Commit 8eb8c738 authored by Emilio G. Cota's avatar Emilio G. Cota Committed by Richard Henderson
Browse files

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



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

Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Message-Id: <1467054136-10430-16-git-send-email-cota@braap.org>
Signed-off-by: default avatarRichard Henderson <rth@twiddle.net>
parent 2a5fe8ae

target-i386/translate.c

+34 −4
Original line number Diff line number Diff line
@@ -4712,12 +4712,42 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s, 
            }

            break;

        case 3: /* neg */

            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 {

                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);

            break;