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qemu / qemu / 9ffa5420e927c327412c9e4ef113ad2f1a564aec / . / tcg / optimize.c
blob: f3a2328fe403866787a29401a1c7bc133b7361eb [file] [log] [blame]
/*
* Optimizations for Tiny Code Generator for QEMU
*
* Copyright (c) 2010 Samsung Electronics.
* Contributed by Kirill Batuzov <batuzovk@ispras.ru>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu/int128.h"
#include "qemu/interval-tree.h"
#include "tcg/tcg-op-common.h"
#include "tcg-internal.h"
#include "tcg-has.h"
typedef struct MemCopyInfo {
IntervalTreeNode itree;
QSIMPLEQ_ENTRY (MemCopyInfo) next;
TCGTemp *ts;
TCGType type;
} MemCopyInfo;
typedef struct TempOptInfo {
TCGTemp *prev_copy;
TCGTemp *next_copy;
QSIMPLEQ_HEAD(, MemCopyInfo) mem_copy;
uint64_t z_mask; /* mask bit is 0 if and only if value bit is 0 */
uint64_t o_mask; /* mask bit is 1 if and only if value bit is 1 */
uint64_t s_mask; /* mask bit is 1 if value bit matches msb */
} TempOptInfo;
typedef struct OptContext {
TCGContext *tcg;
TCGOp *prev_mb;
TCGTempSet temps_used;
IntervalTreeRoot mem_copy;
QSIMPLEQ_HEAD(, MemCopyInfo) mem_free;
/* In flight values from optimization. */
TCGType type;
int carry_state; /* -1 = non-constant, {0,1} = constant carry-in */
} OptContext;
static inline TempOptInfo *ts_info(TCGTemp *ts)
{
return ts->state_ptr;
}
static inline TempOptInfo *arg_info(TCGArg arg)
{
return ts_info(arg_temp(arg));
}
static inline bool ti_is_const(TempOptInfo *ti)
{
/* If all bits that are not known zeros are known ones, it's constant. */
return ti->z_mask == ti->o_mask;
}
static inline uint64_t ti_const_val(TempOptInfo *ti)
{
/* If constant, both z_mask and o_mask contain the value. */
return ti->z_mask;
}
static inline bool ti_is_const_val(TempOptInfo *ti, uint64_t val)
{
return ti_is_const(ti) && ti_const_val(ti) == val;
}
static inline bool ts_is_const(TCGTemp *ts)
{
return ti_is_const(ts_info(ts));
}
static inline bool ts_is_const_val(TCGTemp *ts, uint64_t val)
{
return ti_is_const_val(ts_info(ts), val);
}
static inline bool arg_is_const(TCGArg arg)
{
return ts_is_const(arg_temp(arg));
}
static inline uint64_t arg_const_val(TCGArg arg)
{
return ti_const_val(arg_info(arg));
}
static inline bool arg_is_const_val(TCGArg arg, uint64_t val)
{
return ts_is_const_val(arg_temp(arg), val);
}
static inline bool ts_is_copy(TCGTemp *ts)
{
return ts_info(ts)->next_copy != ts;
}
static TCGTemp *cmp_better_copy(TCGTemp *a, TCGTemp *b)
{
return a->kind < b->kind ? b : a;
}
/* Initialize and activate a temporary. */
static void init_ts_info(OptContext *ctx, TCGTemp *ts)
{
size_t idx = temp_idx(ts);
TempOptInfo *ti;
if (test_bit(idx, ctx->temps_used.l)) {
return;
}
set_bit(idx, ctx->temps_used.l);
ti = ts->state_ptr;
if (ti == NULL) {
ti = tcg_malloc(sizeof(TempOptInfo));
ts->state_ptr = ti;
}
ti->next_copy = ts;
ti->prev_copy = ts;
QSIMPLEQ_INIT(&ti->mem_copy);
if (ts->kind == TEMP_CONST) {
ti->z_mask = ts->val;
ti->o_mask = ts->val;
ti->s_mask = INT64_MIN >> clrsb64(ts->val);
} else {
ti->z_mask = -1;
ti->o_mask = 0;
ti->s_mask = 0;
}
}
static MemCopyInfo *mem_copy_first(OptContext *ctx, intptr_t s, intptr_t l)
{
IntervalTreeNode *r = interval_tree_iter_first(&ctx->mem_copy, s, l);
return r ? container_of(r, MemCopyInfo, itree) : NULL;
}
static MemCopyInfo *mem_copy_next(MemCopyInfo *mem, intptr_t s, intptr_t l)
{
IntervalTreeNode *r = interval_tree_iter_next(&mem->itree, s, l);
return r ? container_of(r, MemCopyInfo, itree) : NULL;
}
static void remove_mem_copy(OptContext *ctx, MemCopyInfo *mc)
{
TCGTemp *ts = mc->ts;
TempOptInfo *ti = ts_info(ts);
interval_tree_remove(&mc->itree, &ctx->mem_copy);
QSIMPLEQ_REMOVE(&ti->mem_copy, mc, MemCopyInfo, next);
QSIMPLEQ_INSERT_TAIL(&ctx->mem_free, mc, next);
}
static void remove_mem_copy_in(OptContext *ctx, intptr_t s, intptr_t l)
{
while (true) {
MemCopyInfo *mc = mem_copy_first(ctx, s, l);
if (!mc) {
break;
}
remove_mem_copy(ctx, mc);
}
}
static void remove_mem_copy_all(OptContext *ctx)
{
remove_mem_copy_in(ctx, 0, -1);
tcg_debug_assert(interval_tree_is_empty(&ctx->mem_copy));
}
static TCGTemp *find_better_copy(TCGTemp *ts)
{
TCGTemp *i, *ret;
/* If this is already readonly, we can't do better. */
if (temp_readonly(ts)) {
return ts;
}
ret = ts;
for (i = ts_info(ts)->next_copy; i != ts; i = ts_info(i)->next_copy) {
ret = cmp_better_copy(ret, i);
}
return ret;
}
static void move_mem_copies(TCGTemp *dst_ts, TCGTemp *src_ts)
{
TempOptInfo *si = ts_info(src_ts);
TempOptInfo *di = ts_info(dst_ts);
MemCopyInfo *mc;
QSIMPLEQ_FOREACH(mc, &si->mem_copy, next) {
tcg_debug_assert(mc->ts == src_ts);
mc->ts = dst_ts;
}
QSIMPLEQ_CONCAT(&di->mem_copy, &si->mem_copy);
}
/* Reset TEMP's state, possibly removing the temp for the list of copies. */
static void reset_ts(OptContext *ctx, TCGTemp *ts)
{
TempOptInfo *ti = ts_info(ts);
TCGTemp *pts = ti->prev_copy;
TCGTemp *nts = ti->next_copy;
TempOptInfo *pi = ts_info(pts);
TempOptInfo *ni = ts_info(nts);
ni->prev_copy = ti->prev_copy;
pi->next_copy = ti->next_copy;
ti->next_copy = ts;
ti->prev_copy = ts;
ti->z_mask = -1;
ti->o_mask = 0;
ti->s_mask = 0;
if (!QSIMPLEQ_EMPTY(&ti->mem_copy)) {
if (ts == nts) {
/* Last temp copy being removed, the mem copies die. */
MemCopyInfo *mc;
QSIMPLEQ_FOREACH(mc, &ti->mem_copy, next) {
interval_tree_remove(&mc->itree, &ctx->mem_copy);
}
QSIMPLEQ_CONCAT(&ctx->mem_free, &ti->mem_copy);
} else {
move_mem_copies(find_better_copy(nts), ts);
}
}
}
static void reset_temp(OptContext *ctx, TCGArg arg)
{
reset_ts(ctx, arg_temp(arg));
}
static void record_mem_copy(OptContext *ctx, TCGType type,
TCGTemp *ts, intptr_t start, intptr_t last)
{
MemCopyInfo *mc;
TempOptInfo *ti;
mc = QSIMPLEQ_FIRST(&ctx->mem_free);
if (mc) {
QSIMPLEQ_REMOVE_HEAD(&ctx->mem_free, next);
} else {
mc = tcg_malloc(sizeof(*mc));
}
memset(mc, 0, sizeof(*mc));
mc->itree.start = start;
mc->itree.last = last;
mc->type = type;
interval_tree_insert(&mc->itree, &ctx->mem_copy);
ts = find_better_copy(ts);
ti = ts_info(ts);
mc->ts = ts;
QSIMPLEQ_INSERT_TAIL(&ti->mem_copy, mc, next);
}
static bool ts_are_copies(TCGTemp *ts1, TCGTemp *ts2)
{
TCGTemp *i;
if (ts1 == ts2) {
return true;
}
if (!ts_is_copy(ts1) || !ts_is_copy(ts2)) {
return false;
}
for (i = ts_info(ts1)->next_copy; i != ts1; i = ts_info(i)->next_copy) {
if (i == ts2) {
return true;
}
}
return false;
}
static bool args_are_copies(TCGArg arg1, TCGArg arg2)
{
return ts_are_copies(arg_temp(arg1), arg_temp(arg2));
}
static TCGTemp *find_mem_copy_for(OptContext *ctx, TCGType type, intptr_t s)
{
MemCopyInfo *mc;
for (mc = mem_copy_first(ctx, s, s); mc; mc = mem_copy_next(mc, s, s)) {
if (mc->itree.start == s && mc->type == type) {
return find_better_copy(mc->ts);
}
}
return NULL;
}
static TCGArg arg_new_constant(OptContext *ctx, uint64_t val)
{
TCGType type = ctx->type;
TCGTemp *ts;
if (type == TCG_TYPE_I32) {
val = (int32_t)val;
}
ts = tcg_constant_internal(type, val);
init_ts_info(ctx, ts);
return temp_arg(ts);
}
static TCGArg arg_new_temp(OptContext *ctx)
{
TCGTemp *ts = tcg_temp_new_internal(ctx->type, TEMP_EBB);
init_ts_info(ctx, ts);
return temp_arg(ts);
}
static TCGOp *opt_insert_after(OptContext *ctx, TCGOp *op,
TCGOpcode opc, unsigned narg)
{
return tcg_op_insert_after(ctx->tcg, op, opc, ctx->type, narg);
}
static TCGOp *opt_insert_before(OptContext *ctx, TCGOp *op,
TCGOpcode opc, unsigned narg)
{
return tcg_op_insert_before(ctx->tcg, op, opc, ctx->type, narg);
}
static bool tcg_opt_gen_mov(OptContext *ctx, TCGOp *op, TCGArg dst, TCGArg src)
{
TCGTemp *dst_ts = arg_temp(dst);
TCGTemp *src_ts = arg_temp(src);
TempOptInfo *di;
TempOptInfo *si;
TCGOpcode new_op;
if (ts_are_copies(dst_ts, src_ts)) {
tcg_op_remove(ctx->tcg, op);
return true;
}
reset_ts(ctx, dst_ts);
di = ts_info(dst_ts);
si = ts_info(src_ts);
switch (ctx->type) {
case TCG_TYPE_I32:
case TCG_TYPE_I64:
new_op = INDEX_op_mov;
break;
case TCG_TYPE_V64:
case TCG_TYPE_V128:
case TCG_TYPE_V256:
/* TCGOP_TYPE and TCGOP_VECE remain unchanged. */
new_op = INDEX_op_mov_vec;
break;
default:
g_assert_not_reached();
}
op->opc = new_op;
op->args[0] = dst;
op->args[1] = src;
di->z_mask = si->z_mask;
di->o_mask = si->o_mask;
di->s_mask = si->s_mask;
if (src_ts->type == dst_ts->type) {
TempOptInfo *ni = ts_info(si->next_copy);
di->next_copy = si->next_copy;
di->prev_copy = src_ts;
ni->prev_copy = dst_ts;
si->next_copy = dst_ts;
if (!QSIMPLEQ_EMPTY(&si->mem_copy)
&& cmp_better_copy(src_ts, dst_ts) == dst_ts) {
move_mem_copies(dst_ts, src_ts);
}
} else if (dst_ts->type == TCG_TYPE_I32) {
di->z_mask = (int32_t)di->z_mask;
di->o_mask = (int32_t)di->o_mask;
di->s_mask |= INT32_MIN;
} else {
di->z_mask |= MAKE_64BIT_MASK(32, 32);
di->o_mask = (uint32_t)di->o_mask;
di->s_mask = INT64_MIN;
}
return true;
}
static bool tcg_opt_gen_movi(OptContext *ctx, TCGOp *op,
TCGArg dst, uint64_t val)
{
/* Convert movi to mov with constant temp. */
return tcg_opt_gen_mov(ctx, op, dst, arg_new_constant(ctx, val));
}
static uint64_t do_constant_folding_2(TCGOpcode op, TCGType type,
uint64_t x, uint64_t y)
{
uint64_t l64, h64;
switch (op) {
case INDEX_op_add:
return x + y;
case INDEX_op_sub:
return x - y;
case INDEX_op_mul:
return x * y;
case INDEX_op_and:
case INDEX_op_and_vec:
return x & y;
case INDEX_op_or:
case INDEX_op_or_vec:
return x | y;
case INDEX_op_xor:
case INDEX_op_xor_vec:
return x ^ y;
case INDEX_op_shl:
if (type == TCG_TYPE_I32) {
return (uint32_t)x << (y & 31);
}
return (uint64_t)x << (y & 63);
case INDEX_op_shr:
if (type == TCG_TYPE_I32) {
return (uint32_t)x >> (y & 31);
}
return (uint64_t)x >> (y & 63);
case INDEX_op_sar:
if (type == TCG_TYPE_I32) {
return (int32_t)x >> (y & 31);
}
return (int64_t)x >> (y & 63);
case INDEX_op_rotr:
if (type == TCG_TYPE_I32) {
return ror32(x, y & 31);
}
return ror64(x, y & 63);
case INDEX_op_rotl:
if (type == TCG_TYPE_I32) {
return rol32(x, y & 31);
}
return rol64(x, y & 63);
case INDEX_op_not:
case INDEX_op_not_vec:
return ~x;
case INDEX_op_neg:
return -x;
case INDEX_op_andc:
case INDEX_op_andc_vec:
return x & ~y;
case INDEX_op_orc:
case INDEX_op_orc_vec:
return x | ~y;
case INDEX_op_eqv:
case INDEX_op_eqv_vec:
return ~(x ^ y);
case INDEX_op_nand:
case INDEX_op_nand_vec:
return ~(x & y);
case INDEX_op_nor:
case INDEX_op_nor_vec:
return ~(x | y);
case INDEX_op_clz:
if (type == TCG_TYPE_I32) {
return (uint32_t)x ? clz32(x) : y;
}
return x ? clz64(x) : y;
case INDEX_op_ctz:
if (type == TCG_TYPE_I32) {
return (uint32_t)x ? ctz32(x) : y;
}
return x ? ctz64(x) : y;
case INDEX_op_ctpop:
return type == TCG_TYPE_I32 ? ctpop32(x) : ctpop64(x);
case INDEX_op_bswap16:
x = bswap16(x);
return y & TCG_BSWAP_OS ? (int16_t)x : x;
case INDEX_op_bswap32:
x = bswap32(x);
return y & TCG_BSWAP_OS ? (int32_t)x : x;
case INDEX_op_bswap64:
return bswap64(x);
case INDEX_op_ext_i32_i64:
return (int32_t)x;
case INDEX_op_extu_i32_i64:
case INDEX_op_extrl_i64_i32:
return (uint32_t)x;
case INDEX_op_extrh_i64_i32:
return (uint64_t)x >> 32;
case INDEX_op_muluh:
if (type == TCG_TYPE_I32) {
return ((uint64_t)(uint32_t)x * (uint32_t)y) >> 32;
}
mulu64(&l64, &h64, x, y);
return h64;
case INDEX_op_mulsh:
if (type == TCG_TYPE_I32) {
return ((int64_t)(int32_t)x * (int32_t)y) >> 32;
}
muls64(&l64, &h64, x, y);
return h64;
case INDEX_op_divs:
/* Avoid crashing on divide by zero, otherwise undefined. */
if (type == TCG_TYPE_I32) {
return (int32_t)x / ((int32_t)y ? : 1);
}
return (int64_t)x / ((int64_t)y ? : 1);
case INDEX_op_divu:
if (type == TCG_TYPE_I32) {
return (uint32_t)x / ((uint32_t)y ? : 1);
}
return (uint64_t)x / ((uint64_t)y ? : 1);
case INDEX_op_rems:
if (type == TCG_TYPE_I32) {
return (int32_t)x % ((int32_t)y ? : 1);
}
return (int64_t)x % ((int64_t)y ? : 1);
case INDEX_op_remu:
if (type == TCG_TYPE_I32) {
return (uint32_t)x % ((uint32_t)y ? : 1);
}
return (uint64_t)x % ((uint64_t)y ? : 1);
default:
g_assert_not_reached();
}
}
static uint64_t do_constant_folding(TCGOpcode op, TCGType type,
uint64_t x, uint64_t y)
{
uint64_t res = do_constant_folding_2(op, type, x, y);
if (type == TCG_TYPE_I32) {
res = (int32_t)res;
}
return res;
}
static bool do_constant_folding_cond_32(uint32_t x, uint32_t y, TCGCond c)
{
switch (c) {
case TCG_COND_EQ:
return x == y;
case TCG_COND_NE:
return x != y;
case TCG_COND_LT:
return (int32_t)x < (int32_t)y;
case TCG_COND_GE:
return (int32_t)x >= (int32_t)y;
case TCG_COND_LE:
return (int32_t)x <= (int32_t)y;
case TCG_COND_GT:
return (int32_t)x > (int32_t)y;
case TCG_COND_LTU:
return x < y;
case TCG_COND_GEU:
return x >= y;
case TCG_COND_LEU:
return x <= y;
case TCG_COND_GTU:
return x > y;
case TCG_COND_TSTEQ:
return (x & y) == 0;
case TCG_COND_TSTNE:
return (x & y) != 0;
case TCG_COND_ALWAYS:
case TCG_COND_NEVER:
break;
}
g_assert_not_reached();
}
static bool do_constant_folding_cond_64(uint64_t x, uint64_t y, TCGCond c)
{
switch (c) {
case TCG_COND_EQ:
return x == y;
case TCG_COND_NE:
return x != y;
case TCG_COND_LT:
return (int64_t)x < (int64_t)y;
case TCG_COND_GE:
return (int64_t)x >= (int64_t)y;
case TCG_COND_LE:
return (int64_t)x <= (int64_t)y;
case TCG_COND_GT:
return (int64_t)x > (int64_t)y;
case TCG_COND_LTU:
return x < y;
case TCG_COND_GEU:
return x >= y;
case TCG_COND_LEU:
return x <= y;
case TCG_COND_GTU:
return x > y;
case TCG_COND_TSTEQ:
return (x & y) == 0;
case TCG_COND_TSTNE:
return (x & y) != 0;
case TCG_COND_ALWAYS:
case TCG_COND_NEVER:
break;
}
g_assert_not_reached();
}
static int do_constant_folding_cond_eq(TCGCond c)
{
switch (c) {
case TCG_COND_GT:
case TCG_COND_LTU:
case TCG_COND_LT:
case TCG_COND_GTU:
case TCG_COND_NE:
return 0;
case TCG_COND_GE:
case TCG_COND_GEU:
case TCG_COND_LE:
case TCG_COND_LEU:
case TCG_COND_EQ:
return 1;
case TCG_COND_TSTEQ:
case TCG_COND_TSTNE:
return -1;
case TCG_COND_ALWAYS:
case TCG_COND_NEVER:
break;
}
g_assert_not_reached();
}
/*
* Return -1 if the condition can't be simplified,
* and the result of the condition (0 or 1) if it can.
*/
static int do_constant_folding_cond(TCGType type, TCGArg x,
TCGArg y, TCGCond c)
{
if (arg_is_const(x) && arg_is_const(y)) {
uint64_t xv = arg_const_val(x);
uint64_t yv = arg_const_val(y);
switch (type) {
case TCG_TYPE_I32:
return do_constant_folding_cond_32(xv, yv, c);
case TCG_TYPE_I64:
return do_constant_folding_cond_64(xv, yv, c);
default:
/* Only scalar comparisons are optimizable */
return -1;
}
} else if (args_are_copies(x, y)) {
return do_constant_folding_cond_eq(c);
} else if (arg_is_const_val(y, 0)) {
switch (c) {
case TCG_COND_LTU:
case TCG_COND_TSTNE:
return 0;
case TCG_COND_GEU:
case TCG_COND_TSTEQ:
return 1;
default:
return -1;
}
}
return -1;
}
/**
* swap_commutative:
* @dest: TCGArg of the destination argument, or NO_DEST.
* @p1: first paired argument
* @p2: second paired argument
*
* If *@p1 is a constant and *@p2 is not, swap.
* If *@p2 matches @dest, swap.
* Return true if a swap was performed.
*/
#define NO_DEST temp_arg(NULL)
static int pref_commutative(TempOptInfo *ti)
{
/* Slight preference for non-zero constants second. */
return !ti_is_const(ti) ? 0 : ti_const_val(ti) ? 3 : 2;
}
static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2)
{
TCGArg a1 = *p1, a2 = *p2;
int sum = 0;
sum += pref_commutative(arg_info(a1));
sum -= pref_commutative(arg_info(a2));
/* Prefer the constant in second argument, and then the form
op a, a, b, which is better handled on non-RISC hosts. */
if (sum > 0 || (sum == 0 && dest == a2)) {
*p1 = a2;
*p2 = a1;
return true;
}
return false;
}
static bool swap_commutative2(TCGArg *p1, TCGArg *p2)
{
int sum = 0;
sum += pref_commutative(arg_info(p1[0]));
sum += pref_commutative(arg_info(p1[1]));
sum -= pref_commutative(arg_info(p2[0]));
sum -= pref_commutative(arg_info(p2[1]));
if (sum > 0) {
TCGArg t;
t = p1[0], p1[0] = p2[0], p2[0] = t;
t = p1[1], p1[1] = p2[1], p2[1] = t;
return true;
}
return false;
}
/*
* Return -1 if the condition can't be simplified,
* and the result of the condition (0 or 1) if it can.
*/
static bool fold_and(OptContext *ctx, TCGOp *op);
static int do_constant_folding_cond1(OptContext *ctx, TCGOp *op, TCGArg dest,
TCGArg *p1, TCGArg *p2, TCGArg *pcond)
{
TCGCond cond;
TempOptInfo *i1;
bool swap;
int r;
swap = swap_commutative(dest, p1, p2);
cond = *pcond;
if (swap) {
*pcond = cond = tcg_swap_cond(cond);
}
r = do_constant_folding_cond(ctx->type, *p1, *p2, cond);
if (r >= 0) {
return r;
}
if (!is_tst_cond(cond)) {
return -1;
}
i1 = arg_info(*p1);
/*
* TSTNE x,x -> NE x,0
* TSTNE x,i -> NE x,0 if i includes all nonzero bits of x
*/
if (args_are_copies(*p1, *p2) ||
(arg_is_const(*p2) && (i1->z_mask & ~arg_const_val(*p2)) == 0)) {
*p2 = arg_new_constant(ctx, 0);
*pcond = tcg_tst_eqne_cond(cond);
return -1;
}
/* TSTNE x,i -> LT x,0 if i only includes sign bit copies */
if (arg_is_const(*p2) && (arg_const_val(*p2) & ~i1->s_mask) == 0) {
*p2 = arg_new_constant(ctx, 0);
*pcond = tcg_tst_ltge_cond(cond);
return -1;
}
/* Expand to AND with a temporary if no backend support. */
if (!TCG_TARGET_HAS_tst) {
TCGOp *op2 = opt_insert_before(ctx, op, INDEX_op_and, 3);
TCGArg tmp = arg_new_temp(ctx);
op2->args[0] = tmp;
op2->args[1] = *p1;
op2->args[2] = *p2;
fold_and(ctx, op2);
*p1 = tmp;
*p2 = arg_new_constant(ctx, 0);
*pcond = tcg_tst_eqne_cond(cond);
}
return -1;
}
static int do_constant_folding_cond2(OptContext *ctx, TCGOp *op, TCGArg *args)
{
TCGArg al, ah, bl, bh;
TCGCond c;
bool swap;
int r;
swap = swap_commutative2(args, args + 2);
c = args[4];
if (swap) {
args[4] = c = tcg_swap_cond(c);
}
al = args[0];
ah = args[1];
bl = args[2];
bh = args[3];
if (arg_is_const(bl) && arg_is_const(bh)) {
tcg_target_ulong blv = arg_const_val(bl);
tcg_target_ulong bhv = arg_const_val(bh);
uint64_t b = deposit64(blv, 32, 32, bhv);
if (arg_is_const(al) && arg_is_const(ah)) {
tcg_target_ulong alv = arg_const_val(al);
tcg_target_ulong ahv = arg_const_val(ah);
uint64_t a = deposit64(alv, 32, 32, ahv);
r = do_constant_folding_cond_64(a, b, c);
if (r >= 0) {
return r;
}
}
if (b == 0) {
switch (c) {
case TCG_COND_LTU:
case TCG_COND_TSTNE:
return 0;
case TCG_COND_GEU:
case TCG_COND_TSTEQ:
return 1;
default:
break;
}
}
/* TSTNE x,-1 -> NE x,0 */
if (b == -1 && is_tst_cond(c)) {
args[3] = args[2] = arg_new_constant(ctx, 0);
args[4] = tcg_tst_eqne_cond(c);
return -1;
}
/* TSTNE x,sign -> LT x,0 */
if (b == INT64_MIN && is_tst_cond(c)) {
/* bl must be 0, so copy that to bh */
args[3] = bl;
args[4] = tcg_tst_ltge_cond(c);
return -1;
}
}
if (args_are_copies(al, bl) && args_are_copies(ah, bh)) {
r = do_constant_folding_cond_eq(c);
if (r >= 0) {
return r;
}
/* TSTNE x,x -> NE x,0 */
if (is_tst_cond(c)) {
args[3] = args[2] = arg_new_constant(ctx, 0);
args[4] = tcg_tst_eqne_cond(c);
return -1;
}
}
/* Expand to AND with a temporary if no backend support. */
if (!TCG_TARGET_HAS_tst && is_tst_cond(c)) {
TCGOp *op1 = opt_insert_before(ctx, op, INDEX_op_and, 3);
TCGOp *op2 = opt_insert_before(ctx, op, INDEX_op_and, 3);
TCGArg t1 = arg_new_temp(ctx);
TCGArg t2 = arg_new_temp(ctx);
op1->args[0] = t1;
op1->args[1] = al;
op1->args[2] = bl;
fold_and(ctx, op1);
op2->args[0] = t2;
op2->args[1] = ah;
op2->args[2] = bh;
fold_and(ctx, op1);
args[0] = t1;
args[1] = t2;
args[3] = args[2] = arg_new_constant(ctx, 0);
args[4] = tcg_tst_eqne_cond(c);
}
return -1;
}
static void init_arguments(OptContext *ctx, TCGOp *op, int nb_args)
{
for (int i = 0; i < nb_args; i++) {
TCGTemp *ts = arg_temp(op->args[i]);
init_ts_info(ctx, ts);
}
}
static void copy_propagate(OptContext *ctx, TCGOp *op,
int nb_oargs, int nb_iargs)
{
for (int i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
TCGTemp *ts = arg_temp(op->args[i]);
if (ts_is_copy(ts)) {
op->args[i] = temp_arg(find_better_copy(ts));
}
}
}
static void finish_bb(OptContext *ctx)
{
/* We only optimize memory barriers across basic blocks. */
ctx->prev_mb = NULL;
}
static void finish_ebb(OptContext *ctx)
{
finish_bb(ctx);
/* We only optimize across extended basic blocks. */
memset(&ctx->temps_used, 0, sizeof(ctx->temps_used));
remove_mem_copy_all(ctx);
}
static bool finish_folding(OptContext *ctx, TCGOp *op)
{
const TCGOpDef *def = &tcg_op_defs[op->opc];
int i, nb_oargs;
nb_oargs = def->nb_oargs;
for (i = 0; i < nb_oargs; i++) {
TCGTemp *ts = arg_temp(op->args[i]);
reset_ts(ctx, ts);
}
return true;
}
/*
* The fold_* functions return true when processing is complete,
* usually by folding the operation to a constant or to a copy,
* and calling tcg_opt_gen_{mov,movi}. They may do other things,
* like collect information about the value produced, for use in
* optimizing a subsequent operation.
*
* These first fold_* functions are all helpers, used by other
* folders for more specific operations.
*/
static bool fold_const1(OptContext *ctx, TCGOp *op)
{
if (arg_is_const(op->args[1])) {
uint64_t t = arg_const_val(op->args[1]);
t = do_constant_folding(op->opc, ctx->type, t, 0);
return tcg_opt_gen_movi(ctx, op, op->args[0], t);
}
return false;
}
static bool fold_const2(OptContext *ctx, TCGOp *op)
{
if (arg_is_const(op->args[1]) && arg_is_const(op->args[2])) {
uint64_t t1 = arg_const_val(op->args[1]);
uint64_t t2 = arg_const_val(op->args[2]);
t1 = do_constant_folding(op->opc, ctx->type, t1, t2);
return tcg_opt_gen_movi(ctx, op, op->args[0], t1);
}
return false;
}
static bool fold_commutative(OptContext *ctx, TCGOp *op)
{
swap_commutative(op->args[0], &op->args[1], &op->args[2]);
return false;
}
static bool fold_const2_commutative(OptContext *ctx, TCGOp *op)
{
swap_commutative(op->args[0], &op->args[1], &op->args[2]);
return fold_const2(ctx, op);
}
/*
* Record "zero" and "sign" masks for the single output of @op.
* See TempOptInfo definition of z_mask and s_mask.
* If z_mask allows, fold the output to constant zero.
* The passed s_mask may be augmented by z_mask.
*/
static bool fold_masks_zosa_int(OptContext *ctx, TCGOp *op,
uint64_t z_mask, uint64_t o_mask,
int64_t s_mask, uint64_t a_mask)
{
const TCGOpDef *def = &tcg_op_defs[op->opc];
TCGTemp *ts;
TempOptInfo *ti;
int rep;
/* Only single-output opcodes are supported here. */
tcg_debug_assert(def->nb_oargs == 1);
/*
* 32-bit ops generate 32-bit results, which for the purpose of
* simplifying tcg are sign-extended. Certainly that's how we
* represent our constants elsewhere. Note that the bits will
* be reset properly for a 64-bit value when encountering the
* type changing opcodes.
*/
if (ctx->type == TCG_TYPE_I32) {
z_mask = (int32_t)z_mask;
o_mask = (int32_t)o_mask;
s_mask |= INT32_MIN;
a_mask = (uint32_t)a_mask;
}
/* Bits that are known 1 and bits that are known 0 must not overlap. */
tcg_debug_assert((o_mask & ~z_mask) == 0);
/* All bits that are not known zero are known one is a constant. */
if (z_mask == o_mask) {
return tcg_opt_gen_movi(ctx, op, op->args[0], o_mask);
}
/* If no bits are affected, the operation devolves to a copy. */
if (a_mask == 0) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
}
ts = arg_temp(op->args[0]);
reset_ts(ctx, ts);
ti = ts_info(ts);
ti->z_mask = z_mask;
/* Canonicalize s_mask and incorporate data from z_mask. */
rep = clz64(~s_mask);
rep = MAX(rep, clz64(z_mask));
rep = MAX(rep, clz64(~o_mask));
rep = MAX(rep - 1, 0);
ti->s_mask = INT64_MIN >> rep;
return false;
}
static bool fold_masks_zosa(OptContext *ctx, TCGOp *op, uint64_t z_mask,
uint64_t o_mask, int64_t s_mask, uint64_t a_mask)
{
fold_masks_zosa_int(ctx, op, z_mask, o_mask, s_mask, -1);
return true;
}
static bool fold_masks_zos(OptContext *ctx, TCGOp *op,
uint64_t z_mask, uint64_t o_mask, uint64_t s_mask)
{
return fold_masks_zosa(ctx, op, z_mask, o_mask, s_mask, -1);
}
static bool fold_masks_zo(OptContext *ctx, TCGOp *op,
uint64_t z_mask, uint64_t o_mask)
{
return fold_masks_zosa(ctx, op, z_mask, o_mask, 0, -1);
}
static bool fold_masks_zs(OptContext *ctx, TCGOp *op,
uint64_t z_mask, uint64_t s_mask)
{
return fold_masks_zosa(ctx, op, z_mask, 0, s_mask, -1);
}
static bool fold_masks_z(OptContext *ctx, TCGOp *op, uint64_t z_mask)
{
return fold_masks_zosa(ctx, op, z_mask, 0, 0, -1);
}
static bool fold_masks_s(OptContext *ctx, TCGOp *op, uint64_t s_mask)
{
return fold_masks_zosa(ctx, op, -1, 0, s_mask, -1);
}
/*
* Convert @op to NOT, if NOT is supported by the host.
* Return true f the conversion is successful, which will still
* indicate that the processing is complete.
*/
static bool fold_not(OptContext *ctx, TCGOp *op);
static bool fold_to_not(OptContext *ctx, TCGOp *op, int idx)
{
TCGOpcode not_op;
bool have_not;
switch (ctx->type) {
case TCG_TYPE_I32:
case TCG_TYPE_I64:
not_op = INDEX_op_not;
have_not = tcg_op_supported(INDEX_op_not, ctx->type, 0);
break;
case TCG_TYPE_V64:
case TCG_TYPE_V128:
case TCG_TYPE_V256:
not_op = INDEX_op_not_vec;
have_not = TCG_TARGET_HAS_not_vec;
break;
default:
g_assert_not_reached();
}
if (have_not) {
op->opc = not_op;
op->args[1] = op->args[idx];
return fold_not(ctx, op);
}
return false;
}
/* If the binary operation has first argument @i, fold to @i. */
static bool fold_ix_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
{
if (arg_is_const_val(op->args[1], i)) {
return tcg_opt_gen_movi(ctx, op, op->args[0], i);
}
return false;
}
/* If the binary operation has first argument @i, fold to NOT. */
static bool fold_ix_to_not(OptContext *ctx, TCGOp *op, uint64_t i)
{
if (arg_is_const_val(op->args[1], i)) {
return fold_to_not(ctx, op, 2);
}
return false;
}
/* If the binary operation has second argument @i, fold to @i. */
static bool fold_xi_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
{
if (arg_is_const_val(op->args[2], i)) {
return tcg_opt_gen_movi(ctx, op, op->args[0], i);
}
return false;
}
/* If the binary operation has second argument @i, fold to identity. */
static bool fold_xi_to_x(OptContext *ctx, TCGOp *op, uint64_t i)
{
if (arg_is_const_val(op->args[2], i)) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
}
return false;
}
/* If the binary operation has second argument @i, fold to NOT. */
static bool fold_xi_to_not(OptContext *ctx, TCGOp *op, uint64_t i)
{
if (arg_is_const_val(op->args[2], i)) {
return fold_to_not(ctx, op, 1);
}
return false;
}
/* If the binary operation has both arguments equal, fold to @i. */
static bool fold_xx_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
{
if (args_are_copies(op->args[1], op->args[2])) {
return tcg_opt_gen_movi(ctx, op, op->args[0], i);
}
return false;
}
/* If the binary operation has both arguments equal, fold to identity. */
static bool fold_xx_to_x(OptContext *ctx, TCGOp *op)
{
if (args_are_copies(op->args[1], op->args[2])) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
}
return false;
}
/*
* These outermost fold_<op> functions are sorted alphabetically.
*
* The ordering of the transformations should be:
* 1) those that produce a constant
* 2) those that produce a copy
* 3) those that produce information about the result value.
*/
static bool fold_addco(OptContext *ctx, TCGOp *op);
static bool fold_or(OptContext *ctx, TCGOp *op);
static bool fold_orc(OptContext *ctx, TCGOp *op);
static bool fold_subbo(OptContext *ctx, TCGOp *op);
static bool fold_xor(OptContext *ctx, TCGOp *op);
static bool fold_add(OptContext *ctx, TCGOp *op)
{
if (fold_const2_commutative(ctx, op) ||
fold_xi_to_x(ctx, op, 0)) {
return true;
}
return finish_folding(ctx, op);
}
/* We cannot as yet do_constant_folding with vectors. */
static bool fold_add_vec(OptContext *ctx, TCGOp *op)
{
if (fold_commutative(ctx, op) ||
fold_xi_to_x(ctx, op, 0)) {
return true;
}
return finish_folding(ctx, op);
}
static void squash_prev_carryout(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t2;
op = QTAILQ_PREV(op, link);
switch (op->opc) {
case INDEX_op_addco:
op->opc = INDEX_op_add;
fold_add(ctx, op);
break;
case INDEX_op_addcio:
op->opc = INDEX_op_addci;
break;
case INDEX_op_addc1o:
op->opc = INDEX_op_add;
t2 = arg_info(op->args[2]);
if (ti_is_const(t2)) {
op->args[2] = arg_new_constant(ctx, ti_const_val(t2) + 1);
/* Perform other constant folding, if needed. */
fold_add(ctx, op);
} else {
TCGArg ret = op->args[0];
op = opt_insert_after(ctx, op, INDEX_op_add, 3);
op->args[0] = ret;
op->args[1] = ret;
op->args[2] = arg_new_constant(ctx, 1);
}
break;
default:
g_assert_not_reached();
}
}
static bool fold_addci(OptContext *ctx, TCGOp *op)
{
fold_commutative(ctx, op);
if (ctx->carry_state < 0) {
return finish_folding(ctx, op);
}
squash_prev_carryout(ctx, op);
op->opc = INDEX_op_add;
if (ctx->carry_state > 0) {
TempOptInfo *t2 = arg_info(op->args[2]);
/*
* Propagate the known carry-in into a constant, if possible.
* Otherwise emit a second add +1.
*/
if (ti_is_const(t2)) {
op->args[2] = arg_new_constant(ctx, ti_const_val(t2) + 1);
} else {
TCGOp *op2 = opt_insert_before(ctx, op, INDEX_op_add, 3);
op2->args[0] = op->args[0];
op2->args[1] = op->args[1];
op2->args[2] = op->args[2];
fold_add(ctx, op2);
op->args[1] = op->args[0];
op->args[2] = arg_new_constant(ctx, 1);
}
}
ctx->carry_state = -1;
return fold_add(ctx, op);
}
static bool fold_addcio(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t1, *t2;
int carry_out = -1;
uint64_t sum, max;
fold_commutative(ctx, op);
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
/*
* The z_mask value is >= the maximum value that can be represented
* with the known zero bits. So adding the z_mask values will not
* overflow if and only if the true values cannot overflow.
*/
if (!uadd64_overflow(t1->z_mask, t2->z_mask, &sum) &&
!uadd64_overflow(sum, ctx->carry_state != 0, &sum)) {
carry_out = 0;
}
if (ctx->carry_state < 0) {
ctx->carry_state = carry_out;
return finish_folding(ctx, op);
}
squash_prev_carryout(ctx, op);
if (ctx->carry_state == 0) {
goto do_addco;
}
/* Propagate the known carry-in into a constant, if possible. */
max = ctx->type == TCG_TYPE_I32 ? UINT32_MAX : UINT64_MAX;
if (ti_is_const(t2)) {
uint64_t v = ti_const_val(t2) & max;
if (v < max) {
op->args[2] = arg_new_constant(ctx, v + 1);
goto do_addco;
}
/* max + known carry in produces known carry out. */
carry_out = 1;
}
if (ti_is_const(t1)) {
uint64_t v = ti_const_val(t1) & max;
if (v < max) {
op->args[1] = arg_new_constant(ctx, v + 1);
goto do_addco;
}
carry_out = 1;
}
/* Adjust the opcode to remember the known carry-in. */
op->opc = INDEX_op_addc1o;
ctx->carry_state = carry_out;
return finish_folding(ctx, op);
do_addco:
op->opc = INDEX_op_addco;
return fold_addco(ctx, op);
}
static bool fold_addco(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t1, *t2;
int carry_out = -1;
uint64_t ign;
fold_commutative(ctx, op);
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
if (ti_is_const(t2)) {
uint64_t v2 = ti_const_val(t2);
if (ti_is_const(t1)) {
uint64_t v1 = ti_const_val(t1);
/* Given sign-extension of z_mask for I32, we need not truncate. */
carry_out = uadd64_overflow(v1, v2, &ign);
} else if (v2 == 0) {
carry_out = 0;
}
} else {
/*
* The z_mask value is >= the maximum value that can be represented
* with the known zero bits. So adding the z_mask values will not
* overflow if and only if the true values cannot overflow.
*/
if (!uadd64_overflow(t1->z_mask, t2->z_mask, &ign)) {
carry_out = 0;
}
}
ctx->carry_state = carry_out;
return finish_folding(ctx, op);
}
static bool fold_and(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask, a_mask;
TempOptInfo *t1, *t2;
if (fold_const2_commutative(ctx, op)) {
return true;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
z_mask = t1->z_mask & t2->z_mask;
o_mask = t1->o_mask & t2->o_mask;
/*
* Sign repetitions are perforce all identical, whether they are 1 or 0.
* Bitwise operations preserve the relative quantity of the repetitions.
*/
s_mask = t1->s_mask & t2->s_mask;
/* Affected bits are those not known zero, masked by those known one. */
a_mask = t1->z_mask & ~t2->o_mask;
if (!fold_masks_zosa_int(ctx, op, z_mask, o_mask, s_mask, a_mask)) {
if (ti_is_const(t2)) {
/*
* Canonicalize on extract, if valid. This aids x86 with its
* 2 operand MOVZBL and 2 operand AND, selecting the TCGOpcode
* which does not require matching operands. Other backends can
* trivially expand the extract to AND during code generation.
*/
uint64_t val = ti_const_val(t2);
if (!(val & (val + 1))) {
unsigned len = ctz64(~val);
if (TCG_TARGET_extract_valid(ctx->type, 0, len)) {
op->opc = INDEX_op_extract;
op->args[2] = 0;
op->args[3] = len;
}
}
} else {
fold_xx_to_x(ctx, op);
}
}
return true;
}
static bool fold_andc(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask, a_mask;
TempOptInfo *t1, *t2;
if (fold_const2(ctx, op) ||
fold_xx_to_i(ctx, op, 0) ||
fold_xi_to_x(ctx, op, 0) ||
fold_ix_to_not(ctx, op, -1)) {
return true;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
if (ti_is_const(t2)) {
/* Fold andc r,x,i to and r,x,~i. */
switch (ctx->type) {
case TCG_TYPE_I32:
case TCG_TYPE_I64:
op->opc = INDEX_op_and;
break;
case TCG_TYPE_V64:
case TCG_TYPE_V128:
case TCG_TYPE_V256:
op->opc = INDEX_op_and_vec;
break;
default:
g_assert_not_reached();
}
op->args[2] = arg_new_constant(ctx, ~ti_const_val(t2));
return fold_and(ctx, op);
}
z_mask = t1->z_mask & ~t2->o_mask;
o_mask = t1->o_mask & ~t2->z_mask;
s_mask = t1->s_mask & t2->s_mask;
/* Affected bits are those not known zero, masked by those known zero. */
a_mask = t1->z_mask & t2->z_mask;
return fold_masks_zosa(ctx, op, z_mask, o_mask, s_mask, a_mask);
}
static bool fold_bitsel_vec(OptContext *ctx, TCGOp *op)
{
/* If true and false values are the same, eliminate the cmp. */
if (args_are_copies(op->args[2], op->args[3])) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[2]);
}
if (arg_is_const(op->args[2]) && arg_is_const(op->args[3])) {
uint64_t tv = arg_const_val(op->args[2]);
uint64_t fv = arg_const_val(op->args[3]);
if (tv == -1 && fv == 0) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
}
if (tv == 0 && fv == -1) {
if (TCG_TARGET_HAS_not_vec) {
op->opc = INDEX_op_not_vec;
return fold_not(ctx, op);
} else {
op->opc = INDEX_op_xor_vec;
op->args[2] = arg_new_constant(ctx, -1);
return fold_xor(ctx, op);
}
}
}
if (arg_is_const(op->args[2])) {
uint64_t tv = arg_const_val(op->args[2]);
if (tv == -1) {
op->opc = INDEX_op_or_vec;
op->args[2] = op->args[3];
return fold_or(ctx, op);
}
if (tv == 0 && TCG_TARGET_HAS_andc_vec) {
op->opc = INDEX_op_andc_vec;
op->args[2] = op->args[1];
op->args[1] = op->args[3];
return fold_andc(ctx, op);
}
}
if (arg_is_const(op->args[3])) {
uint64_t fv = arg_const_val(op->args[3]);
if (fv == 0) {
op->opc = INDEX_op_and_vec;
return fold_and(ctx, op);
}
if (fv == -1 && TCG_TARGET_HAS_orc_vec) {
op->opc = INDEX_op_orc_vec;
op->args[2] = op->args[1];
op->args[1] = op->args[3];
return fold_orc(ctx, op);
}
}
return finish_folding(ctx, op);
}
static bool fold_brcond(OptContext *ctx, TCGOp *op)
{
int i = do_constant_folding_cond1(ctx, op, NO_DEST, &op->args[0],
&op->args[1], &op->args[2]);
if (i == 0) {
tcg_op_remove(ctx->tcg, op);
return true;
}
if (i > 0) {
op->opc = INDEX_op_br;
op->args[0] = op->args[3];
finish_ebb(ctx);
} else {
finish_bb(ctx);
}
return true;
}
static bool fold_brcond2(OptContext *ctx, TCGOp *op)
{
TCGCond cond;
TCGArg label;
int i, inv = 0;
i = do_constant_folding_cond2(ctx, op, &op->args[0]);
cond = op->args[4];
label = op->args[5];
if (i >= 0) {
goto do_brcond_const;
}
switch (cond) {
case TCG_COND_LT:
case TCG_COND_GE:
/*
* Simplify LT/GE comparisons vs zero to a single compare
* vs the high word of the input.
*/
if (arg_is_const_val(op->args[2], 0) &&
arg_is_const_val(op->args[3], 0)) {
goto do_brcond_high;
}
break;
case TCG_COND_NE:
inv = 1;
QEMU_FALLTHROUGH;
case TCG_COND_EQ:
/*
* Simplify EQ/NE comparisons where one of the pairs
* can be simplified.
*/
i = do_constant_folding_cond(TCG_TYPE_I32, op->args[0],
op->args[2], cond);
switch (i ^ inv) {
case 0:
goto do_brcond_const;
case 1:
goto do_brcond_high;
}
i = do_constant_folding_cond(TCG_TYPE_I32, op->args[1],
op->args[3], cond);
switch (i ^ inv) {
case 0:
goto do_brcond_const;
case 1:
goto do_brcond_low;
}
break;
case TCG_COND_TSTEQ:
case TCG_COND_TSTNE:
if (arg_is_const_val(op->args[2], 0)) {
goto do_brcond_high;
}
if (arg_is_const_val(op->args[3], 0)) {
goto do_brcond_low;
}
break;
default:
break;
do_brcond_low:
op->opc = INDEX_op_brcond;
op->args[1] = op->args[2];
op->args[2] = cond;
op->args[3] = label;
return fold_brcond(ctx, op);
do_brcond_high:
op->opc = INDEX_op_brcond;
op->args[0] = op->args[1];
op->args[1] = op->args[3];
op->args[2] = cond;
op->args[3] = label;
return fold_brcond(ctx, op);
do_brcond_const:
if (i == 0) {
tcg_op_remove(ctx->tcg, op);
return true;
}
op->opc = INDEX_op_br;
op->args[0] = label;
finish_ebb(ctx);
return true;
}
finish_bb(ctx);
return true;
}
static bool fold_bswap(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *t1 = arg_info(op->args[1]);
int flags = op->args[2];
if (ti_is_const(t1)) {
return tcg_opt_gen_movi(ctx, op, op->args[0],
do_constant_folding(op->opc, ctx->type,
ti_const_val(t1), flags));
}
z_mask = t1->z_mask;
o_mask = t1->o_mask;
s_mask = 0;
switch (op->opc) {
case INDEX_op_bswap16:
z_mask = bswap16(z_mask);
o_mask = bswap16(o_mask);
if (flags & TCG_BSWAP_OS) {
z_mask = (int16_t)z_mask;
o_mask = (int16_t)o_mask;
s_mask = INT16_MIN;
} else if (!(flags & TCG_BSWAP_OZ)) {
z_mask |= MAKE_64BIT_MASK(16, 48);
}
break;
case INDEX_op_bswap32:
z_mask = bswap32(z_mask);
o_mask = bswap32(o_mask);
if (flags & TCG_BSWAP_OS) {
z_mask = (int32_t)z_mask;
o_mask = (int32_t)o_mask;
s_mask = INT32_MIN;
} else if (!(flags & TCG_BSWAP_OZ)) {
z_mask |= MAKE_64BIT_MASK(32, 32);
}
break;
case INDEX_op_bswap64:
z_mask = bswap64(z_mask);
o_mask = bswap64(o_mask);
break;
default:
g_assert_not_reached();
}
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_call(OptContext *ctx, TCGOp *op)
{
TCGContext *s = ctx->tcg;
int nb_oargs = TCGOP_CALLO(op);
int nb_iargs = TCGOP_CALLI(op);
int flags, i;
init_arguments(ctx, op, nb_oargs + nb_iargs);
copy_propagate(ctx, op, nb_oargs, nb_iargs);
/* If the function reads or writes globals, reset temp data. */
flags = tcg_call_flags(op);
if (!(flags & (TCG_CALL_NO_READ_GLOBALS | TCG_CALL_NO_WRITE_GLOBALS))) {
int nb_globals = s->nb_globals;
for (i = 0; i < nb_globals; i++) {
if (test_bit(i, ctx->temps_used.l)) {
reset_ts(ctx, &ctx->tcg->temps[i]);
}
}
}
/* If the function has side effects, reset mem data. */
if (!(flags & TCG_CALL_NO_SIDE_EFFECTS)) {
remove_mem_copy_all(ctx);
}
/* Reset temp data for outputs. */
for (i = 0; i < nb_oargs; i++) {
reset_temp(ctx, op->args[i]);
}
/* Stop optimizing MB across calls. */
ctx->prev_mb = NULL;
return true;
}
static bool fold_cmp_vec(OptContext *ctx, TCGOp *op)
{
/* Canonicalize the comparison to put immediate second. */
if (swap_commutative(NO_DEST, &op->args[1], &op->args[2])) {
op->args[3] = tcg_swap_cond(op->args[3]);
}
return finish_folding(ctx, op);
}
static bool fold_cmpsel_vec(OptContext *ctx, TCGOp *op)
{
/* If true and false values are the same, eliminate the cmp. */
if (args_are_copies(op->args[3], op->args[4])) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[3]);
}
/* Canonicalize the comparison to put immediate second. */
if (swap_commutative(NO_DEST, &op->args[1], &op->args[2])) {
op->args[5] = tcg_swap_cond(op->args[5]);
}
/*
* Canonicalize the "false" input reg to match the destination,
* so that the tcg backend can implement "move if true".
*/
if (swap_commutative(op->args[0], &op->args[4], &op->args[3])) {
op->args[5] = tcg_invert_cond(op->args[5]);
}
return finish_folding(ctx, op);
}
static bool fold_count_zeros(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, s_mask;
TempOptInfo *t1 = arg_info(op->args[1]);
TempOptInfo *t2 = arg_info(op->args[2]);
if (ti_is_const(t1)) {
uint64_t t = ti_const_val(t1);
if (t != 0) {
t = do_constant_folding(op->opc, ctx->type, t, 0);
return tcg_opt_gen_movi(ctx, op, op->args[0], t);
}
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[2]);
}
switch (ctx->type) {
case TCG_TYPE_I32:
z_mask = 31;
break;
case TCG_TYPE_I64:
z_mask = 63;
break;
default:
g_assert_not_reached();
}
s_mask = ~z_mask;
z_mask |= t2->z_mask;
s_mask &= t2->s_mask;
return fold_masks_zs(ctx, op, z_mask, s_mask);
}
static bool fold_ctpop(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask;
if (fold_const1(ctx, op)) {
return true;
}
switch (ctx->type) {
case TCG_TYPE_I32:
z_mask = 32 | 31;
break;
case TCG_TYPE_I64:
z_mask = 64 | 63;
break;
default:
g_assert_not_reached();
}
return fold_masks_z(ctx, op, z_mask);
}
static bool fold_deposit(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t1 = arg_info(op->args[1]);
TempOptInfo *t2 = arg_info(op->args[2]);
int ofs = op->args[3];
int len = op->args[4];
int width = 8 * tcg_type_size(ctx->type);
uint64_t z_mask, o_mask, s_mask;
if (ti_is_const(t1) && ti_is_const(t2)) {
return tcg_opt_gen_movi(ctx, op, op->args[0],
deposit64(ti_const_val(t1), ofs, len,
ti_const_val(t2)));
}
/* Inserting a value into zero at offset 0. */
if (ti_is_const_val(t1, 0) && ofs == 0) {
uint64_t mask = MAKE_64BIT_MASK(0, len);
op->opc = INDEX_op_and;
op->args[1] = op->args[2];
op->args[2] = arg_new_constant(ctx, mask);
return fold_and(ctx, op);
}
/* Inserting zero into a value. */
if (ti_is_const_val(t2, 0)) {
uint64_t mask = deposit64(-1, ofs, len, 0);
op->opc = INDEX_op_and;
op->args[2] = arg_new_constant(ctx, mask);
return fold_and(ctx, op);
}
/* The s_mask from the top portion of the deposit is still valid. */
if (ofs + len == width) {
s_mask = t2->s_mask << ofs;
} else {
s_mask = t1->s_mask & ~MAKE_64BIT_MASK(0, ofs + len);
}
z_mask = deposit64(t1->z_mask, ofs, len, t2->z_mask);
o_mask = deposit64(t1->o_mask, ofs, len, t2->o_mask);
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_divide(OptContext *ctx, TCGOp *op)
{
if (fold_const2(ctx, op) ||
fold_xi_to_x(ctx, op, 1)) {
return true;
}
return finish_folding(ctx, op);
}
static bool fold_dup(OptContext *ctx, TCGOp *op)
{
if (arg_is_const(op->args[1])) {
uint64_t t = arg_const_val(op->args[1]);
t = dup_const(TCGOP_VECE(op), t);
return tcg_opt_gen_movi(ctx, op, op->args[0], t);
}
return finish_folding(ctx, op);
}
static bool fold_dup2(OptContext *ctx, TCGOp *op)
{
if (arg_is_const(op->args[1]) && arg_is_const(op->args[2])) {
uint64_t t = deposit64(arg_const_val(op->args[1]), 32, 32,
arg_const_val(op->args[2]));
return tcg_opt_gen_movi(ctx, op, op->args[0], t);
}
if (args_are_copies(op->args[1], op->args[2])) {
op->opc = INDEX_op_dup_vec;
TCGOP_VECE(op) = MO_32;
}
return finish_folding(ctx, op);
}
static bool fold_eqv(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *t1, *t2;
if (fold_const2_commutative(ctx, op) ||
fold_xi_to_x(ctx, op, -1) ||
fold_xi_to_not(ctx, op, 0)) {
return true;
}
t2 = arg_info(op->args[2]);
if (ti_is_const(t2)) {
/* Fold eqv r,x,i to xor r,x,~i. */
switch (ctx->type) {
case TCG_TYPE_I32:
case TCG_TYPE_I64:
op->opc = INDEX_op_xor;
break;
case TCG_TYPE_V64:
case TCG_TYPE_V128:
case TCG_TYPE_V256:
op->opc = INDEX_op_xor_vec;
break;
default:
g_assert_not_reached();
}
op->args[2] = arg_new_constant(ctx, ~ti_const_val(t2));
return fold_xor(ctx, op);
}
t1 = arg_info(op->args[1]);
z_mask = (t1->z_mask | ~t2->o_mask) & (t2->z_mask | ~t1->o_mask);
o_mask = ~(t1->z_mask | t2->z_mask) | (t1->o_mask & t2->o_mask);
s_mask = t1->s_mask & t2->s_mask;
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_extract(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, a_mask;
TempOptInfo *t1 = arg_info(op->args[1]);
int pos = op->args[2];
int len = op->args[3];
if (ti_is_const(t1)) {
return tcg_opt_gen_movi(ctx, op, op->args[0],
extract64(ti_const_val(t1), pos, len));
}
z_mask = extract64(t1->z_mask, pos, len);
o_mask = extract64(t1->o_mask, pos, len);
a_mask = pos ? -1 : t1->z_mask ^ z_mask;
return fold_masks_zosa(ctx, op, z_mask, o_mask, 0, a_mask);
}
static bool fold_extract2(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t1 = arg_info(op->args[1]);
TempOptInfo *t2 = arg_info(op->args[2]);
uint64_t z1 = t1->z_mask;
uint64_t z2 = t2->z_mask;
uint64_t o1 = t1->o_mask;
uint64_t o2 = t2->o_mask;
int shr = op->args[3];
if (ctx->type == TCG_TYPE_I32) {
z1 = (uint32_t)z1 >> shr;
o1 = (uint32_t)o1 >> shr;
z2 = (uint64_t)((int32_t)z2 << (32 - shr));
o2 = (uint64_t)((int32_t)o2 << (32 - shr));
} else {
z1 >>= shr;
o1 >>= shr;
z2 <<= 64 - shr;
o2 <<= 64 - shr;
}
return fold_masks_zo(ctx, op, z1 | z2, o1 | o2);
}
static bool fold_exts(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *t1;
if (fold_const1(ctx, op)) {
return true;
}
t1 = arg_info(op->args[1]);
z_mask = t1->z_mask;
o_mask = t1->o_mask;
s_mask = t1->s_mask;
switch (op->opc) {
case INDEX_op_ext_i32_i64:
s_mask |= INT32_MIN;
z_mask = (int32_t)z_mask;
o_mask = (int32_t)o_mask;
break;
default:
g_assert_not_reached();
}
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_extu(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask;
TempOptInfo *t1;
if (fold_const1(ctx, op)) {
return true;
}
t1 = arg_info(op->args[1]);
z_mask = t1->z_mask;
o_mask = t1->o_mask;
switch (op->opc) {
case INDEX_op_extrl_i64_i32:
case INDEX_op_extu_i32_i64:
z_mask = (uint32_t)z_mask;
o_mask = (uint32_t)o_mask;
break;
case INDEX_op_extrh_i64_i32:
z_mask >>= 32;
o_mask >>= 32;
break;
default:
g_assert_not_reached();
}
return fold_masks_zo(ctx, op, z_mask, o_mask);
}
static bool fold_mb(OptContext *ctx, TCGOp *op)
{
/* Eliminate duplicate and redundant fence instructions. */
if (ctx->prev_mb) {
/*
* Merge two barriers of the same type into one,
* or a weaker barrier into a stronger one,
* or two weaker barriers into a stronger one.
* mb X; mb Y => mb X|Y
* mb; strl => mb; st
* ldaq; mb => ld; mb
* ldaq; strl => ld; mb; st
* Other combinations are also merged into a strong
* barrier. This is stricter than specified but for
* the purposes of TCG is better than not optimizing.
*/
ctx->prev_mb->args[0] |= op->args[0];
tcg_op_remove(ctx->tcg, op);
} else {
ctx->prev_mb = op;
}
return true;
}
static bool fold_mov(OptContext *ctx, TCGOp *op)
{
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
}
static bool fold_movcond(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *tt, *ft;
int i;
/* If true and false values are the same, eliminate the cmp. */
if (args_are_copies(op->args[3], op->args[4])) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[3]);
}
/*
* Canonicalize the "false" input reg to match the destination reg so
* that the tcg backend can implement a "move if true" operation.
*/
if (swap_commutative(op->args[0], &op->args[4], &op->args[3])) {
op->args[5] = tcg_invert_cond(op->args[5]);
}
i = do_constant_folding_cond1(ctx, op, NO_DEST, &op->args[1],
&op->args[2], &op->args[5]);
if (i >= 0) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[4 - i]);
}
tt = arg_info(op->args[3]);
ft = arg_info(op->args[4]);
z_mask = tt->z_mask | ft->z_mask;
o_mask = tt->o_mask & ft->o_mask;
s_mask = tt->s_mask & ft->s_mask;
if (ti_is_const(tt) && ti_is_const(ft)) {
uint64_t tv = ti_const_val(tt);
uint64_t fv = ti_const_val(ft);
TCGCond cond = op->args[5];
if (tv == 1 && fv == 0) {
op->opc = INDEX_op_setcond;
op->args[3] = cond;
} else if (fv == 1 && tv == 0) {
op->opc = INDEX_op_setcond;
op->args[3] = tcg_invert_cond(cond);
} else if (tv == -1 && fv == 0) {
op->opc = INDEX_op_negsetcond;
op->args[3] = cond;
} else if (fv == -1 && tv == 0) {
op->opc = INDEX_op_negsetcond;
op->args[3] = tcg_invert_cond(cond);
}
}
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_mul(OptContext *ctx, TCGOp *op)
{
if (fold_const2(ctx, op) ||
fold_xi_to_i(ctx, op, 0) ||
fold_xi_to_x(ctx, op, 1)) {
return true;
}
return finish_folding(ctx, op);
}
static bool fold_mul_highpart(OptContext *ctx, TCGOp *op)
{
if (fold_const2_commutative(ctx, op) ||
fold_xi_to_i(ctx, op, 0)) {
return true;
}
return finish_folding(ctx, op);
}
static bool fold_multiply2(OptContext *ctx, TCGOp *op)
{
swap_commutative(op->args[0], &op->args[2], &op->args[3]);
if (arg_is_const(op->args[2]) && arg_is_const(op->args[3])) {
uint64_t a = arg_const_val(op->args[2]);
uint64_t b = arg_const_val(op->args[3]);
uint64_t h, l;
TCGArg rl, rh;
TCGOp *op2;
switch (op->opc) {
case INDEX_op_mulu2:
if (ctx->type == TCG_TYPE_I32) {
l = (uint64_t)(uint32_t)a * (uint32_t)b;
h = (int32_t)(l >> 32);
l = (int32_t)l;
} else {
mulu64(&l, &h, a, b);
}
break;
case INDEX_op_muls2:
if (ctx->type == TCG_TYPE_I32) {
l = (int64_t)(int32_t)a * (int32_t)b;
h = l >> 32;
l = (int32_t)l;
} else {
muls64(&l, &h, a, b);
}
break;
default:
g_assert_not_reached();
}
rl = op->args[0];
rh = op->args[1];
/* The proper opcode is supplied by tcg_opt_gen_mov. */
op2 = opt_insert_before(ctx, op, 0, 2);
tcg_opt_gen_movi(ctx, op, rl, l);
tcg_opt_gen_movi(ctx, op2, rh, h);
return true;
}
return finish_folding(ctx, op);
}
static bool fold_nand(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *t1, *t2;
if (fold_const2_commutative(ctx, op) ||
fold_xi_to_not(ctx, op, -1)) {
return true;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
z_mask = ~(t1->o_mask & t2->o_mask);
o_mask = ~(t1->z_mask & t2->z_mask);
s_mask = t1->s_mask & t2->s_mask;
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_neg_no_const(OptContext *ctx, TCGOp *op)
{
/* Set to 1 all bits to the left of the rightmost. */
uint64_t z_mask = arg_info(op->args[1])->z_mask;
z_mask = -(z_mask & -z_mask);
return fold_masks_z(ctx, op, z_mask);
}
static bool fold_neg(OptContext *ctx, TCGOp *op)
{
return fold_const1(ctx, op) || fold_neg_no_const(ctx, op);
}
static bool fold_nor(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *t1, *t2;
if (fold_const2_commutative(ctx, op) ||
fold_xi_to_not(ctx, op, 0)) {
return true;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
z_mask = ~(t1->o_mask | t2->o_mask);
o_mask = ~(t1->z_mask | t2->z_mask);
s_mask = t1->s_mask & t2->s_mask;
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
static bool fold_not(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t1;
if (fold_const1(ctx, op)) {
return true;
}
t1 = arg_info(op->args[1]);
return fold_masks_zos(ctx, op, ~t1->o_mask, ~t1->z_mask, t1->s_mask);
}
static bool fold_or(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask, a_mask;
TempOptInfo *t1, *t2;
if (fold_const2_commutative(ctx, op) ||
fold_xi_to_x(ctx, op, 0) ||
fold_xx_to_x(ctx, op)) {
return true;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
z_mask = t1->z_mask | t2->z_mask;
o_mask = t1->o_mask | t2->o_mask;
s_mask = t1->s_mask & t2->s_mask;
/* Affected bits are those not known one, masked by those known zero. */
a_mask = ~t1->o_mask & t2->z_mask;
return fold_masks_zosa(ctx, op, z_mask, o_mask, s_mask, a_mask);
}
static bool fold_orc(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask, a_mask;
TempOptInfo *t1, *t2;
if (fold_const2(ctx, op) ||
fold_xx_to_i(ctx, op, -1) ||
fold_xi_to_x(ctx, op, -1) ||
fold_ix_to_not(ctx, op, 0)) {
return true;
}
t2 = arg_info(op->args[2]);
if (ti_is_const(t2)) {
/* Fold orc r,x,i to or r,x,~i. */
switch (ctx->type) {
case TCG_TYPE_I32:
case TCG_TYPE_I64:
op->opc = INDEX_op_or;
break;
case TCG_TYPE_V64:
case TCG_TYPE_V128:
case TCG_TYPE_V256:
op->opc = INDEX_op_or_vec;
break;
default:
g_assert_not_reached();
}
op->args[2] = arg_new_constant(ctx, ~ti_const_val(t2));
return fold_or(ctx, op);
}
t1 = arg_info(op->args[1]);
z_mask = t1->z_mask | ~t2->o_mask;
o_mask = t1->o_mask | ~t2->z_mask;
s_mask = t1->s_mask & t2->s_mask;
/* Affected bits are those not known one, masked by those known one. */
a_mask = ~t1->o_mask & t2->o_mask;
return fold_masks_zosa(ctx, op, z_mask, o_mask, s_mask, a_mask);
}
static bool fold_qemu_ld_1reg(OptContext *ctx, TCGOp *op)
{
const TCGOpDef *def = &tcg_op_defs[op->opc];
MemOpIdx oi = op->args[def->nb_oargs + def->nb_iargs];
MemOp mop = get_memop(oi);
int width = 8 * memop_size(mop);
uint64_t z_mask = -1, s_mask = 0;
if (width < 64) {
if (mop & MO_SIGN) {
s_mask = MAKE_64BIT_MASK(width - 1, 64 - (width - 1));
} else {
z_mask = MAKE_64BIT_MASK(0, width);
}
}
/* Opcodes that touch guest memory stop the mb optimization. */
ctx->prev_mb = NULL;
return fold_masks_zs(ctx, op, z_mask, s_mask);
}
static bool fold_qemu_ld_2reg(OptContext *ctx, TCGOp *op)
{
/* Opcodes that touch guest memory stop the mb optimization. */
ctx->prev_mb = NULL;
return finish_folding(ctx, op);
}
static bool fold_qemu_st(OptContext *ctx, TCGOp *op)
{
/* Opcodes that touch guest memory stop the mb optimization. */
ctx->prev_mb = NULL;
return true;
}
static bool fold_remainder(OptContext *ctx, TCGOp *op)
{
if (fold_const2(ctx, op) ||
fold_xx_to_i(ctx, op, 0)) {
return true;
}
return finish_folding(ctx, op);
}
/* Return 1 if finished, -1 if simplified, 0 if unchanged. */
static int fold_setcond_zmask(OptContext *ctx, TCGOp *op, bool neg)
{
uint64_t a_zmask, b_val;
TCGCond cond;
if (!arg_is_const(op->args[2])) {
return false;
}
a_zmask = arg_info(op->args[1])->z_mask;
b_val = arg_const_val(op->args[2]);
cond = op->args[3];
if (ctx->type == TCG_TYPE_I32) {
a_zmask = (uint32_t)a_zmask;
b_val = (uint32_t)b_val;
}
/*
* A with only low bits set vs B with high bits set means that A < B.
*/
if (a_zmask < b_val) {
bool inv = false;
switch (cond) {
case TCG_COND_NE:
case TCG_COND_LEU:
case TCG_COND_LTU:
inv = true;
/* fall through */
case TCG_COND_GTU:
case TCG_COND_GEU:
case TCG_COND_EQ:
return tcg_opt_gen_movi(ctx, op, op->args[0], neg ? -inv : inv);
default:
break;
}
}
/*
* A with only lsb set is already boolean.
*/
if (a_zmask <= 1) {
bool convert = false;
bool inv = false;
switch (cond) {
case TCG_COND_EQ:
inv = true;
/* fall through */
case TCG_COND_NE:
convert = (b_val == 0);
break;
case TCG_COND_LTU:
case TCG_COND_TSTEQ:
inv = true;
/* fall through */
case TCG_COND_GEU:
case TCG_COND_TSTNE:
convert = (b_val == 1);
break;
default:
break;
}
if (convert) {
if (!inv && !neg) {
return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
}
if (!inv) {
op->opc = INDEX_op_neg;
} else if (neg) {
op->opc = INDEX_op_add;
op->args[2] = arg_new_constant(ctx, -1);
} else {
op->opc = INDEX_op_xor;
op->args[2] = arg_new_constant(ctx, 1);
}
return -1;
}
}
return 0;
}
static void fold_setcond_tst_pow2(OptContext *ctx, TCGOp *op, bool neg)
{
TCGCond cond = op->args[3];
TCGArg ret, src1, src2;
TCGOp *op2;
uint64_t val;
int sh;
bool inv;
if (!is_tst_cond(cond) || !arg_is_const(op->args[2])) {
return;
}
src2 = op->args[2];
val = arg_const_val(src2);
if (!is_power_of_2(val)) {
return;
}
sh = ctz64(val);
ret = op->args[0];
src1 = op->args[1];
inv = cond == TCG_COND_TSTEQ;
if (sh && neg && !inv && TCG_TARGET_sextract_valid(ctx->type, sh, 1)) {
op->opc = INDEX_op_sextract;
op->args[1] = src1;
op->args[2] = sh;
op->args[3] = 1;
return;
} else if (sh && TCG_TARGET_extract_valid(ctx->type, sh, 1)) {
op->opc = INDEX_op_extract;
op->args[1] = src1;
op->args[2] = sh;
op->args[3] = 1;
} else {
if (sh) {
op2 = opt_insert_before(ctx, op, INDEX_op_shr, 3);
op2->args[0] = ret;
op2->args[1] = src1;
op2->args[2] = arg_new_constant(ctx, sh);
src1 = ret;
}
op->opc = INDEX_op_and;
op->args[1] = src1;
op->args[2] = arg_new_constant(ctx, 1);
}
if (neg && inv) {
op2 = opt_insert_after(ctx, op, INDEX_op_add, 3);
op2->args[0] = ret;
op2->args[1] = ret;
op2->args[2] = arg_new_constant(ctx, -1);
} else if (inv) {
op2 = opt_insert_after(ctx, op, INDEX_op_xor, 3);
op2->args[0] = ret;
op2->args[1] = ret;
op2->args[2] = arg_new_constant(ctx, 1);
} else if (neg) {
op2 = opt_insert_after(ctx, op, INDEX_op_neg, 2);
op2->args[0] = ret;
op2->args[1] = ret;
}
}
static bool fold_setcond(OptContext *ctx, TCGOp *op)
{
int i = do_constant_folding_cond1(ctx, op, op->args[0], &op->args[1],
&op->args[2], &op->args[3]);
if (i >= 0) {
return tcg_opt_gen_movi(ctx, op, op->args[0], i);
}
i = fold_setcond_zmask(ctx, op, false);
if (i > 0) {
return true;
}
if (i == 0) {
fold_setcond_tst_pow2(ctx, op, false);
}
return fold_masks_z(ctx, op, 1);
}
static bool fold_negsetcond(OptContext *ctx, TCGOp *op)
{
int i = do_constant_folding_cond1(ctx, op, op->args[0], &op->args[1],
&op->args[2], &op->args[3]);
if (i >= 0) {
return tcg_opt_gen_movi(ctx, op, op->args[0], -i);
}
i = fold_setcond_zmask(ctx, op, true);
if (i > 0) {
return true;
}
if (i == 0) {
fold_setcond_tst_pow2(ctx, op, true);
}
/* Value is {0,-1} so all bits are repetitions of the sign. */
return fold_masks_s(ctx, op, -1);
}
static bool fold_setcond2(OptContext *ctx, TCGOp *op)
{
TCGCond cond;
int i, inv = 0;
i = do_constant_folding_cond2(ctx, op, &op->args[1]);
cond = op->args[5];
if (i >= 0) {
goto do_setcond_const;
}
switch (cond) {
case TCG_COND_LT:
case TCG_COND_GE:
/*
* Simplify LT/GE comparisons vs zero to a single compare
* vs the high word of the input.
*/
if (arg_is_const_val(op->args[3], 0) &&
arg_is_const_val(op->args[4], 0)) {
goto do_setcond_high;
}
break;
case TCG_COND_NE:
inv = 1;
QEMU_FALLTHROUGH;
case TCG_COND_EQ:
/*
* Simplify EQ/NE comparisons where one of the pairs
* can be simplified.
*/
i = do_constant_folding_cond(TCG_TYPE_I32, op->args[1],
op->args[3], cond);
switch (i ^ inv) {
case 0:
goto do_setcond_const;
case 1:
goto do_setcond_high;
}
i = do_constant_folding_cond(TCG_TYPE_I32, op->args[2],
op->args[4], cond);
switch (i ^ inv) {
case 0:
goto do_setcond_const;
case 1:
goto do_setcond_low;
}
break;
case TCG_COND_TSTEQ:
case TCG_COND_TSTNE:
if (arg_is_const_val(op->args[3], 0)) {
goto do_setcond_high;
}
if (arg_is_const_val(op->args[4], 0)) {
goto do_setcond_low;
}
break;
default:
break;
do_setcond_low:
op->args[2] = op->args[3];
op->args[3] = cond;
op->opc = INDEX_op_setcond;
return fold_setcond(ctx, op);
do_setcond_high:
op->args[1] = op->args[2];
op->args[2] = op->args[4];
op->args[3] = cond;
op->opc = INDEX_op_setcond;
return fold_setcond(ctx, op);
}
return fold_masks_z(ctx, op, 1);
do_setcond_const:
return tcg_opt_gen_movi(ctx, op, op->args[0], i);
}
static bool fold_sextract(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask, a_mask;
TempOptInfo *t1 = arg_info(op->args[1]);
int pos = op->args[2];
int len = op->args[3];
if (ti_is_const(t1)) {
return tcg_opt_gen_movi(ctx, op, op->args[0],
sextract64(ti_const_val(t1), pos, len));
}
s_mask = t1->s_mask >> pos;
s_mask |= -1ull << (len - 1);
a_mask = pos ? -1 : s_mask & ~t1->s_mask;
z_mask = sextract64(t1->z_mask, pos, len);
o_mask = sextract64(t1->o_mask, pos, len);
return fold_masks_zosa(ctx, op, z_mask, o_mask, s_mask, a_mask);
}
static bool fold_shift(OptContext *ctx, TCGOp *op)
{
uint64_t s_mask, z_mask, o_mask;
TempOptInfo *t1, *t2;
if (fold_const2(ctx, op) ||
fold_ix_to_i(ctx, op, 0) ||
fold_xi_to_x(ctx, op, 0)) {
return true;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
s_mask = t1->s_mask;
z_mask = t1->z_mask;
o_mask = t1->o_mask;
if (ti_is_const(t2)) {
int sh = ti_const_val(t2);
z_mask = do_constant_folding(op->opc, ctx->type, z_mask, sh);
o_mask = do_constant_folding(op->opc, ctx->type, o_mask, sh);
s_mask = do_constant_folding(op->opc, ctx->type, s_mask, sh);
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
switch (op->opc) {
case INDEX_op_sar:
/*
* Arithmetic right shift will not reduce the number of
* input sign repetitions.
*/
return fold_masks_s(ctx, op, s_mask);
case INDEX_op_shr:
/*
* If the sign bit is known zero, then logical right shift
* will not reduce the number of input sign repetitions.
*/
if (~z_mask & -s_mask) {
return fold_masks_s(ctx, op, s_mask);
}
break;
default:
break;
}
return finish_folding(ctx, op);
}
static bool fold_sub_to_neg(OptContext *ctx, TCGOp *op)
{
TCGOpcode neg_op;
bool have_neg;
if (!arg_is_const_val(op->args[1], 0)) {
return false;
}
switch (ctx->type) {
case TCG_TYPE_I32:
case TCG_TYPE_I64:
neg_op = INDEX_op_neg;
have_neg = true;
break;
case TCG_TYPE_V64:
case TCG_TYPE_V128:
case TCG_TYPE_V256:
neg_op = INDEX_op_neg_vec;
have_neg = (TCG_TARGET_HAS_neg_vec &&
tcg_can_emit_vec_op(neg_op, ctx->type, TCGOP_VECE(op)) > 0);
break;
default:
g_assert_not_reached();
}
if (have_neg) {
op->opc = neg_op;
op->args[1] = op->args[2];
return fold_neg_no_const(ctx, op);
}
return false;
}
/* We cannot as yet do_constant_folding with vectors. */
static bool fold_sub_vec(OptContext *ctx, TCGOp *op)
{
if (fold_xx_to_i(ctx, op, 0) ||
fold_xi_to_x(ctx, op, 0) ||
fold_sub_to_neg(ctx, op)) {
return true;
}
return finish_folding(ctx, op);
}
static bool fold_sub(OptContext *ctx, TCGOp *op)
{
if (fold_const2(ctx, op) ||
fold_xx_to_i(ctx, op, 0) ||
fold_xi_to_x(ctx, op, 0) ||
fold_sub_to_neg(ctx, op)) {
return true;
}
/* Fold sub r,x,i to add r,x,-i */
if (arg_is_const(op->args[2])) {
uint64_t val = arg_const_val(op->args[2]);
op->opc = INDEX_op_add;
op->args[2] = arg_new_constant(ctx, -val);
}
return finish_folding(ctx, op);
}
static void squash_prev_borrowout(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t2;
op = QTAILQ_PREV(op, link);
switch (op->opc) {
case INDEX_op_subbo:
op->opc = INDEX_op_sub;
fold_sub(ctx, op);
break;
case INDEX_op_subbio:
op->opc = INDEX_op_subbi;
break;
case INDEX_op_subb1o:
t2 = arg_info(op->args[2]);
if (ti_is_const(t2)) {
op->opc = INDEX_op_add;
op->args[2] = arg_new_constant(ctx, -(ti_const_val(t2) + 1));
/* Perform other constant folding, if needed. */
fold_add(ctx, op);
} else {
TCGArg ret = op->args[0];
op->opc = INDEX_op_sub;
op = opt_insert_after(ctx, op, INDEX_op_add, 3);
op->args[0] = ret;
op->args[1] = ret;
op->args[2] = arg_new_constant(ctx, -1);
}
break;
default:
g_assert_not_reached();
}
}
static bool fold_subbi(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t2;
int borrow_in = ctx->carry_state;
if (borrow_in < 0) {
return finish_folding(ctx, op);
}
ctx->carry_state = -1;
squash_prev_borrowout(ctx, op);
if (borrow_in == 0) {
op->opc = INDEX_op_sub;
return fold_sub(ctx, op);
}
/*
* Propagate the known carry-in into any constant, then negate to
* transform from sub to add. If there is no constant, emit a
* separate add -1.
*/
t2 = arg_info(op->args[2]);
if (ti_is_const(t2)) {
op->args[2] = arg_new_constant(ctx, -(ti_const_val(t2) + 1));
} else {
TCGOp *op2 = opt_insert_before(ctx, op, INDEX_op_sub, 3);
op2->args[0] = op->args[0];
op2->args[1] = op->args[1];
op2->args[2] = op->args[2];
fold_sub(ctx, op2);
op->args[1] = op->args[0];
op->args[2] = arg_new_constant(ctx, -1);
}
op->opc = INDEX_op_add;
return fold_add(ctx, op);
}
static bool fold_subbio(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t1, *t2;
int borrow_out = -1;
if (ctx->carry_state < 0) {
return finish_folding(ctx, op);
}
squash_prev_borrowout(ctx, op);
if (ctx->carry_state == 0) {
goto do_subbo;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
/* Propagate the known borrow-in into a constant, if possible. */
if (ti_is_const(t2)) {
uint64_t max = ctx->type == TCG_TYPE_I32 ? UINT32_MAX : UINT64_MAX;
uint64_t v = ti_const_val(t2) & max;
if (v < max) {
op->args[2] = arg_new_constant(ctx, v + 1);
goto do_subbo;
}
/* subtracting max + 1 produces known borrow out. */
borrow_out = 1;
}
if (ti_is_const(t1)) {
uint64_t v = ti_const_val(t1);
if (v != 0) {
op->args[2] = arg_new_constant(ctx, v - 1);
goto do_subbo;
}
}
/* Adjust the opcode to remember the known carry-in. */
op->opc = INDEX_op_subb1o;
ctx->carry_state = borrow_out;
return finish_folding(ctx, op);
do_subbo:
op->opc = INDEX_op_subbo;
return fold_subbo(ctx, op);
}
static bool fold_subbo(OptContext *ctx, TCGOp *op)
{
TempOptInfo *t1 = arg_info(op->args[1]);
TempOptInfo *t2 = arg_info(op->args[2]);
int borrow_out = -1;
if (ti_is_const(t2)) {
uint64_t v2 = ti_const_val(t2);
if (v2 == 0) {
borrow_out = 0;
} else if (ti_is_const(t1)) {
uint64_t v1 = ti_const_val(t1);
borrow_out = v1 < v2;
}
}
ctx->carry_state = borrow_out;
return finish_folding(ctx, op);
}
static bool fold_tcg_ld(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask = -1, s_mask = 0;
/* We can't do any folding with a load, but we can record bits. */
switch (op->opc) {
case INDEX_op_ld8s:
s_mask = INT8_MIN;
break;
case INDEX_op_ld8u:
z_mask = MAKE_64BIT_MASK(0, 8);
break;
case INDEX_op_ld16s:
s_mask = INT16_MIN;
break;
case INDEX_op_ld16u:
z_mask = MAKE_64BIT_MASK(0, 16);
break;
case INDEX_op_ld32s:
s_mask = INT32_MIN;
break;
case INDEX_op_ld32u:
z_mask = MAKE_64BIT_MASK(0, 32);
break;
default:
g_assert_not_reached();
}
return fold_masks_zs(ctx, op, z_mask, s_mask);
}
static bool fold_tcg_ld_memcopy(OptContext *ctx, TCGOp *op)
{
TCGTemp *dst, *src;
intptr_t ofs;
TCGType type;
if (op->args[1] != tcgv_ptr_arg(tcg_env)) {
return finish_folding(ctx, op);
}
type = ctx->type;
ofs = op->args[2];
dst = arg_temp(op->args[0]);
src = find_mem_copy_for(ctx, type, ofs);
if (src && src->base_type == type) {
return tcg_opt_gen_mov(ctx, op, temp_arg(dst), temp_arg(src));
}
reset_ts(ctx, dst);
record_mem_copy(ctx, type, dst, ofs, ofs + tcg_type_size(type) - 1);
return true;
}
static bool fold_tcg_st(OptContext *ctx, TCGOp *op)
{
intptr_t ofs = op->args[2];
intptr_t lm1;
if (op->args[1] != tcgv_ptr_arg(tcg_env)) {
remove_mem_copy_all(ctx);
return true;
}
switch (op->opc) {
case INDEX_op_st8:
lm1 = 0;
break;
case INDEX_op_st16:
lm1 = 1;
break;
case INDEX_op_st32:
lm1 = 3;
break;
case INDEX_op_st:
case INDEX_op_st_vec:
lm1 = tcg_type_size(ctx->type) - 1;
break;
default:
g_assert_not_reached();
}
remove_mem_copy_in(ctx, ofs, ofs + lm1);
return true;
}
static bool fold_tcg_st_memcopy(OptContext *ctx, TCGOp *op)
{
TCGTemp *src;
intptr_t ofs, last;
TCGType type;
if (op->args[1] != tcgv_ptr_arg(tcg_env)) {
return fold_tcg_st(ctx, op);
}
src = arg_temp(op->args[0]);
ofs = op->args[2];
type = ctx->type;
/*
* Eliminate duplicate stores of a constant.
* This happens frequently when the target ISA zero-extends.
*/
if (ts_is_const(src)) {
TCGTemp *prev = find_mem_copy_for(ctx, type, ofs);
if (src == prev) {
tcg_op_remove(ctx->tcg, op);
return true;
}
}
last = ofs + tcg_type_size(type) - 1;
remove_mem_copy_in(ctx, ofs, last);
record_mem_copy(ctx, type, src, ofs, last);
return true;
}
static bool fold_xor(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, o_mask, s_mask;
TempOptInfo *t1, *t2;
if (fold_const2_commutative(ctx, op) ||
fold_xx_to_i(ctx, op, 0) ||
fold_xi_to_x(ctx, op, 0) ||
fold_xi_to_not(ctx, op, -1)) {
return true;
}
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
z_mask = (t1->z_mask | t2->z_mask) & ~(t1->o_mask & t2->o_mask);
o_mask = (t1->o_mask & ~t2->z_mask) | (t2->o_mask & ~t1->z_mask);
s_mask = t1->s_mask & t2->s_mask;
return fold_masks_zos(ctx, op, z_mask, o_mask, s_mask);
}
/* Propagate constants and copies, fold constant expressions. */
void tcg_optimize(TCGContext *s)
{
int nb_temps, i;
TCGOp *op, *op_next;
OptContext ctx = { .tcg = s };
QSIMPLEQ_INIT(&ctx.mem_free);
/* Array VALS has an element for each temp.
If this temp holds a constant then its value is kept in VALS' element.
If this temp is a copy of other ones then the other copies are
available through the doubly linked circular list. */
nb_temps = s->nb_temps;
for (i = 0; i < nb_temps; ++i) {
s->temps[i].state_ptr = NULL;
}
QTAILQ_FOREACH_SAFE(op, &s->ops, link, op_next) {
TCGOpcode opc = op->opc;
const TCGOpDef *def;
bool done = false;
/* Calls are special. */
if (opc == INDEX_op_call) {
fold_call(&ctx, op);
continue;
}
def = &tcg_op_defs[opc];
init_arguments(&ctx, op, def->nb_oargs + def->nb_iargs);
copy_propagate(&ctx, op, def->nb_oargs, def->nb_iargs);
/* Pre-compute the type of the operation. */
ctx.type = TCGOP_TYPE(op);
/*
* Process each opcode.
* Sorted alphabetically by opcode as much as possible.
*/
switch (opc) {
case INDEX_op_add:
done = fold_add(&ctx, op);
break;
case INDEX_op_add_vec:
done = fold_add_vec(&ctx, op);
break;
case INDEX_op_addci:
done = fold_addci(&ctx, op);
break;
case INDEX_op_addcio:
done = fold_addcio(&ctx, op);
break;
case INDEX_op_addco:
done = fold_addco(&ctx, op);
break;
case INDEX_op_and:
case INDEX_op_and_vec:
done = fold_and(&ctx, op);
break;
case INDEX_op_andc:
case INDEX_op_andc_vec:
done = fold_andc(&ctx, op);
break;
case INDEX_op_brcond:
done = fold_brcond(&ctx, op);
break;
case INDEX_op_brcond2_i32:
done = fold_brcond2(&ctx, op);
break;
case INDEX_op_bswap16:
case INDEX_op_bswap32:
case INDEX_op_bswap64:
done = fold_bswap(&ctx, op);
break;
case INDEX_op_clz:
case INDEX_op_ctz:
done = fold_count_zeros(&ctx, op);
break;
case INDEX_op_ctpop:
done = fold_ctpop(&ctx, op);
break;
case INDEX_op_deposit:
done = fold_deposit(&ctx, op);
break;
case INDEX_op_divs:
case INDEX_op_divu:
done = fold_divide(&ctx, op);
break;
case INDEX_op_dup_vec:
done = fold_dup(&ctx, op);
break;
case INDEX_op_dup2_vec:
done = fold_dup2(&ctx, op);
break;
case INDEX_op_eqv:
case INDEX_op_eqv_vec:
done = fold_eqv(&ctx, op);
break;
case INDEX_op_extract:
done = fold_extract(&ctx, op);
break;
case INDEX_op_extract2:
done = fold_extract2(&ctx, op);
break;
case INDEX_op_ext_i32_i64:
done = fold_exts(&ctx, op);
break;
case INDEX_op_extu_i32_i64:
case INDEX_op_extrl_i64_i32:
case INDEX_op_extrh_i64_i32:
done = fold_extu(&ctx, op);
break;
case INDEX_op_ld8s:
case INDEX_op_ld8u:
case INDEX_op_ld16s:
case INDEX_op_ld16u:
case INDEX_op_ld32s:
case INDEX_op_ld32u:
done = fold_tcg_ld(&ctx, op);
break;
case INDEX_op_ld:
case INDEX_op_ld_vec:
done = fold_tcg_ld_memcopy(&ctx, op);
break;
case INDEX_op_st8:
case INDEX_op_st16:
case INDEX_op_st32:
done = fold_tcg_st(&ctx, op);
break;
case INDEX_op_st:
case INDEX_op_st_vec:
done = fold_tcg_st_memcopy(&ctx, op);
break;
case INDEX_op_mb:
done = fold_mb(&ctx, op);
break;
case INDEX_op_mov:
case INDEX_op_mov_vec:
done = fold_mov(&ctx, op);
break;
case INDEX_op_movcond:
done = fold_movcond(&ctx, op);
break;
case INDEX_op_mul:
done = fold_mul(&ctx, op);
break;
case INDEX_op_mulsh:
case INDEX_op_muluh:
done = fold_mul_highpart(&ctx, op);
break;
case INDEX_op_muls2:
case INDEX_op_mulu2:
done = fold_multiply2(&ctx, op);
break;
case INDEX_op_nand:
case INDEX_op_nand_vec:
done = fold_nand(&ctx, op);
break;
case INDEX_op_neg:
done = fold_neg(&ctx, op);
break;
case INDEX_op_nor:
case INDEX_op_nor_vec:
done = fold_nor(&ctx, op);
break;
case INDEX_op_not:
case INDEX_op_not_vec:
done = fold_not(&ctx, op);
break;
case INDEX_op_or:
case INDEX_op_or_vec:
done = fold_or(&ctx, op);
break;
case INDEX_op_orc:
case INDEX_op_orc_vec:
done = fold_orc(&ctx, op);
break;
case INDEX_op_qemu_ld:
done = fold_qemu_ld_1reg(&ctx, op);
break;
case INDEX_op_qemu_ld2:
done = fold_qemu_ld_2reg(&ctx, op);
break;
case INDEX_op_qemu_st:
case INDEX_op_qemu_st2:
done = fold_qemu_st(&ctx, op);
break;
case INDEX_op_rems:
case INDEX_op_remu:
done = fold_remainder(&ctx, op);
break;
case INDEX_op_rotl:
case INDEX_op_rotr:
case INDEX_op_sar:
case INDEX_op_shl:
case INDEX_op_shr:
done = fold_shift(&ctx, op);
break;
case INDEX_op_setcond:
done = fold_setcond(&ctx, op);
break;
case INDEX_op_negsetcond:
done = fold_negsetcond(&ctx, op);
break;
case INDEX_op_setcond2_i32:
done = fold_setcond2(&ctx, op);
break;
case INDEX_op_cmp_vec:
done = fold_cmp_vec(&ctx, op);
break;
case INDEX_op_cmpsel_vec:
done = fold_cmpsel_vec(&ctx, op);
break;
case INDEX_op_bitsel_vec:
done = fold_bitsel_vec(&ctx, op);
break;
case INDEX_op_sextract:
done = fold_sextract(&ctx, op);
break;
case INDEX_op_sub:
done = fold_sub(&ctx, op);
break;
case INDEX_op_subbi:
done = fold_subbi(&ctx, op);
break;
case INDEX_op_subbio:
done = fold_subbio(&ctx, op);
break;
case INDEX_op_subbo:
done = fold_subbo(&ctx, op);
break;
case INDEX_op_sub_vec:
done = fold_sub_vec(&ctx, op);
break;
case INDEX_op_xor:
case INDEX_op_xor_vec:
done = fold_xor(&ctx, op);
break;
case INDEX_op_set_label:
case INDEX_op_br:
case INDEX_op_exit_tb:
case INDEX_op_goto_tb:
case INDEX_op_goto_ptr:
finish_ebb(&ctx);
done = true;
break;
default:
done = finish_folding(&ctx, op);
break;
}
tcg_debug_assert(done);
}
}