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target-i386: emulate LOCK'ed NEG using cmpxchg helper 

[rth: Move redundant qemu_load out of cmpxchg loop.]

Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1467054136-10430-16-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Emilio G. Cota 2016-06-27 15:02:01 -04:00 committed by Richard Henderson
parent 2a5fe8ae14
commit 8eb8c73856
1 changed files with 34 additions and 4 deletions
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38
target-i386/translate.c
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@ -4712,11 +4712,41 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
}
break;
case 3: /* neg */
tcg_gen_neg_tl(cpu_T0, cpu_T0);
if (mod != 3) {
gen_op_st_v(s, ot, cpu_T0, cpu_A0);
if (s->prefix & PREFIX_LOCK) {
TCGLabel *label1;
TCGv a0, t0, t1, t2;
if (mod == 3) {
goto illegal_op;
}
a0 = tcg_temp_local_new();
t0 = tcg_temp_local_new();
label1 = gen_new_label();
tcg_gen_mov_tl(a0, cpu_A0);
tcg_gen_mov_tl(t0, cpu_T0);
gen_set_label(label1);
t1 = tcg_temp_new();
t2 = tcg_temp_new();
tcg_gen_mov_tl(t2, t0);
tcg_gen_neg_tl(t1, t0);
tcg_gen_atomic_cmpxchg_tl(t0, a0, t0, t1,
s->mem_index, ot | MO_LE);
tcg_temp_free(t1);
tcg_gen_brcond_tl(TCG_COND_NE, t0, t2, label1);
tcg_temp_free(t2);
tcg_temp_free(a0);
tcg_gen_mov_tl(cpu_T0, t0);
tcg_temp_free(t0);
} else {
gen_op_mov_reg_v(ot, rm, cpu_T0);
tcg_gen_neg_tl(cpu_T0, cpu_T0);
if (mod != 3) {
gen_op_st_v(s, ot, cpu_T0, cpu_A0);
} else {
gen_op_mov_reg_v(ot, rm, cpu_T0);
}
}
gen_op_update_neg_cc();
set_cc_op(s, CC_OP_SUBB + ot);