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Re: [Qemu-devel] [PATCH RFC v8 01/12] target/rx: TCG translation
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH RFC v8 01/12] target/rx: TCG translation |
Date: |
Fri, 3 May 2019 11:43:23 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 |
On 5/2/19 7:33 AM, Yoshinori Sato wrote:
> +/* conditional branch helper */
> +static void rx_bcnd_main(DisasContext *ctx, int cd, int dst)
> +{
> + DisasCompare dc;
> + TCGLabel *t, *done;
> +
> + switch (cd) {
> + case 0 ... 13:
> + dc.temp = tcg_temp_new();
> + psw_cond(&dc, cd);
> + t = gen_new_label();
> + done = gen_new_label();
> + tcg_gen_brcondi_i32(dc.cond, dc.value, 0, t);
> + gen_goto_tb(ctx, 0, ctx->base.pc_next);
> + tcg_gen_br(done);
> + gen_set_label(t);
> + gen_goto_tb(ctx, 1, ctx->pc + dst);
> + gen_set_label(done);
> + tcg_temp_free(dc.temp);
> + break;
> + case 14:
> + /* always true case */
> + gen_goto_tb(ctx, 0, ctx->pc + dst);
> + break;
> + case 15:
> + /* always false case */
> + /* Nothing do */
> + break;
> + }
> + ctx->base.is_jmp = DISAS_JUMP;
> +}
Do not set is_jmp to DISAS_JUMP here. We have already set is_jmp to
DISAS_NORETURN in gen_goto_tb. For case 15, we do not need to exit the TB in
order to treat the never-taken branch as a nop.
This assignment means that we will emit *another* exit from the TB in
rx_tr_tb_stop, which will be unreachable code.
This is the only bug I see in this revision. Thanks for your patience!
r~
- [Qemu-devel] [PATCH RFC v8 07/12] hw/timer: RX62N internal timer modules, (continued)
- [Qemu-devel] [PATCH RFC v8 07/12] hw/timer: RX62N internal timer modules, Yoshinori Sato, 2019/05/02
- [Qemu-devel] [PATCH RFC v8 06/12] hw/intc: RX62N interrupt controller (ICUa), Yoshinori Sato, 2019/05/02
- [Qemu-devel] [PATCH RFC v8 04/12] target/rx: RX disassembler, Yoshinori Sato, 2019/05/02
- [Qemu-devel] [PATCH RFC v8 01/12] target/rx: TCG translation, Yoshinori Sato, 2019/05/02
- Re: [Qemu-devel] [PATCH RFC v8 01/12] target/rx: TCG translation,
Richard Henderson <=
- [Qemu-devel] [PATCH RFC v8 09/12] hw/rx: RX Target hardware definition, Yoshinori Sato, 2019/05/02
- Re: [Qemu-devel] [PATCH RFC v8 00/12] Add RX archtecture support, Alex Bennée, 2019/05/03