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authorEmilio G. Cota <cota@braap.org>2016-06-27 15:02:01 -0400
committerRichard Henderson <rth@twiddle.net>2016-10-26 08:29:01 -0700
commit8eb8c7385608b99bed6055a22d897ff727a6cb8e (patch)
tree059c95caf491c7c72ceb0e69fe55bf950d6a1a17 /target-i386/translate.c
parent2a5fe8ae145ef7a3ab480922116d27efcc97b85d (diff)
downloadqemu-arm-8eb8c7385608b99bed6055a22d897ff727a6cb8e.tar.gz
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>
Diffstat (limited to 'target-i386/translate.c')
-rw-r--r--target-i386/translate.c38
1 files changed, 34 insertions, 4 deletions
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 6d71564317..d2edbd9b29 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -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);