target-i386: emulate LOCK'ed XADD using atomic helper

Backports commit f53b01817f95781d2bcc8a82e057d1416601e13b from qemu
This commit is contained in:
Emilio G. Cota 2018-02-27 23:05:50 -05:00 committed by Lioncash
parent f9ed728f27
commit 089965fa8d
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@ -5784,19 +5784,24 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
modrm = cpu_ldub_code(env, s->pc++); modrm = cpu_ldub_code(env, s->pc++);
reg = ((modrm >> 3) & 7) | rex_r; reg = ((modrm >> 3) & 7) | rex_r;
mod = (modrm >> 6) & 3; mod = (modrm >> 6) & 3;
gen_op_mov_v_reg(tcg_ctx, ot, cpu_T0, reg);
if (mod == 3) { if (mod == 3) {
rm = (modrm & 7) | REX_B(s); rm = (modrm & 7) | REX_B(s);
gen_op_mov_v_reg(tcg_ctx, ot, cpu_T0, reg);
gen_op_mov_v_reg(tcg_ctx, ot, cpu_T1, rm); gen_op_mov_v_reg(tcg_ctx, ot, cpu_T1, rm);
tcg_gen_add_tl(tcg_ctx, cpu_T0, cpu_T0, cpu_T1); tcg_gen_add_tl(tcg_ctx, cpu_T0, cpu_T0, cpu_T1);
gen_op_mov_reg_v(tcg_ctx, ot, reg, cpu_T1); gen_op_mov_reg_v(tcg_ctx, ot, reg, cpu_T1);
gen_op_mov_reg_v(tcg_ctx, ot, rm, cpu_T0); gen_op_mov_reg_v(tcg_ctx, ot, rm, cpu_T0);
} else { } else {
gen_lea_modrm(env, s, modrm); gen_lea_modrm(env, s, modrm);
gen_op_mov_v_reg(tcg_ctx, ot, cpu_T0, reg); if (s->prefix & PREFIX_LOCK) {
gen_op_ld_v(s, ot, cpu_T1, cpu_A0); tcg_gen_atomic_fetch_add_tl(tcg_ctx, cpu_T1, cpu_A0, cpu_T0,
tcg_gen_add_tl(tcg_ctx, cpu_T0, cpu_T0, cpu_T1); s->mem_index, ot | MO_LE);
gen_op_st_v(s, ot, cpu_T0, cpu_A0); tcg_gen_add_tl(tcg_ctx, cpu_T0, cpu_T0, cpu_T1);
} else {
gen_op_ld_v(s, ot, cpu_T1, cpu_A0);
tcg_gen_add_tl(tcg_ctx, cpu_T0, cpu_T0, cpu_T1);
gen_op_st_v(s, ot, cpu_T0, cpu_A0);
}
gen_op_mov_reg_v(tcg_ctx, ot, reg, cpu_T1); gen_op_mov_reg_v(tcg_ctx, ot, reg, cpu_T1);
} }
gen_op_update2_cc(tcg_ctx); gen_op_update2_cc(tcg_ctx);