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tcg: Optimize double-word comparisons against zero

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Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Richard Henderson 2012-10-02 11:32:25 -07:00 committed by Aurelien Jarno
parent 6e14e91b66
commit bc1473eff4
1 changed files with 39 additions and 0 deletions
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39
tcg/optimize.c
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@ -752,6 +752,45 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
}
goto do_default;
case INDEX_op_brcond2_i32:
/* Simplify LT/GE comparisons vs zero to a single compare
vs the high word of the input. */
if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE)
&& temps[args[2]].state == TCG_TEMP_CONST
&& temps[args[3]].state == TCG_TEMP_CONST
&& temps[args[2]].val == 0
&& temps[args[3]].val == 0) {
gen_opc_buf[op_index] = INDEX_op_brcond_i32;
gen_args[0] = args[1];
gen_args[1] = args[3];
gen_args[2] = args[4];
gen_args[3] = args[5];
gen_args += 4;
args += 6;
memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
break;
}
goto do_default;
case INDEX_op_setcond2_i32:
/* Simplify LT/GE comparisons vs zero to a single compare
vs the high word of the input. */
if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE)
&& temps[args[3]].state == TCG_TEMP_CONST
&& temps[args[4]].state == TCG_TEMP_CONST
&& temps[args[3]].val == 0
&& temps[args[4]].val == 0) {
gen_opc_buf[op_index] = INDEX_op_setcond_i32;
gen_args[0] = args[0];
gen_args[1] = args[2];
gen_args[2] = args[4];
gen_args[3] = args[5];
gen_args += 4;
args += 6;
break;
}
goto do_default;
case INDEX_op_call:
nb_call_args = (args[0] >> 16) + (args[0] & 0xffff);
if (!(args[nb_call_args + 1] & (TCG_CALL_CONST | TCG_CALL_PURE))) {