_costs x_udiv_cost;
int x_mul_widen_cost[2][NUM_MODE_INT];
int x_mul_highpart_cost[2][NUM_MODE_INT];
/* Conversion costs are only defined between two scalar integer modes
of different sizes. The first machine mode is the destination mode,
and the second is the source mode. */
int x_convert_cost[2][NUM_MODE_IP_INT][NUM_MODE_IP_INT];
};
extern struct target_expmed default_target_expmed;
#if SWITCHABLE_TARGET
extern struct target_expmed *this_target_expmed;
#else
#define this_target_expmed (&default_target_expmed)
#endif
/* Return a pointer to the alg_hash_entry at IDX. */
inline struct alg_hash_entry *
alg_hash_entry_ptr (int idx)
{
return &this_target_expmed->x_alg_hash[idx];
}
/* Return true if the x_alg_hash field might have been used. */
inline bool
alg_hash_used_p (void)
{
return this_target_expmed->x_alg_hash_used_p;
}
/* Set whether the x_alg_hash field might have been used. */
inline void
set_alg_hash_used_p (bool usedp)
{
this_target_expmed->x_alg_hash_used_p = usedp;
}
/* Compute an index into the cost arrays by mode class. */
inline int
expmed_mode_index (machine_mode mode)
{
switch (GET_MODE_CLASS (mode))
{
case MODE_INT:
return mode - MIN_MODE_INT;
case MODE_PARTIAL_INT:
/* If there are no partial integer modes, help the compiler
to figure out this will never happen. See PR59934. */
if (MIN_MODE_PARTIAL_INT != VOIDmode)
return mode - MIN_MODE_PARTIAL_INT + NUM_MODE_INT;
break;
case MODE_VECTOR_INT:
/* If there are no vector integer modes, help the compiler
to figure out this will never happen. See PR59934. */
if (MIN_MODE_VECTOR_INT != VOIDmode)
return mode - MIN_MODE_VECTOR_INT + NUM_MODE_IP_INT;
break;
default:
break;
}
gcc_unreachable ();
}
/* Return a pointer to a boolean contained in EOC indicating whether
a particular operation performed in MODE is cheap when optimizing
for SPEED. */
inline bool *
expmed_op_cheap_ptr (struct expmed_op_cheap *eoc, bool speed,
machine_mode mode)
{
int idx = expmed_mode_index (mode);
return &eoc->cheap[speed][idx];
}
/* Return a pointer to a cost contained in COSTS when a particular
operation is performed in MODE when optimizing for SPEED. */
inline int *
expmed_op_cost_ptr (struct expmed_op_costs *costs, bool speed,
machine_mode mode)
{
int idx = expmed_mode_index (mode);
return &costs->cost[speed][idx];
}
/* Subroutine of {set_,}sdiv_pow2_cheap. Not to be used otherwise. */
inline bool *
sdiv_pow2_cheap_ptr (bool speed, machine_mode mode)
{
return expmed_op_cheap_ptr (&this_target_expmed->x_sdiv_pow2_cheap,
speed, mode);
}
/* Set whether a signed division by a power of 2 is cheap in MODE
when optimizing for SPEED. */
inline void
set_sdiv_pow2_cheap (bool speed, machine_mode mode, bool cheap_p)
{
*sdiv_pow2_cheap_ptr (speed, mode) = cheap_p;
}
/* Return whether a signed division by a power of 2 is cheap in MODE
when optimizing for SPEED. */
inline bool
sdiv_pow2_cheap (bool speed, machine_mode mode)
{
return *sdiv_pow2_cheap_ptr (speed, mode);
}
/* Subroutine of {set_,}smod_pow2_cheap. Not to be used otherwise. */
inline bool *
smod_pow2_cheap_ptr (bool speed, machine_mode mode)
{
return expmed_op_cheap_ptr (&this_target_expmed->x_smod_pow2_cheap,
speed, mode);
}
/* Set whether a signed modulo by a power of 2 is CHEAP in MODE when
optimizing for SPEED. */
inline void
set_smod_pow2_cheap (bool speed, machine_mode mode, bool cheap)
{
*smod_pow2_cheap_ptr (speed, mode) = cheap;
}
/* Return whether a signed modulo by a power of 2 is cheap in MODE
when optimizing for SPEED. */
inline bool
smod_pow2_cheap (bool speed, machine_mode mode)
{
return *smod_pow2_cheap_ptr (speed, mode);
}
/* Subroutine of {set_,}zero_cost. Not to be used otherwise. */
inline int *
zero_cost_ptr (bool speed)
{
return &this_target_expmed->x_zero_cost[speed];
}
/* Set the COST of loading zero when optimizing for SPEED. */
inline void
set_zero_cost (bool speed, int cost)
{
*zero_cost_ptr (speed) = cost;
}
/* Return the COST of loading zero when optimizing for SPEED. */
inline int
zero_cost (bool speed)
{
return *zero_cost_ptr (speed);
}
/* Subroutine of {set_,}add_cost. Not to be used otherwise. */
inline int *
add_cost_ptr (bool speed, machine_mode mode)
{
return expmed_op_cost_ptr (&this_target_expmed->x_add_cost, speed, mode);
}
/* Set the COST of computing an add in MODE when optimizing for SPEED. */
inline void
set_add_cost (bool speed, machine_mode mode, int cost)
{
*add_cost_ptr (speed, mode) = cost;
}
/* Return the cost of computing an add in MODE when optimizing for SPEED. */
inline int
add_cost (bool speed, machine_mode mode)
{
return *add_cost_ptr (speed, mode);
}
/* Subroutine of {set_,}neg_cost. Not to be used otherwise. */
inline int *
neg_cost_ptr (bool speed, machine_mode mode)
{
return expmed_op_cost_ptr (&this_target_expmed->x_neg_cost, speed, mode);
}
/* Set the COST of computing a negation in MODE when optimizing for SPEED. */
inline void
set_neg_cost (bool speed, machine_mode mode, int cost)
{
*neg_cost_ptr (speed, mode) = cost;
}
/* Return the cost of computing a negation in MODE when optimizing for
SPEED. */
inline int
neg_cost (bool speed, machine_mode mode)
{
return *neg_cost_ptr (speed, mode);
}
/* Subroutine of {set_,}shift_cost. Not to be used otherwise. */
inline int *
shift_cost_ptr (bool speed, machine_mode mode, int bits)
{
int midx = expmed_mode_index (mode);
return &this_target_expmed->x_shift_cost[speed][midx][bits];
}
/* Set the COST of doing a shift in MODE by BITS when optimizing for SPEED. */
inline void
set_shift_cost (bool speed, machine_mode mode, int bits, int cost)
{
*shift_cost_ptr (speed, mode, bits) = cost;
}
/* Return the cost of doing a shift in MODE by BITS when optimizing for
SPEED. */
inline int
shift_cost (bool speed, machine_mode mode, int bits)
{
return *shift_cost_ptr (speed, mode, bits);
}
/* Subroutine of {set_,}shiftadd_cost. Not to be used otherwise. */
inline int *
shiftadd_cost_ptr (bool speed, machine_mode mode, int bits)
{
int midx = expmed_mode_index (mode);
return &this_target_expmed->x_shiftadd_cost[speed][midx][bits];
}
/* Set the COST of doing a shift in MODE by BITS followed by an add when
optimizing for SPEED. */
inline void
set_shiftadd_cost (bool speed, machine_mode mode, int bits, int cost)
{
*shiftadd_cost_ptr (speed, mode, bits) = cost;
}
/* Return the cost of doing a shift in MODE by BITS followed by an add
when optimizing for SPEED. */
inline int
shiftadd_cost (bool speed, machine_mode mode, int bits)
{
return *shiftadd_cost_ptr (speed, mode, bits);
}
/* Subroutine of {set_,}shiftsub0_cost. Not to be used otherwise. */
inline int *
shiftsub0_cost_ptr (bool speed, machine_mode mode, int bits)
{
int midx = expmed_mode_index (mode);
return &this_target_expmed->x_shiftsub0_cost[speed][midx][bits];
}
/* Set the COST of doing a shift in MODE by BITS and then subtracting a
value when optimizing for SPEED. */
inline void
set_shiftsub0_cost (bool speed, machine_mode mode, int bits, int cost)
{
*shiftsub0_cost_ptr (speed, mode, bits) = cost;
}
/* Return the cost of doing a shift in MODE by BITS and then subtracting
a value when optimizing for SPEED. */
inline int
shiftsub0_cost (bool speed, machine_mode mode, int bits)
{
return *shiftsub0_cost_ptr (speed, mode, bits);
}
/* Subroutine of {set_,}shiftsub1_cost. Not to be used otherwise. */
inline int *
shiftsub1_cost_ptr (bool speed, machine_mode mode, int bits)
{
int midx = expmed_mode_index (mode);
return &this_target_expmed->x_shiftsub1_cost[speed][midx][bits];
}
/* Set the COST of subtracting a shift in MODE by BITS from a value when
optimizing for SPEED. */
inline void
set_shiftsub1_cost (bool speed, machine_mode mode, int bits, int cost)
{
*shiftsub1_cost_ptr (speed, mode, bits) = cost;
}
/* Return the cost of subtracting a shift in MODE by BITS from a value
when optimizing for SPEED. */
inline int
shiftsub1_cost (bool speed, machine_mode mode, int bits)
{
return *shiftsub1_cost_ptr (speed, mode, bits);
}
/* Subroutine of {set_,}mul_cost. Not to be used otherwise. */
inline int *
mul_cost_ptr (bool speed, machine_mode mode)
{
return expmed_op_cost_ptr (&this_target_expmed->x_mul_cost, speed, mode);
}
/* Set the COST of doing a multiplication in MODE when optimizing for
SPEED. */
inline void
set_mul_cost (bool speed, machine_mode mode, int cost)
{
*mul_cost_ptr (speed, mode) = cost;
}
/* Return the cost of doing a multiplication in MODE when optimizing
for SPEED. */
inline int
mul_cost (bool speed, machine_mode mode)
{
return *mul_cost_ptr (speed, mode);
}
/* Subroutine of {set_,}sdiv_cost. Not to be used otherwise. */
inline int *
sdiv_cost_ptr (bool speed, machine_mode mode)
{
return expmed_op_cost_ptr (&this_target_expmed->x_sdiv_cost, speed, mode);
}
/* Set the COST of doing a signed division in MODE when optimizing
for SPEED. */
inline void
set_sdiv_cost (bool speed, machine_mode mode, int cost)
{
*sdiv_cost_ptr (speed, mode) = cost;
}
/* Return the cost of doing a signed division in MODE when optimizing
for SPEED. */
inline int
sdiv_cost (bool speed, machine_mode mode)
{
return *sdiv_cost_ptr (speed, mode);
}
/* Subroutine of {set_,}udiv_cost. Not to be used otherwise. */
inline int *
udiv_cost_ptr (bool speed, machine_mode mode)
{
return expmed_op_cost_ptr (&this_target_expmed->x_udiv_cost, speed, mode);
}
/* Set the COST of doing an unsigned division in MODE when optimizing
for SPEED. */
inline void
set_udiv_cost (bool speed, machine_mode mode, int cost)
{
*udiv_cost_ptr (speed, mode) = cost;
}
/* Return the cost of doing an unsigned division in MODE when
optimizing for SPEED. */
inline int
udiv_cost (bool speed, machine_mode mode)
{
return *udiv_cost_ptr (speed, mode);
}
/* Subroutine of {set_,}mul_widen_cost. Not to be used otherwise. */
inline int *
mul_widen_cost_ptr (bool speed, machine_mode mode)
{
gcc_assert (GET_MODE_CLASS (mode) == MODE_INT);
return &this_target_expmed->x_mul_widen_cost[speed][mode - MIN_MODE_INT];
}
/* Set the COST for computing a widening multiplication in MODE when
optimizing for SPEED. */
inline void
set_mul_widen_cost (bool speed, machine_mode mode, int cost)
{
*mul_widen_cost_ptr (speed, mode) = cost;
}
/* Return the cost for computing a widening multiplication in MODE when
optimizing for SPEED. */
inline int
mul_widen_cost (bool speed, machine_mode mode)
{
return *mul_widen_cost_ptr (speed, mode);
}
/* Subroutine of {set_,}mul_highpart_cost. Not to be used otherwise. */
inline int *
mul_highpart_cost_ptr (bool speed, machine_mode mode)
{
gcc_assert (GET_MODE_CLASS (mode) == MODE_INT);
int m = mode - MIN_MODE_INT;
gcc_assert (m < NUM_MODE_INT);
return &this_target_expmed->x_mul_highpart_cost[speed][m];
}
/* Set the COST for computing the high part of a multiplication in MODE
when optimizing for SPEED. */
inline void
set_mul_highpart_cost (bool speed, machine_mode mode, int cost)
{
*mul_highpart_cost_ptr (speed, mode) = cost;
}
/* Return the cost for computing the high part of a multiplication in MODE
when optimizing for SPEED. */
inline int
mul_highpart_cost (bool speed, machine_mode mode)
{
return *mul_highpart_cost_ptr (speed, mode);
}
/* Subroutine of {set_,}convert_cost. Not to be used otherwise. */
inline int *
convert_cost_ptr (machine_mode to_mode, machine_mode from_mode,
bool speed)
{
int to_idx = expmed_mode_index (to_mode);
int from_idx = expmed_mode_index (from_mode);
gcc_assert (IN_RANGE (to_idx, 0, NUM_MODE_IP_INT - 1));
gcc_assert (IN_RANGE (from_idx, 0, NUM_MODE_IP_INT - 1));
return &this_target_expmed->x_convert_cost[speed][to_idx][from_idx];
}
/* Set the COST for converting from FROM_MODE to TO_MODE when optimizing
for SPEED. */
inline void
set_convert_cost (machine_mode to_mode, machine_mode from_mode,
bool speed, int cost)
{
*convert_cost_ptr (to_mode, from_mode, speed) = cost;
}
/* Return the cost for converting from FROM_MODE to TO_MODE when optimizing
for SPEED. */
inline int
convert_cost (machine_mode to_mode, machine_mode from_mode,
bool speed)
{
return *convert_cost_ptr (to_mode, from_mode, speed);
}
extern int mult_by_coeff_cost (HOST_WIDE_INT, machine_mode, bool);
extern rtx emit_cstore (rtx target, enum insn_code icode, enum rtx_code code,
machine_mode mode, machine_mode compare_mode,
int unsignedp, rtx x, rtx y, int normalizep,
machine_mode target_mode);
/* Arguments MODE, RTX: return an rtx for the negation of that value.
May emit insns. */
extern rtx negate_rtx (machine_mode, rtx);
/* Arguments MODE, RTX: return an rtx for the flipping of that value.
May emit insns. */
extern rtx flip_storage_order (machine_mode, rtx);
/* Expand a logical AND operation. */
extern rtx expand_and (machine_mode, rtx, rtx, rtx);
/* Emit a store-flag operation. */
extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, machine_mode,
int, int);
/* Like emit_store_flag, but always succeeds. */
extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
machine_mode, int, int);
extern void canonicalize_comparison (machine_mode, enum rtx_code *, rtx *);
/* Choose a minimal N + 1 bit approximation to 1/D that can be used to
replace division by D, and put the least significant N bits of the result
in *MULTIPLIER_PTR and return the most significant bit. */
extern unsigned HOST_WIDE_INT choose_multiplier (unsigned HOST_WIDE_INT, int,
int, unsigned HOST_WIDE_INT *,
int *, int *);
#ifdef TREE_CODE
extern rtx expand_variable_shift (enum tree_code, machine_mode,
rtx, tree, rtx, int);
extern rtx expand_shift (enum tree_code, machine_mode, rtx, poly_int64, rtx,
int);
extern rtx maybe_expand_shift (enum tree_code, machine_mode, rtx, int, rtx,
int);
#ifdef GCC_OPTABS_H
extern rtx expand_divmod (int, enum tree_code, machine_mode, rtx, rtx,
rtx, int, enum optab_methods = OPTAB_LIB_WIDEN);
#endif
#endif
extern void store_bit_field (rtx, poly_uint64, poly_uint64,
poly_uint64, poly_uint64,
machine_mode, rtx, bool, bool);
extern rtx extract_bit_field (rtx, poly_uint64, poly_uint64, int, rtx,
machine_mode, machine_mode, bool, rtx *);
extern rtx extract_low_bits (machine_mode, machine_mode, rtx);
extern rtx expand_mult (machine_mode, rtx, rtx, rtx, int, bool = false);
extern rtx expand_mult_highpart_adjust (scalar_int_mode, rtx, rtx, rtx,
rtx, int);
#endif // EXPMED_H