tcg/optimize: Rename "mask" to "z_mask"

Prepare for tracking different masks by renaming this one.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-08-23 13:07:49 -07:00
parent 023462978a
commit b1fde411d0
1 changed files with 72 additions and 70 deletions

View File

@ -41,7 +41,7 @@ typedef struct TempOptInfo {
TCGTemp *prev_copy;
TCGTemp *next_copy;
uint64_t val;
uint64_t mask;
uint64_t z_mask; /* mask bit is 0 if and only if value bit is 0 */
} TempOptInfo;
static inline TempOptInfo *ts_info(TCGTemp *ts)
@ -81,7 +81,7 @@ static void reset_ts(TCGTemp *ts)
ti->next_copy = ts;
ti->prev_copy = ts;
ti->is_const = false;
ti->mask = -1;
ti->z_mask = -1;
}
static void reset_temp(TCGArg arg)
@ -111,14 +111,14 @@ static void init_ts_info(TCGTempSet *temps_used, TCGTemp *ts)
if (ts->kind == TEMP_CONST) {
ti->is_const = true;
ti->val = ts->val;
ti->mask = ts->val;
ti->z_mask = ts->val;
if (TCG_TARGET_REG_BITS > 32 && ts->type == TCG_TYPE_I32) {
/* High bits of a 32-bit quantity are garbage. */
ti->mask |= ~0xffffffffull;
ti->z_mask |= ~0xffffffffull;
}
} else {
ti->is_const = false;
ti->mask = -1;
ti->z_mask = -1;
}
}
@ -186,7 +186,7 @@ static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op, TCGArg dst, TCGArg src)
const TCGOpDef *def;
TempOptInfo *di;
TempOptInfo *si;
uint64_t mask;
uint64_t z_mask;
TCGOpcode new_op;
if (ts_are_copies(dst_ts, src_ts)) {
@ -210,12 +210,12 @@ static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op, TCGArg dst, TCGArg src)
op->args[0] = dst;
op->args[1] = src;
mask = si->mask;
z_mask = si->z_mask;
if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_mov_i32) {
/* High bits of the destination are now garbage. */
mask |= ~0xffffffffull;
z_mask |= ~0xffffffffull;
}
di->mask = mask;
di->z_mask = z_mask;
if (src_ts->type == dst_ts->type) {
TempOptInfo *ni = ts_info(si->next_copy);
@ -621,7 +621,7 @@ void tcg_optimize(TCGContext *s)
}
QTAILQ_FOREACH_SAFE(op, &s->ops, link, op_next) {
uint64_t mask, partmask, affected, tmp;
uint64_t z_mask, partmask, affected, tmp;
int nb_oargs, nb_iargs;
TCGOpcode opc = op->opc;
const TCGOpDef *def = &tcg_op_defs[opc];
@ -855,170 +855,172 @@ void tcg_optimize(TCGContext *s)
/* Simplify using known-zero bits. Currently only ops with a single
output argument is supported. */
mask = -1;
z_mask = -1;
affected = -1;
switch (opc) {
CASE_OP_32_64(ext8s):
if ((arg_info(op->args[1])->mask & 0x80) != 0) {
if ((arg_info(op->args[1])->z_mask & 0x80) != 0) {
break;
}
QEMU_FALLTHROUGH;
CASE_OP_32_64(ext8u):
mask = 0xff;
z_mask = 0xff;
goto and_const;
CASE_OP_32_64(ext16s):
if ((arg_info(op->args[1])->mask & 0x8000) != 0) {
if ((arg_info(op->args[1])->z_mask & 0x8000) != 0) {
break;
}
QEMU_FALLTHROUGH;
CASE_OP_32_64(ext16u):
mask = 0xffff;
z_mask = 0xffff;
goto and_const;
case INDEX_op_ext32s_i64:
if ((arg_info(op->args[1])->mask & 0x80000000) != 0) {
if ((arg_info(op->args[1])->z_mask & 0x80000000) != 0) {
break;
}
QEMU_FALLTHROUGH;
case INDEX_op_ext32u_i64:
mask = 0xffffffffU;
z_mask = 0xffffffffU;
goto and_const;
CASE_OP_32_64(and):
mask = arg_info(op->args[2])->mask;
z_mask = arg_info(op->args[2])->z_mask;
if (arg_is_const(op->args[2])) {
and_const:
affected = arg_info(op->args[1])->mask & ~mask;
affected = arg_info(op->args[1])->z_mask & ~z_mask;
}
mask = arg_info(op->args[1])->mask & mask;
z_mask = arg_info(op->args[1])->z_mask & z_mask;
break;
case INDEX_op_ext_i32_i64:
if ((arg_info(op->args[1])->mask & 0x80000000) != 0) {
if ((arg_info(op->args[1])->z_mask & 0x80000000) != 0) {
break;
}
QEMU_FALLTHROUGH;
case INDEX_op_extu_i32_i64:
/* We do not compute affected as it is a size changing op. */
mask = (uint32_t)arg_info(op->args[1])->mask;
z_mask = (uint32_t)arg_info(op->args[1])->z_mask;
break;
CASE_OP_32_64(andc):
/* Known-zeros does not imply known-ones. Therefore unless
op->args[2] is constant, we can't infer anything from it. */
if (arg_is_const(op->args[2])) {
mask = ~arg_info(op->args[2])->mask;
z_mask = ~arg_info(op->args[2])->z_mask;
goto and_const;
}
/* But we certainly know nothing outside args[1] may be set. */
mask = arg_info(op->args[1])->mask;
z_mask = arg_info(op->args[1])->z_mask;
break;
case INDEX_op_sar_i32:
if (arg_is_const(op->args[2])) {
tmp = arg_info(op->args[2])->val & 31;
mask = (int32_t)arg_info(op->args[1])->mask >> tmp;
z_mask = (int32_t)arg_info(op->args[1])->z_mask >> tmp;
}
break;
case INDEX_op_sar_i64:
if (arg_is_const(op->args[2])) {
tmp = arg_info(op->args[2])->val & 63;
mask = (int64_t)arg_info(op->args[1])->mask >> tmp;
z_mask = (int64_t)arg_info(op->args[1])->z_mask >> tmp;
}
break;
case INDEX_op_shr_i32:
if (arg_is_const(op->args[2])) {
tmp = arg_info(op->args[2])->val & 31;
mask = (uint32_t)arg_info(op->args[1])->mask >> tmp;
z_mask = (uint32_t)arg_info(op->args[1])->z_mask >> tmp;
}
break;
case INDEX_op_shr_i64:
if (arg_is_const(op->args[2])) {
tmp = arg_info(op->args[2])->val & 63;
mask = (uint64_t)arg_info(op->args[1])->mask >> tmp;
z_mask = (uint64_t)arg_info(op->args[1])->z_mask >> tmp;
}
break;
case INDEX_op_extrl_i64_i32:
mask = (uint32_t)arg_info(op->args[1])->mask;
z_mask = (uint32_t)arg_info(op->args[1])->z_mask;
break;
case INDEX_op_extrh_i64_i32:
mask = (uint64_t)arg_info(op->args[1])->mask >> 32;
z_mask = (uint64_t)arg_info(op->args[1])->z_mask >> 32;
break;
CASE_OP_32_64(shl):
if (arg_is_const(op->args[2])) {
tmp = arg_info(op->args[2])->val & (TCG_TARGET_REG_BITS - 1);
mask = arg_info(op->args[1])->mask << tmp;
z_mask = arg_info(op->args[1])->z_mask << tmp;
}
break;
CASE_OP_32_64(neg):
/* Set to 1 all bits to the left of the rightmost. */
mask = -(arg_info(op->args[1])->mask
& -arg_info(op->args[1])->mask);
z_mask = -(arg_info(op->args[1])->z_mask
& -arg_info(op->args[1])->z_mask);
break;
CASE_OP_32_64(deposit):
mask = deposit64(arg_info(op->args[1])->mask,
op->args[3], op->args[4],
arg_info(op->args[2])->mask);
z_mask = deposit64(arg_info(op->args[1])->z_mask,
op->args[3], op->args[4],
arg_info(op->args[2])->z_mask);
break;
CASE_OP_32_64(extract):
mask = extract64(arg_info(op->args[1])->mask,
op->args[2], op->args[3]);
z_mask = extract64(arg_info(op->args[1])->z_mask,
op->args[2], op->args[3]);
if (op->args[2] == 0) {
affected = arg_info(op->args[1])->mask & ~mask;
affected = arg_info(op->args[1])->z_mask & ~z_mask;
}
break;
CASE_OP_32_64(sextract):
mask = sextract64(arg_info(op->args[1])->mask,
op->args[2], op->args[3]);
if (op->args[2] == 0 && (tcg_target_long)mask >= 0) {
affected = arg_info(op->args[1])->mask & ~mask;
z_mask = sextract64(arg_info(op->args[1])->z_mask,
op->args[2], op->args[3]);
if (op->args[2] == 0 && (tcg_target_long)z_mask >= 0) {
affected = arg_info(op->args[1])->z_mask & ~z_mask;
}
break;
CASE_OP_32_64(or):
CASE_OP_32_64(xor):
mask = arg_info(op->args[1])->mask | arg_info(op->args[2])->mask;
z_mask = arg_info(op->args[1])->z_mask
| arg_info(op->args[2])->z_mask;
break;
case INDEX_op_clz_i32:
case INDEX_op_ctz_i32:
mask = arg_info(op->args[2])->mask | 31;
z_mask = arg_info(op->args[2])->z_mask | 31;
break;
case INDEX_op_clz_i64:
case INDEX_op_ctz_i64:
mask = arg_info(op->args[2])->mask | 63;
z_mask = arg_info(op->args[2])->z_mask | 63;
break;
case INDEX_op_ctpop_i32:
mask = 32 | 31;
z_mask = 32 | 31;
break;
case INDEX_op_ctpop_i64:
mask = 64 | 63;
z_mask = 64 | 63;
break;
CASE_OP_32_64(setcond):
case INDEX_op_setcond2_i32:
mask = 1;
z_mask = 1;
break;
CASE_OP_32_64(movcond):
mask = arg_info(op->args[3])->mask | arg_info(op->args[4])->mask;
z_mask = arg_info(op->args[3])->z_mask
| arg_info(op->args[4])->z_mask;
break;
CASE_OP_32_64(ld8u):
mask = 0xff;
z_mask = 0xff;
break;
CASE_OP_32_64(ld16u):
mask = 0xffff;
z_mask = 0xffff;
break;
case INDEX_op_ld32u_i64:
mask = 0xffffffffu;
z_mask = 0xffffffffu;
break;
CASE_OP_32_64(qemu_ld):
@ -1026,43 +1028,43 @@ void tcg_optimize(TCGContext *s)
MemOpIdx oi = op->args[nb_oargs + nb_iargs];
MemOp mop = get_memop(oi);
if (!(mop & MO_SIGN)) {
mask = (2ULL << ((8 << (mop & MO_SIZE)) - 1)) - 1;
z_mask = (2ULL << ((8 << (mop & MO_SIZE)) - 1)) - 1;
}
}
break;
CASE_OP_32_64(bswap16):
mask = arg_info(op->args[1])->mask;
if (mask <= 0xffff) {
z_mask = arg_info(op->args[1])->z_mask;
if (z_mask <= 0xffff) {
op->args[2] |= TCG_BSWAP_IZ;
}
mask = bswap16(mask);
z_mask = bswap16(z_mask);
switch (op->args[2] & (TCG_BSWAP_OZ | TCG_BSWAP_OS)) {
case TCG_BSWAP_OZ:
break;
case TCG_BSWAP_OS:
mask = (int16_t)mask;
z_mask = (int16_t)z_mask;
break;
default: /* undefined high bits */
mask |= MAKE_64BIT_MASK(16, 48);
z_mask |= MAKE_64BIT_MASK(16, 48);
break;
}
break;
case INDEX_op_bswap32_i64:
mask = arg_info(op->args[1])->mask;
if (mask <= 0xffffffffu) {
z_mask = arg_info(op->args[1])->z_mask;
if (z_mask <= 0xffffffffu) {
op->args[2] |= TCG_BSWAP_IZ;
}
mask = bswap32(mask);
z_mask = bswap32(z_mask);
switch (op->args[2] & (TCG_BSWAP_OZ | TCG_BSWAP_OS)) {
case TCG_BSWAP_OZ:
break;
case TCG_BSWAP_OS:
mask = (int32_t)mask;
z_mask = (int32_t)z_mask;
break;
default: /* undefined high bits */
mask |= MAKE_64BIT_MASK(32, 32);
z_mask |= MAKE_64BIT_MASK(32, 32);
break;
}
break;
@ -1074,9 +1076,9 @@ void tcg_optimize(TCGContext *s)
/* 32-bit ops generate 32-bit results. For the result is zero test
below, we can ignore high bits, but for further optimizations we
need to record that the high bits contain garbage. */
partmask = mask;
partmask = z_mask;
if (!(def->flags & TCG_OPF_64BIT)) {
mask |= ~(tcg_target_ulong)0xffffffffu;
z_mask |= ~(tcg_target_ulong)0xffffffffu;
partmask &= 0xffffffffu;
affected &= 0xffffffffu;
}
@ -1472,7 +1474,7 @@ void tcg_optimize(TCGContext *s)
vs the high word of the input. */
do_setcond_high:
reset_temp(op->args[0]);
arg_info(op->args[0])->mask = 1;
arg_info(op->args[0])->z_mask = 1;
op->opc = INDEX_op_setcond_i32;
op->args[1] = op->args[2];
op->args[2] = op->args[4];
@ -1498,7 +1500,7 @@ void tcg_optimize(TCGContext *s)
}
do_setcond_low:
reset_temp(op->args[0]);
arg_info(op->args[0])->mask = 1;
arg_info(op->args[0])->z_mask = 1;
op->opc = INDEX_op_setcond_i32;
op->args[2] = op->args[3];
op->args[3] = op->args[5];
@ -1543,7 +1545,7 @@ void tcg_optimize(TCGContext *s)
/* Default case: we know nothing about operation (or were unable
to compute the operation result) so no propagation is done.
We trash everything if the operation is the end of a basic
block, otherwise we only trash the output args. "mask" is
block, otherwise we only trash the output args. "z_mask" is
the non-zero bits mask for the first output arg. */
if (def->flags & TCG_OPF_BB_END) {
memset(&temps_used, 0, sizeof(temps_used));
@ -1554,7 +1556,7 @@ void tcg_optimize(TCGContext *s)
/* Save the corresponding known-zero bits mask for the
first output argument (only one supported so far). */
if (i == 0) {
arg_info(op->args[i])->mask = mask;
arg_info(op->args[i])->z_mask = z_mask;
}
}
}