> > + if (env->sregs[LEND] != v) {
> > + tb_invalidate_phys_page_range(
> > + env->sregs[LEND] - 1, env->sregs[LEND], 0);
> > + env->sregs[LEND] = v;
> > + tb_invalidate_phys_page_range(
> > + env->sregs[LEND] - 1, env->sregs[LEND], 0);
> > + }
>
> Why are you invalidating twice?
TB at the old LEND and at the new. Although it will work correctly without
first invalidation.
> > +static void gen_check_loop_end(DisasContext *dc, int slot)
> > +{
> > + if (option_enabled(dc, XTENSA_OPTION_LOOP) &&
> > + !(dc->tb->flags & XTENSA_TBFLAG_EXCM) &&
> > + dc->next_pc == dc->lend) {
> > + int label = gen_new_label();
> > +
> > + tcg_gen_brcondi_i32(TCG_COND_NE, cpu_SR[LEND], dc->next_pc, label);
> > + tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_SR[LCOUNT], 0, label);
> > + tcg_gen_subi_i32(cpu_SR[LCOUNT], cpu_SR[LCOUNT], 1);
> > + gen_jump(dc, cpu_SR[LBEG]);
> > + gen_set_label(label);
> > + gen_jumpi(dc, dc->next_pc, slot);
>
> If you're going to pretend that LEND is a constant, you might as well
> pretend that LBEG is also a constant, so that you get to chain the TB's
> around the loop.
But there may be three exits from TB at the LEND if its last command is a
branch: to the LBEG, to the branch target and to the next insn.
Thanks.
-- Max
