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tcg: Constant fold add2 and sub2

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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 11:32:28 -07:00 • committed by Aurelien Jarno
parent 6c4382f8f4
commit 212c328d61
2 changed files with 44 additions and 0 deletions
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35
tcg/optimize.c
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@ -796,6 +796,41 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
}
goto do_default;
case INDEX_op_add2_i32:
case INDEX_op_sub2_i32:
if (temps[args[2]].state == TCG_TEMP_CONST
&& temps[args[3]].state == TCG_TEMP_CONST
&& temps[args[4]].state == TCG_TEMP_CONST
&& temps[args[5]].state == TCG_TEMP_CONST) {
uint32_t al = temps[args[2]].val;
uint32_t ah = temps[args[3]].val;
uint32_t bl = temps[args[4]].val;
uint32_t bh = temps[args[5]].val;
uint64_t a = ((uint64_t)ah << 32) | al;
uint64_t b = ((uint64_t)bh << 32) | bl;
TCGArg rl, rh;
if (op == INDEX_op_add2_i32) {
a += b;
} else {
a -= b;
}
/* We emit the extra nop when we emit the add2/sub2. */
assert(gen_opc_buf[op_index + 1] == INDEX_op_nop);
rl = args[0];
rh = args[1];
gen_opc_buf[op_index] = INDEX_op_movi_i32;
gen_opc_buf[++op_index] = INDEX_op_movi_i32;
tcg_opt_gen_movi(&gen_args[0], rl, (uint32_t)a);
tcg_opt_gen_movi(&gen_args[2], rh, (uint32_t)(a >> 32));
gen_args += 4;
args += 6;
break;
}
goto do_default;
case INDEX_op_brcond2_i32:
tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]);
if (tmp != 2) {