tcg/optimize: Simply some logical ops to NOT

Given, of course, an appropriate constant.  These could be generated
from the "canonical" operation for inversion on the guest, or via
other optimizations.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2014-01-28 13:15:38 -08:00
parent 23ec69ed37
commit e201b56418

View File

@ -655,6 +655,63 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
}
}
break;
CASE_OP_32_64(xor):
CASE_OP_32_64(nand):
if (temps[args[1]].state != TCG_TEMP_CONST
&& temps[args[2]].state == TCG_TEMP_CONST
&& temps[args[2]].val == -1) {
i = 1;
goto try_not;
}
break;
CASE_OP_32_64(nor):
if (temps[args[1]].state != TCG_TEMP_CONST
&& temps[args[2]].state == TCG_TEMP_CONST
&& temps[args[2]].val == 0) {
i = 1;
goto try_not;
}
break;
CASE_OP_32_64(andc):
if (temps[args[2]].state != TCG_TEMP_CONST
&& temps[args[1]].state == TCG_TEMP_CONST
&& temps[args[1]].val == -1) {
i = 2;
goto try_not;
}
break;
CASE_OP_32_64(orc):
CASE_OP_32_64(eqv):
if (temps[args[2]].state != TCG_TEMP_CONST
&& temps[args[1]].state == TCG_TEMP_CONST
&& temps[args[1]].val == 0) {
i = 2;
goto try_not;
}
break;
try_not:
{
TCGOpcode not_op;
bool have_not;
if (def->flags & TCG_OPF_64BIT) {
not_op = INDEX_op_not_i64;
have_not = TCG_TARGET_HAS_not_i64;
} else {
not_op = INDEX_op_not_i32;
have_not = TCG_TARGET_HAS_not_i32;
}
if (!have_not) {
break;
}
s->gen_opc_buf[op_index] = not_op;
reset_temp(args[0]);
gen_args[0] = args[0];
gen_args[1] = args[i];
args += 3;
gen_args += 2;
continue;
}
default:
break;
}